Funding source: Florida Department of Transportation Total Budget: $407,000 Project Period: April 2001 – April 2004 The Florida Fish and Wildlife Conservation Commission (FWC) has documented an increase in the number of transportation-related bear deaths (roadkill) since the late 1970’s. In addition to impacts on bear populations, vehicle collisions with bears often are traumatic for the people involved and may cause significant collateral damage and personal injury. For these reasons, and because of the lack of definitive information on the subject, the FWC partnered with the Florida Department of Transportation to design a project that would quantify the impacts of roadkill on bear populations in Florida. Our study design incorporates two main features: population size enumeration and range delineation for bears in six core areas across Florida. As genetic analyses have improved and laboratory costs decreased, DNA techniques have been used for a wide variety of studies on bears. Our methodology involves sampling bears via hairs left on barbed wire strands surrounding bait sites (hair snare) randomly placed in a systematic grid across each study area. We will then derive population abundance estimates by using individual identification from the DNA analysis within a mark-recapture framework. We will determine both core and peripheral bear range across Florida. Core bear range is defined as that which contains breeding females and peripheral range as that which contains bear signs but no evidence of breeding females. Using an estimate of minimum patch size needed for bears, we sectioned the entire state into 10,000-acre blocks to determine whether bears are present or absent in each block. We polled local residents and area biologists to help ascertain areas occupied by bears. We will extrapolate densities derived from the mark-recapture abundance estimates to the entire area of core bear range within each of the six areas. The final product will be a detailed range map and corresponding population estimate for each of the core populations. We will calculate the impacts of roads within each core population and across the state by determining the proportion of roadkill in relation to abundance estimates derived from the DNA analysis. The numbers generated from this analysis will be compared to literature and published data on sustainable mortality rates for black bears. We will document and examine the relationship between roadkill, road density, traffic volume, and estimated abundance for trends in these parameters. We will identify areas of significant impact and, if necessary, make recommendations on how to improve the relationship between roads and black bears in these areas. Lastly, we will examine the updated bear range maps for signs of fragmentation and isolation related to roads.

The high number of vehicle-bear collisions and the potential impact of these collisions on both humans and bears prompted a re-evaluation of principal roadkill areas for the Florida black bear (Ursus americanus floridanus). The Florida Fish and Wildlife Conservation Commission has documented an increasing statewide trend in the number of roadkill bears since 1976. Previous research indicates roadkills are concentrated in particular areas based on several habitat features (Gilbert and Wooding 1996). Additionally, Gilbert and Wooding (1996) suggest the areas with the largest bear populations (Apalachicola, Big Cypress, and Ocala) have accounted for the greatest number of roadkill, particularly Ocala National Forest. Most recently, Gilbert et al. (2001) prioritized “chronic” bear roadkill areas using roadkill data and habitat characteristics. A subset of black bear roadkill locations (May 2001-September 2003) was evaluated as part of a larger study focusing on several variables, including changes in patterns of principal roadkill areas. Using a simple density analysis (ESRI), principal roadkill areas were identified as those areas which have three or more roadkill instances within a distance of one mile. A one-mile buffer was established surrounding each of these identified areas to ensure that all roadkill locations were included. From the established criteria and analysis, principal roadkill areas were defined during the time frame May 2001 through September 2003. These principal roadkill areas were located in Apalachicola, Chassahowitzka, Ocala, and St. Johns. The majority of the principal roadkill areas, similar to previous research (Gilbert and Wooding 1996), were identified in Ocala. Although the results from the 2001-2003 analysis identified a number of principal roadkill areas documented by Gilbert and Wooding (1996) and Gilbert et al. (2001), several segments were no longer classified as principal roadkill areas, and a few new areas were documented. These new results prompted a re-evaluation of the data using the same time frame as Gilbert and Wooding (1996) as well as the full data set (1976-2004) to determine the causes of variation. These results identify trends in the occurrence of principal roadkill areas and determine re-occurring “chronic” areas. This evaluation provides information for managers and planners who must take direct management action in an effort to minimize road impacts on bears.