PARENT SESSION
Oral Session #92: Conservation Ecology: Genetics, population viability, interactions.
Presiding: W. Wirtz
Thursday, August 8. 1:00 PM to 3:45 PM. Grand Ballroom West, Radisson.
Landscape connectivity mediates gene flow among puma subpopulations in a patchy landscape.
McRae, Brad*,1, Huynh, Lynn1, Beier, Paul1, Keim, Paul1, 1 Northern Arizona University, Flagstaff, AZ
ABSTRACT- Landscape connectivity has been defined as the degree to which a landscape facilitates or impedes movement of organisms among resource patches. Despite much attention to the concept of landscape connectivity as an important factor in maintaining gene flow across large areas, few studies have attempted to validate models of connectivity with measures of genetic differentiation among subpopulations connected by dispersal. We studied the effects of landscape connectivity on genetic structuring of puma (Puma concolor) populations in a heterogeneous landscape using 19 microsatellite markers. We obtained approximately 500 DNA samples from hunter-killed pumas in Arizona, Colorado, New Mexico and Utah, and delineated subpopulations based on kill locations. We examined genetic structure throughout the study area with respect to 1) Euclidean geographic distance between subpopulations and 2) a simple, a priori Geographic Information System (GIS) model of "functional distance" between subpopulations, which incorporated the permeability of habitats encountered by dispersing pumas. The landscape connectivity model better predicted rates of gene flow among subpopulations than did geographic distance alone (Mantel regressions, R2 = 0.46, p <0.001 for genetic distance vs. geographic distance; R2 = 0.64, p <0.001 for genetic distance vs. functional distance). Males were less closely related to their physical neighbors than were females and juveniles (p <0.01), consistent with observations of greater dispersal distances in males. The latter result suggests that these data may be useful in investigating how connectivity affects not only gene flow over multiple generations, but also dispersal behavior within individual lifespans.
KEY WORDS: landscape connectivity, gene flow, habitat fragmentation, microsatellite