Record Details

Day, Jennifer Mae-White
Exploring Drivers of Gene Flow in Jaguars and Pumas in Southern Mexico via Molecular Scatology and Eco-Evo Simulations
University of Washington
The profound fragmentation and degradation of Neotropical forests over the past 50-100 years poses a significant threat to the wildlife populations in Mesoamerica. Neotropical large carnivores, jaguars (Panthera onca) and pumas (Puma concolor), are at particular risk from forest conversion due to their large spatial requirements and high vagility, and are key contributors to ecosystem function in their roles as top predators. Diminishing structural connectivity of the landscape is likely to impede gene flowfor both species, with potential impacts on population or species persistence. However, the mechanistic drivers behind gene floware poorly understood. In this dissertation, I explore how landscape patternsandhabitat selection interact to influencegene flowofjaguars and pumasin southern Mexico. The first halfof this dissertation is dedicated to the quantification of jaguar and puma landscape use, gene flow, and genetic diversityin southern Mexico, where we know little about the remaining populations (Chapters 1 & 2). This work was based onnoninvasive genetic samples, collected with the aid of wildlife detector dogs, in the Uxpanapa valley of Veracruz, andnorthern Quintana Roo. Resourceselection analysis suggestsless ubiquitoususe of the landscape by jaguars due to greater habitat specificity for natural vegetation, rugged terrain, and avoidance of human activity, as compared to use of a broader array of habitats by pumas.However, I did not find evidence of gene flowrestriction within Uxpanapa despite low predicted connectivity between forest patches.At the regional scale between study locations, pumas exhibitedgreater genetic discontinuity than sympatric jaguars. These findings are also echoed in the literatureandhighlight an apparent disconnect between predicted structural connectivity at fine-scales and gene flowat broader scales, suggesting that behavioral components of movement ecology may differ between resource use within home ranges and juvenile dispersal. In the second half of this dissertation, I turnedto computer simulations to explore the possible drivers of gene flowby scaling-up fine-scale processes, such as resource selection, to broader-scale patterns, such as gene flow(Chapters 3 & 4).I explored the utility of an individual-basedmodeling(IBM)platform, HexSim, for integrating population dynamics, movement ecology and behavior, and evolutionary processes on spatiallyexplicit landscapes.I thenemployedthis modeling platform to build abiologically and spatially realistic eco-evo IBMof large felid gene flow. I used thismodel to conduct a pilot test of hypothesized drivers ofgene flowthrough Mexico, Guatemala, and Belize. Results suggest that gene flowwas decreased by territorial habitat specialization and increased by sensitivity to landscape features during dispersal. Myresults showcase the model’s ability to investigatehowspecific components of complex movement behavior driveof gene flow. The large-felid eco-evo IBM offers a powerful tool for future investigations of mechanistic connections between fine-scale resource selection and gene flowat broader scales, as well as for forecasting the effects of habitat preservation versus connectivity conservation. Jaguars appear to have greater forest selectivity and sensitivity to human activity as compared to pumas, highlighting the need to bolster the existing national incentives for forest preservation in order to protect this declining species. Finally, my results stressthe need for state or federal protection of the Uxpanapa valley, Veracruz, as a biological hotspot that provides a stepping stone for movement between Central and North American wildlife populations.