INDIANAPOLIS (AP) — Indiana officials are asking motorists to be more watchful for deer on the state’s roadways as fall weather and mating season approach.

The Indiana Department of Transportation, the Indiana State Police and the Indiana Department of Natural Resources all say deer become more active as the weather cools. Statistics show nearly half of vehicle crashes involving deer happen between October and December. State officials say deer are on the move during this time and could encounter roads more frequently, increasing the potential for collisions.

Officials say there were more than 15,000 deer-related collisions in Indiana last year. They urge drivers to be alert and take safety measures like using high-beam headlights at night and slowing speed if a deer is spotted.