Use of modified snares to estimate bobcat abundance

Abstract

Although genetic and analytical methods for estimating wildlife abundance have improved rapidly over the last decade, effective methods for collecting hair samples from terrestrial carnivores in a mark–recapture framework have lagged. Hair samples are generally collected using methods that permit sampling of multiple individuals during a single sampling period that can cause genotyping errors due to cross‐contamination. We evaluated a modified body snare as a single‐sample method to obtain bobcat hair samples suitable for individual identification using DNA analyses to estimate population size. We used a systematic grid (2.5 × 2.5 km) overlaid on a 278.5 km2 study area in Michigan's Upper Peninsula to distribute sampling effort. In each of 44 grid cells, we placed 2–6 snares at established sampling stations and collected hair samples weekly for 8 weeks during January–March 2010. We collected 230 hair samples overall, with 91% of sampling stations obtaining at least 1 hair sample. Fifty‐seven percent of samples had sufficient DNA for species identification, which included bobcat (Lynx rufus, n = 17); raccoon (Procyon lotor, n = 62); coyote, dog, or wolf (Canis spp., n = 29); fox (Vulpes vulpes or Urocyon cinereoargenteus, n = 4); and fisher (Martes pennanti, n = 1). We identified 8 individual bobcats and using Huggins closed capture population models with a one‐half mean maximum distance moved buffer, estimated 10 individuals within the trapping area (95% confidence interval = 8–28) with a density of 3.0 bobcats/100 km2. Our method provides an effective, single‐sample technique for detecting bobcats and estimating abundance. © 2012 The Wildlife Society.

Carnivore space use shifts in response to seasonal resource availability

“…Although bobcats occurred at low densities within our study area (Stricker et al. ), investigation of carnivore GPS locations during LMP and SMP suggested bobcats killed fawns at a rate greater than other carnivore species. Similarly, bobcats killed more radio‐collared fawns during LMP and SMP than all other carnivores except coyotes.…”

“…), bobcat density was 0.03/km 2 (Stricker et al. ), and black bear density was 0.14–0.19/km 2 (J. L. Belant, unpublished data ). Wolf density was 0.012/km 2 (T. R. Petroelje, unpublished data ).…”

American marten and fisher do not segregate in space and time during winter in a mixed‐forest system

“…This study was originally designed to collect data on bobcats Lynx rufus; thus, habitat deemed suitable for bobcats was selected, though the design was also considered appropriate for collecting data on martens and fishers, as all three species occupy similar habitats (forested landscapes with a preference for conifer‐dominated stands [Buskirk & Powell, ; Fisher et al, ; Lovallo & Anderson, ; Reed et al, ]). At each site, we constructed a circular barrier of woody vegetation 0.7–1.0 m high with four entrances containing wire snares to obtain hair samples from any animals entering them and then baited the stations using vehicle‐ or hunter‐killed carcasses of white‐tailed deer Odocoileus virginianus or beaver Castor canadensis , wired to a central tree (Stricker et al, ). A commercial skunk‐based lure was applied to a tree approximately 1.7 m above ground.…”

“…At each site, we constructed a circular barrier of woody vegetation 0.7-1.0 m high with four entrances containing wire snares to obtain hair samples from any animals entering them and then baited the stations using vehicle-or hunter-killed carcasses of white-tailed deer Odocoileus virginianus or beaver Castor canadensis, wired to a central tree (Stricker et al, 2012). A commercial skunk-based lure was applied to a tree approximately 1.7 m above ground.…”

Den use and Activity Patterns in Female Canada Lynx (Lynx canadensis) in the Northern Rocky Mountains

“…Climate varies due to lake-effect weather patterns, but typical May-August temperatures range from 3-258C with extremes reaching 328C; rainfall during this period is typically 12.2-14.5 cm (National Oceanic and Atmospheric Administration 2010). Bobcat density in our study area is about 3 individuals/100 km 2 (Stricker et al 2012).…”