Ecological study of herpetofauna in the Arabuko-Sokoke and Gede coastal forests of Kenya
Abstract
The herpetofauna of the two coastal forests (Arabuko-
Sokoke and Gede) of Kenya, were sampled using three methods
namely: Quadrat, Time constraint and Opportunistic methods.
During the study, 2,201 individuals were recorded comprising
49 species. The reptiles were represented by 14 families,
33 genera, 41 species and the amphibians by 4 families, 6
genera and 8 species. Snakes followed by lizards were the
most diverse and abundant accounting for 24 and 16 species
respectively. One species was testudine. Among the amphibian
species, the Ranidae and Bufonidae were the most diverse
with 4 species each followed by the Rhachopholidae and the
Hicrohylidae with 1 species each.
The forest differed in different vegetation types
with a slight decrease in species richness from November to
July. For each vegetation type, there was dominance of one
or two lizard species, (e.g. Heliobolus spekii was found in
Brachystegia woodland-only).
There was diurnal variation in abundance
activity of herpetofauna in various vegetation types,
maximum activity falling between 9.00am and 12.00 noon,
all vegetation types.
Diversity was least in Cynometra vegetation type for
both time constraint and- quadrat samples. Significant
changes were registered in diversity ov~r time for both
samples. Brachystegia woodland and Cynometra vegetation
type& emerged as the most similar compared to the rest of
and
with
for
- x -
the vegetation types. Population changes occurred over the
sampling period with peaks in March-April in most of the
vegetation types. Significant changes in species composition
were recorded in Afzelia, Lowland rain forest and Gede
forests. The highest species densities were observed in
Brachystegia for H. spekii in January-February and the
lowest for Habuya brevicollis in Afzelia and Gede in
November-December.
Seasonal variations occurreq and there was an
increase in number of individuals during the dry season,
especially the species which are specialists of a particular
vegetation type (e.g. H. spekii). This could be due to
improved visibility or more favourable conditions during the
dry season than in the wet season.
Citation
MScPublisher
School of Biological Sciences, University of Nairobi
Description
Master of Science