The World's Largest Orgies
When red-sided garter snakes emerge from hibernation, up to 75,000 gather in writhing 'mating balls' — some of the largest mating aggregations on Earth.
Every spring in Manitoba, Canada, one of nature's most spectacular — and slightly disturbing — mating events occurs. Tens of thousands of red-sided garter snakes emerge from their winter dens and immediately begin mating.
Males emerge first and wait near the den entrances. When females emerge, they're immediately swarmed by dozens of eager males, forming writhing "mating balls" — tangled masses of snakes all competing for the chance to mate.
Some males have evolved a devious strategy: they produce female pheromones, tricking other males into wasting energy pursuing them. These "she-males" can then sneak in and mate while competitors are distracted.
The sheer numbers are staggering: the Narcisse Snake Dens in Manitoba can contain up to 75,000 snakes in a single location. It's considered one of the greatest wildlife spectacles on Earth.
The entire mating season lasts only 2-3 weeks. After mating, the snakes disperse across the landscape, only to return to the same dens the following fall. They navigate using the Earth's magnetic field and their memory of the landscape.