Friday, July 10, 2015

Summary of 2014 Bobcat Observations in Ohio

Bobcat at Columbus Zoo
Division of Wildlife
Ohio Department of Natural Resources
Waterloo Wildlife Research Station
Athens, OH 45701 15

June 2015

Summary of 2014 Bobcat Observations in Ohio

  Bobcats were found throughout Ohio in early settlement times. They were concentrated primarily in the large, lowland areas of the north and unglaciated Allegheny Plateau region of the southeastern portion of the state. As swamps and lowlands were drained and forests cleared to make way for settlements and cropland, the bobcat population declined. By 1850, they were considered extirpated from the state. From 1850 through the 1960s, there were occasional reports of bobcats, mainly in eastern Ohio. From 1970 through 2014, there have been 1,195 verified (e.g., positive identification via roadkill, incidental trappings, etc.) reports of bobcats in Ohio. The bobcat was removed from the Ohio Endangered and Threatened Species List in July 2014, but remains protected (no harvest season). In 1997, a project was initiated by the Division of Wildlife to systematically monitor the status of bobcats in Ohio.

  Unverified reports – A total of 2,349 unverified bobcat sightings was received from 1970-2014; the annual number of which has been declining over the past several years: 176 in 2014, 226 in 2013, and 242 unverified reports in 2012. Unverified sightings were reported from 54 counties during 2014 and from 86 counties since 1970 (Fig. 1). Unverified reports in 2014 were obtained primarily through Call Center (n = 63; 36%).

  Verified reports – Verified reports represent positive identification of a bobcat, usually as a result of the animal being killed on the road, photographed, or incidentally trapped. Verified reports provide the best information regarding the distribution and abundance of bobcats in Ohio. Further, they provide an important index of change in annual relative abundance. Since 1970, there have been 1,195 verified reports of bobcats in Ohio, of which the great majority have occurred since 2000 (n = 1,167; 98%). There were 197 verified bobcat reports in 2014, similar to that of the previous year (n = 200). These 197 reports included 110 trail camera pictures or videos, 43 roadkills, 16 incidentally trapped bobcats, 15 photographs, 12 sightings by Ohio Department of Natural Resources staff or other qualified personnel, and 1 observation of tracks. Verified bobcat reports were documented in 39 counties during 2014 and in 58 counties since 1970 (Fig. 2). Bobcat sightings during 2014 continue to be highly aggregated. Of the 197 verified reports, 22 (11%) were from Noble County, and 97 (49%) were reported within a 1-county radius of Noble County.

  Overall, verified sightings have increased steadily over the past decade, only decreasing in apparent growth over the past year (Fig. 3). Bobcat mortality, particularly vehicle-related, has historically been the primary source of verified sightings. Prior to 2006, trail cameras photos were a negligible source of sightings. Since that time, however, the number of sightings via trail camera photos has increased dramatically. In 2008, trail camera photographs became the primary source. Other sources of verified sightings, although generally increasing over time, have not shown the same rapid increase (Fig. 4). It is likely that the growing popularity of trail cameras, as well as the decline in their cost, is largely responsible for the increase in the receipt of trail camera photos of bobcats. As such, this source of data is biased and should be interpreted with caution.

  The decline in the number of unverified sightings over the past several years and the stabilization of verified sightings over the past 2 years is likely due in part to decreased interest in reporting sightings given the bobcat’s change in status to threatened and subsequent delisting. Given the numerous confounding factors involved in the use of sighting data as an index to relative abundance, a new method of tracking bobcat abundance (e.g., track stations, camera stations, etc.) should be implemented and initial data obtained before a trapping season is implemented.

  We thank Division of Wildlife personnel who were involved in investigating and reporting observations.

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