title: Individual behaviors dominate the dynamics of an urban mountain lion population isolated by roads.
abstract: Large carnivores can be particularly sensitive to the effects of habitat fragmentation on genetic diversity [1, 2]. The Santa Monica Mountains (SMMs), a large natural area within Greater Los Angeles, is completely isolated by urban development and the 101 freeway to the north. Yet the SMMs support a population of mountain lions (Puma concolor), a very rare example of a large carnivore persisting within the boundaries of a megacity. GPS locations of radio-collared lions indicate that freeways are a near-absolute barrier to movement. We genotyped 42 lions using 54 microsatellite loci and found that genetic diversity in SMM lions, prior to 2009, was lower than that for any population in North America except in southern Florida, where inbreeding depression led to reproductive failure [3-5]. We document multiple instances of father-daughter inbreeding and high levels of intraspecific strife, including the unexpected behavior of a male killing two of his offspring and a mate and his son killing two of his brothers. Overall, no individuals from the SMMs have successfully dispersed. Gene flow is critical for this population, and we show that a single male immigrated in 2009, successfully mated, and substantially enhanced genetic diversity. Our results imply that individual behaviors, most likely caused by limited area and reduced opportunities to disperse, may dominate the fate of small, isolated populations of large carnivores. Consequently, comprehensive behavioral monitoring can suggest novel solutions for the persistence of small populations, such as the transfer of individuals across dispersal barriers.
authors.affiliation: Santa Monica Mountains National Recreation Area, National Park Service, 401 West Hillcrest Drive, Thousand Oaks, CA 91360, USA; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA. Electronic address: seth_riley@nps.gov.
authors.forename: Seth P D
authors.initials: SP
authors.lastname: Riley
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
authors.forename: Laurel E K
authors.initials: LE
authors.lastname: Serieys
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Pollinger
authors.affiliation: Santa Monica Mountains National Recreation Area, National Park Service, 401 West Hillcrest Drive, Thousand Oaks, CA 91360, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Sikich
authors.affiliation: Wildlife and Ecology Unit, Veterinary Genetics Laboratory and Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, CA 95616, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Dalbeck
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Wayne
authors.affiliation: Wildlife and Ecology Unit, Veterinary Genetics Laboratory and Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, CA 95616, USA.
authors.forename: Holly B
authors.initials: HB
authors.lastname: Ernest
mesh_terms: D000374:Aggression; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002140:California; D004777:Environment; D005260:Female; D051456:Gene Flow; D014644:Genetic Variation; D007178:Inbreeding; D008297:Male; D011157:Population Dynamics; D046011:Puma / Q000235:genetics / Q000502:physiology*; D014505:Urban Population