Population trends of large non-migratory wild herbivores and livestock in the Masai Mara ecosystem, Kenya, between 1977 and 1997

The total of all non-migratory wildlife species in the Masai Mara ecosystem has declined by 58% in the last 20 years. This decline ranges from 49% in small brown antelopes to 72% in medium brown antelopes. In individual wildl ife species, the decline ranges from 52% in Grant's gazelle to 88% in the w arthog. Declines of over 70% have been recorded in buffalo, giraffe, eland and waterbuck. Only elephant, impala and ostrich have not shown any signifi cant decline or increase. Overall, there has not been any significant diffe rence in decline of all wildlife population sizes inside and outside the re serve, except for Thomson's gazelle and warthog. Livestock have not signifi cantly declined over the entire analysis period. However, livestock and cat tle populations significantly declined during the 1983-88 period. Donkey de clined by 67%, while shoats (goats and sheep) remained stable. In the case of wildlife, land use and vegetation changes, drought effects and poaching are considered to be among the potential factors that may have been respons ible for the decline; the decline in livestock during the 1983-84 period wa s probably due to drought effects.