Garter snake mating

I filmed first a pair of mating garter snakes, then (beginning at the 3:00 minute mark) a ball of somewhere around ten snakes, in late morning, April 2.

We’ve always had a healthy garter snake population on the farm, but since we stopped mowing most of the lawns some 15 years ago, their numbers have increased dramatically, we think because a recovering wet meadow environment is better habitat for them than the drier lawn that preceded it. Major gathering points for the emerging snakes in early April include the environs of the old springhouse and a stone decorative well at the base of the slope beneath the main house. Underground hibernacula are presumably located in both spots.

Garter snakes are famous for their mating balls, which we’ve observed at both locations. I shot this scene below the well. The female is identifiable as the largest snake at the center. The Wikipedia article on garter snakes describes what’s going on as well as any source:

Garter snakes begin mating as soon as they emerge from brumation. During mating season, the males mate with several females. In chillier parts of their range, male common garter snakes awaken from brumation first, giving themselves enough time to prepare to mate with females when they finally appear. Males come out of their dens and, as soon as the females begin coming out, surround them. Female garter snakes produce a sex-specific pheromone that attracts male snakes in droves, sometimes leading to intense male-male competition and the formation of mating balls of up to 100 males per female. After copulation, a female leaves the den/mating area to find food and a place to give birth. Female garter snakes are able to store the male’s sperm for years before fertilization. The young are incubated in the lower abdomen, at about the midpoint of the length of the mother’s body. Garter snakes are ovoviviparous, meaning they give birth to live young. Gestation is two to three months in most species. As few as 3 or as many as 50 snakes are born in a single litter. The babies are independent upon birth.