Dfw informs the public about dvcs and the methods

DFW informs the public about DVCs and the methods that can be used to avoid collisions
through the media, via news releases and the DNREC website, especially in emphasizing when
DVCs are the most prevalent. This peak usually occurs during the deer breeding season, or
“rut,” that takes place in November. During this time of the year, deer are most active while
seeking out potential mates.
Presently, roadside fencing, constructing overpasses or underpasses for direct passage, and deer
population reduction are most productive for reducing deer-vehicle collisions. Various wildlife
reflectors have also been marketed in an effort to deter DVCs. Reflectors are most commonly
mounted on posts along roadsides and redirect light from automobile headlights through colored
lenses. The theory is that the redirected beams of light form a “fence” or optical barrier that
deters deer from running into the path of the passing automobile.
Thorough studies with sound experimental designs of wildlife reflectors are limited. Most
recently and most convincingly, D’Angelo et al. (2007) used FLIR video to investigate the
effects of wildlife reflectors on deer and found that the reflectors were ineffective in changing
deer behavior such that deer-vehicle collisions would be prevented. Similarly, Reeve and
Anderson (1993) concluded that roadside reflectors were not effective in reducing vehicle
collisions with mule deer in Wyoming. However, there was some question as to whether the
reflectors were properly maintained. Schafer and Penland (1985) documented a decrease in deer-
vehicle collisions with white-tailed deer and mule deer when reflectors were used along
roadsides in Washington. Due to small sample sizes, though, it is unclear whether the decrease in
deer-vehicle collisions when using reflectors was a result of altered deer behavior or increased
driver awareness due to the reflectors being present. The Division of Fish & Wildlife continues
to monitor developments of deterrents for deer-vehicle collisions and will actively promote any
advances in technology.
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Wildlife warning whistles (deer whistles) attached to cars also have been used in an attempt to
reduce deer/vehicle collisions. These whistles operate at frequencies of 16 to 20 kHz and are
intended to warn animals of approaching vehicles. There is no research, however, that indicates
that deer are frightened by a particular frequency or decibel level of sound, and in a Utah study,
whistles did not alter deer behavior or prevent them from crossing highways. It appears wildlife
warning whistles are not alarming to deer and are not loud enough to be heard above the engine
noise associated with moving vehicles (Romin and Dalton 1992). Therefore, cars equipped with
warning whistles will not prevent deer from crossing roads or reduce deer-vehicle collisions.