The Space Between: a geospatial analysis of connectivity between lion populations in East Africa

Abstract

Lion (Panthera leo) populations and habitat range are in steep decline. Lions are increasingly isolated in protected areas and other pockets of habitat. Habitat fragmentation lowers effective population size and increases vulnerability to threats such as inbreeding depression and localized catastrophes. Conserving connecting habitat between lion populations is critical for mitigating effects from fragmentation. With approximately half of all remaining lions and a rich network of protected areas, the East African Community presents vital opportunities to preserve connectivity. I collected 69,068 lion presence locations from field researchers and overlaid these locations with a suite of environmental variables. Due to strong biases in the presence data, I used an intuitive approach of creating a habitat envelope from observed presence data, and then identified combinations of environmental conditions that are conducive to lion presence. By determining the distribution of these environmental conditions, I predict areas with habitat through which lions can disperse, though may not be resident. I then identify contiguous patches of connecting habitat that link protected areas with documented lion populations. I find that while many protected areas remain connected, Uganda’s lion populations in Murchison Falls and Queen Elizabeth National Parks are critically isolated. Furthermore, my analysis suggests several bottlenecks and gaps that constitute high priority areas for conserving or restoring connectivity.