Individual study: Florida Key deer Odocoileus virginianus clavium underpass use and movements along a highway corridor
Braden A.W., Lopez R.R., Roberts C.W., Silvy N.J., Owen C.B. & Frank P.A. (2008) Florida Key deer Odocoileus virginianus clavium underpass use and movements along a highway corridor. Wildlife Biology, 14, 155-163
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Install barrier fencing and underpasses along roads
A before-and-after study in 1996–2004 in Florida, USA (Braden et al. 2008, same experimental set-up as Parker et al. 2008 and Parker et al. 2011) found that two underpasses, along with roadside barrier fencing, reduced Florida Key deer Odocoileus virginianus clavium collisions with vehicles by 94%. There were 2 collisions/year over two years after fence construction compared to 12–20 collisions/year over five years before construction (total 79 collisions). Underpass use increased over time, with 22 photographs of deer/month over the first six months and 59/month over the following six months. Average annual deer ranges and core areas did not change after underpass construction. Only 45% (5/11) of radio-collared deer were located on both sides of the highway after construction compared to 100% (9/9) before. In 2002, two box underpasses (14 × 8 × 3 m) were constructed with 2.6-km-long barrier fencing (2.4 m high) and four deer guards (modified cattle guards) installed between them, along a two-lane highway. Deer mortalities on roads were recorded from 1996, by direct sightings, law enforcement reports and observations of vultures. Underpass use was monitored using infrared-triggered cameras from February 2003–January 2004. Deer were radio-tracked between January 1998 and December 2000 (44 deer) and between February 2003 and January 2004 (32 deer) and were located 6–7 times/week.
(Summarised by Rebecca K. Smith)