A southern California freeway is a physical and social barrier to gene flow in carnivores.

摘要: Roads present formidable barriers to dispersal. We examine movements of two highly mobile carnivores across the Ventura Freeway near Los Angeles, one busiest highways in United States. The species, bobcats and coyotes, can disappear from habitats isolated fragmented by roads, their ability disperse tests limits vertebrates overcome anthropogenic obstacles. combine radiotelemetry data genetically based assignments identify individuals that have crossed freeway. Although freeway is a significant barrier dispersal, we find cross 5–32% sampled over 7-year period. However, despite moderate levels migration, populations on either side are differentiated, coalescent modelling shows genetic isolation consistent with migration fraction less than 0.5% per generation. These results imply rarely reproduce. Highways development impose artificial home range boundaries territorial reproductive hence decrease effective migration. Further, territory pile-up at may opportunities for dispersing do manage cross. Consequently, freeways filters favouring add rate but little gene flow. Our demonstrate restrict flow even wide-ranging species suggest animals, need be an order magnitude larger commonly assumed counteract differentiation.