WASHINGTON — Long the bane of gardeners and unwary motorists, soaring deer populations are also nuisances for airports and threats to pilots, especially at this time of year, according to aviation and wildlife experts.

Whether driven by hunger or just crazy for love, deer will do seemingly anything to get onto airport grounds and runways, including leaping over tall fences or squeezing under them. Once there, they like to warm themselves by sauntering on runways, which hold heat longer than cold ground. But put a deer and a plane together on a runway and both can have a very bad day.

From 1990 to 2013, there were 1,088 collisions between planes and deer, elk, moose and caribou, according to a recent joint report by the Federal Aviation Administration and the Agriculture Department. Most of the planes suffered damage, and some were destroyed, the report said. One person was killed and 29 others injured. No mention is made of the fate of the deer.

The vast majority of collisions involved white-tailed deer, the smallest member of the North American deer family, but big enough to wreck a plane. There were only about 350,000 of the creatures in the U.S. in 1900. By 1984 there were 15 million and by 2010 more than 28 million. They’ve caused $44 million in aircraft damage and 238,000 hours of lost flying time over the past 24 years. About 30 percent of collisions occurred during the October-November mating season.