Along with bird and salmon migration, autumn brings a major shift to deer activity that can cause collisions with cars.
In 2023, there were 31,329 crashes with a deer in New York state, according to the University at Albany’s Institute for Traffic Safety Management and Research, with five of them fatal.
While there are no state deer census figures, Ryan Rockefeller, wildlife biologist for the state Department of Environmental Conservation’s Region 9 office for Western New York, said bucks harvested per square mile and crop damage complaints inform the department of management needs.
Based on input from the Lake Plains wildlife management units, Rockefeller said deer populations have been on the upswing.
“We have not been able to see the antlerless harvest we’ve wanted to see for a few years,” he said.
Rockefeller said October through December brings the biggest surge of deer collisions due to the animals’ breeding season.
“The bucks are out chasing does, and they become a little less wary,” Rockefeller said. “The one factor that is overlooked a little bit is that our days are shortening, but our work hours are not. As the days shorten, the twilight hours are the exact time deer are most active and on their feet. Our commutes are lining up exactly with the dawn and dusk hours.”
Across seasons, Rockefeller said deer form small female family units that will often stay together for many years. Expecting these groups near roads is one of the first things to consider in avoiding animal collisions, he said.
“It can be an older doe and her female offspring,” he said. “Antlerless deer probably make up more of the deer vehicle mortalities because there are more of them. You get family groups of does together and you will see that one will be a little more cautious crossing the road and the ones behind keep coming.”
Rockefeller advises to always suspect multiple deer when you see one.
Young bucks get into trouble in the fall, he said, because they are no longer welcome in the doe groups.
“Towards fall, with testosterone increasing even in button bucks, they’ll get less tolerant of that year’s male fawns,” Rockefeller said. “They can be very susceptible to deer vehicle collisions.”
Actively chased off familiar ground, young bucks are on the run in less familiar surroundings, he said.
Josh Randall, natural resources educator for Cornell Cooperative Extension of Niagara County, who manages the Lytle Nature Preserve, said it’s important to recognize the environments that deer prefer.
“I think the main thing to be thinking about with deer behavior is that deer are always attracted to young shoots of plants,” Randall said. “Really old dense forests are not a place where deer like to be. They like to be in places with mixed generations of trees and shrubs. That’s really why deer are a problem for land managers. They really like those tree seedlings.”
Fruit trees are an added attraction to deer in fall, Rockefeller said, with some hidden within wild areas.
“All of the sudden, an apple tree is loaded somewhere, and that can be a hub for deer activity,” he said.
Rockefeller said certain road crossings and wild corridors are consistently used by deer, even outside of the breeding season. He suggests that drivers proceed more slowly in areas marked with deer crossings or where deer have been seen in the past.
“They get disoriented with the lights, being that they have such sensitive eyes,” he said. “… That often causes them to run in the wrong direction or be spooked by the shadows behind them.”
Authorities say there are no devices for vehicles that are proven to deter deer. Recommended strategies for avoiding collisions include:
• Driving slower during times of high deer activity
• Assuming that one deer is followed by more
• Adjusting drive times or routes based on deer activity
• Never swerve when a deer is in your path. Stay in your lane and apply the brakes.
• If you see deer, alert other drivers with a headlight flash.