Distribution, abundance and population status of Burchell’s zebra (Equus quagga) in Yabello Wildlife Sanctuary, Southern Ethiopia

Abstract

A study on the distribution, abundance and population status of Burchell’s zebra (Equus quagga, Gray
1824) was carried out in the Yabello Wildlife Sanctuary, Southern Ethiopia from October, 2009 to March,
2010 including wet and dry seasons. Distance sampling line-transect counting method was used to
estimate the population status. A total of 5151 individuals were estimated with a population density of
6.5 km
2
. The population was female biased. The sex ratio of adult male to adult female was 1.0:1.27 and
adult to young ratio was 2.9:0.6. Age composition of Burchell’s zebra comprised 78.2% adult, 13.0% subadult,
5.3% juvenile and 3.5% foal. Group size changed seasonally and the mean group size was 12.5.
The average herd sizes of one male harem and bachelor stallion herds were 7.8 and 5.3, respectively.
Distribution and vegetation utilization of the animal showed a marked preference for open grassland
habitat. However, there was a seasonal change in the preference of habitat. Increase in human and
livestock population was observed in the study area. Overgrazing by cattle and encroachment are the
primary factors that affect the population status of Burchell’s zebra by reducing the grass quality in the
Sanctuary. The study recommends an effective and realistic management policy to control illegal human
settlement and encroachment in the sanctuary.