Vol.3, No.5, 325-330 (2013) Open Journal of Ecology
Nesting patterns of raptors; White backed vulture
(Gyps africanus) and African fish eagle (Haliaeetus
vocifer), in Lochinvar National Park on the kafue flat s,
Chansa Chomba1*, Eneya M’Simuko2
1Disaster Management Training Centre, Mulungushi University, Kabwe, Zambia;
*Corresponding Auth o r : chansachomba@rocketmail.com, ritachansa@yahoo.com
2School of Natural Resources, Copperbelt University, Kitwe, Zambia
Received 29 May 2013; revised 29 June 2013; accepted 15 July 2013
Copyright © 2013 Chansa Chomba, Eneya M’Simuko. This is an open access article distributed under the Creative Commons Attri-
bution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
This study assessed the nesting patterns of
raptors, Gyps africanus and Haliaeetus vocifer
in Lochinvar National Park. The main objective
of the study was to determine whether tree spe-
cies, height, girth size, and habitat influenced
raptor’s nest placement within Lochinvar Na-
tional Park. Two species were selected as indi-
cator species for the raptors. Habitat types and
tree species were identified and measurements
of tree species with nests measured. It was
found that the minimum height of nest place-
ment was 10 meters above ground and Acacia
woodland was found to be the most preferred
habitat for nest placement. Raptors avoided hu-
man disturbance by placing their nests at least
100 meters away from human disturbance and
from the National park boundary inwards or
abandoning if human encroachment comes
close to the nest. More research is required to
assess nesting materials u sed, and to d eterm ine
whether raptors can swap nets or return to the
abandoned nests when human disturbance
Keywords: Raptors; Nest Placement; Tree Height;
Lochinvar; Kafue Flats; Habitat
Raptors are birds of prey which are on top of the food
chain and as such play an important role in overall fun c-
tioning of ecosystems. The word raptor is derived from a
Latin word raptare meaning to seize and all raptors are
biologically characterized by hooked bills and keen eye-
sight as well as powerful feet with sharp talons. This
group of birds is facing global challenges due to habitat
loss and reduction in prey species usually in competition
with man. In this study, which was carried out in
Lochinvar National Park, on the Kafue Flats, Zambia,
two species of raptors; white backed vulture (Gyps afri-
canus) (Figure 1) and African fish eagle (Haliaeetus
vocifer) (Figure 2), were chosen as representatives of the
group, as they are both susceptible to habitat conversion
and loss of prey.
The white backed vulture for instance, faces similar
threats to other African vultures, of being susceptible to;
habitat conversion due to expanding agro-pastoral sys-
tems, loss of wild ungulates leading to a reduced avail-
ability of carrion, hunting for trade, persecution and poi-
soning. In East Africa, the primary issue is poison ing [1]
particularly from the highly toxic pesticide carbofuran,
which o ccur s primar il y ou tsi de pro te cted areas . Th e large
range size requirements of this and G. rueppellii species
puts them at significant risk as it means they inevitably
spend considerable time outside protected areas [2]. Re-
cent evidence from wing-tagging and telemetry studies
suggests that annual mortality, primarily from incidental
poisoning, can be as high as 25% for G. africanus
(Kendall and Virani in press). In addition, the ungulate
wildlife populations on which this species relies have
declined precipitously throughout East Africa, even in
protected areas [1]. In 2007, diclofenac, a non-steroidal
anti-inflammatory drug often used for livestock, and
which is fatal to Gyps spp. when ingested at livestock
carcasses, was found to be on sale at a veterinary practice
in Tanzania. It was also reported that in Tanzania, a Bra-
Copyright © 2013 SciRes. OPEN ACCESS
C. Chomba, E. M’Simuko / Open Journal of Ecology 3 (2013) 325-330
Figure 1. White backed vulture on a perch. Large tall trees are
important for perching but branches must be large enough to
support the weight.
Figure 2. Type of nest used by fish eagle. The nest is usually
large measuring about 2 meters across and made of principally
zilian manufacturer had been aggressively marketing the
drug for veterinary purposes and exporting it to 15 Afri-
can countries [2]. In southern Africa, vultures are caught
and consumed for perceived medicinal and psychological
benefits and the decline and possible extirpation in Nige-
ria has been attributed to the trade in vulture parts for
traditional juju practices. As a result of this and envi-
ronmental pressures, it is predicted th at the population of
G. africanus in Zululand could be become locally extinct
in 26 years, unless harvest rates have been underesti-
mated, in which case local extinction could be 10 - 11
years away. There is evidence that it is also captured for
international trade; fo r example in 2005, at least 1 3 indi-
viduals of this species being kept illegally in Italy were
reportedly confiscated. Electrocution on power lines is
also a problem in parts of its range, and it is vulnerable to
nest harvesting or disturbance by humans [1]; perhaps
more so than G. rueppellii, as it breeds in trees rather
than on inaccessible cliffs.
The African Fish Eagles unlike the true fish eagles
(Ichthyoph aga) [3] are mainly fresh water birds and ind i-
genous to sub-Saharan Africa, ranging over most of con-
tinental Africa south of the Sahara Desert and are is still
quite common near freshwater lakes, reservoirs, and ri-
vers. It requires open water with sufficient prey and a
good perch. This is evident by the number of habitat
types that this species may be found in, including
grassland, swamps, marsh e s , tropical rainforest, fynbos
and even desert bordering coastlines, but absent from
arid areas with little surface water. Its choice of habitat,
along water bodies often brings it in direct competition
with humans, particularly fishing communities.
Fish eagles have a remarkable breeding behaviour.
They pair up and mate for life. Pairs often maintain two
or more nests, which they will frequently re-u se. Because
nests are re-used and built upon over the years, they can
grow to be quite large, some reaching 2 m across. The
nests are placed in a large tree and built mostly of sticks
and other pieces of wood. Loss of habitat therefore, parti-
cularly cutting of big trees would affect the species. Like
sea eagles, the African Fish Eagle has structures on its
toes called spiricules that allows it to grasp fish an d other
slippery prey. The Osprey, a winter visitor to Africa, also
has this adaptation. Should the African Fish Eagle catch
a fish over 1.8 kg it will be too heavy to allow the eagle
to get lift, so it will instead drag the fish across the
surface of the water until it reaches the shore. If it
catches a fish that is too heavy to even allow the eagle to
sustain flight, it will drop into the water and padd le to the
nearest shore with its wings. So if the shore line of water
bodies is heavily settled by fishing camps as is usually
the case in Zambia, its feeding would be affected. Prey-
ing on domestic fowl (chickens), also causes conflicts
with humans and attempts to destroy fish eagles nests by
humans are on record (personal obs.).
2.1. Location and Description of Study Area
The study was conducted in Lochinvar National Park,
Zambia which is 410 km2 in extent and is located at
Latitude 15˚43' - 16 ˚01' South, Longitude 27˚11' - 27˚19'
East and altitude of between 970 and 1038 m above sea
About half of the area is pa rt of the Kafue flood p lain.
The Lochinvar National Park is on the south bank of the
Kafue River. Soils are dark grey and are of alluvial origin.
South of the flood plain, is a flat Terminalia zone on
sandy clay to clay soils which are water logged during
the wet season. Hot springs which are indicative of a
structural geologic fault occur where the woodlands meet
the southern boundary of the southern edge of Terminalia
zone. Average annual rainfall is 750 mm. Dominant grass
species on the flood plain vary. However, the most com-
Copyright © 2013 SciRes. OPEN ACCESS
C. Chomba, E. M’Simuko / Open Journal of Ecology 3 (2013) 325-330
Copyright © 2013 SciRes.
mon species are: Oryza birthii, Vossia cuspidata, Echi-
nocloa stagnina and Panicum ripens. The commonest
herbs are Aeschynomone fluitans and Nymphaea capen-
sis. Steria sphacelata is the characteristic species in the
Terminalia grassland. This type of grassland is du e to the
high water table which is in this zone. South of the Na-
tional Park is a fire climax woodland of Aca cia, Albizia
and Combretum spp. In terms of large mammals, the
Kafue Flats in which Lochnivar National Park is lo cated,
has about 40,000 herds of endemic species of lechwe
(Kobus leche kafuensis), several thousands of other spe-
cies and has one of the largest concentrations of cattle in
the country. The Kafue River runs in between dividing
the Kafue Flats into North and South banks making it
suitable for this study as the fish eagle is at home with
fish in the Kafue River and lagoons while the white
backed vulture feasts on cattle and wild animal carcasses
(Figure 3).
the right hand side and two on the left hand side of the
transect. One carried a fire arm for the protection of the
research team against dangerous game such as African
buffalo (Syncerus caffer) and the other member was
navigating the transect to ensure that it is straight from
one end of the vegetation community to the other. About
17% of the National Pa r k was sampled.
The team members had a set of Garmin GPS 45 XL
each, for taking GPS locations of all trees with nests, a
pair of tasco 20 × binoculars for observing the species of
raptor on the nest, Bushn ell Yardage pro 500 range finder
to measure distance from the roads, park boundary or hu-
man disturbance where necessary, one tree height meas-
uring rod for measuring tree height, a 5 m steel tape for
measuring tree diameter at 1.3 m above ground, and a
canon power shot A 470 digital camera for taking pic-
tures of the nests, birds in the nest and other critical fea-
tures. Identification of trees with nests was done with the
aid of Tr ees of Southern Africa [4]. Identification of rap-
tors was done based on Oberprieler and Cillie’s raptor
guide of Southern Africa [5]. When a tree with a nest was
observed, a GPS location of the tree was taken, the tree
species name was identified and recor ded and the bird in
the nest identified and recorded as well. Tree height
2.2. Field Methods
The National Park was divided according to vegetation
communities. Line ground transects were used in both
wooded and flood plain habitats. A team of six resear-
chers walked along the transect. Two were observing on
Figure 3. Location of study area, Lochinvar National park on the Kafue Flats, Zambia 2012.
C. Chomba, E. M’Simuko / Open Journal of Ecology 3 (2013) 325-330
was then determined and DBH taken. Distance from the
park boundary was determined by the length of the tran-
sect and if the vegetation community was inside the Na-
tional Park, the remaining d istance was added. Since this
was the breeding season, it was expected that the nest
would have chicks or the parent would be present on
visit to the nest or incubating eggs. Five other visits were
made after the GPS locations were taken during the first
visit. Where no visits of the parents were observed or
chicks seen in the n est, an atte mpt was made to climb the
nearest tall tree from which we used a pair of binoculars
to see whether the nest was abandon ed or not.
An abandoned nest was relatively easy to tell as there
were no chicks in the nest, no parent brooding over the
eggs or bringing food to the chicks, it had no fresh drop-
pings on the ground, no fresh looking feathers which
often drop from the nest or some food remains which
may drop when the parent is feeding the young. Active
nests had all or most of these features.
Data collected were entered on data sheets and pic-
tures taken were downloaded at the base camp to verify
the species in instances where some times only the head
of the parent w as seen .
3.1. Selection of Tree Species for Placement
of Nests by Raptors
A total of 19 trees had raptor nests, of which 13 (68%
of total) had active nests and six (6) (32%) had aban-
doned nests. Of the 13 nests 8 (62%) were for White
backed vulture and 5 (32%) were for African Fish Eagle.
Of the 13 occupied nests, 8 (62%) were on Faidherbia
albida, 2 (15%) on Acacia xanthophloea, 2 (15%) on
Acacia nigrescens, and 1 (7.5%) on Albizia harveyii. The
difference in the placement of nests between tree species
was significantly different (
2, P < 0.05) in favour of
Faidherbia al b i da (Figure 4).
The mean height for the placement of nests in both
species was above 10 meters above ground. In African
fish eagle the mean height was 11.4 meters (n = 5) above
ground and 16.6 meters (n = 8) above ground for White
backed vulture .
3.2. Nest Placement with Respect to
Vegetation Community
Four vegetation communities were surveyed, Acacia
woodland, Mopane woodland, Shrubland, and flood
plain. Of the four vegetation co mmunities, 6 (46%) were
in Acacia woodland, 5 (39%) in Mopane woodland, 1
(7%) in shrubland, and 1 (7%) in flood plain. The differ-
ence in nest placement was found to be significantly dif-
ferent in favour of Acacia woodland (
2, P < 0.05),
(Figure 5).
3.3. Nest Placement in Relation to Distance
from Human Activity
Results obtained suggest that raptors avoided human
disturbance by abandoning nests. As reported above, the
total number of nests observed during the study was 19.
Of the 19 nests, 13 (68%) were occupied (active) and 6
(32%) were abandoned (inactive). Of the 6 that were
abandoned 5 (83%) were within 100 meters of human
disturbance near the park boundary, and 1 (7%) was near
the main road inside the National Park. All the occupied
nests were more than 100 meters away from human dis-
turbance or National Park boundary, suggesting that hu-
man encroachment and associated activities can impact
negatively on raptors by contriving them to abandon
their nests.
4.1. Selection of Tree Species for
Placement of Nests b y Raptors
Large trees are important for the two species of raptors;
first because the two species of birds are of large size and
construct large nests to support their weight and that of
their chicks. A highly placed nest also provides a vantage
point from which the bird can have a wide view to scan
the landscape for food.
It is also assumed that a highly placed nest would al-
low the nestling s to glide as they learn to fly. Such flight
requires horizontal movement of air over an aerofoil
surface. Perhaps it would also be easy for nestlings to
take advantage of thermals, a large vortex of sun heated
air to take flight [6]. Since raptor nests are made of dry
twigs and an assortment of pieces of wood, it would be
much safer to place a nest at a height which is out of
reach of dry season fires. Placing the nest at lower height
nigrescens, 2
albida, 8
xanthophlea , 2
Figure 4. Selection of tree species for placement of raptor nests,
Lochinvar National Park, Kafue Flats, Zambia, 2012.
Copyright © 2013 SciRes. OPEN ACCESS
C. Chomba, E. M’Simuko / Open Journal of Ecology 3 (2013) 325-330 329
y = -14.9x + 62
R2 = 0.864
Acacia woodland Mopane woodlandShrubland Flood plain
Vegetation community
Number; percent relative frequency
Number Percentage Linear (Percentag e )
Figure 5. Raptor nest placement with respect to vegetation
community selects, Lochinvar National Park, Kafue Flats,
Zambia, 2012.
would expose it to wild fires, implying that the eggs or
chicks would be destroyed by fire and the parents would
have to repeat the task of rebuilding a new nest and re-
investing energy in laying another clutch of eggs.
4.2. Nest Placement with Respect to
Vegetation Community
The Acacia and Mopane woodlands are the only vege-
tation communities in Lochinvar National Park with
large and tall trees which can accommodate raptor nests.
Since raptors require placing their nests at least 10 me-
ters above ground, they would only select vegetation
communities with large tall trees. Additionally, the
change in the flooding regime since the construction of
the Itezhi Tezhi dam in 1979 [7], has contributed to the
loss of some old trees and emergence of new secondary
vegetation communities which may not yet have large
trees suitable for raptor nest placement. The extension of
agricultural activities on the periphery of the National
Park coupled with charcoal production may have con-
tributed to loss of large trees in neighbouring vegetation
4.3. Nest Placement in Relation to Distance
from Human Activity
The Lochinvar National Park, on the Kafue Flats is a
source of fish protein from the Chunga lagoon and Kafue
River. Once or twice a week, the National Park authori-
ties permit fish traders to enter the National Park and buy
fish from fisher men on the shores of Chunga lagoon.
More than 30 pickup trucks each carrying more than ten
people which is a min imum of 300 p eople may enter the
National Park. Such large groups of people with the as-
sociated noise from vehicle exhaust systems and hooting
would disturb the birds. Anecdotal reports also indicate
that sometimes people stop to view raptor nests near the
main road, which due to their size is an attraction and
cannot be easily hidden from people’s view. The Kafue
flats is also home to more than 15,000 herds of cattle,
and every day herds men bring cattle into the National
Park for gr azing. Such human disturbances combined are
disruptive enou gh to force raptors to abandon th eir nests.
Frequent visits by humans and passersby in general may
reduce nest attendance by parents and may lead to the
nest being abandoned. There is also a belief that fish ea-
gle and vulture parts have magical and mythical powers
and many people would need them to be used as medi-
cine in magic spells. A nest for a vulture or eagle located
in an area that is not secured would definitely be a target
as people attempt to get at the parent bird or the chicks.
This observation is in agreement with an observation
made in Nigeria where vultures were caught and con-
sumed for perceived medicinal and psychological bene-
fits and the decline and possible ex tirpation in that coun-
try was attributed to the trade in vulture parts for tradi-
tional juju practices as indicated in [2] above.
After analyzing the data and testing the hypotheses, it
was concluded as follows:
1) Tall trees of the height exceeding 10 m are critical for
placement of raptor nests.
2) Human disturbance would lead to raptors abandoning
their nests and thereb y reducing breeding success.
3) Lochinvar National Park authorities should consider
zoning key breeding areas for raptors in the National
Park as low visitor use zones as frequent and unregu-
lated visitation may lead to nest aban donment.
4) Construction of roads and other facilities for man-
agement and visitor use should take into account the
need to maintain large trees for raptor nest place-
It was therefore, established that mature trees of more
than ten meters in height, located in areas with minimum
human disturbance are critical to successful breeding of
raptors on the Kafue Flats, Zambia. Opening of new
roads, construction of new buildings as well as increase-
ing human activities in such habitats may lead to raptors
abandoning their nests. New infrastructure in the Na-
tional Park should avoid areas with high density of raptor
nests as they are known to return to the same nest to lay
We wish to thank the Regional Manager Mrs. Marina Sibbuku for
allowing the researchers to operate in the National Park un interrupted,
Ms Hellen Nkole Mwaba the area ecologist, for providing logistics and
participating in the exercise, Mr. Chaka Harold Kaumba for preparing
Copyright © 2013 SciRes. OPEN ACCESS
C. Chomba, E. M’Simuko / Open Journal of Ecology 3 (2013) 325-330
Copyright © 2013 SciRes.
the map, Microsoft Incarta Encyclopaedia for the pictures for white
backed vulture and African fish eagle.
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Red List of Threatened Species. International Union for
Conservation of Nature.
[2] Birdlife International (2007) Haliaeetus vocifer. IUCN
Red List of Threatened Species. International Union for
Conservation of Nature.
[3] Wink, M., Heidrich, P. and Fentzloff, C. (1996) A mtDNA
phylogeny of sea eagles (genus Haliaeetus) based on
nucleotide sequences of the cytochrome b gene. Bioche-
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Holland Publishing, Cape Town.
[5] Oberprieler, U. and Cillie B. (2009) The raptor guide of
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[6] Maclean, G.L. (1990) Ornithology for Africa. A text book
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[7] Chansa, W. and Kampamba, G. (2009) The population
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