And, of course, another sign of spring in our yard is the emergence of hibernating garter snakes! (For the record, Thamnophis sirtalis.) Thursday (March 1) was a banner day for us in this respect, since we saw, for the first time, with our own eyes, a garter snake “mating ball.”
We’d read about it but, well, words don’t do it justice!
But here’s a picture Sue took. They were right outside our front steps, in a sunny spot on our front walk, in early afternoon.
The phrase “mating ball” doesn’t describe what we saw very well. I’d call it a “writhing snarl of snakes” or a “serpent tangle” or something. I’m pretty sure there were about a dozen in this group. We watched as two snakes arrived and joined the fray.
They looked like they were having fun!
There’s not much reason for me to tell you what you can find online, but for what it’s worth, here are some selections from the “garter snake” entry in Wikipedia.
Garter snakes have complex systems of pheromonal communication. They can find other snakes by following their pheromone-scented trails. Male and female skin pheromones are so different as to be immediately distinguishable. However, sometimes male garter snakes produce both male and female pheromones. During mating season, this fact fools other males into attempting to mate with these "she-males". This causes the transfer of heat to them in kleptothermy which is an advantage immediately after hibernation so allowing them to be more active. She-males have been shown to garner more copulations than normal males in the mating balls that form at the den when females emerge into the mating melee.
Garter snakes go into brumation before they mate. They stop eating for about two weeks beforehand to clear their stomach of any food that would rot there otherwise. 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 25 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. However, this is different than being truly viviparous, which is seen in mammals. Gestation is two to three months in most species. As few as 3 or as many as 80 snakes are born in a single litter. The young are independent upon birth. On record, the greatest number of garter snakes to be born in a single litter is 98.