Relative Sensitivities of Mammalian Carnivores to Habitat Fragmentation

• Published in: Conservation biology 2002-04, Vol.16 (2), p.488-502
• Main Author: Crooks, Kevin R.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Autoecology; Biological and medical sciences; Bobcats; Carnivores; Cats; Coastal ecology; Conservation biology; Conservation, protection and management of environment and wildlife; Fundamental and applied biological sciences. Psychology; General aspects; Habitat conservation; Habitat fragmentation; Mammalia; Skunks; Species; Urban habitats; Vertebrata
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1046/j.1523-1739.2002.00386.x

I examined the effects of habitat fragmentation on the distribution and abundance of mammalian carnivores in coastal southern California and tested the prediction that responses to fragmentation varied with the body size of carnivore species. I conducted track surveys for nine native and two exotic carnivore species in 29 urban habitat fragments and 10 control sites. Fragment area and isolation were the two strongest landscape descriptors of predator distribution and abundance. Six species were sensitive to fragmentation, generally disappearing as habitat patches became smaller and more isolated; three species were enhanced by fragmentation, with increased abundance in highly fragmented sites; and two species were tolerant of fragmentation, with little to no effect of landscape variables on their distribution and abundance. Within urban habitat fragments, the carnivore visitation rate increased at sites with more exotic cover and closer to the urban edge, a pattern driven largely by the increased abundance of fragmentation-enhanced carnivores at edge sites. Finally, body size, in conjunction with other ecological characteristics, partially accounted for the heterogeneity in responses to fragmentation among carnivore species. These differential sensitivities are useful criteria for choosing appropriate focal species for ecological research and conservation planning, a choice that depends on the scale of fragmentation in a region and the commensurate responses of carnivore populations at that scale.