| In Western North America, many rural areas are being converted to ranchette-style residential development (2-16+-ha plots), potentially degrading habitat for large carnivores including pumas (Puma concolor), and impacting ecosystem integrity. In a rapidly developing rural region of California's Western Sierra Nevada, I studied the impacts of low-density development on puma habitat utility, behavioral ecology, mortality, and viability. I characterized properties experiencing puma depredation, a major puma mortality cause in the study region, and compared attributes of properties that had, and had not, experienced depredation. Most depredations (67%) occurred on ranchette-sized parcels and hobby farms, while 3 professional ranches (2.9% of properties experiencing puma depredations) accounted for a disproportionate share (17%) of depredations and pumas killed (23%). Numbers and densities of goats and sheep most strongly predicted puma depredation on a property, followed by geographic features including high slope and elevation, brushy cover, and proximity to rivers and national forests. I then investigated whether rural development reduced puma habitat utility by examining habitat use and movement parameters from GPS-collared pumas in undeveloped and developed rural areas of the same ecosystem. Development appeared to limit habitat utility, with pumas in the developed zone occupying smaller, less round home ranges than undeveloped zone animals. Unlike undeveloped zone pumas, developed zone animals avoided roads and appeared to use riparian areas as movement corridors, and steep-sided canyons bordering residential areas for rest and feeding cover. Finally, I examined whether rural development functionally fragmented puma habitat at the population, landscape, and individual scales. Dispersal and survival parameters, including a high developed zone mortality rate (42.9%), suggested a "source-sink" population structure. Pumas crossed highways 7.9 times less and housing developments 3.7 times less than expected, and these obstacles threatened to disrupt landscape connectivity. Within their home ranges, pumas avoided developed areas (≤20-acre parcels) and preferentially used less developed areas (>40-acre parcels), especially during the day. Low-density rural development exacerbated puma depredation and mortality, constrained habitat utility, and fragmented habitat. Conserving pumas and associated wildlife communities will require efforts to reduce human-caused mortality, protect corridors, retain open spaces, preserve source populations, and limit anthropogenic obstacles to landscape connectivity. |
