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Coping Strategies by Chimpanzees (Pan troglodytes
schweinfurthii) during Fruit Scarcity in Gishwati
Montane Forest Fragment, Rwanda
Rebecca L. Chancellor, Aaron S. Rundus, and Sylvain
Nyandwi
Forest of Hope Association, Gishwati Forest Reserve, PO
Box 538 Rubavu, Rwanda
Email for correspondence: sylnyapi@gmail.com
Abstract
The increased number of primates living in fragmented
habitats necessitates greater knowledge of how they
cope with large-scale changes to their environment.
Chimpanzees are exceptionally vulnerable to forest
fragmentation; however, little is known about
chimpanzee feeding ecology in fragments. Although
chimpanzees have been shown to prefer fruit when it is
available and fall back foods during periods of fruit
scarcity, the information is still needed for appropriate
conservation strategy. We examined how chimpanzees
cope with fruit scarcity in Gishwati, a disturbed montane
forest fragment. We assessed seasonal changes in
chimpanzee diet and the use of preferred and fallback
foods through faecal and food site analysis. We also
examined seasonal variation in nest group size and
habitat use through marked nest censuses. We realized
that chimpanzees experienced a seasonal reduction in
preferred fruit availability, which led to a seasonal diet
change. Our results suggest that during periods of fruit
scarcity the chimpanzees reduced nest group size.
However, we found that the chimpanzees did not alter
their habitat use between high- and low-fruit seasons,
which suggests that the forest smallness limits their
ability to change their seasonal habitat use.
Consequently, fallback foods appear to be particularly
important in small food-impoverished habitats with
limited ranging options.
Keywords:Fallback foods, Forest fragments, Gishwati,
Pan troglodytes, Rwanda
Study on Density and Diversity of Leaf Litter Insects at
Amani Nature Reserve, Tanzania
EsraElfaki
University of Khartoum faculty of Science department of
Zoology
Email for correspondence: remma94@gmail.com
Abstract
Leaf litter provides food and shelter for earthworms,
millipedes, spiders and other forest insects. Insects are
essential components of the food web and ecosystem;
and most importantly, leaf litter insects are one of the
most important components of a forest ecosystem due
to the role they play in processes such as
decomposition, nutrient cycling and maintenance of soil
fertility within a forest. The spatial variation in leaf litter
composition is expected to affect both the density and
diversity of leaf litter insects which is good indicator for
environmental health and forest biotic integrity. This
study therefore focused on the comparative analysis of
leaf-litter insects in three different habits which include
Bamboo shrubs, Japanese camphor and Eucalyptus
species located in Amani Nature Reserve, Tanzania. A
total of 1919 insects from 8 different orders Blattodea,
Coleoptera, Collembola, Diptera, Hemiptera,
Hymenoptera, Orthoptera and Thysanura were
collected from pitfall traps, and 658 species from
quadrat plots. Diptera had higher numbers compared to
other orders with 13 families. Results revealed no
difference in diversity of leaf litter insects between
habitats. Furthermore, the depth of litter had no
influence on insects’ abundance between habitats. Most
of the insects are also discovered to be active at night.
The quadrat method gave better results in studies of
leaf litter insects. Amani Forest is rich in leaf litter insect
diversity; this indicates forest stability and good for
conservation of forest insects.
Keywords: Insect diversity, Leaf litter, Amani Nature
Reserve, insect abundance
TAAG First African Student’s Conference, Nairobi. 2-4 July, 2013 49