A practical map-analysis tool for detecting potential dispersal corridors

We describe the Pathway Analysis Through Habitat (PATH) tool, which can predict the location of potential corridors of animal movement between patches of habitat within any map. The algorithm works by launching virtual entities that we call 'walkers' from each patch of habitat in the map, simulating their travel as they Journey through land cover types in the intervening matrix, and finally arrive at a different habitat 'island.' Each walker is imbued with a Set Of User-specified habitat preferences that make its walking behavior resemble a particular animal species. Because the tool operates in parallel on a supercomputer, large numbers of walkers can be efficiently simulated. The importance of each habitat patch as a source or a sink for a species is calculated, consistent with existing concepts in the metapopulation literature. The manipulation of a series of contrived artificial landscapes demonstrates that the location of potential dispersal corridors and relative Source and sink importance among patches can be purposefully altered in expected ways. Finally, potential dispersal corridors are predicted among remnant woodlots within three actual landscape maps.