Modeling Pronghorn Migration Corridors in the Northern Great Plains

Abstract

While terrestrial seasonal migrations worldwide continue to decline, the migrations of pronghorn antelope (Antilocapra americana) in the Northern Great Plains remain poorly studied. Development due to energy exploration and extraction within this region has recently increased, possibly placing restrictions on pronghorn movement. In this study, I used two habitat modeling methods, maximum entropy and Analytical Hierarchy Process (AHP), to identify suitable pronghorn habitat, and two corridor modeling methods, circuit theory and least-cost path, to identify seasonal migration corridors. I used pronghorn locations during the 2008 spring and fall migration seasons to identify which habitat and corridor models perform the best based on pronghorn occupancy and area included in the corridor. The maximum entropy model performed better than AHP, resulting in corridors that included more pronghorn locations than those created using AHP. Additionally, corridors derived from circuit theory included more pronghorn locations within a smaller area than those created using the least-cost path method. I recommend using the maximum entropy cost surface and the area of overlap between the two corridors at 15% habitat suitability level for future management actions. Without further study and conservation efforts built on this new knowledge, pronghorn populations may eventually decline and the functioning and biodiversity of the Northern Great Plains may be greatly impaired.