Analyzing land use change to identify migration corridors of African elephants (Loxodonta africana) in the Kenyan-Tanzanian borderlands

Abstract

East African ecosystems are characterized by the migrations of large herbivores that are highly vulnerable to the recent development of anthropogenic land use change. We analyzed land cover changes in the Kenyan-Tanzanian borderlands of the greater Amboseli ecosystem to evaluate landscape connectivity using African elephants as an indicator species. We used multi-temporal Landsat imagery and a post classification approach to monitor land cover changes over a 43-year period. GIS based methods were accompanied by a literature review for spatial data on land cover changes and elephant migrations. Land cover changed considerably between 1975 and 2017. Wood- and bushlands declined by 16.3% while open grasslands increased throughout the study region (+ 10.3%). Agricultural expansion was observed (+ 12.2%) occupying important wildlife habitats and narrowing migration corridors. This development has led to the isolation of Nairobi National Park which was previously part of a large contiguous ecosystem. Eight migration corridors were identified of which only one is formally protected. Two others are almost completely blocked by agriculture and three are expected to become endangered under continuing land use changes. Landscape connectivity is still viable for this ecosystem (except for Nairobi National Park). However, the current situation is very fragile as anthropogenic land use changes are threatening most of the identified large mammal migration corridors. Sustainable land use planning with regard to important wildlife habitats and connecting corridors is a crucial task for further conservation work to safeguard a viable future for wildlife populations in the Kenyan-Tanzanian borderlands.