Spatial and Temporal Trends of Deer Harvest and Deer-Vehicle Accidents in Ohio

White-tailed deer (Odocoileus virginianus} have been increasing dramatically in the eastern United States, with concomitant increases in impacts resulting from deer browsing and deer-vehicle collisions. In Ohio, the number of deer were estimated at near zero in 1940 to over 450,000 in 1995. We analyzed estimates of deer harvest and deer-vehicle collisions in 1995 for 88 counties in Ohio. These data were also related to county-level spatial data on the length of major highways, urban land, rural land, crop land, forest land, all land, and human population. The objectives of this study were to evaluate the spatial and temporal trends of white-tailed deer across Ohio and to relate these patterns to the formerly mentioned environmental and human variables. For 1995 data, positive relationships existed between the amount of urban land in the county versus the number of deer-vehicle collisions, the amount of forest land in the county versus the number of deer harvested, the human population of a county versus the number of deer-vehicle collisions, and the length of major highways in a county versus the number of deer-vehicle collisions. Negative relationships existed between the amount of crop land in a county versus the number of deer harvested, the amount of crop land versus the number of deer-vehicle collisions, and the amount of urban land versus the number of deer harvested. Nine counties, representing various levels of land-use and human population tendencies, were analyzed for historic trends in deer harvest (19851995) and deer-vehicle collisions (1988-1995); in each case, there were substantial rises over the previous decade. Extensions of the resulting regression lines show the possibility for continued increases in deervehicle collisions, especially those with a high human population and forest cover. The dramatic increases in deer populations can be attributed to increasing forest land in the state, more habitat of shrubby land, few predators, mild winters, and the deer's ability to adapt to human-inhabited environments. OHIO J SCI 99 (4): 84-94, 1999 INTRODUCTION Deer overabundance is one of the most challenging problems facing wildlife and land managers across the United States today (Alverson and others 1988; Healy and others 1997; Warren 1997; McShea and others 1997; Stromayer and Warren 1997). Most people have long considered the white-tailed deer {Odocoileus virginianus) to be a highly desired wildlife resource, so that society has had a difficult time accepting the fact that deer are increasingly becoming detrimental in many areas. Marchinton (1997) summed up the primary obstacle to deer management with the term urbanism. By urbanism, he states that "...we have a public that seems to be developing a very unnatural relationship with nature." Thus, the opinions and views of some people contrast with a healthy and sustaining ecosystem. Before European colonists in the pre-1700s settled Ohio, land was not ideal for deer. The forests were too dense, and covered over 95% of the state (Griffith and others 1993). With dense forest canopy, the shrubs and other low vegetation within the 'deer molar zone' did not grow well. These shrubs were the deer's main food and, without that necessity, deer did not flourish and their population was minimal. The settling of Ohio in the early 1800s expanded the deer population as the settlers cleared more and more of the forested land and growth of the low, deer-accessible vegetation increased. The settlers also killed many of the deer's predators. The combination of these factors led to a rise of deer population for a time. However, in the later 1800s and early 1900s, deer were practically extirpated from the state, due to habitat loss and unrestricted exploitation. In the 1920s, deer started immigrating from Pennsylvania and Michigan into Ohio. The population went from being nearly extirpated, to an estimated 550,000 for the fall of 1996 (Fig. 1, ODNR 1996). This great increase can be credited to better habitat and improved deer harvest and population management. The white-tailed deer now thrives in Ohio Total Deer Population Since 1940 o o o