Juniata Environmental Science Students Crunch Numbers on Deer Collisions

(Posted October 12, 2009)

HUNTINGDON, Pa. -- Drivers in Pennsylvania see deer carcasses along the side of the road all year round, but a wildlife researcher at Juniata College reminds drivers that deer collisions are more prevalent at certain times of the year and in certain locations.

"In general, drivers should be more aware in November and December, which is breeding season for deer and they are much more active and more likely to cross roads," explains Uma Ramakrishnan, assistant professor of environmental science at Juniata College. "There also is a smaller spike in collisions in June during fawning season."

"In general, drivers should be more aware in November and December, which is breeding season for deer and they are much more active and more likely to cross roads."
Uma Ramakrishnan, assistant professor of biology

Ramakrishnan, who was a deer biologist at the Connecticut Agricultural Experiment Station before coming to Juniata, completed a 2006 study of the effects of gender and season on deer-vehicle collisions, publishing an article on the study in the proceedings of the 2006 International Conference on Ecology and Transportation.

The study's findings revealed that there are significantly less doe-vehicle collisions during the time period excluding breeding season. "During breeding season the incidents of collision are much more evenly distributed," Ramakrishnan says.

The study also found that the highest incidence of collision occurred during dawn and dusk, a logical finding since that is the period of time when deer are most active and when the density of traffic is at its height. "Based on the data the average driver should be more aware of possible collisions driving to and from work during late fall," she explains.

In 2007, Ramakrishnan and Juniata collaborated with the Pennsylvania Game Commission and Penn State University on a research project where Penn State and game commission researchers tracked 40 male deer wearing GPS collars through Armstrong and Centre counties. Ramakrishnan and a group of undergraduate students volunteered to take the study's mapping data and use a GIS (Geographic Information Systems) program to analyze where deer tend to cross roadways.

The Juniata students overlaid Pennsylvania roadways data and traffic volume data onto the deer study maps and saw some interesting patterns.

According to the Juniata GIS data:

--Deer are much more likely to cross a road when there is agricultural land on one side and forested land on the other. "Deer like to forage on the edge of forested areas, so this is sort of expected," she says.

--Home range for deer tends to be limited or defined by major roads such as interstates or large state highways. "Even though we tend to see more deer carcasses on these larger roadways, it seems deer don't cross these roads as frequently as smaller roads," she explains.

--When crossing larger roads with more traffic, deer tend to cross at the same places. "Most crossings are not random, they tend to follow the same paths," Ramakrishnan says. "The time of day is important, too. In general deer like to hang out in agricultural lands at night and in the day remain in wooded areas, but if there are local or unpaved roads deer will cross them at almost any time, especially if the agricultural lands and woods are very close to the roadway."

Contact John Wall at wallj@juniata.edu or (814) 641-3132 for more information.