There's a story going around the Internet about a woman who calls the highway department and asks them to move the “deer crossing” sign near her home. A lot of deer have been hit by cars in the area, she explains, and she would like the state to move the deer crossing to a safer location.
Deer don't read highway signs, of course, but there may be signs of a different nature that could clue in highway planners to high-risk areas for deer-vehicle collisions.
“Arkansas has a substantial white-tailed deer population,” said Philip Tappe, University of Arkansas Division of Agriculture wildlife ecologist. “The Arkansas Game and Fish Commission estimates the deer population at greater than 1 million.
“A very visible negative consequence of this is a large number of collisions between deer and cars or trucks,” Tappe said.
These collisions cost Arkansans more than $2.7 million in vehicle damages annually, he said. Each accident costs an average of about $2,000. But the reported deer-vehicle collisions may be only the tip of the iceberg.
A substantial number of collisions are not reported because damage to the vehicle was not severe, or because the owner didn't want the accident recorded on an insurance policy, said Becky McPeake, UA wildlife specialist. In many cases, the injured deer leave the area, only to die in another location.
“Some hunters report finding deer with old injuries that appear to be from collisions with cars,” McPeake said.
The actual number of deer-vehicle collisions may be as many as six times the number reported, according to a national study conducted at Cornell University, she said.
Tappe and his graduate students at the Forest Resource Center in Monticello used data from the Arkansas State Police and the Game and Fish Commission to map reported deer-vehicle collisions across Arkansas. He overlaid that with other geographic information system (GIS) data to see what factors are contributing to the areas with the highest incidences of collisions.
“When you look on a countrywide scale, you find the highest number of collisions is related to densest human populations, particularly in fast-growing areas, like northwest Arkansas, where urbanization is moving people and traffic into the country,” Tappe said.
“When you look at it on a closer level, at specific stretches of highway where a lot of deer are hit by cars, the contributing factors have more to do with habitat,” he said.
These factors include the types of vegetation present and availability of water — resources that draw and support deer populations.
“We've developed a model to predict the likelihood of deer-vehicle collisions for any point along a highway for each of the ecological areas of Arkansas,” Tappe said. These areas are the Delta, the Ozarks and Ouachitas, the Arkansas River Valley and the southern forests.
“Now, we have a means of taking a stretch of highway and predicting likelihood of collisions,” he said. “We can also make predictions along proposed highway routes where no roads exist.”
“The next big question is, what do we do about it,” Tappe said. “Right now, putting up warning signs is the limit of action taken in Arkansas.”
In Europe, Canada and Florida, highway overpasses or underpasses have been built to give deer and other wildlife safe passage across highways, he said. “These models give us a means to plan effectively for whatever actions we may take to reduce collisions between vehicles and wildlife.”
Fred Miller is science editor for the Arkansas Agricultural Experiment Station. e-mail: firstname.lastname@example.org.