Protected areas in Eastern Africa like Maasai Mara, Amboseli and the Serengeti have seen populations of large mammals decline according to a study published online in Biological Conservation.
Ian Craigie and colleagues from Cambridge University, London Zoological Society, UNEP World Conservation Monitoring Centre and Royal Society for the protection of Birds, created a multi–species index of change.
The index revealed on average about 60 % decline in population abundance in protected areas between 1970 and 2005. The results show that although protected areas (parks and national reserves) are the cornerstone of national and global biodiversity conservation, they have generally failed to prevent widespread loss of Africa’s large mammal populations.
Protected areas, especially in Eastern Africa are visited by thousands of tourists drawn by charismatic wildlife species including lion, elephant, buffalo, leopard and rhino. The continued decline of these mammals will undoubtedly have huge economic implications as a result of decline in tourism
The authors suggest that the observed decline has multiple causes including over–hunting and habitat conversion, both driven by rapid population growth and the commensurate increase in resource consumption.
It is interesting that in the Craigie study, climate change (especially precipitation), did not explain the observed patterns of decline in wildlife population abundance. Statistically, I find this implausible. On the contrary, the most recent and notable widespread wildlife deaths in Kenya’s Amboseli National Park have been attributed to prolonged drought.
Moreover, a recent study by J. Ogutu published in the Journal of Zoology showed that wildlife population declines coincided with habitat deterioration due to desiccation attributable to rising temperatures and recurrent severe droughts. I am surprised that the Ian Craigie and his colleagues did not cite this paper.
It is not clear whether the authors paid attention to the fact that existing protected areas are becoming increasing isolated and hence unlikely to provide the full range of habitat resources necessary for the maintenance of viable populations of large mammals.
The authors make reference to local scale ecological and anthropogenic interactions occurring in individual protected areas but it is unclear from the paper how this might explain regional variation in decline patterns, especially between Eastern and Southern Africa.