Design and evaluation of deer guards for Florida Key Deer

Abstract

Because of increased deer/vehicle collisions involving endangered Florida Key deer (Odocoileus virginianus clavium), the Florida Department of Transportation (FDOT) developed a plan to construct a fence along a portion of US Highway 1 that crosses Big Pine Key, Florida. A problem associated with this plan involved access points where small public roads bisect US-1, which would allow deer to enter the fenced portion of the highway. Currently there are no structures (deer guard) that are effective in preventing deer from entering access roads. The purpose of this study was to design, construct, and test a deer guard that would allow normal passage of vehicles while preventing Key deer from crossing. Between September 1998 and December 1999, deer guard prototypes were constructed and tested within a deer-holding facility at the Welder Wildlife Foundation Refuge near Sinton, Texas. Wild-trapped Texas white-tailed deer (O. v. tenanus) were used as test animals. Deer-guard prototypes were subjected to 4 tests: (1) no incentive to cross; (2) extra food and water incentive to cross; (3) fawn separated from doe; and, (4) estrous doe separated from mature buck. Three deer guard designs tested included: (1) a guard installed at ground level; (2) a guard raised off the ground; and, (3) a raised guard with sloped ends. Deer guards were tested at 2 lengths (either 3.6 m or 5.5 m) and had 1.9 cm cross-member spacing. Effectiveness was monitored visually and/or with infrared triggered camera systems. All tests were conducted for 2 weeks except the fawn separated from doe tests (2 hours). Tests were replicated 4 times except the buck/doe separation test, which was replicated only twice. No deer crossed a raised 5.5-m guard during any of the tests. It is recommended that FDOT construct and install deer guards measuring at least 7.3 m with the center portion raised 0.6 m above the ground. Ends should be sloped to facilitate vehicular traffic and cross-member spacing should be 1.9 cm or more. Side panels should extend the length of both sides of the guard. With slight modifications, the design should be useful with other species.