Critical Effects of Urbanization on a Charismatic Carnivore: Genetic Change, Disease and Toxicant Exposure, and Disease Susceptibility in Bobcat Populations in an Urban, Fragmented Landscape

摘要: Urbanization has profound ecological impacts that reach beyond city boundaries. Obvious consequences of urbanization include habitat loss and fragmentation. Anthropogenic barriers reduce connectivity, impede gene flow between populations accelerate the genetic diversity in due to drift. may have also cryptic such as effects human-introduced toxicants on wildlife populations. Toxicants are a leading cause population decline for variety animal species worldwide directly threaten by causing direct mortalities, or indirectly through sublethal, chronic reproductive impairment, decreased immune competence, increased disease susceptibility emergence. If population-level occur result toxicant exposure, accompany reduced sizes connectivity. These inbreeding depression increase probability extinction adaptive potential reduces ability respond novel selection regimes. Overall, presents with many stressors which they must adapt perish. is increasing at an unprecedented pace; understanding both obvious threats wild persisting near urban areas will be vital promoting conservation maintenance global biodiversity.To address populations, I focused well-studied bobcats (Lynx rufus) living around Santa Monica Mountains National Recreation Area (SMMNRA). This region comprises collection protected park downtown Los Angeles. Bobcats inhabiting SMMNRA been monitored Park Service (NPS) biologists since 1996. Within localized SMMNRA, NPS demonstrated major freeway (US-101) acts not only barrier movement bobcat coyote (Canis latrans) but potentially social barrier. Further, from 2002-2005, notoedric mange epizootic associated secondary anticoagulant rat poison exposure was greatest source mortality bobcats. During this period, annual survival rate radio-collared animals fell > 50% 2003 reached high 51%. Long-term samples were collected 1996-2012, allowing rare opportunity make comparisons before, during, after decline. Using these data foundation, my research three main objectives. First, characterized neutral adaptively relevant across fragmented natural areas. Second, examined rodenticide southern California, contrasting seasonal, demographic spatial risk factors urbanized Third, physiological immunological parameters evaluate health urban, landscape.I found two freeways significant flow. 3-year epizootic, caused bottleneck led differentiation pre- post-disease greater than separated 60 years. However, balancing acted immune-linked loci during maintaining variation functional regions. With respect detected prevalence (89%, liver; 39%, blood) individuals paired liver blood (N = 64), 92% exposed most frequently equal 3 compounds. Prevalence amounts contaminants human activities included commercial, residential, agricultural development. strong association AR 0.25 ppm 2 compounds ectoparasitic disease, mange. Finally, observed stimulatory suppressive explain rodenticides. ARs had elevated lymphocyte, specifically B cell counts, percentages neutrophils. highlight even free-ranging considered relatively adaptable urbanization, fragmentation can level long-term stability increasingly landscape.