Abstracts of student project reports: Tanzania courses since 1998
BIRDS
CONTENTS
Behavioural ecology
Distribution
Predation
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BEHAVIOURAL ECOLOGY
Behavioural traits of group living birds: Case study on silvery-cheeked
hornbills Ceratogymna brevis in Amani Nature Reserve, East Usambara’s,
Tanzania
Abstract
An analysis of some behavioural traits and its relationship with group sizes of silvery-cheeked
hornbills Ceratogymna brevis was conducted within the month of July 2015 in Amani Nature Reserve,
Tanzania. This was done to ascertain if there were changes in feeding time and vigilance in relation to
flock sizes. All behavioural traits measured were based on time measurement, and focal animal
observations were used to examine behaviours of Ceratogymna brevis for 22 different sites. However,
neither the feeding time (t= 1.170, p=0.2450) nor vigilance (t= -0.145, p=0.8847) was influenced by
different flock sizes, which may be due to factors such as abundance of fruiting trees and presence of
predators.
Alicia Bailey, University of Salford, UK
Michael Ekwemuka, A.P. Leventis Ornithological Research Institute, Nigeria
Cedric Maforimbo, Dambari Wildlife Trust, Zimbabwe
Vera Pfannerstill, University of Potsdam, Germany
2015
Resource partitioning in the sunbird community in Amani Nature Reserve,
Tanzania
Abstract
For conservation of sunbird species in Amani Nature Reserve, it is important to identify their food
resource utilisation. It is also important to know the role of alien flowering plants in food supply for
the sunbird community. We investigated the resource partitioning in the sunbird community and the
role of alien plant species as nectar suppliers for the sunbirds in Amani Nature Reserve in the East
Usambara Mountains in north-eastern Tanzania. We used point counts and opportunistic searches
along transects to collect data about the visitations of different sunbird species to flowering plants.
Additionally we collected data about the abundance of the sunbirds and the abundance of the plant
species visited by sunbirds. Out of 14 sunbird species recorded from Amani we found eight sunbird
species; Collared (Hedydipna collaris), Purple-banded (Cinnyris bifasciata) and Olive Sunbird
(Cyanomitra olivacea) were the most common. Our result indicates that these three species use the
food resources differently. Collared Sunbirds primarily forage on insects whereas Purple-banded
Sunbirds mainly seek nectar on small flowering plants. Olive Sunbirds forage on insects as well as
on nectar, but focus in contrast to Purple-banded Sunbirds on plants with big flowers. Out of 15
flowering plants species, Spathodea campanulata, Lantana camara and Stachytarpheta jamaicensis
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Abstracts of student project reports: Tanzania courses since 1998
BIRDS
were the most visited by sunbirds. Of the flower visits 87% were recorded on alien plant species.
This indicates that alien flowering plants play an important role in providing food supply for
sunbirds in Amani Nature Reserve.
Hailu Menale, Wolaita Sodo University, Ethiopia
Jonas Landolt, ETH Zurich, Switzerland
2013
Risk-perception and escape-decision in Common Bulbul (Pychnonotus barbatus)
Abstract
Human presence has a variety of impacts on wildlife and may influence how animals assess the risk of
predation but we know less about the scale of such impacts. We quantified flush distance in
Pychnonotus barbatus (Common Bulbul) in and around the Amani Nature Reserve field station. An
observer approached a focal individual at a measured spot distance and flush distance. We observed
that escape-decision in P. barbatus is influenced significantly by activity and perching height and
vegetation cover. The effect of flock size on flush distance was not significant.
Nerioya Neri Akemien, University of Jos, Nigeria
Bomey Clement Gba,University of Cocody-Abidjan, Ivory Coast
2012
The influence of nectar amount and quality on sunbird visitation in Amani
Nature Reserve, Tanzania
Abstract
Amani Nature Reserve is situated in an international hotspot of biodiversity. It hosts a wide range of
bird species including 10 sunbird species. Sunbirds have recently evolved the ability to extract
nectar from flowers to use as a food source. This new feeding behaviour is unexplored in Amani
and the aim of the study is determine if nectar volume and sucrose percentage influence the
sunbirds’ feeding habits. Three different exotic plant species were chosen to observe sunbird
feeding times on flowers, Thunbergia grandiflora, Stachytarpheta jamaicensis and Hibiscus sp.
These plants were observed on three different sites and repeated twice. Observations were
conducted over 4 different time periods. Nectar volume was extracted from the six flowers four
times a day and an average was taken. The sucrose percentage was measured in unison with nectar
measurements. Results showed no significant relationship between bird visits against nectar volume
and sucrose percentage. No significant relationship was found between bird feeding times against
nectar volume and sucrose percentage. This study has shown that neither nectar volume or sucrose
percentage is influencing bird visits to the three plants species examined.
Roseanne Hennessy, National University of Ireland, Galway, Ireland
Nahla Mahmoud, University of Khartoum, Sudan
Linda van Os, Wageningen University, The Netherlands
2010
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Abstracts of student project reports: Tanzania courses since 1998
BIRDS
Spatial and temporal variation in song rate and song duration in the
Little Greenbul Andropadus virens
Abstract
We studied variation in the singing behaviour of the Little Greenbul Andropadus virens at two sites in
Amani Nature Reserve, over a period of 6 days. Variation was measured in terms of singing rate per
minute and mean song duration. The effects of differences in population densities, neighbouring
birdsong and playbacks were measured over time. Our results show a significant peak in singing
activity in the early morning. Singing rate and duration show a similar but non-significant trend.
Neither measure of song co-varied with population densities. We found a weak, marginally
significant correlation in rate of singing between neighbouring birds and some evidence of a
sequential pattern in song. Playback experiments elicited varied responses but there was no
significant difference in song before and after playback. Temporal variation over the course of the
day occurs even though the Little Greenbul sings all day. The results of song interactions between
neighbours and of playback experiments suggest that their song is signalling both territorial and
mate attraction messages.
Abigail Bunker, Anglia Polytechnic University, UK
Ellinor Lillieholm, University of Stockholm, Sweden
2005
The role of calling in the social behaviour of Silvery-cheeked Hornbills
Abstract
Silvery-cheeked Hornbills, Ceratogymna brevis, live in social groups whose members communicate
with each other by harsh quacking calls. We investigated whether the rate of calling depends on the
size of a group, its sex ratio, and what activity the birds are engaged in. We also looked at how the
rates of calling and patterns of activity changed throughout the day. Our observations consisted of
three-minute focal watches and scanning observations at three different times daily, over a period of
six days. We found a significant correlation between group size and calling rate, but no relationship
between calling rate and sex ratio. The birds called significantly more in the morning and evening
than during midday, a pattern that we attribute to the sharing of information at the roosting site.
There was significantly more calling during flight than during other activities such as feeding and
preening, and no significant difference between the relative amounts of time the hornbills spent
on different activities at different times of day. We conclude that calling is a mechanism of
information transfer between group members, for example about food availability and the presence
of predators.
Jessie Barker, University of Cambridge, UK
Jonas Holgersson, University of Gothenburg, Sweden
2005
The foraging behaviour of the Olive Sunbird (Nectarinia olivacea) on Spathodea
campanulata
Abstract
The foraging behaviour of the olive sunbird (Nectarinia olivacea) on Spathodea campanulata was
studied in the Amani Nature Reserve (ANR). Observations were made for six trees within the early
and late morning periods. The olive sunbirds spent more of the active time feeding than perching.
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Abstracts of student project reports: Tanzania courses since 1998
BIRDS
There was no significant difference in the time the olive sunbird spent on feeding between the two
periods. However, there was a difference in the feeding bouts. Also flower abundance on a tree had
no effect on birds’ feeding time. Other bird species were found to be feeding on Spathodea
campanulata with no observed aggressive interactions. The olive sunbird was also found to feed on
six other plants in the ANR.
Cheso Walters, Bamenda Highlands Forest Project, Cameroun
Azariah Mavis Lilian, Ghana Wildlife Society, Accra, Ghana
Staufer Martina, University of Vienna, Austria
2001
Foraging and social behaviour of Silvery-cheeked Hornbill Ceratogymna
brevis, Amani Nature Reserve, Tanzania
Abstract
This project was carried out from September 14-23, 2000 at Amani Nature Reserve, Tanzania, on
foraging and social behaviour of the Silvery-cheeked Hornbill, Ceratogymna brevis. This mainly
frugivorous species is among the most important seed dispersers. The objectives of this study are to
know if the main behaviour of the species is constant or varies throughout the day, to know if the
number of birds per foraging flock varies and to see whether there is sexual segregation during the
day or at roost. Sampling was undertaken using focal-animal method. Sexual segregation is shown to
be highly relevant at roosting site and the main behaviour shows a clear pattern.
Rafael Matias, Universidade de Lisboa, Portugal
Adal Melaku, Addis Ababa University, Ethiopia
2000
DISTRIBUTION______________________________________________
The distribution of the Olive Sunbird, Nectarinia olivacea, in relation with
forest habitats
Abstract
The study compared the distribution of the Olive Sunbird with the different kinds of habitats along a
road in Amani Nature Reserve. The birds’ distribution was also compared to the distribution of
Maesopsis eminii and Lantana camara. The birds were mapped using the calling method, but also
visible birds were recorded. Habitats were mapped according to the vegetation using density,
openness, and presence of fruiting and/or flowering plants as categories. The results show that the
olive sunbirds prefer habitats with dense undergrowth and fairly open canopy, near or in forest
edges. There were no significant correlation between the sunbirds’ distribution and flowering and
fruiting plants.
Ina Bloch, University of Vienna, Austria
Sara Malmroth, Gotland University, Sweden
2002
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Abstracts of student project reports: Tanzania courses since 1998
BIRDS
The importance of a linear strip of remnant forest for understorey birds in the
East Usambara Mountains, Tanzania
Abstract
The function of linear strips of vegetation in a fragmented forest on understorey birds was examined in
the East Usambara Mountains in north-eastern Tanzania. In this preliminary study, using mist- nets
and telemetry, we find support for the hypothesis that forest specialist species tend to avoid linear
strips of forest vegetation in tea plantation and that two species of greenbuls tend to use linear strips
for their movements in a fragmented landscape.
Anna Gustafsson, Swedish University for Agricultural Science, Sweden
Bernhard Majer, University of Vienna, Austria
Charles Kahindo, Bukavu University, Congo & Makerere University, Uganda
1998
PREDATION__________________________________________________
Predation on artificial nests with distance from forest edge in the East
Usambara Mountains, Tanzania
Abstract
We conducted our artificial nest predation experiment in the fragmented landscape of the East
Usambara Mountains, Tanzania. We determined whether predation rate on artificial nests varied
with distance from the edge of a block of primary rain forest into the matrix (tea plantation) and into
the forest interior. The study was conducted in September 1998 towards the end of the dry season.
The overall predation rate on nests of 17.5% (7/40) was much lower than expected based on results
from previous artificial nest predation studies; we did not find that predation rates varied
significantly with distance from the forest edge.
Bernard M. Kissui, Serengeti Wildlife Research Institute, Tanzania
Coralie F. Abbott, University of Cambridge, UK
1998
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