Evaluating landscape and wildlife changes over time in Tanzania's protected areas

Abstract

Declines in wildlife and their habitats associated with land cover changes are documented worldwide. Wildlife protected areas are established as a strategy to maintain and protect viable wildlife populations. International and national policies and regulations are set-forth in countries across the globe to emphasize wildlife species protection. Tanzania has allocated 26.5% (250,425 km2) of its total land area for wildlife protection, and its government established in 1998 a National Wildlife Policy to ensure the maintenance of viable protected areas and survival of important species, habitat and ecosystems. After more than a decade of its implementation, the level and rate of anthropogenic activities experienced in and around protected areas, and the consequent declines of wildlife species, was expected to be reduced to a minimum. Yet, recent studies show that degradation and isolation of wildlife habitats and declines in species populations continue to occur in Tanzanian protected areas. I evaluated changes in landscape and wildlife in three protected areas in Tanzania from the 1980s to the 2010s. Specifically, we investigated changes in land cover and species abundance over time, inside and outside the protected areas, and determined the effects of changes in the types of land cover on wildlife abundance. First, I used Maximum Likelihood classification procedure to derive land cover classes from Landsat TM and ETM+ satellite images of the 1980s, 1990s and 2010s, and to detect changes using post-classification comparison technique and landscape metrics approach. Second, I analysed animal density data for six species or groups of large herbivores, from 1991 to 2012. Thirdly, I evaluated the effect of land cover change on three species of large herbivores. The results show evidence of loss and degradation of types of land covers utilized by large herbivores. Habitats for large herbivores species have shrunken, inside and outside protected areas, resulting in declines of large herbivore populations. Wildlife protected areas in Tanzania appear not effective in protecting and maintaining wildlife populations and their habitats. As a result, revision of the existing wildlife policy is needed in order to come up with techniques that could assist protected areas achieve their intended goal.