Not a Scene from an Indiana Jones Movie
This slithering carpet of 75,000 snakes is for real. They are coming out of an 8-month hibernation near the remote hamlet of Narcisse in Manitoba, Canada. The annual “emergence” attracts its share of wild life aficionados.
Over the winter, the red garter snakes seek shelter from below-freezing temperatures in limestone caverns, surviving on stored fat. “When they wake up, you’d think they’d head for a meal,” but according to Bob Mason, a reproductive biologist at Oregon State University who studies these snakes, “the first thing on the snake’s agenda is sex.” The males pour out of the dens first and wait for the females to trickle out over the course of a few weeks.
In this sea of snakes, a female isn’t easy for a human to spot, even though she’s three to four times larger. “Imagine trying to find a slightly bigger piece of spaghetti in a colander of moving spaghetti strands,” Dr. Mason said.
At times, the ratio of the number of males to females is 10,000 to 1. A female secretes pheromones from her skin, so males use scent to locate a sweetheart. The males court by rubbing their chins along their chosen’s back and flicking their tongues.
The male who wins leaves a stinky plug inside her that tells others to back off. She can wait a couple days for the plug to dissolve and mate with another snake, or she can slither off into the swamps to feed and give live birth to her babies. The female ultimately decides which sperm will succeed by a mysterious mechanism called cryptic female choice.
Adapted from NY Times article by Joanna Klein