Many wildlife species persist in fragmented habitat where movement between patches is essential for long term demographic and genetic stability. In the absence of direct observation of movement, connectivity or isolation metrics are a useful method of characterizing potential patch-level connectivity. However, multiple metrics exist at varying levels of complexity, and empirical data on wildlife distribution are rarely used to compare performance of metrics. We compare 12 connectivity metrics of varying degrees of complexity to determine which best predict the distribution of prairie dog colonies along an urban gradient of 384 isolated habitat patches in Denver, Colorado, USA.
Results/Conclusions
We found that a modified version of the incidence function model including area-weighting of patches and a cost parameterized surface had the best predictive power, where we assumed roads were fairly impermeable to movement, and low-lying drainages provide dispersal corridors. Thus, both patch area and the composition of the surrounding matrix affected the persistence of prairie dog colonies. Our results provide guidance for landscape habitat modeling in fragmented landscapes and can help identify target habitat for conservation and management of prairie dogs in urban habitat.
