Black bears are headed north in New York

April 27 (UPI) -- New research suggests New York's black bear population is spreading out and moving northward.

In an effort to understand why bear-human interactions are happening more frequently, researchers at Cornell University set out to measure the distribution of New York's black bear population.

Scientists estimate southern New York hosts one bear every three square miles. Farther upstate, the bears are more spread out. The findings suggest the state's bears are expanding their range northward.

Their analysis -- detailed in the Journal of Wildlife Management -- revealed no correlation between land use and bear density, undermining the theory that shifts in land use are driving bear movement and encouraging an uptick in human-bear interactions.

It's more likely, researchers believe, that interactions are happening more frequently as a result of the growing bear population.

Still, understanding how bears respond to their surroundings remains an important part of predicting future behavior.

"There might be limited constraints to bears continuing to move northward because they are using a diversity of land cover types," Angela Fuller, an associate professor of natural resources at Cornell, said in a news release.

In southern New York, the previously separate Catskill and Allegheny black bear populations have grown into a single geographical range. Researchers tracked bears using DNA from hair samples collected by strategic strips of barbed wire at more than 200 research stations.

"We are using a noninvasive genetic approach, an important new method that wasn't available 15 to 20 years ago," said Fuller. "In the past, we had to go out and capture and then physically tag each bear."

Fuller and her colleagues are currently working to recruit the help of citizen scientists to more accurately measure bear densities in northern New York.

"It's likely there is going to be further expansion of bear populations northward, which reaches into areas that have higher human populations," Fuller said.