EFA Namibia Birds (Avifauna)
Okavango River Basin Transboundary
Diagnostic Analysis:
Environmental Flow Module
Specialist Report
Country: Namibia
Discipline: Birds (Avifauna)
Mark Paxton
May 2009
1
EFA Namibia Birds (Avifauna).
Okavango River Basin
Transboundary
Diagnostic Analysis:
Environmental Flow Module
Specialist Report
Country: Namibia
Discipline: Birds (Avifauna)
Author: Mark Paxton
Date: May 2009
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EFA Namibia Birds (Avifauna).
EXECUTIVE SUMMARY
A series of field trips to the two sites (Kapako and Popa Falls) was undertaken
during the period from October 2008 until March 2009, involving myself and
various other specialists. These excursions were primarily orientation and
information gathering visits but also involved a fair degree of information sharing
between the available disciplines. This information sharing helped to clear up
many aspects within each discipline and how each section relates to the other.
The group discussions and interactions gave me some valuable insight although
living in the area and on the river system itself for sixteen years allowed for more of
an understanding along with subsequent visits to each sight for further
familiarisation regarding the changing river levels and how it affected the birds at
each individual site thereby broadening the knowledge base for the birding
indicators. From 30th March to 4th April 2009 during the "knowledge capturing"
workshop, that was held in Windhoek with the participation of specialists in all
other disciples from all of the three countries. Here we collaboratively
generated response curves for each of the indicator species and tied this into
hydrological and rainfall information over the past forty five years since 1964.
Available relevant literature on this aspect i.e. birds was extremely difficult to find
or access being plainly unavailable, this being a very much understudied river
system with regard to bird species and their relationship with the changing river
water levels. We therefore had to rely heavily on "gut-feeling" based on over
16yrears of living on this river system and involving personal knowledge with birds
as one of the prime areas of interest.
In this report it has been difficult in most cases to isolate specific indicators into
individual species and we have had to combine many species into sometimes
large and diverse groups. These groups of indicators consequently differ in
various ways in their biology while sharing one common characteristic which
qualifies them for group inclusion in a common indicator category. With the more
intricate analysis of these indicators categories it is sometimes impossible to
generalise within a large group of diverse species and therefore predictions on
behaviour are far from accurate. Minimising the diversity would have been easier
to analyse but would risk exclusion of possibly vital species only to reveal
themselves as in the future. This river system is a dynamic ecosystem and home
to a huge diversity of birdlife dependent on its many facets of habitat and food
resources. It is also a fragile river system which has remained relatively
ecologically sound and pure in nature while supporting a human population from
three countries, Angola, Namibia and Botswana without major detrimental effects.
Being a dynamic and ever changing river system in its very nature the bird life
dependent on it has learned to adapt to these changes and in some cases thrive.
However, these natural changes or variable characteristics have been gradual
enough to allow adaptation and not so sudden as to cause mass migrations and
population declines. The species diversity handled in this report is a testament to
its stability as an ecosystem and the adaptability of most bird species within it and
their tolerance of most natural changes.
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EFA Namibia Birds (Avifauna).
TABLE OF CONTENTS
EXECUTIVE SUMMARY ............................................................................................. 3
ACKNOWLEDGEMENTS ......................................................................................... 7
1. INTRODUCTION ................................................................................................ 8
1.1 Background .................................................................................................. 8
1.2 Okavango River Basin EFA Objectives and Workplan ................................. 8
1.2.1 Project objectives ......................................................................................... 8
1.3 Layout of this report ........................................................................................ 9
2. STUDY AREA .................................................................................................. 10
2.1 Description of the Okavango Basin ................................................................ 10
2. 2 Delineation of the Okavango Basin into Integrated Units of Analysis ............... 11
3. Discipline-specific description of Namibia sites ................................................... 19
3.1 Site 4: Kapako ............................................................................................... 19
3.2 Site 5: Popa Rapids ...................................................................................... 19
4. IDENTIFICATION OF INDICATORS AND FLOW CATEGORIES ....................... 20
4.1 Indicators.................................................................................................... 20
4.1.1 Introduction .............................................................................................. 20
4.1.2 Indicator list for Bird Indicators ............................................................... 20
4.1.3 Description and location of indicators ........................................................ 22
5. BIRD INDICATORS ............................................................................................ 23
6. FLOW CATEGORIES RIVER SITES .............................................................. 28
6.2 Inundation categories delta sites ............................................................... 30
7. LITERATURE REVIEW ...................................................................................... 31
7.1 Introduction ...................................................................................................... 31
8 Namibia Bird Indicators (10) ............................................................................ 32
8.1 Indicator 1: Piscivores of open water ......................................................... 32
8.1.1 Main characteristics ................................................................................... 32
8.1.2 Life cycle attributes .................................................................................... 32
8.2.1 Links to flow ............................................................................................. 32
8.2 Indicator 2: Piscivores of shallow water and lagoons etc. ............................ 33
8.2.1 Main characteristics ................................................................................ 33
8.2.2. Life cycle attributes ................................................................................... 33
8.2.3 Links to flow ............................................................................................... 33
8.3 Indicator 3: Piscivores and invertebrate feeders, floodplains and isolated
pools .................................................................................................................... 33
8.3.1 Main characteristics ................................................................................... 33
8.3.2 Life cycle attributes ................................................................................... 34
8.3.3 Links to flow ............................................................................................... 34
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EFA Namibia Birds (Avifauna).
8.4 Indicator 4: Specialist feeders on floodplains, rising and receding waters .. 34
8.4.1. Main characteristics ................................................................................. 34
8.4.2 Life cycle attributes .................................................................................... 34
8.4.3 Links to flow ............................................................................................... 35
8.5 Indicator 5: Specialist feeders on water-lily covered inlets ........................... 35
8.5.1 Main characteristics .................................................................................. 35
8.5.2 Life cycle attributes ................................................................................... 35
8.5.3 Links to flow ............................................................................................... 35
8.6 Indicator 6: Specialist feeders in riverine fruit trees ................................... 35
8.6.1 Main characteristics ................................................................................... 35
8.6.2 Life cycle attributes .................................................................................... 36
8.6.3 Links to flow ............................................................................................... 36
8.7 Indicator 7: Breeders in reedbeds and floodplains ..................................... 36
8.7.1 Main characteristics ................................................................................. 36
8.7.2 Life cycle attributes ................................................................................... 37
8.7.3 Links to flow ............................................................................................. 37
8.8 Indicator 8: Breeders in riverine overhanging trees .................................... 37
8.8.1 Main characteristics ................................................................................. 37
8.8.2 Life cycle attributes .................................................................................. 37
8.8.3 Links to flow .............................................................................................. 37
8.9 Indicator 9: Breeders on banks .................................................................. 38
8.9.1 Main characteristics ................................................................................... 38
8.9.2 Life cycle attributes .................................................................................... 38
8.9.3 Links to flow ............................................................................................... 38
8.10 Indicator 10: Breeders on emergent rocks, sandbars and islands ........... 38
8.10.1 Main characteristics 9............................................................................... 38
5.10.2
Life cycle attributes ............................................................................... 39
8.10.3 Links to flow ............................................................................................ 39
9. SUMMARY ......................................................................................................... 40
10. DATA COLLECTION AND ANALYSIS ............................................................. 41
10.1 Methods for data collection and analysis .................................................... 41
11. RESULTS ......................................................................................................... 42
12. INDICATORS .................................................................................................... 43
Indicator 1 Piscivores of open water .............................................................. 43
Indicator 2 Piscivores of shallow water & lagoons etc. ............................... 45
Indicator 3 Piscivores and Interbrates feeders. Floodplains, isolated
pools .................................................................................................................... 47
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EFA Namibia Birds (Avifauna).
Indicator 4 Specialist feeders on floodplains, receding and rising waters
............................................................................................................................. 49
Indicator 5 specialist feeders in water lily covered inlets .......................... 51
Indicator 6 Specialist feeders in riverine fruit trees .............................................. 53
Indicator 7 Breeders in Reedbeds and Floodplains .............................................. 55
Indicator 8 Breeders in riverine over-hanging trees ............................................ 57
Indicator 9 Breeders on banks ............................................................................. 59
Indicator 10 Breeders on emergent rocks, sandbars & islands .......................... 61
13. CONCLUSION ................................................................................................. 63
14.
FLOW-RESPONSE RELATIONSHIPS FOR USE IN THE OKAVANGO EF-
DSS 64
15. REFERENCES ................................................................................................. 64
LIST OF FIGURES
Figure 2. 1: Upper Okavango River Basin from sources to the northern end of the
Delta ............................................................................................................................ 10
Figure 2. 2: The Okavango River Basin, showing drainage into the Okavango Delta
and the Makgadikgadi Pans ........................................................................................ 11
LIST OF TABLES
Table 1.1: Location of the eight EFA sites ................................................................... 12
Table 2: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 43
Table 3: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 45
Table 4: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 47
Table 5: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 49
Table 6: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 51
Table 7: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 53
Table 8: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 55
Table 9: Predicted response to possible changes in the flow regime in the Okavango
River ecosystem .......................................................................................................... 57
Table 10: Predicted response to possible changes in the flow regime in the
OkavangoRiver ecosystem ......................................................................................... 59
Table 11: Predicted response to possible changes in the flow regime in the
OkavangoRiver ecosystem ......................................................................................... 61
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EFA Namibia Birds (Avifauna).
ACKNOWLEDGEMENTS
I have to say that without my wife Charlie I would not have been able to transcribe
my hand written notes into the required format for this report given my very limited
computer skills. Barbara Curtis was always available for the most sensible advice
with nobody else was. I also have Jackie King to thank for tolerating my
sometimes untimely phone calls with what were often quite stupid questions but for
which I needed answers. Shirley Bethunie went to a great deal of trouble to
organize the very valuable field trips to the sites and was always there to
"directionalize" a sometime vague group of people into a productive and cohesive
team. Personally these were of great benefit to me primarily for the information
sharing forum they provided.
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EFA Namibia Birds (Avifauna).
1. INTRODUCTION
1.1 Background
An Environmental Protection and Sustainable Management of the Okavango River Basin
(EPSMO) Project is being implemented under the auspices of the Food and Agriculture
Organization of the United Nations (UN-FAO). One of the activities is to complete a
transboundary diagnostic assessment (TDA) for the purpose of developing a Strategic Action
Plan for the basin. The TDA is an analysis of current and future possible causes of
transboundary issues between the three countries of the basin: Angola, Namibia and
Botswana. The Okavango Basin Steering Committee (OBSC) of the Okavango River Basin
Water Commission (OKACOM) noted during a March 2008 meeting in Windhoek, Namibia,
that future transboundary issues within the Okavango River basin are likely to occur due to
developments that would modify flow regimes. The OBSC also noted that there was
inadequate information about the physico-chemical, ecological and socio-economic effects of
such possible developments. OBSC recommended at this meeting that a preliminary
Environmental Flow Assessment (EFA) be carried out to predict possible development-driven
changes in the flow regime of the Okavango River system, the related ecosystem changes,
and the consequent impacts on people using the river's resources.
This preliminary EFA is a joint project of EPSMO and the Biokavango Project. One
component of the preliminary EFA is a series of country-specific specialist studies, of which
this is the Aquatic Macroinvertebrates Report for Namibia.
1.2 Okavango River Basin EFA Objectives and Workplan
1.2.1 Project objectives
The goals of the preliminary EFA are:
To summarize all relevant information on the Okavango River system and its users,
and collect new data as appropriate within the constraints of this preliminary EFA to
use these to provide scenarios of possible development pathways into the future for
consideration by decision makers, enabling them to discuss and negotiate on
sustainable development of the Okavango River Basin; to include in each scenario
the major positive and negative ecological, resource-economic and social impacts of
the relevant developments; to complete this suite of activities as a preliminary EFA,
due to time constraints, as input to the TDA and to a future comprehensive EFA.
The specific objectives at a preliminary level are:
to ascertain at different points along the Okavango River system, including the Delta,
the existing relationships between the flow regime and the ecological nature and
functioning of the river ecosystem; to ascertain the existing relationships between the
river ecosystem and peoples' livelihoods; to predict possible development-driven
changes to the flow regime and thus to the river ecosystem; to predict the impacts of
such river ecosystem changes on people's livelihoods. To use these preliminary EFA
outputs to enhance biodiversity management of the Delta. To develop skills for
conducting EFA's in Angola, Botswana, and Namibia.
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EFA Namibia Birds (Avifauna).
1.3 Layout of this report
Chapter 1 gives a brief introduction, to the background of the project and lists project
objectives. Chapter 2 describes the broad study area of the Okavango River Basin and
gives more detail on the two specific sites chosen for this preliminary EFA within the
Namibian section of the river- Kapako and Popa rapids. In Chapter 3, the agreed bird
indicators are described for the two Namibian sites. Flow categories are also indicated. A
short literature review pertinent to birds work in the Okavango River and other similar
systems is given in Chapter 4, with indicators listed in full. The field survey work undertaken
for the aquatic invertebrate investigation within Namibia in both the dry season (October
2008) and wet season (February 2009); together with data collection, analysis and results
are outlined in Chapter 5. Chapter 6 is a first attempt to link aquatic invertebrates to flow and
provide information on the flow-response relationships for use in the Okavango EF-DSS.
References are found in Chapter 7. Appendix A gives a full description of indicators and
Appendix B contains my raw field data.
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EFA Namibia Birds (Avifauna).
2. STUDY AREA
2.1 Description of the Okavango Basin
The Okavango River Basin consists of the areas drained by the Cubango, Cutato, Cuchi,
Cuelei, Cuebe, and Cuito rivers in Angola, the Okavango River in Namibia and Botswana,
and the Okavango Delta (figure 2.1). This basin topographically includes the inactive
drainage area of the Omatako Omuramba. Although this ephemeral river still regularly floods
along its southern portion, it has not contributed any flow to the Okavango River. Outflows
from the Okavango Delta are drained through the Thamalakane and then Boteti Rivers, the
latter eventually joining the Makgadikgadi Pans. The Nata River, which drains the western
part of Zimbabwe, also joins the Makgadikgadi Pans. On the basis of topography, the
Okavango River Basin thus includes the Makgadikgadi Pans and Nata River Basin (figure
2.2). This study, however, focuses on the active drainage parts of the basin in Angola and
Namibia, and the Okavango delta in Botswana. The Omatako Omuramba, Makgadikgadi
Pans and Nata River are not included.
Upper Okavango River Basin
N
W
E
S
C
u
tato
Cu
#
c
h
i
#
C
C
u
u
#
it
a
o
nava
#
le
Cu
#
C
Menongue
ba
u
n
c
g
h
#
Major settlement
o
i
# Cuito Cuanavale
River
C
#
ue
Fossil river
be
C
Panhandle
ANGOLA
uiri
Permanent swamps
ri
#
Seasonal swamps
Cubango
Cuito
NAMIBIA
Okavango
#
Rundu
#
#
#
0
300 Kilometers
#
Figure 2. 1: Upper Okavango River Basin from sources to the northern end of the Delta
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EFA Namibia Birds (Avifauna).
Okavango River Basin
N
W
E
S
Cu
t
a
Cu
#
t
o
c
h
i#
C
C
ui
ua
#
t
o
nava
#
l
e
C
# Menongue
ub
C
a
u
n
c
g
h
o
i
# Cuito Cuanavale
# Cuebe
C
ANGOLA
uirir
#
i
Cubango
Cuito
NAMIBIA
Okavango
#
Rundu
#
# #
#
##
#
#
#
Maun
#
Makgadikgadi Pans
# Ghanzi
#
Major settlement
River
Fossil river
Panhandle
0
600 Kilometers
Permanent swamps
Seasonal swamps
Figure 2. 2: The Okavango River Basin, showing drainage into the Okavango Delta and the
Makgadikgadi Pans
2. 2 Delineation of the Okavango Basin into Integrated Units of Analysis
Within the Okavango River Basin, no study could address every kilometre stretch of the river,
or every person living within the area, particularly a pilot study such as this one. These
representative areas that are reasonably homogeneous in their ecological characteristics
and can be delineated and used to choose several sites in which focus for data-collection
and monitoring can be done. The results from each representative site can then be
extrapolated over the respective wider areas.
Using this approach, the Basin was delineated into Integrated Units of Analysis
(EPSMO/Biokavango Report Number 2; Delineation Report) by:
dividing the river into relatively homogeneous longitudinal zones in terms of:
hydrology;
geomorphology;
water chemistry;
fish;
aquatic macroinvertebrates;
vegetation;
wildlife
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EFA Namibia Birds (Avifauna).
birds
harmonising the results from each discipline into one set of biophysical river zones;
dividing the basin into relatively homogeneous areas in terms of social systems;
harmonising the biophysical river zones and the social areas into one set of Integrated
Units of Analysis (IUAs). See delineation report for details
The 19 recognised IUAs were then considered by each national team as candidates for the
location of the allocated number of study sites:
Angola: three
sites
Namibia: two
sites
Botswana: three
sites.
The sites chosen by the national teams are given in (table 2.1).
Table 1.1: Location of the eight EFA sites
EFA Site No
Country
River
Location
1 Angola
Cuebe
Capico
2 Angola
Cubango
Mucundi
3 Angola
Cuito Cuito
Cuanavale
4 Namibia
Okavango
Kapako
5 Namibia
Okavango
Popa
Rapids
Upper Panhandle
6 Botswana
Okavango
around Shakawe
Xakanaka lagoon
7 Botswana
Xakanaka in Delta
and Khwai River
8
Botswana
Boteti Rivers
Maun and Chanoga
2.3 Overview
of
sites
In the Namibian section of the Okavango River, the majority of the human population lives
along the river and the main road, with several hot spots such as Rundu, Divundu and
Nkurenkuru which have a high population density. The river can be divided into four clear
units of analysis, the longest section that extends from where the river enters Namibia at
Katwitwi to the Cuito confluence that is typified by the meandering mainstream and large
seasonally-flooded floodplains on either side to the river (Kapako site 4, was chosen as a
typical floodplain and mainstream site within this section); the section immediately
downstream of the Cuito confluence that has permanently swamped areas and large islands
(not included in the preliminary survey but essential to include in a later more detailed EFA
study); the southward flowing rocky, braided section from Mukwe to just below the Popa
Rapids where the river is largely confined to the mainstream and flows around several sand
and rock based islands (Popa rapids Site 5, was chosen as a typical rocky river site within
this section) and the protected section of the river downstream of Popa to the border with
Botswana at Mohembo that lies within the newly declared Bwabwata National Park which as
two of its core conservation areas on either side of the river, the Buffalo core area on the
west bank and the Muhango core area on the east bank.
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EFA Namibia Birds (Avifauna).
2.3.1 Site 4: Kapako
The main focus point for socio-economic work at the Kapako floodplain site 4 is Kapako
village: S-17.94 E 19.56, situated some distance inland from the river on the other side of
the main road.
Figure Site 4: Kapako showing the village of Kapako, the surrounding town and the position
of the main road and the villages in relation to the river. Most of the area between the road
and the river is floodplain. The border shows the area covered by the socio-economics
team. Map by Socio-economics team.
The main villages close to Kapako village are Mupini to the east (downstream) , Mukundu to
the south, Ruugua and Sinzogoro to the weat (upstream).
The floodplain site itself is situated on the Okavango River and three main sites on the
floodplain and the mainstream were used for sampling. They were:
Kapako site 1 S-17.87775 E- 19.58200 (start south bank) S- 17.87850 E-19.58211 (end of
site 1)
Kapako site 2 S- 17.86557 E-19.58057 (start at floodplain only 3 observations due to
flooding)
Kapako site 3 S- 17.86209 E-19.57855 (deep pool)
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EFA Namibia Birds (Avifauna).
Figure shows two satellite images of the Kapako floodplain site 4, one in the dry season and
one in the wet or flood season, the main sampling sites used are indicated.Maps by Celeste
Espach.
The riverine landscape includes the main Okavango River channel or mainstream, the
annually flooded floodplains with several braided side channels and deeper pools or
backwaters, as well as the higher fluvial terrace with alluvial deposits are very seldom
flooded. There is a steep, well vegetated bank at the edge of the floodplain close to the
main road that rises to several meters above the floodplain.
Kapako area has a population of approximately 2,500 people within 10 km of Kapako village.
The greatest density of people (over 100 per km2 ) live alongside the river in the area just
west of the Kapako study site whilst at the site itself the density varies from no people on the
floodplain, 6 25 / km2 at the Ebenezer mission, to a density of 25 50 /km2 closer to the
road and 51 100 /km2 on the other side of the main road, rapidly decreasing again with
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EFA Namibia Birds (Avifauna).
distance inland. (See Map 3 in Poplations Demographics Report prepared by Celeste
Espach). We can assume that some of these people make some use of the floodplain site at
Kapako and elsewhere along this stretch of river.
During the focus group discussion held at Kapako village, the basin residents mentioned
that, the flooding starts when the rising river and channel waters push out over flat
surrounding ground and the biggest floodplains form in years when river levels are highest.
They said that the most important feature of the flooded areas is that they are rich in
nutrients. The floodplains also offer the young fish refuge from larger, predatory species and
thus offer the greatest survival of young fish. They had noted that an overall increase in fish
population occurs in years when water levels are high and flooding lasts longest. Local
people have recognised that water quality and fish resources are decreasing in the
Okavango River. Fish and fishing remain significant features in the lives of people at
Kapako, who fish for food or to earn incomes by selling their catches. In addition some earn
money by providing trips for tourists. They estimate fish stocks in the floodplains to be four
times higher than in the main channel.
About 47% of households at Kapako catch fish, and each person consumes an average of
10-20 kilograms of fish per year. September to December is the peak fishing period at
Kapako when the river is at its lowest and fish are concentrated in the mainstream. The
kinds of traps or gear used to catch fish are separated into traditional and modern methods.
The most used traditional gear are fish funnels, kraal traps, scoop baskets, push baskets,
bows and arrows, set fish hooks and spears.
Modern gear consists of line and hooks, wire mesh fykes, illegal mosquito nets, and gill and
seine nets. The use of fish for recreational angling forms part of the tourism value associated
with the river. Biophysical response curves for the angling species would feed into the
tourism values for the river reducing them partially. Only a small part of tourism value is
attributable to angling.
At Kapako, as elsewhere along the Namibian section of the river, the ever -increasing human
population and clearing for crops and livestock has put increasing pressure on the natural
resources along the main channel. The vegetation along the river bank is overgrazed and in
some areas depleted, thus at Kapako the residents graze their livestock across the river on
the Angolan floodplain. Cattle were routinely seen being swam across the river at this site
during fieldwork.
Associated with this population growth, has been an increase in livestock, fire frequency as
well as the area of land cleared for crops and fuel. These associated land use changes are
an undeniable factor of increasing settlement and development at a Kapako and indeed all
along the Okavango.
The road westwards from Rundu has been upgraded and is currently being tarred. It runs
parallel to the Okavango River all the way to the border post with Angola at Katwitwi.
This has opened up the region allowing people to exploit the land alongside the road. As
expected highest densities are alongside the road parallel to the river. As the population
continues to increase, exploitation of the land that new roads have opened up should
disperse the pressure on the Okavango River floodplains and its resources to land further
inland from the river, although the river will always remain the main source of water even for
livestock watering.
The extent of erosion and clearing and thus of bare ground has also increased; yet the
people perceive the overall water quality not to have declined substantially. The only
exceptions mentioned were an increase in phosphate concentrations, a decrease in water
clarity and a related increase in suspended sediments. There are more short term, seasonal
variations in water quality particularly in the floodplain pools, than any long term water quality
change. So far there does not seem to have been an excessive exploitation of the water
resources in the main channel, although the basin further inland has some serious water
15
EFA Namibia Birds (Avifauna).
shortages at times and a lack of deep boreholes. The Kalahari sands that overlay the area
are deep.
2.3.2 Site 5: Popa rapids
The main focus for the socio-economic work at the Popa rapids Site 5 was the village of
Popa and the Popa Falls Rest Camp run by Namibia Wildlife Resorts. The main transect
used for the physical and biological field survey work was a transect across the river
immediately above the Popa Rapids from the irrigation water drawoff point used by the
Prison Services on the eastern ban (West Caprivi) where the gauge plate was put up to the
protected section close to the Popa Falls Rest Camp on the western bank. Popa rapids: S-
18.15316 E- 21.6045 (Popa Falls rest camp)
Popa falls (gauge plate) S- 18.11603 E- 21.57900. Figure XXX below shows the main
villages.
Figure Site two, Popa rapids is shown in the map above; The majority of population lives
along the river and the main road. Map from the socio-economic team.
Figure below shows the Popa rapids site 5 in both the dry and the wet season and indicates
the main field survey transect and team sampling sites. The individual discipline reports all
have more specific maps of their sampling sites.
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EFA Namibia Birds (Avifauna).
Figure Satellite images of the wet and dry season for Popa rapids here showing transect
and main sampling sites. Maps prepared by Celeste Espach.
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EFA Namibia Birds (Avifauna).
About 3,000 people live in the area surrounding Popa. The highest population density in the
area is immediately upstream of the Popa rapids at the Bagani/Divundu settlement, within an
area of over 12 km2 . At the Popa rapids site itself the population density is much lower at 6
25 people/km2 and it must be remembered that the Popa camp is within an 8 km2 park, the
islands are uninhabited and the opposite bank supports a community campsite reserved for
tourists. Immediately downstream of Popa camp the riverside population increases to 26-50
people/km2 and includes several lodges. See Map 3 in the Population Demographics report
prepared by Celeste Espach for the TDA.
At the Popa rapids, the entire width of the river cascades down several meters before
resuming its normal slow and leisurely flow. The quartzite rocks were formed from sediments
deposited in rift valleys about 900 million years ago, (el Obeid, S., Mendelsohn 2004).
During the focus group discussion, it was mentioned that due to the Popa rapids and rocky
areas, it's difficult for the local fishermen to catch fish as desired. Therefore, only a few
individuals that own local mukoros, hook and line, and gill fish nets have access to fish
catches in the main channel. Thus fishing is a secondary activity for most people at the
Popa area, contributing little to the overall cash or in-kind incomes of the majority of
households. People also pay much less attention to fishing than to farming and business
activities. Each household depends on a different mix of incomes derives from wages,
business earnings, pensions and remittances
Papyrus cyperus, papyrus, dominates the deepest water margins alongside the main
channels. Water can seep through the walls of papyrus to the reedbeds behind the papyrus
and in places where they exits into backwaters and side channels. The sandy sediments are
confined to the channels. These are flanked by reed beds of Phragmites, Typha capensis or
bulrushes and the sedge Miscanthus junceus in the shallower waters. The resident donot
experience floods as there are no floodplains in this area. They depend in the main channel
for most of their water and wetland resources. Most houses at Popa village are thatched with
grass and reeds, while reeds are used extensively to make sleeping mats, walls, palisades,
courtyards and fences.
Farming activity is an important source of income; households are engaged in both crop and
livestock farming. Planting is staggered through the raining reason and is initiated only after
a good rainfall event. This increases the chance of crop survival during the hot dry periods.
Livestock farming is dominated by cattle and goats, not kept within fields but are moved for
grazing and between water sources, mainly the Okavango River.
Tourism is a major source of income to the Popa resident; most of them are employed within
the lodges around the Popa area. They value tourism as their major source of income.
18
EFA Namibia Birds (Avifauna).
3. Discipline-specific description of Namibia sites
3.1 Site 4: Kapako
This site is situated within a seasonal floodplain which is exposed to cattle/livestock grazing,
fires and reed/grass harvesting by the local population in the low water periods. During this
time the fires and trampling hoof action of livestock actually creates favourable nesting and
feeding habitat for some of the indicator species and therefore constitutes a positive
influence. The harvesting of reeds/grass by the local community however, has a more
negative affect on the floodplain bird species by removing suitable nesting and feeding
habitat.
During the high-water periods this site would be exposed to fishing practices by the local
community. These practices would negatively impact fish availability for some of the
indicator bird species as all sizes of fish are harvested and even residual pans are depleted
of fish stocks leaving little or no feeding opportunities for fish eating bird species.
This site offers diverse habitat selection suitable for most of the indicator species. Particularly
the floodplain breeders and feeders
3.2 Site 5: Popa Rapids
This site does not have any significant floodplains and is made up mostly of fast flowing
water with many intermittent rocky outcrops and flows between banks that are too high to
allow overflow during normal years. The river spreads out substantially here forming
papyrus and phragmites dominated islands. The vegetation on these islands have well
established climax trees located above the high water level up against the banks, where they
have been afforded some protection against deforestation, as such, there is some well
established forests offering prime habitat for some of the indicator species. With almost
total exclusion of any significant flood plain habitat this site offers only limited habitat for the
remaining few the indicator species which prefer this habitat. Particularly the species relying
on trees lining the banks as well as those requiring rocky outcrops and islands
19
EFA Namibia Birds (Avifauna).
4. IDENTIFICATION OF INDICATORS AND FLOW CATEGORIES
4.1 Indicators
4.1.1 Introduction
Biophysical indicators are discipline-specific attributes of the river system that respond to a
change in river flow by changing in their:
abundance;
concentration; or
extent (area).
Social indicators are attributes of the social structures linked to the river that respond to
changes in the availability of riverine resources (as described by the biophysical indicators).
The indicators are used to characterise the current situation and changes that could occur
with development-driven flow changes.
Within any one biophysical discipline, key attributes can be grouped if they are expected to
respond in the same way to the flow regime of the river. By example, fish species that all
move on to floodplains at about the same time and for the same kinds of breeding or feeding
reasons could be grouped as Fish Guild X.
4.1.2
Indicator list for Bird Indicators
In order to cover the major characteristics of the river system and its users many indicators
may be deemed necessary. For any one EFA site, however, the number of indicators is
limited to ten (or fewer) in order to make the process manageable. Despite logistical and
technological communication problems, the list of indicators was developed collaboratively
by the country representatives for the discipline of birds i.e. Carmen Santos (Angola), Mark
Paxton (Namibia) and Pete Hancock (Botswana) and finalised in a workshop in April 2009.
The final list is provided in Table 4.1. Further details of each indicator, including the
representative species of each, are given in Appendix 1 and discussed fully in Chapter 8
20
EFA Namibia Birds (Avifauna).
4.1 List of indicators for Birds/Avifauna
Indicator
Sites represented no more than ten indicators per site
Indicator name
Number
1 2 3 4
5 6
7 8
Kapako
Popa
1
Piscivores of open
water
2
Piscivores of shallow
Kapako
Popa
water & lagoons etc.
Piscivores and
Invertebrate feeders,
3
Kapako
Popa
floodplains, isolated
pools
Specialist feeders on
4
floodplains, receding
Kapako
Popa
waters
5
Specialist feeders in
Kapako
Popa
water-lily covered inlets
6
Specialist feeders in
Kapako
Popa
riverine fruit trees
7
Breeders in reedbeds,
Kapako
Popa
floodplains
8
Breeders in riverine
Kapako
Popa
overhanging trees
9
Breeders on banks
Kapako
Popa
Breeders on emergent
10
rocks, sandbars &
Popa
islands
21
EFA Namibia Birds (Avifauna).
4.1.3 Description and location of indicators
Eleven indicators were collaboratively agreed for Angola, Namibia and Botswana. Please
refer to this table when reading this section. A more detailed description and a list of
representative bird species for each is given in the table App. 1.
22
EFA Namibia Birds (Avifauna).
5. BIRD INDICATORS
5.1 BIRD INDICATOR 1 Piscivores of open water
Description:
Fish-eating birds which prey on larger fish species generally in the main river system. They
catch fish directly from above, by using bank vegetation as hunting perches or by swimming
underwater to explore the river bottom or rocky crevices
Representative species:
African Fish Eagle, Osprey, Pied Kingfisher, Malachite Kingfisher, Giant Kingfisher, Reed
Cormorant, African Darter
Other characteristic species:
None
Flow-related location:
The main faster flowing mainstream margin or side stream channels and inlets.
Known water needs:
They need fast flowing mainstream river currents where only larger fish species occur during
most of the year. Also needed are the slower flowing water where larger fish breed during
the
high water periods in shallower water making them easier to prey on.
5.2 BIRD INDICATOR 2: Piscivores of shallow water and lagoons etc.
Description:
Fish eating birds preying on variable size fish species which inhabit shallow slow flowing
water provided by lagoons, inlets, channels directly connected to the mainstream river or by
sandbanks.
Representative species:
Pel's Fishing Owl, Purple Heron, Grey Heron, Great Egret, Little Egret, Pied Kingfisher,
Malachite Kingfisher, Whiskered Tern, White-winged Tern.
Other characteristic species:
Great While Pelican, pink-backed Pelican
Flow-related location:
The slow flowing water within lagoons, inlets and channels directly connected to the main
river, also the slower and shallower water flowing around the sand banks within the main
river system.
Known water needs:
They need a regulated water level adjustment to create sandbanks and lagoons with similar
slow water habitat for prey availability
23
EFA Namibia Birds (Avifauna).
5.3 BIRD INDICATOR 3: Piscivores and invertebrate feeders of floodplains and
isolated pools.
Description:
Bird species which feed on fish and a variety of other invertebrates, amphibians,
crustaceans and aquatic animals which require a floodplain system in which to flourish
Representative species:
Squacco Heron, Rufous-bellied Heron, White-backed Night-heron, Black-crowned Night-
heron, Green-backed Heron, Little Bittern, Yellow-billed Stork, African Spoonbill,
Hammerkop, African Sacred Ibis, Painted Snipe, African Snipe, Lesser Moorhen, Black
Crake, African Rail, Wattled Crane, Three-banded Plover, White-fronted Plover, African
Wattled Lapwing, Blacksmith Lapwing, Ruff, Little Stint, Common Sandpiper, Wood
Sandpiper, Common Greenshank.
Other characteristic species:
Yellow-bellied Egret, Black Heron, Slaty Egret, Dwarf Bittern, Saddle-billed Stork, Woolly-
necked Stork, Glossy Ibis, Great Snipe, Common Moorhen, African Crake, Spotted
Crake, Baillon's Crake, Common Ringed Plover, Kittlitz's Plover, Long-toed Lapwing, Curlew
Sandpiper, Marsh Sandpiper.
Flow-related location:
With the rising water during the rainy season, the river inundates several sometimes vast
expanses of low-lying flat areas called floodplains. These expanses of relatively shallow
water and slow to negligible flow, provide habitat for a variety of plant species, which in turn,
provide ideal and essential habitat for a variety of invertebrates, aquatic animals and fish
species. This wealth of life attracts a large diversity of birds some of which migrate from the
northern hemisphere to this bountiful food source on the river system.
Known water needs:
They need a substantial seasonal input of water into the main river, enough to overflow the
banks and fill up the surrounding floodplains and otherwise isolated pools. Without an
annual rejuvenation of these areas the system would dry up and become barren.
5.4 BIRD INDICATOR 4: : Specialist feeders on floodplains, rising and receding water
Description:
Bird species occupying specific habitats provided in the floodplain when rising and lowering
water levels provide ideal conditions, where specific prey items, such as snails, mollusks,
frogs and other invertebrates or other food provided by water plants are located.
Representative species:
African Openbill, Pygmy Goose, Purple Swamphen, Allen's Gallinule
Other characteristic species:
None
Flow-related location:
Rising water levels create ideal essential conditions for particular plant species on which
these birds feed like water lilies (Nymphaea spp). Rising water levels in the floodplain areas
also dislodge mollusc species and make them more accessible to particular birds
physically adapted to feed on them. Alternatively receding water levels leave these food
24
EFA Namibia Birds (Avifauna).
items stranded and easily available.
Known water needs:
Rising and receding water-levels in the main river system are essential to fill up the
surrounding floodplains and create suitable conditions for the food items of these specialised
feeders.
5.5 BIRD INDICATOR 5: : Specialist feeders in water-lily covered inlets and pools
Description:
Bird species which are physically adapted to use the lily covered inlets and floodplain pools
as a food source.
Representative species:
African Jacana, Lesser Jacana
Other characteristic species:
None
Flow-related location:
Water-lily species grow abundantly in slow-flowing inlets, channels and pools within the
floodplains and eventually cover the surface with their large, flat leaves during the high water
periods.
Known water needs:
High water periods are essential to the overflow into the inlets and pools of the adjoining
floodplains. These flowing or even stagnant water bodies covered over by water lilies are
crucial feeding and breeding areas for specially adapted bird species. Deeper floodplain
pools may remain long after the floods have receded retaining this important habitat into the
dry season too
5.6 BIRD INDICATOR 6: : Specialist feeders in riverine fruit trees
Description:
Several predominantly frugivorous bird species utilizing fruit bearing trees of riverine forests
lining the riverbanks.
Representative species:
Meyers Parrot, Grey go-away Bird, Grey Hornbill, Dark-capped Bulbul, Yellow-bellied
Greenbul, Violet-backed Starling, Glossy Starling, Greater Blue-eared Starling, Red-faced
Mousebird, Green Pigeon, Black-collared Barbet, Black-headed Oriole, Arrow-marked
Babbler.
Other characteristic species:
Other insectivorous bird species which feed on the insects attracted to the fruit bearing trees,
as well as Grey-headed Parrot, Bradfield's Hornbill, African red-eyed Bulbul, Terrestrial
Brownbul, Burchell's Starling, Meves Starling, African Golden Oriole, European Golden
Oriole,
Flow-related location:
The high water mark and above on the banks of the river system where the soil type and
structure offers suitable stability for deep-rooted trees.
25
EFA Namibia Birds (Avifauna).
Known water needs:
Seasonal high-water periods are essential for these trees which require large amounts of
ground water to bear enough fruit to sustain a large diversity of bird species.
5.7 BIRD INDICATOR 7: : Breeders in reed beds and floodplains
Description:
Bird species which require thick reed beds or grassy areas surrounded by water in which to
safely nest and successfully rear offspring.
Representative species:
Village weaver, Golden Weaver, Southern Brown-throated Weaver, Red-billed Quelea,
Southern Red Bishop, Fan-tailed Widowbird, Tawny-flanked Prinia, Little Rush Warbler,
Luapula Cisticola, Chirping Cisticola, African Purple Swamphen, Allen's Gallinule, Black
Crake, Lesser Moorhen, African Rail, African Marsh Harrier, Spur-winged Goose, Red-billed
Teal, White-faced Duck, Purple Heron, Little Egret, Squacco Heron, Rufous-bellied Heron,
Black-crowned Night-heron, Little Bittern.
Other characteristic species:
Thick-billed Weaver, Southern Masked-Weaver, Lesser Masked-weaver, Spectacled
Weaver, Lesser Swamp Warbler, Greater Swamp Warbler, African Reed Warbler, Zitting
Cisticola, Common Moorhen, Baillons Crake, White-backed Duck, Black Heron, Slaty Egret,
Flow-related location:
Although most reedbeds and floodplains remain as such during low-water periods they only
become suitable breeding areas during high water levels. The overflow from the main river
then fills them up thereby adding a safety factor as well as a nest material source for the
dependent bird species.
Known water needs:
High water levels with filled-up floodplains and reedbeds are necessary to ensure safe and
adequate breeding habitat for this large diversity of bird species.
5.8 BIRD INDICATOR 8: Breeders in riverine overhanging trees
Description:
Bird species which require the safety aspect provided by overhanging trees on the river edge
to successfully nest and rear young.
Representative species:
Green-backed Heron, White-backed Night-heron, Hammerkop, Pygmy Goose, Comb Duck,
Reed Cormorant, African Darter.
Other characteristic species:
Flow-related location:
High water levels that surround riverine trees with water thereby making them relatively
inaccessible to most predators which prey on eggs or nestlings.
Known water needs:
A sustained high water level which partially submerges riverine trees and which lasts long
26
EFA Namibia Birds (Avifauna).
enough to provide a safety factor to birds throughout the nesting period.
5.9 BIRD INDICATOR 9: Breeders on banks
Description:
Birds which require vertical exposed banks on the river in which to burrow nesting holes, or
dry, grass covered banks on which their eggs are laid.
Representative species:
Carmine Bee-eater, White-fronted Bee-eater, Little Bee-eater, Collared Pratincole, Wattled
Lapwing, Blacksmith Lapwing.
Other characteristic species:
None
Flow-related location:
At low-water levels river banks become exposed and offer suitable nest location sites for
birds.
Known water needs:
Sustained low water periods leaving river banks and adjoining grassland exposed for long
enough for the birds to complete their nesting period.
5.10 BIRD INDICATOR 10: Breeders on emergent rocks, sandbars and islands
Description:
Birds which require emergent rocks, sandbars and islands on which to nest and rear young.
Representative species:
Rock Pratincole, African Skimmer, Water Thick-knee, White-fronted Plover.
Other characteristic species:
None
Flow-related location:
At low-water levels exposed bare to partially vegetated sandbars and completely bare rocks
which are located in the centre of the river and surrounded by fast flowing water.
Known water needs:
Sustained and reliable low water levels are required to provide these emergent habitats
crucial for successful breeding of these birds which migrate here from the Northern
Hemisphere especially for breeding purposes.
27
EFA Namibia Birds (Avifauna).
6. FLOW CATEGORIES RIVER SITES
One of the main assumptions underlying the EFA process to be used in the TDA is that it is
possible to identify parts of the flow regime that are ecologically relevant in different ways
and to describe their nature using the historical hydrological record. Thus, one of the first
steps in the EFA process, for any river, is to consult with local river ecologists to identify
these ecologically most important flow categories. This process was followed at the
Preparation Workshop in September 2008 and four flow categories were agreed on for the
Okavango Basin river sites:
Dry season
Transitional Season 1 (rising flood waters)
Flood Season
Transitional Season 2. (receding flood waters)
Tentative seasonal divisions for river Sites 1-5 are shown in Figure . These seasonal
divisions will be formalised by the project hydrological team in the form of hydrological rules
in the hydrological model. In the interim they provide useful insights into the flow regime of
the river system suggesting a higher within-year flow variability of the Cuebe River and a
higher year-on-year variability of the Cubango River.
It is planned to use similar flow seasons for the remaining river sites: 6 and 8.
1000
900
Wet
We
800
Dry
Dr
Tra
Tr n
a s
n 1
s
Tra
Tr n
a s
n 2
s
Dry
Dr
700
600
Year 1
500
Year 2
400
Year 3
300
200
100
0
O
N
D
J
F
M
A
M
J
J
M
J
A
S
Figure 6.1 Three representative years for Site 4: Okavango River @ Kapoka (hydrological data
from Rundu), illustrating the approximate division of the flow regime into four flow
seasons
28
EFA Namibia Birds (Avifauna).
1800
1600
Wet
1400
Dry
Trans 1
Trans 2
Dry
1200
1000
Year 3
00
Year 2
800
Year 1
600
400
200
0
O
N
D
J
F
M
A
M
J
J
M
J
A
S
Figure 6.2 Three representative years for Site 5: Okavango River @ Popa (hydrological data
from Mukwe), illustrating the approximate division of the flow regime into four flow
seasons
29
EFA Namibia Birds (Avifauna)
The literature review (Chapter 4) and data collection and analysis exercises (Chapter 5) are
focused on addressing what is initially expected to be nine main questions related to these
flow seasons (Table ).
Table 3.2 Questions to be addressed at the Knowledge Capture Workshop, per indicator per site.
In all cases, `natural' embraces the full range of natural variability
Question
number Season
Response of indicator if:
1
Onset is earlier or later than natural mode/average
2
Dry Season
Water levels are higher or lower than natural mode/average
3
Extends longer than natural mode/average
Duration is longer or shorter than natural mode/average - i.e. hydrograph is
4
Transition 1
steeper or shallower
5
Flows are more or less variable than natural mode/average and range
Onset is earlier or later than natural mode/average synchronisation with rain
6
Flood season
may be changed
7
Natural proportion of different types of flood year changed
8
Onset is earlier or later than natural mode/average
Transition 2
9
Duration is longer or shorter than natural mode/average i.e. hydrograph is
steeper or shallower
6.2 Inundation categories delta sites
The recognised river flow categories are not relevant in the Delta, where inundation is the
major driver of ecosystem form and functioning. The main inundation categories
recognised by the inundation model developed by the Harry Oppenheimer Okavango
Research Centre (HOORC) are used here
30
EFA Namibia Birds (Avifauna)
7. LITERATURE REVIEW
7.1 Introduction
There is a wealth of information available on the birds of this region, their breeding biology,
feeding habits and many other aspects. Most of this information is collectively available in
the recently published Roberts Birds of Southern Africa VIIth Edition which has a
comprehensive list of all other relevant publications. There is, however, little or no available
literature which focuses specifically on the responses of birds to changes in flow regime and
more specifically on this particular river. I have however conducted some work of my own
over the years e.g. African Skimmers breeding in Mahango Game Park and almost 15yrs of
bird counts for Wetlands International on two areas of this river system. Many capture and
ringing exercises over this period that have also been conducted along this river system by
myself and this has contributed substantially to my knowledge.
What follows therefore is based largely on personal observations, interest and knowledge
gleaned from literature and active experience over a 16 year period while living and working
on the Okavango River.
31
EFA Namibia Birds (Avifauna)
8 NAMIBIA BIRD INDICATORS (10)
8.1 Indicator 1: Piscivores of open water
8.1.1 Main characteristics
This is a group of bird species which are adapted to only eating fish species captured
generally from an open water situation existing in the main river system. In this location the
fish are captured in different ways;
· From an aerial attack directly overhead where the bird is flying or hovering, i.e. African
Fish Eagle, Osprey, Pied Kingfisher, Giant Kingfisher
· From a vantage point along the river bank like a tree, other riverine vegetation or from the
bank itself, i.e. African Fish Eagle, Pied Kingfisher, Malachite Kingfisher, Giant
Kingfisher
· Underwater where the bird submerges itself entirely and swims around to actively search
out and capture fish within rocky crevices and underwater vegetation, i.e. Reed Cormorant,
African Darter
These birds make use of the main river where currents are stronger and larger specially
adapted fish exist comfortably against strong currents. This category contains the top
predatory bird species and they can only exist comfortably in a healthy environment
providing for ideal conditions of habitat and food source. Their presence on the river
system is therefore a good indicator of a healthy ecosystem.
8.1.2 Life cycle attributes
Although this group of birds utilize open water situations they are opportunistic in nature
and during the high water periods when the floodplains fill up and many fish species move
into these shallower areas to breed and they are more easily captured. Their methods of
capture however remain the same though but their success rate during these easier times
is higher and therefore generally coincides with the breeding time when young birds need to
be fed regularly. Their variable use of river characteristics makes it possible for this group
of birds to stay on the same river system throughout the year with its variable water level
changes.
8.2.1 Links to flow
During the high water months (January to May) these birds are generally utilizing the shallower
water habitats in the floodplains where breeding fish are more vulnerable to the larger aerial
predators and the young newly born fry are in greater numbers.
During the low water level months (June December) these birds species move towards the
main river system once the floodplains have dried up. The Kingfishers in this group breed
during these months when vertical sandbanks are exposed and available for them to
excavate their nest tunnels while food supply is still available as most of the smaller current
adapted fishes are found along the edges of the river or in the inlets where they occupy the
top strata just below the surface and are more vulnerable to aerial predation by these
smaller aerial predators. African Fish Eagles also peak their breeding activities during this
period presumably to coincide with the swelled number of fish species available in the main
stream after the breeding season.
32
EFA Namibia Birds (Avifauna)
8.2 Indicator 2: Piscivores of shallow water and lagoons etc.
8.2.1 Main characteristics
This group of bird species are all fish eating but are mostly only adapted to capturing their food
items in shallow or sluggish water systems created in the floodplains with lagoon, inlets and
tree lined pools offering the ideal conditions. These predatory birds use the following
capture techniques;
· Aerial attack using overhanging trees as hunting perches, i.e. Pel's Fishing Owl, Aerial
attack using grassy vegetation on the edges of shallow water or by wading into the shallow
water and waiting completely immobile for unsuspecting fish to swim within striking distance
of beaks adapted to piercing and holding onto wriggling fish, i.e. Purple Heron, Grey Heron,
Great Egret, Little Egret.
8.2.2. Life cycle attributes
Shallow and sluggish water conditions created in the floodplains during the high water level
months create ideal feeding situations with an abundance of prey. This period of growth
and abundance is also ideal for breeding opportunities when excessive plant cover provides
nesting material as well as secure and safe nesting sites. Food abundance makes the
rearing of every-hungry young birds less of a hardship for the parent birds. For these
reasons most of the species in this group will breed during this period and in this habitat.
8.2.3 Links to flow
Rising water levels during the rainy months reach a point where they overflow into adjoining
floodplains generally during January and February. Breeding fish then move into these
filling up and as yet shallow areas to breed. At this time they become very vulnerable to
predatory birds that are unable to catch them in deeper waters. This situation is repeated
again in the months May to July when the water levels drop and the flood plains empty back
into the main river system, this time exposing both adult fish and the newly hatched young
fish making their way back into the main stream. Receding waters also leave shallow and
often isolated pools with an abundant food supply.
8.3 Indicator 3: Piscivores and invertebrate feeders, floodplains and isolated
pools
8.3.1 Main characteristics
This is a group of bird which feed on fishes or other invertebrates and aquatic animals found in
floodplains either during filling up or receding water levels creating isolated pools. Prey or
food items are collected in the following ways;
· Aerial attack from above on small fish near the surface or insects attracted to the water
surface or surrounding vegetation' i.e. Whiskered Tern, White-winged Tern
· Sitting motionless on the edges or within shallow water to capture unsuspecting fish within
reach of specially adapted piercing and holding beaks, i.e. Yellow-bellied Egret, Squacco
Heron, Black Heron, Slaty Egret, Rufous-bellied Heron, White-backed Night-heron, Black-
crowned Night-heron, Green-backed heron, Dwarf bittern, Little Bittern Yellow-billed Stork,
Saddle-billed Stork, Woolly-necked Stork, Hamerkop, Glossy Ibis, African Sacred Ibis,
Wattled Crane
· Patrolling the outer edges of a wetland and amongst floating or half submerged vegetation
foraging for insects, amphibians and other invertebrates not found in the water itself, i.e.
Painted Snipe, Great Snipe, African Snipe, Common Moorhen, Lesser Moorhen, Long-toed
33
EFA Namibia Birds (Avifauna)
Lapwing, African Wattled Lapwing, Blacksmith Lapwing, Ruff, Curlew Sandpiper, Little Stint,
Common Sandpiper, Wood Sandpiper, Common Greenshank, Marsh Sandpiper
· Swimming or floating on the water surface and either foraging from surrounding vegetation
or diving to the bottom to feed off detritus or invertebrates within, i.e. White-faced Duck,
Red-billed Teal, Egyptian Goose, Comb Duck, Spur-winged Goose.
This diversity of bird species utilizes a large spectrum of aquatic invertebrates and fish species
which use this floodplain system as breeding grounds.
8.3.2 Life cycle attributes
Shallow and sluggish water conditions are ideal for an abundance of aquatic invertebrates that
breeds in these pools and associated vegetation as well as within the water bodies where
fish species breed at this time only. This situation creates profitable feeding opportunities
for a diversity of bird species some of which migrate from the Northern hemisphere to make
us of this limited seasonal food source. This situation may last for an extended period from
December (where the rains bring fresh plant growth to the dry floodplains) until July when
the waters of the floodplain have receded leaving isolated pools and the onset of the colder
winter months brings a gradual lull in most invertebrate breeding activities.
8.3.3 Links to flow
During the rainy months January to February when the water level rises and feeds into the
adjoining floodplains the fish breeding activity intensifies and the large piscivorous birds of
this group thrive. Later from March to July when the floodplains extend and swell with
burgeoning plant growth the insects, invertebrates and other aquatic life go into frenzied
breeding mode. This situation them becomes more suitable for the rest of this indicator bird
group with food acquisition habitat more suitable to their specific physical adaptations and
they then move into this system. Staying for the duration until the winter months from July
when the isolated pools are mostly dry and essentially lifeless with all the water having
retreated back to the mainstream. As the pools gradually dry out, the vegetation dries and
rots increasing nutrient levels and eventually providing fertile soils for "mulapo" gardens.
8.4 Indicator 4: Specialist feeders on floodplains, rising and receding waters
8.4.1. Main characteristics
Bird species with special physical adaptations to deal with selected food items or species
which require a specialized habitat in which their food requirements are located.
· These birds will source their individual food items by wading and probing or merely by
moving around within their specific habitat in search of selected food items, i.e. African
Openbill, Purple Swamphen, Allens Gallinule
8.4.2 Life cycle attributes
Their specific food items or habitat requirements are generally not suitable or easily
available on this river system throughout the year, but rather during the rainy season
months when the floodplains are inundated with either rising or receding water. During this
time these birds occupy the area in large numbers which dwindle to a mere remnant
population as conditions become less suitable or when the majority migrate to other more
suitable river systems or areas that suit their needs. A small remnant number of these birds
do however remain here during these unsuitable times and undoubtedly modify their food or
34
EFA Namibia Birds (Avifauna)
habitat requirements temporarily during this period to survive on what is available at the
time.
8.4.3 Links to flow
Rising water levels and rain cause soggy floodplains through to April, exposing specific
food items like snails and molluscs, and accelerating water lily growth to create suitable
conditions for these birds. When the waters recede from April through to August some
areas still provide adequate conditions for these birds in smaller numbers.
8.5 Indicator 5: Specialist feeders on water-lily covered inlets
8.5.1 Main characteristics
This small group of birds is physically adapted to walk on or move around within water-lily
covered water surfaces, nesting on floating vegetation in this habitat and with specific
dietary requirements associated with water-lilies (Nymphaea spp)
· African Jacana, Lesser Jacana, Allens Gallinule, Pygmy Goose, White-backed Duck
8.5.2 Life cycle attributes
The habitat created by water lilies which cover surfaces of water bodies within floodplains
like pools, channels and the associated inlets and lagoons is specific in nature and only a
few select bird species have adapted to utilize it successfully. These species have adapted
their breeding and dietary requirements and even behavioral habits around this ecosystem
otherwise un-utilized by other bird species. Although water lilies are found during all
months of the year on this river system and most of this bird group with them, they are more
prolific with larger numbers and accelerated growth during the rainy months November
through to March. It is during these months that larger numbers of these bird species move
into this habitat to feed and breed, some of which migrate here from the more northerly
parts of Africa.
8.5.3 Links to flow
Water-lily growth is only suited to slower flowing, sluggish shallow water on the edges of the
main river, inlets, lagoons or the vast adjoining floodplains when they fill up with water
during the high water-level months.
8.6 Indicator 6: Specialist feeders in riverine fruit trees
8.6.1 Main characteristics
This group opportunistically utilizes the fruit-bearing riverine trees for the relatively short
period when ripened fruits are available.
· Some of this group would be entirely frugivorous and these riverine trees would only be
occupied during their fruit bearing period, after which they then would move inland to utilize
other fruit sources, i.e. Grey-headed Parrot, Meyers Parrot, Green Pigeon, Red-faced
Mousebird,
· Others of this group utilize these fruit-bearing riverine trees as only part of their dietary
requirements and when this source is exhausted will change their dietary requirements to
insects or other food items available without leaving this environment, i.e. Grey Go-away
Bird, Bradfield's Hornbill, Grey Hornbill, African red-eyed Bulbul, Dark-capped Bulbul,
35
EFA Namibia Birds (Avifauna)
Terrestrial Brownbul, Yellow-bellied Greenbul, Violet-backed Starling, Burchells Starling,
Meve's Starling, Glossy Starling, Greater Blue-eared Starling, Black-collared Barbet, Black-
headed Oriole, Arrow-marked Babbler.
Many of this group of birds would alter their distribution or change their migratory patterns if
this food source were altered or eliminated.
These birds could be more extensive as these fruit bearing riverine trees, when in fruit, have a
secondary function as a feeding source and breeding location for a variety of insects which
in turn attract many more species of insectivorous birds during the fruiting period. The
presence of these birds indicates a healthy and sustainable riverine ecosystem and their
absence may indicate deforestation.
8.6.2 Life cycle attributes
This habitat remains relatively dormant during most of the year until the rainy months
December, January and February when the fruits of these trees ripen in abundance. At this
time the birds alter their normal movement patterns to make use of this favoured resource
for the relatively short fruiting period.
8.6.3 Links to flow
As these riverine trees are located on the edges of the river channel or in copses or clusters
on higher ground within the floodplain itself, or on islands within the main-stream their
productive fruiting period is directly linked to the rising water levels providing sufficient water
to the root system. The bird activity related to them is then also similarly regulated to the
high water levels being high and good enough to generate fruit production.
8.7 Indicator 7: Breeders in reedbeds and floodplains
8.7.1 Main characteristics
· This wide category of birds requires fully-matured reedbeds and floodplain vegetation
surrounded by water of varying depths in which to safely build their nests and rear young.
The reedbeds are utilized by the following species, Village Weaver, Thick-billed Weaver,
Southern Masked Weaver, Lesser Masked Weaver, Spectacled Weaver, Southern-brown-
throated Weaver, Red-billed Quelea, Southern Red Bishops, Tawny-flanked Prinia, Little
Rush Warbler, Lesser Swamp Warbler, Greater Swamp Warbler , African Reed Warbler,
Luapula's Cisicola, Chirping Cisticola, Purple Heron, Little Egret, Squacco Heron, Rufous-
bellied heron, Black Heron, Slaty Egret, Black-crowned Night-heron, Little Bittern, African
Marsh Harrier.
· The floodplain areas with low grass vegetation is utilised by the following species; Fan-
tailed Widowbird, Zitting's Cisticola, African Purple Swamphen, Allen's Gallinule, Black
Crake, Common Moorhen, African Rail, Baillon's Crake, Spur-winged Goose, Red-billed
Teal, White-backed Duck, White-faced Duck.
The distribution of these bird species indicates a healthy and undisturbed habitat which
provides the required safety and nesting needs. The absence of these birds would indicate
human disturbance, over-utilization of the reed resource and inadequate high-water levels.
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EFA Namibia Birds (Avifauna)
8.7.2 Life cycle attributes
These groups of birds choose this habitat because it provides the necessary nest
construction requirements i.e. upright mature reeds for tightly woven, attached or hanging
nests, thickly matted low floodplain grasses in which to hide nests or floating floodplain
vegetation on which to construct a well camouflaged nest platform. All these birds
however, choose their nest locations within this habitat primarily for the safety factor from
predators which surrounding water provides. Some also choose to nest colonially or in
loose colonies for the safety factor provided by the colony (safety in numbers).
8.7.3 Links to flow
As maximum high water levels are a critical safety factor for these bird species particularly the
reedbed nesters, most will wait until the highest water level is reached before actively
constructing their nests and resuming their relatively short nesting period, thereby deriving
the most benefit from the high water levels. These are normally the months of February to
April.
8.8 Indicator 8: Breeders in riverine overhanging trees
8.8.1 Main characteristics
· This is a smaller group of birds that choose to construct their nests in trees on the river
bank or floodplain edges generally overhanging the water; eg. Village Weave, Southern
Masked Weaver, Lesser Masked Weaver, Golden Weaver, Green-backed Night Heron,
White-backed Night-heron, Hamerkop, Pygmy Goose, Comb Duck, Reed Cormorant,
African Darter.
The presence of these bird species would indicate the availability of an adequate amount of
mature riverine trees either on the main river system or on islands or higher ground within a
floodplain.
8.8.2 Life cycle attributes
The choice of this nesting habitat is related to the size and weight of the nest needing a
strong support structure, the close proximity of water to the newly hatched young or the
safety factor involved from being over the water and not easily accessible to most
predators. Some of the birds within this group are large, heavy and colonial nesters with
dense colonies which require a strong structural system to support the weight of a large
colony of nests and young. Some are adapted to living on water and the newly-hatched
young need to get safely to water as soon after hatching as possible to minimize mortalities.
All, however, benefit from the safety factor provided by being surrounded by, or
overhanging, water thereby minimizing access from predators.
8.8.3 Links to flow
The nesting trees remain unutilized until the maximum high water levels have been reached
and these birds regulate nest construction and breeding activities until the ideal water levels
have been reached. This occurs during February to April during normal rainy seasons.
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EFA Namibia Birds (Avifauna)
8.9 Indicator 9: Breeders on banks
8.9.1 Main characteristics
This group of birds are specific about their nesting requirements being riverbank habitat.
Some of this group require the vertical cliff-like surface of the washed away riverbank in
which to burrow horizontal tunnels sometimes as deep as two metres with a breeding
chamber at the end, e.g. Carmine Bee-eater, White-fronted Bee-eater, Little Bee-eater.
The rest of this group require the short grassy areas found along the upper part of the
riverbanks on which to nest in shallow well camouflaged scraped hollows among the short
grass stubble provided in this habitat particularly after being burnt. They sometimes breed
in loose colonies eg. Collared Pratincoles or singularly, e.g. African Wattled Lapwing,
Blacksmith Lapwing. The vertical bank breeding birds require a specific soil type in these
sandbanks which is soft enough to burrow long tunnels into, yet compact enough to resist
caving in on themselves when structurally weakened by sometimes hundreds of colonial
nest tunnels very close together. Only some banks are used which conform to these soil
type requirements while others are completely ignored. This group of birds may then be
indicating a specific soil type by this selectivity. The grassy bank birds can only occupy this
habitat throughout the year if their specific food requirements are met with and their
presence here would therefore indicate a nutrient rich ecosystem.
8.9.2 Life cycle attributes
These birds will occupy this riverbank habitat for as long as it is available during the dry
season during the months July to December or January. Here they will congregate and
feed before and during the breeding season. For the vertical bank breeders these banks
are critical as the vertical surface with water below substantially minimizes predator
accessibility to their otherwise completely exposed and unprotected burrow/tunnel
entrances.
8.9.3 Links to flow
Low water periods are required to leave these banks exposed for breeding purposes, while the
high water periods are necessary to rejuvenate the otherwise poorly nourished grassy
areas with food items required for these birds to exist here throughout the year. At the high
water periods when this habitat should be underwater they will temporarily move inland to
the floodplain edges to feed on the food source provided there.
8.10 Indicator 10: Breeders on emergent rocks, sandbars and islands
8.10.1 Main characteristics 9
This very small and select group of birds choose these otherwise inhospitable specific areas
and no other habitat on which to nest and breed, e.g. African Skimmer, Rock Pratincole and,
to a lesser extent, Whitefronted Plover and Water Thick-knee. The exposed nature of this
habitat makes their nests difficult or impossible to hide from predators particularly human
interference and their absence from a river system would therefore indicate excessive
interference levels.
38
EFA Namibia Birds (Avifauna)
5.10.2 Life cycle attributes
The majority of this indicator group will only occupy this habitat during the breeding periods of
June December, after which they leave, either to other higher ground like tree copses within
the floodplains, or to other river systems within Africa which offer them suitable living
conditions. One species of this group, African Skimmer, has exceptionally short tarsi and can
therefore only perch or settle on a sandy area entirely devoid of vegetation.
8.10.3 Links to flow
A regular sustainable low water cycle is essential to expose the rocks and sandbars critical for
these birds to nest and breed on at the correct time of the year. Water levels too low will make
their isolated rock and sandbar nest locations vulnerable to predators and other disturbance.
Water levels too high will force them to vacate the river system entirely.
39
EFA Namibia Birds (Avifauna)
9. SUMMARY
"Birds have wings and can fly". This is a statement I have heard often, and which goes a long
way to explain bird responses to changing habitat conditions. Trying to predict the indicator
bird responses to changing river flow responses is therefore often quite easy if they don't like
the situation and cannot adapt to the changes in the river flow they simply leave to search
elsewhere for more suitable conditions. Obviously this is not what we all want, and one is
constantly trying to adapt ones thoughts to reflect the specific bird indicators tolerance level of
changes and integrate this aspect into the report. Many of the indicators are too specialized in
their habitat requirements to withstand any changes and are forced to leave almost
immediately once changes are detected. Others however have the capacity to adapt and
these birds have a prolonged tolerance level. One factor always to be considered is the fact
that there are no or very few nearby and available alternative water systems for many of the
indicator bird species to relocate to, should this Okavango River become intolerable to them.
Therefore habitat changes here could very likely negatively affect whole populations of bird
species in the whole region.
The Okavango River Basin is one of the few remaining significant life sustaining ecosystems
for many bird species, particularly those that move southwards from the Northern Hemisphere
and pause here to restore condition before resuming their long waterless journey to their
Southern African destinations. Therefore any interference with this vital resource could
seriously interfere with bird populations in the rest of the African Sub-region.
Bearing this in mind, it is surprising that there is an obvious lack of informative studies made to
emphasize this in the available bird literature. This study, is to the best of my knowledge, one
of the first and possibly too short and not specific enough to obtain quantifiable results of high
quality.
40
EFA Namibia Birds (Avifauna)
10. DATA COLLECTION AND ANALYSIS
Timing of project did not allow for this sequence of events for a literature survey preempts to
fieldwork. Field work commenced prior to specialist report template being available and late
"agreement of indicators".
10.1 Methods for data collection and analysis
Both sites were visited during October 21st in order to establish the sites and make an initial
assessment. During this time a basic bird list was drawn up to give me a general idea of what
to expect in the two sites before concentrating on the actual indicator list (Table Chapter 3.1.2)
Subsequent visits to Popa Falls site were made on 18 November 2008, 23 December 2008, 7
January 2009, 20 January 2009 and 14th March 2009. The Kapako site was visited on 20
December 2008, 9 January 2009 and 23 January 2009.
On these occasions the basic bird lists were updated but with an emphasis on the indicators
especially over these changing months with many migratory bird species occupying suitable
habitat created by the rainy season.
Most observations were done on foot using binoculars however when the opportunity
presented itself the sites were explored by boat while assisting with fish sampling. Other
observations were done from vehicle while driving to and from as well as within the site areas.
While working on this report all available literature was consulted given the time constraint.
Much of my analysis was made based on over 16 years o experience with birds as my major
interest and income generation activities on the Okavango River where I live and work.
In addition, observations on birds and their activity patterns related to the beginning of the
rainy season and the subsequent rise in the river water levels were made at my home base
situated at Shamvura Camp on the Okavango River almost midway between both sites.
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EFA Namibia Birds (Avifauna)
11. RESULTS
River water levels seemed to rise some 2 to 3 weeks earlier this year presumably as a direct
result of early good rains in the Angolan catchment areas. This early rising level seemed to
catch some Collared Pratincoles in the last stages of their breeding activity, with very young
hatchlings unable to fly well and thus threatened by rising water levels covering the nesting
banks.
Carmine Bee-eaters arrived about a month earlier to commence colonial bank breeding
activities this season. This behavior may be linked to their breeding colony of the previous
year being seriously affected by over 40 mm of early rain which soften the banks and caused
their nesting tunnels to cave in, exposing the nests to human and predator depredations and
negatively affecting their nesting success rate.
At the Kapako site the water levels appeared to rise earlier than normal in January and then
drop while floodplains were being filled up. This caused some colonial Weavers and Bishops
here to nest earlier than usual. This was not the case at the Popa site where the Cuito
tributary seemed to normalize the rise and drop of water levels. Here these groups of birds
are not yet nesting seriously still waiting for the true high water period in February March.
The Kapako situation may result in a double clutch situation if this section starts rising again.
It is uncertain if this is a normal situation or true for this year only.
Purple Swamphen population seemed to have increased in many areas except within the
confines of Mahango Game Park. This may be due to more suitable feeding and breeding
habitat being created by increased trampling effect of cattle herds grazing the floodplain areas.
42
EFA Namibia Birds (Avifauna)
12. INDICATORS
Indicator 1 Piscivores of open water
Table 2: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in prediction
Question
(very low,
number
Season
Possible flow change
Predicted response of indicator
low, med,
high)
The opportunistic nature of most of this group enables them to adapt and they will follow
Onset is earlier or later than
1
the fish species from the mainstream to the flood plains when suitable levels exist.
High
natural
Those others that migrate will adjust their migration accordingly.
(Sept, Oct,
This group have the ability to change their preferred hunting habitats. This allows them
Nov)
2
Water levels are higher or
to adjust to climatic changes affecting water levels which are naturally variable in normal High
Dry Season
lower than natural
times anyway
3
Extends longer than natural
This extension may affect their breeding dates to fit in with prey availability. For those
High
dependent on shallow water the effect will be positive
Duration is longer or shorter
Very little significant affect, they will be able to adjust here
4
than natural - i.e. hydrograph
High
(Dec, Jan,
is steeper or shallower
Feb)
Transition 1
Very little significant effect. They adjust their habitat preference to changes in prey
5
Flows are more or less
availability except for Skimmers which will have to adjust migration times to move to
High
variable than natural
more suitable habitat availability
Onset is earlier or later than
Changes affecting prey will impact these top predatory birds which rely heavily on this
6
(Mar, Apr,
natural synchronisation with period and they may have to leave
Medium
May) Flood
rain may be changed
season
This will undoubtedly change the prey species behaviour and availability and cause this
7
Natural proportion of different
types of flood year changed
group to move on not being able to adjust to these conditions
Medium
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EFA Namibia Birds (Avifauna)
Onset is earlier or later than
Breeding months and breeding success rate may be negatively affected
8
High
(June, July,
natural
Aug)
Duration is longer or shorter
Breeding aspects will be negatively affected with fledglings dependent for too long on
9
Transition 2
than natural i.e. hydrograph parents unable to provide food or fledglings not allowed enough time to develop if the
High
is steeper or shallower
period is too short.
44
EFA Namibia Birds (Avifauna)
Indicator 2 Piscivores of shallow water & lagoons etc.
Table 3: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in prediction
Question
(very low,
number
Season
Possible flow change
Predicted response of indicator
low, med,
high)
Onset is earlier or later than
Birds arriving from other regions will be adversely affected as their arrival may not
1
natural
coincide favourably with prey availability
High
(Sept, Oct,
Water levels are higher or
Very little significant effect so long as the water levels are high enough to inundate the
2
Nov)
floodplains and provide shallow water systems with prey available
High
Dry Season
lower than natural
3
Extends longer than natural
Fish stocks may be exhausted and birds may starve being unable to move to other
Medium
suitable habitats in other regions quick enough to survive
Starvation due to fish stock exhaustion levels and birds being unable or unwilling to
Duration is longer or shorter
move long distances to other more suitable habitats.
4
than natural - i.e. hydrograph
High
(Dec, Jan,
is steeper or shallower
Feb)
Transition 1
Variability in flow is not critical unless prey species are adversely affected
5
Flows are more or less
High
variable than natural
Migratory birds of this group move in response to rain. They may then be adversely
Onset is earlier or later than
affected by prey availability if their arrival doesn't coincide with favourable prey
6
(Mar, Apr,
natural synchronisation with conditions. In other words having been misled by the rain.
High
May) Flood
rain may be changed
season
Disruption of prey species my be advantageous if conditions are such to make them
7
Natural proportion of different
types of flood year changed
vulnerable
Medium
(June, July,
Food availability may not coincide with arrival times and cause disruption in movement
Onset is earlier or later than
8
Aug)
patterns
High
natural
Transition 2
45
EFA Namibia Birds (Avifauna)
Breeding aspects will be affected
Duration is longer or shorter
9
than natural i.e. hydrograph
High
is steeper or shallower
46
EFA Namibia Birds (Avifauna)
Indicator 3 Piscivores and Interbrates feeders. Floodplains, isolated pools
Table 4: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
Food items becoming unavailable or hard to locate will cause competition in this large
Onset is earlier or later than
group and result in most species to move if the season is earlier than usual. Later than
1
Medium
natural
usual may cause the opposite effect and result in these birds staying longer or
(Sept, Oct,
increasing their concentrations.
Nov)
High water levels will negatively affect food availability and decrease the concentration
2
Water levels are higher or
Dry Season
of this group however water levels will probably have the opposite effect and
Medium
lower than natural
concentrations will be higher with food items being more easily available
3
Extends longer than natural
Most birds in this group will be adversely affected by the unavailability of food and
Medium
unsuitable habitat. They will therefore leave or concentrations will decrease
Long duration will be advantageous with increased food availability and habitat. Shorter
Duration is longer or shorter
duration my not affect this group too negatively as the rainy season, if normal, will help
4
than natural - i.e. hydrograph
(Dec, Jan,
to create suitable conditions for most of this group
High
Feb)
is steeper or shallower
Transition 1
No real affect should be detected as suitable habitat is usually affected by the rain
5
Flows are more or less
High
variable than natural
An early flood would increase concentration of this group that are resident or close
Onset is earlier or later than
enough to make use of early abundance of food items. The migratory species of this
6
(Mar, Apr,
natural synchronisation with group may arrive too late and be adversely affected with a later flood season
Medium
May) Flood
rain may be changed
season
As long as there are flooded situations this group of birds should be able to exist and
7
Natural proportion of different
types of flood year changed
breed adequately without these conditions they will be affected negatively.
Medium
47
EFA Namibia Birds (Avifauna)
Onset is earlier or later than
Early onset will affect breeding success negatively for most of this group a later onset
8
natural
should have the same effect
Low
(June, July,
Aug)
A longer duration will cause food shortages and adversely affect breeding success for
Duration is longer or shorter
Transition 2
most of this group. A shorter duration my be advantageous but likely only for the more
9
than natural i.e. hydrograph resident species of this group, as the food shortage period will be shorter too, probably
Medium
is steeper or shallower
lessening the need to leave for greener pastures.
48
EFA Namibia Birds (Avifauna)
Indicator 4 Specialist feeders on floodplains, receding and rising waters
Table 5: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
A late onset would prolong the better feeding months and therefore be advantageous.
Onset is earlier or later than
1
An early onset would decrease food availability and force movement to other more
High
natural
(Sept, Oct,
suitable ecosystems
Nov)
Higher water levels extends food availability periods and would increase concentrations
2
Water levels are higher or
Dry Season
lower than natural
however water levels may not necessarily cause stress and force movement away
Medium
3
Extends longer than natural
A long dry season would cause stress and force movement away
High
A long duration will increase food availability and encourage larger concentrations, of
Duration is longer or shorter
this group to occupy this system. A shorter duration should not have much affect and
4
than natural - i.e. hydrograph
(Dec, Jan,
only hasten on the flood season
Medium
is steeper or shallower
Feb)
Transition 1
In an already variable system this should not adversely affect this group
5
Flows are more or less
High
variable than natural
Being the time of plenty depending on rising water levels the presence or absence of
Onset is earlier or later than
rain should not be a factor. The longer this season lasts the better for this group
6
(Mar, Apr,
natural synchronisation with
Medium
May) Flood
rain may be changed
season
Being the time of plenty depending on rising water levels the presence or absence of
7
Natural proportion of different
types of flood year changed
rain should not be a factor. The longer this season lasts the better for this group
Medium
49
EFA Namibia Birds (Avifauna)
An early onset would cause evacuation and movement out of the areas whereas a later
Onset is earlier or later than
onset would extend food availability and increase concentrations
8
Medium
natural
(June, July,
Aug)
Transition 2
Being the time of plenty depending on rising water levels the presence or absence of
Duration is longer or shorter
rain should not be a factor. The longer this season lasts the better for this group
9
than natural i.e. hydrograph
Medium
is steeper or shallower
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EFA Namibia Birds (Avifauna)
Indicator 5 specialist feeders in water lily covered inlets
Table 6: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
Onset is earlier or later than
Early onset will result in food shortage and cause movement out. Later onset will
High
1
natural
lengthen period of food availability and extension of this groups occupation period
Sept, Oct,
Higher water levels may increase water lily flowering periods and extend this time these
High
Nov
2
Water levels are higher or
birds can occupy this habitat. Lower water levels should have little or not effect
Dry Season
lower than natural
High
3
Extends longer than natural
Migrations period could be affected with food shortages causing mortality or
unsuccessful breeding
A longer transition period would increase period of food availability and encourage a
Duration is longer or shorter
longer stay. A shorter period will hasten the flood season and have little or not effect on
4
than natural - i.e. hydrograph
Dec, Jan,
these birds
High
is steeper or shallower
Feb
Transition 1
Increased variability will cause too much uncertainty of the food resource and negatively
5
Flows are more or less
variable than natural
influence movement into this system.
High
An early flood season would increase the length of good food availability and probably
High
Onset is earlier or later than
encourage increased concentrations. A late flood season should cause food stress and
6
March, Apr,
natural synchronisation with decreased concentrations. Rains too early will encourage lily growth and influence
May
rain may be changed
movement into the area too early to sustain increased concentrations.
Flood
season
High
7
Natural proportion of different
types of flood year changed
Confusion and vacation of the system
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EFA Namibia Birds (Avifauna)
An early winter could negatively affect breeding success. A later winter could
High
Onset is earlier or later than
encourage a longer stay and a change in migratory patterns which could have long term
8
natural
detrimental affects
June, July,
Aug
Transition 2
A long winter will impact negatively on breeding success and concentrations. A short
Duration is longer or shorter
winter could influence migration patterns and unnatural over wintering behaviour which
9
than natural i.e. hydrograph may not be sustainable in the long term
High
is steeper or shallower
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EFA Namibia Birds (Avifauna)
Indicator 6 Specialist feeders in riverine fruit trees
Table 7: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
An early dry season will cause food stress and negatively affect breeding success and
Onset is earlier or later than
influence movement to other resources regions. A late dry season will only have a
1
High
natural
positive influence if fruiting trees extend their fruit bearing period which is unlikely so
(Sept, Oct,
this situation should have no effect generally
Nov)
There should be not effect as water levels should not affect the fruit bearing potential
High
Dry Season
2
Water levels are higher or
lower than natural
of the trees these birds depend on
3
Extends longer than natural
A long dry season can cause food shortage, stress and movement
High
A long duration will cause stress and movement to seek alternative sources. A short
High
Duration is longer or shorter
duration will speed up the flood season on arrival and cause increased concentrations
4
than natural - i.e. hydrograph
(Dec, Jan,
and breeding
is steeper or shallower
Feb)
Transition 1
Flows being variable should have no effect
High
5
Flows are more or less
variable than natural
An early flood season
High
Onset is earlier or later than
6
(Mar, Apr,
natural synchronisation with
May) Flood
rain may be changed
season
High
7
Natural proportion of different
types of flood year changed
Confusion but adaptation may occur
53
EFA Namibia Birds (Avifauna)
Early winter may negatively affect breeding success due to food shortages. A late
High
Onset is earlier or later than
winter may have the opposite effect and encourage double clutches
8
natural
(June, July,
Aug)
Transition 2
Early winter may negatively affect breeding success due to food shortages. A late
High
Duration is longer or shorter
winter may have the opposite effect and encourage double clutches
9
than natural i.e. hydrograph
is steeper or shallower
54
EFA Namibia Birds (Avifauna)
Indicator 7 Breeders in Reedbeds and Floodplains
Table 8: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
Onset is earlier or later than
Food shortages will negatively affect the breeding success
1
Medium
natural
(Sept, Oct,
So long as the water levels are high enough to fill up the flood plains and encourage
High
Nov)
2
Water levels are higher or
plant growth to create suitable nesting habitat there should be no effect
Dry Season
lower than natural
High
3
Extends longer than natural
Birds should adapt and hold off breeding until conditions are suitable if food is
available
A short duration will hasten the floods and be advantageous. A long duration will
High
Duration is longer or shorter
probably cause stress but can be adapted to. This group can wait for the right
4
than natural - i.e. hydrograph
(Dec, Jan,
conditions
is steeper or shallower
Feb)
Transition 1
Variability can be adapted to
High
5
Flows are more or less
variable than natural
An early onset will increase breeding success whereas a late onset will not negatively
Medium
Onset is earlier or later than
affect the groups occupation period
6
(Mar, Apr,
natural synchronisation with
May) Flood
rain may be changed
season
Medium
7
Natural proportion of different
types of flood year changed
Confusion that can be adapted to
55
EFA Namibia Birds (Avifauna)
An early winter will negatively affect breeding success and may affect the return of
Medium
Onset is earlier or later than
some of these species the following year
8
natural
(June, July,
Aug)
Transition 2
A short winter may encourage over wintering whereas a longer winter may cause
Medium
Duration is longer or shorter
mortalities and change in migration patterns
9
than natural i.e. hydrograph
is steeper or shallower
56
EFA Namibia Birds (Avifauna)
Indicator 8 Breeders in riverine over-hanging trees
Table 9: Predicted response to possible changes in the flow regime in the Okavango River ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
Onset is earlier or later than
This group should be able to adapt their breeding activity to either of these conditions
High
1
natural
(Sept, Oct,
Nov)
High water levels should be advantageous to breeding success with an early start to
High
2
Water levels are higher or
Dry Season
lower than natural
breeding activity. Low waters should have little or not effect during this time
3
Extends longer than natural
This group should be able to adapt
High
Changes here should not affect the majority of this group except the Pygmy Geese
Medium
Duration is longer or shorter
which may adapt
4
than natural - i.e. hydrograph
(Dec, Jan,
is steeper or shallower
Feb)
Transition 1
Variability can be adapted
High
5
Flows are more or less
variable than natural
Either changes may have little or not effect as their breeding activities should have
Medium
Onset is earlier or later than
ceased by now and they will be dispersed with fully fledged young
6
(Mar, Apr,
natural synchronisation with
May) Flood
rain may be changed
season
Should have little or no effect
Medium
7
Natural proportion of different
types of flood year changed
57
EFA Namibia Birds (Avifauna)
High
Onset is earlier or later than
8
natural
Breeding activities should be adapted to these conditions
(June, July,
Aug)
Transition 2
A long winter may cause some degree of food stress and decrease breeding success
High
Duration is longer or shorter
with the opposite effect for a short winter period
9
than natural i.e. hydrograph
is steeper or shallower
58
EFA Namibia Birds (Avifauna)
Indicator 9 Breeders on banks
Table 10: Predicted response to possible changes in the flow regime in the OkavangoRiver ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
Onset is earlier or later than
An early onset will stimulate breeding activity and increase breeding success. A later
1
natural
onset will delay breeding but probably not adversely affect breeding success rate
Medium
(Sept, Oct,
Nov)
High water levels will delay breeding activity but not be detrimental to breeding
High
2
Water levels are higher or
Dry Season
success. Lower water levels will increase the vulnerability factor of the nest sites and
lower than natural
adversely affect breeding success rate
3
Extends longer than natural
Should not necessarily affect this group
High
A long duration of this season will be advantageous to chick development with the
High
Duration is longer or shorter
opposite affect for a shorter duration
4
than natural - i.e. hydrograph
(Dec, Jan,
is steeper or shallower
Feb)
Transition 1
This group will be able to adapt and cope with variability
5
Flows are more or less
Medium
variable than natural
An early flood season may adversely affect chick development and flood or wash away
Onset is earlier or later than
occupied nests causing mortalities and negative breeding success rate. A late flood
6
(Mar, Apr,
natural synchronisation with would have a neutral affect
High
May) Flood
rain may be changed
season
7
Natural proportion of different
types of flood year changed
They will adapt
Medium
59
EFA Namibia Birds (Avifauna)
An early winter may slightly affect chick development and survival rates may be low
High
Onset is earlier or later than
with the opposite effect for a late winter period
8
natural
(June, July,
Aug)
Transition 2
A short winter may increase breeding and encourage double clutches. A long winter
High
Duration is longer or shorter
should have minimal negative impact
9
than natural i.e. hydrograph
is steeper or shallower
60
EFA Namibia Birds (Avifauna)
Indicator 10 Breeders on emergent rocks, sandbars & islands
Table 11: Predicted response to possible changes in the flow regime in the OkavangoRiver ecosystem
Confidence
in
Question
prediction
number
Season
Possible flow change
Predicted response of indicator
(very low,
low, med,
high)
Onset is earlier or later than
Early onset will encourage early breeding activity. A later onset will only delay
1
natural
breeding activity but not necessarily negatively affect the breeding success.
High
(Sept, Oct,
High water levels will lessen suitable nesting habitat availability and be detrimental to
Nov)
2
Water levels are higher or
breeding success. Lower than natural may increase the vulnerability aspect although
Medium
Dry Season
lower than natural
nest site availability opportunities are increased
3
Extends longer than natural
A long extension is advantageous for chick development and may encourage double
High
clutches
A long duration is advantageous for successful chick development and a positive
Duration is longer or shorter
influence on breeding success rate. A short duration may not necessarily have too
4
than natural - i.e. hydrograph
(Dec, Jan,
much affect but my influence migratory patterns
Medium
is steeper or shallower
Feb)
Transition 1
A reliable flow rate would be overall advantageous. Unreliable flow rates may cause
5
Flows are more or less
variable than natural
changes in migration patterns to adapt and have long-term negative affects
Medium
Unseasonal rain will affect breeding success rate an early flood will cause egg
High
Onset is earlier or later than
hatching failures and chick mortality when sandbar nests are flooded by rising waters.
6
(Mar, Apr,
natural synchronisation with Late floods will extend chick development period and be advantageous.
May) Flood
rain may be changed
season
High
7
Natural proportion of different
types of flood year changed
May cause radical changes to populations of endangered species
61
EFA Namibia Birds (Avifauna)
Early appearance of suitable habitat will encourage early breeding and increased
High
Onset is earlier or later than
breeding success rate. A late onset will have little or no adverse affect.
8
natural
(June, July,
Aug)
Transition 2
The longer the duration the better chances of breeding success the shorter the
High
Duration is longer or shorter
duration the lower the chances become
9
than natural i.e. hydrograph
is steeper or shallower
62
EFA Namibia Birds (Avifauna)
13. CONCLUSION
This is clearly a complicated dynamic river system with a constantly changing
character and a rich diversity of bird species dependent on it. Being an ever
changing system these birds have become adaptable in many ways, during the
last 15yrs during while the river has been under direct observation, there has been
the appearance of new species. However, one thing has remained constant, the
flow of the river. It has never dried up and ceased to flow and as such can be
depended on as a reliably flowing river ecosystem offering some sort of sanctuary
or support mechanism to many bird species migrating South from the Northern
hemisphere.
This study is the first of its kind to be conducted on this river system and hopefully
will show that more diverse research needs to be done and not only in the realm of
birds. This is a river shared by Angola, Namibia and Botswana with Botswana
being particularly dependent on it as the lifeline to its Tourism Industry. Any
interference with it could have far reaching and long term consequences. It is also
one of the cleanest and purest rives in Africa in many ways not only related to
water quality by ecological integrity as well. It is therefore quite surprising to find
so little available literature on this vital river and specifically related to birds and
their response to riverflow changes. With the drastic improvement of the living
conditions in the catchment country, namely Angola there will no doubt be
increased demands for development which has to affect this river, as we all know
these development activities tend to be overwhelming for any environment. It is
therefore of vital importance to know what to do and how best to go about it on
this, one of the last remaining un-spoilt river systems in Africa, so as not to misuse
this valuable resource.
This study was too short and hurried and should at least have been conducted
strategically over a full year period to fully understand and quantify the interactions
between birds and the changes in flow regime. More realistic and regular
information swapping between countries within each discipline could have been
improved; this would have increased the confidence of predictions and only have
been beneficial to the quality aspect of this report. Inter-disciplinary connections
and information swapping was to a fair degree achieved during the field trips
arranged by the Namibian coordinator More interactions of this nature could only
have been rewarding, increasing the level of understanding between participants,
and a group participation atmosphere. In Namibia particularly the team members
all have knowledge and interest in the other disciplines involved in this study and
the value of the group participation especially in the field should not be
underestimated.
Stable and secure institutions along this river system, such as game parks,
research institutes, tourism ventures, schools, hospitals/clinics, Ministries of Inland
Fisheries, Agricultural projects (e.g. (MADI) Mashare Agricultural Development
Institute, regional councils, traditional authorities and other recognized bodies
should all be encouraged to have monitoring programmes in place for long term
evaluation. Such information, if made available through a central data collection
agency, could lessen the costs of any other project of this sort in the future. It
would also go a long way towards increased awareness of the fragility and value of
this remarkable resource amongst the people who live and depend on this river for
their livelihood.
63
EFA Namibia Birds (Avifauna)
14. FLOW-RESPONSE RELATIONSHIPS FOR USE IN THE OKAVANGO EF-
DSS
There was a "knowledge Capture Workshop" held in Windhoek from 30th
March to the 4th April 2009. During which the combined Bird specialist team
representing all three countries draw up the Response Curves. These are
now available on CD and therefore do not appear here.
15. REFERENCES
Literature on birds is generally easily available and covers a large range of aspects.
However information specifically with reference to the Okavango River System itself is
relatively scarce and only covers general aspects of bird biology. Information on birds and
their interaction with water level changes on the Okavango River is particularly unavailable
indicating a completely under studied aspect of birds. The time and budget constraints of
their survey did not allow for in depth searches and extensive information gathering
exercises. As a result I made use of my own library collection and information from some
surveys, bird counts and other information gathering exercises conducted on this river
system over the past 16 year period that I have lived here. The most recent version of
"Roberts birds of Southern Africa" 7th Edition (Par Hockey, WRJ Dean and PG Ryan) is
widely recognised as the most up-to-date and comprehensive publication on Southern
African birds available today. It boasts a huge list of references which be consulted if
necessary.
64
EFA Namibia Birds (Avifauna)
App.
A
Country and Site Relevance
Representative Species
Indicators
Angola Namibia Botswana
Angola
Namibia
Botswana
Comments
Fish Eagle,
Osprey,
Predominantly feed on fish
1
Piscivores of open
Kingfishers,
available in main river
water
Yes
Yes
Vereaux Eagle Owl?
Reed Cormorant
cormorants,
system or adjoining pools.
Darters
Pels Fishing
Need overhanging trees for
Owl, Larger
hunting perches and
2
Piscivores of shallow
Herons, Larger
water & lagoons etc. Yes
Yes
shallow backwaters for
Egrets, , Terns,
ambush hunting techniques
Kingfishers
Smaller herons,
Smaller Egrets,
Piscivores and
Storks, Cranes,
Feed on fish-fry at receding
Invertebrate feeders,
Snipe, Plovers,
3
Yes
Yes
Little Egret, Black
water level times while
floodplains, isolated
heron, Glossy Ibis,
Lapwings,
spawning in flood-plains.
pools
Crowned Crane,
Sandpipers,
Saddle-billed Stork,
Moorhens, Rails,
Spurwinged Lapwing
Crakes
Feed on molluscs, frogs,
Open-billed
Specialist feeders on
fish or selective vegetation
Stork, Ducks,
4
floodplains, receding Yes
Yes
and organisms occurring in
Geese,
waters
shallow floodplain
Gallinules
situations
Floodplain pools and inlets
during rising and receding
African Jacana
5
Specialist feeders in Yes
Yes
African Jacana,
water levels with lily-pad
Lesser Jacana
Lesser Jacana
water-lily covered
covered surfaces. Essential
inlets
for feeding habitat
Parrots,
When riverine fruit trees
Turacoos,
are in fruit they are an
6
Yes
Yes
Specialist feeders in
Bulbuls,
important food source for a
riverine fruit trees
hornbills,
large variety of birds
65
EFA Namibia Birds (Avifauna)
Starlings, Orioles
Weavers,
Bishops,
Widowbirds,
Whydahs,
Breeders in
Nesting habitat in reedbeds
Prinias,
7
reedbeds,
Yes
Yes
white winged
lining river banks and on
Widowbird
cisticolas,
floodplains
islands.
Warblers,
Gallinules
Crakes, Herons,
Egrets
Colonial breeders or
Herons,
solitary nesters requiring
8
Breeders in riverine
Cormorants,
over-hanging vegetation for
overhanging trees
Yes
Yes
Darters
nest safety or fledglings
vacating the nest safely
White-fronted bee-
Bee-eaters,
Require vertical banks for
eater, Blue-cheecked
Collared
nest holes or the grassy
9
Breeders on banks
Yes
Yes
Bee-eater, European
Pratincoles,
banks for nest sites and
bee-eater
Lapwings
fledgling development
Rock
Pratincoles,
Totally dependent on
Breeders on
African Skimmer,
African Skimmer,
emergent rocks, sand bars
10
emergent rocks,
No
Yes
Rock Pratincoles,
White-fronted
and islands in the main
sandbars & islands
Sand Plovers
Sand Plover,
river for nesting purposes
Water Thick-
knee
66
EFA Namibia Birds (Avifauna)
The Okavango River Basin Transboundary Diagnostic Analysis Technical Reports
I
Diagnostic Analysis to establish a base of available
n 1994, the three riparian countries of the Okavango
scientific evidence to guide future decision making.
River Basin Angola, Botswana and Namibia agreed
The study, created from inputs from multi-disciplinary
to plan for collaborative management of the natural
teams in each country, with specialists in hydrology,
resources of the Okavango, forming the Permanent
hydraulics, channel form, water quality, vegetation,
Okavango River Basin Water Commission (OKACOM).
aquatic invertebrates, fish, birds, river-dependent
In 2003, with funding from the Global Environment
terrestrial wildlife, resource economics and socio-
Facility, OKACOM launched the Environmental
cultural issues, was coordinated and managed by a
Protection and Sustainable Management of the
group of specialists from the southern African region
Okavango River Basin (EPSMO) Project to coordinate
in 2008 and 2009.
development and to anticipate and address threats to
the river and the associated communities and
The following specialist technical reports were
environment. Implemented by the United Nations
produced as part of this process and form
Development Program and executed by the United
substantive background content for the Okavango
Nations Food and Agriculture Organization, the project
River Basin Trans-boundary Diagnostic Analysis
produced the Transboundary.
Final Study
Reports integrating findings from all country and background reports, and covering the entire
Reports
basin.
Aylward, B.
Economic Valuation of Basin Resources: Final Report to
EPSMO Project of the UN Food & Agriculture Organization as
an Input to the Okavango River Basin Transboundary
Diagnostic Analysis
Barnes, J. et al.
Okavango River Basin Transboundary Diagnostic Analysis:
Socio-Economic Assessment Final Report
King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment Project
C.A.
Initiation Report (Report No: 01/2009)
King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment EFA
C.A.
Process Report (Report No: 02/2009)
King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Guidelines for Data Collection, Analysis and Scenario Creation
(Report No: 03/2009)
Bethune,
S.
Mazvimavi,
Okavango River Basin Environmental Flow Assessment
D. and Quintino, M.
Delineation Report (Report No: 04/2009)
Beuster, H.
Okavango River Basin Environmental Flow Assessment
Hydrology Report: Data And Models(Report No: 05/2009)
Beuster,
H. Okavango River Basin Environmental Flow Assessment
Scenario Report : Hydrology (Report No: 06/2009)
Jones, M.J.
The Groundwater Hydrology of The Okavango Basin (FAO
Internal Report, April 2010)
King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Scenario Report: Ecological and Social Predictions (Volume 1
of 4)(Report No. 07/2009)
King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Scenario Report: Ecological and Social Predictions (Volume 2
of 4: Indicator results) (Report No. 07/2009)
King, J.M. and Brown,
Okavango River Basin Environmental Flow Assessment
C.A.
Scenario Report: Ecological and Social Predictions: Climate
Change Scenarios (Volume 3 of 4) (Report No. 07/2009)
King, J., Brown, C.A.,
Okavango River Basin Environmental Flow Assessment
Joubert, A.R. and
Scenario Report: Biophysical Predictions (Volume 4 of 4:
Barnes, J.
Climate Change Indicator Results) (Report No: 07/2009)
King, J., Brown, C.A.
Okavango River Basin Environmental Flow Assessment Project
and Barnes, J.
Final Report (Report No: 08/2009)
Malzbender, D.
Environmental Protection And Sustainable Management Of The
Okavango River Basin (EPSMO): Governance Review
Vanderpost, C. and
Database and GIS design for an expanded Okavango Basin
Dhliwayo, M.
Information System (OBIS)
Veríssimo, Luis
GIS Database for the Environment Protection and Sustainable
Management of the Okavango River Basin Project
Wolski,
P.
Assessment of hydrological effects of climate change in the
Okavango Basin
Country Reports
Angola
Andrade e Sousa,
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Biophysical Series
Helder André de
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina: Sedimentologia &
67
EFA Namibia Birds (Avifauna)
Geomorfologia
Gomes, Amândio
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina: Vegetação
Gomes,
Amândio
Análise Técnica, Biofísica e Socio-Económica do Lado
Angolano da Bacia Hidrográfica do Rio Cubango: Relatório
Final:Vegetação da Parte Angolana da Bacia Hidrográfica Do
Rio Cubango
Livramento, Filomena
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina:Macroinvertebrados
Miguel, Gabriel Luís
Análise Técnica, Biofísica E Sócio-Económica do Lado
Angolano da Bacia Hidrográfica do Rio Cubango:
Subsídio Para o Conhecimento Hidrogeológico
Relatório de Hidrogeologia
Morais, Miguel
Análise Diagnóstica Transfronteiriça da Bacia do Análise Rio
Cubango (Okavango): Módulo da Avaliação do Caudal
Ambiental: Relatório do Especialista País: Angola Disciplina:
Ictiofauna
Morais,
Miguel
Análise Técnica, Biófisica e Sócio-Económica do Lado
Angolano da Bacia Hidrográfica do Rio Cubango: Relatório
Final: Peixes e Pesca Fluvial da Bacia do Okavango em Angola
Pereira, Maria João
Qualidade da Água, no Lado Angolano da Bacia Hidrográfica
do Rio Cubango
Santos,
Carmen
Ivelize
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Van-Dúnem S. N.
Okavango: Módulo do Caudal Ambiental: Relatório de
Especialidade: Angola: Vida Selvagem
Santos, Carmen Ivelize
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Van-Dúnem S.N.
Okavango:Módulo Avaliação do Caudal Ambiental: Relatório de
Especialidade: Angola: Aves
Botswana Bonyongo, M.C.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Botswana: Discipline: Wildlife
Hancock, P.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module : Specialist Report: Country:
Botswana: Discipline: Birds
Mosepele,
K. Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Botswana: Discipline: Fish
Mosepele, B. and
Okavango River Basin Technical Diagnostic Analysis:
Dallas, Helen
Environmental Flow Module: Specialist Report: Country:
Botswana: Discipline: Aquatic Macro Invertebrates
Namibia
Collin Christian &
Okavango River Basin: Transboundary Diagnostic Analysis
Associates CC
Project: Environmental Flow Assessment Module:
Geomorphology
Curtis, B.A.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report Country:
Namibia Discipline: Vegetation
Bethune, S.
Environmental Protection and Sustainable Management of the
Okavango River Basin (EPSMO): Transboundary Diagnostic
Analysis: Basin Ecosystems Report
Nakanwe, S.N.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Namibia: Discipline: Aquatic Macro Invertebrates
Paxton,
M. Okavango River Basin Transboundary Diagnostic Analysis:
Environmental Flow Module: Specialist
Report:Country:Namibia: Discipline: Birds (Avifauna)
Roberts, K.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Namibia: Discipline: Wildlife
Waal,
B.V. Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module: Specialist Report: Country:
Namibia:Discipline: Fish Life
Country Reports
Angola
Gomes, Joaquim
Análise Técnica dos Aspectos Relacionados com o Potencial
Socioeconomic
Duarte
de Irrigação no Lado Angolano da Bacia Hidrográfica do Rio
Series
Cubango: Relatório Final
Mendelsohn,
.J.
Land use in Kavango: Past, Present and Future
Pereira, Maria João
Análise Diagnóstica Transfronteiriça da Bacia do Rio
Okavango: Módulo do Caudal Ambiental: Relatório do
Especialista: País: Angola: Disciplina: Qualidade da Água
Saraiva, Rute et al.
Diagnóstico Transfronteiriço Bacia do Okavango: Análise
Socioeconómica Angola
68
EFA Namibia Birds (Avifauna)
Botswana Chimbari, M. and
Okavango River Basin Trans-Boundary Diagnostic Assessment
Magole, Lapologang
(TDA): Botswana Component: Partial Report: Key Public Health
Issues in the Okavango Basin, Botswana
Magole,
Lapologang
Transboundary Diagnostic Analysis of the Botswana Portion of
the Okavango River Basin: Land Use Planning
Magole, Lapologang
Transboundary Diagnostic Analysis (TDA) of the Botswana p
Portion of the Okavango River Basin: Stakeholder Involvement
in the ODMP and its Relevance to the TDA Process
Masamba,
W.R.
Transboundary Diagnostic Analysis of the Botswana Portion of
the Okavango River Basin: Output 4: Water Supply and
Sanitation
Masamba,W.R.
Transboundary Diagnostic Analysis of the Botswana Portion of
the Okavango River Basin: Irrigation Development
Mbaiwa.J.E. Transboundary Diagnostic Analysis of the Okavango River
Basin: the Status of Tourism Development in the Okavango
Delta: Botswana
Mbaiwa.J.E. &
Assessing the Impact of Climate Change on Tourism Activities
Mmopelwa, G.
and their Economic Benefits in the Okavango Delta
Mmopelwa,
G.
Okavango River Basin Trans-boundary Diagnostic Assessment:
Botswana Component: Output 5: Socio-Economic Profile
Ngwenya, B.N.
Final Report: A Socio-Economic Profile of River Resources and
HIV and AIDS in the Okavango Basin: Botswana
Vanderpost,
C.
Assessment of Existing Social Services and Projected Growth
in the Context of the Transboundary Diagnostic Analysis of the
Botswana Portion of the Okavango River Basin
Namibia
Barnes, J and
Okavango River Basin Technical Diagnostic Analysis:
Wamunyima, D
Environmental Flow Module: Specialist Report:
Country: Namibia: Discipline: Socio-economics
Collin Christian &
Technical Report on Hydro-electric Power Development in the
Associates CC
Namibian Section of the Okavango River Basin
Liebenberg, J.P.
Technical Report on Irrigation Development in the Namibia
Section of the Okavango River Basin
Ortmann, Cynthia L.
Okavango River Basin Technical Diagnostic Analysis:
Environmental Flow Module : Specialist Report Country:
Namibia: discipline: Water Quality
Nashipili,
Okavango River Basin Technical Diagnostic Analysis: Specialist
Ndinomwaameni
Report: Country: Namibia: Discipline: Water Supply and
Sanitation
Paxton,
C.
Transboundary Diagnostic Analysis: Specialist Report:
Discipline: Water Quality Requirements For Human Health in
the Okavango River Basin: Country: Namibia
69
EFA Namibia Birds (Avifauna)
1