Bobcat Population Ecology in West Virginia

Bobcat Population Ecology in West Virginia Stephanie Michelle Landry Bobcats (Lynx rufus) are a popular furbearer and game species throughout their range in North America, where they serve as a top predator in many of their ecosystems. However, bobcat populations across their range declined during the 1800s and early 1900s due to overharvest. Overharvest and habitat loss in Europe also affected the Iberian lynx (L. pardinus), resulting in the listing of all Lynx spp. under the Convention on International Trade in Endangered Species in 1977. Bobcats were listed under Appendix II, which required that state management agencies monitor their bobcat populations for stability. Since their listing, bobcat populations have experienced a large-scale increase in abundance in most areas of their range, partly due to the conversion of agricultural lands to early successional forests that supported ample prey populations during the mid-20 century. However, as forests in West Virginia mature, their common, early-successional prey species, such as rabbits and small rodents, may experience population declines. Availability of small mammal populations during winter is an important factor for survival of juvenile bobcats. Bobcats are harvested annually for their pelts in West Virginia, where the bobcat harvest season runs from November – February with a 3-bobcat limit per licensed person per season. West Virginia’s bobcat population has not been studied since the late 1970s when there was no annual harvest limit enacted on the population. Therefore, current estimates and demographic data are needed before making further management decisions for the bobcat population. We collected 524 bobcat carcasses from hunters and trappers across West Virginia over 2 harvest seasons (i.e., 2014–2015, 2015–2016) to determine current demographic data, such as age structure, sex ratio, reproductive rates, and survival, which are used to determine population change rates for bobcats under current state harvest regulations. We also subsampled 300 bobcats for stomach contents to determine current winter dietary habits. Proportion and diversity of prey items selected by bobcats is often correlated with prey abundances and habitat quality, which can allude to dietary availability for bobcats over winter. We found that bobcats in West Virginia have an even sex ratio and are predominately adults >2 years old (50%), followed by yearlings (1–2 yr; 30%) and juveniles (<1 yr; 20%). Reproductively active females (>1 yr) averaged 1.54 kittens/female annually, with young born from mid-April to mid-August. Mean juvenile survival over both harvest seasons was 0.82, while mean yearling survival was 0.77 and mean adult survival was 0.61 over both harvest seasons. Rate of population change was +44% after the first harvest season and remained stable after the second. White-tailed deer (Odocoileus virginianus), Virginia opossum (Didelphis virginiana), and raccoon (Procyon lotor) occurred more frequently in the diets of male bobcats, whereas lagomorphs occurred more frequently in females. Small and medium-sized rodents, such as squirrel, mice, and chipmunks (Tamias spp.), occurred more frequently in the diets of juveniles than yearling and adults, whereas white-tailed deer occurred more frequently in adults than juveniles and yearlings. There was 92% overlap in overall dietary selection between sexes and 35% overlap between stage classes, with an 87% diversity in prey selection overall. Managers can use these data to determine proper harvest limits and to enact necessary habitat manipulations to support management goals for bobcats in West Virginia.