Raccoon Movement on the Virginia Barrier Islands (USA): A Challenge for Avian Habitat Restoration on a Naturally Fragmented Coastal Landscape

The raccoon ( Procyon lotor Linnaeus ) is a keystone carnivore on the Virginia barrier islands (USA), where it is a major predator on beach-nesting and colonial waterbirds. Raccoon distribution is dynamic in both time and space: populations persist on 11 islands, and individuals occur sporadically on at least 13 others. Using mark-recapture and radiotelemetry methods in 1999-2007, only 3 of 297 (1%) tagged/collared individuals were observed to move across open water (< 0.5 km) between islands. On the contrary, 22 of 32 (69%) animals that were translocated between islands were observed to return to their original capture site (< 2.4 km) within days. Least-cost path analysis identified a number of relatively cost-effective pathways of movement on this landscape. Preliminary genetic analyses suggest substantial correspondence between these pathways and actual raccoon movement. Avian habitat restoration on the islands will require that inter-island raccoon dispersal be impeded by removals, barriers or behavioral modification.