The largest gathering of snakes in the world woke up from a nap — and the photos are insane

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National Geographic/YouTube

Each year at the break of spring, red-sided garter snakes in Narcisse, Canada, engage in an unusual ritual.

Thousands of them begin emerging from their underground dens during the last week of April, and their numbers peak during the second week of May. The reason? They’re all out to mate.

Here is what goes down at the snake dens:


Like all other snakes, red-sided garters are cold-blooded. During the winter, when the temperatures drop to below freezing, they hibernate for eight months.

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National Geographic/YouTube

Source: National Geographic


Manitoba, Canada, is laced with sinkholes that line its superficial limestone bedrock. Underground dens form here, attracting the snakes, who see them as the ideal spots for an eight-month snooze.

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Ruchika Agarwal/Google Maps

Source: National Geographic


But space is limited. Thousands of snakes end up in dens as large as an average living room.

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Reuters

Once spring arrives, thousands of the the red-sided garters slither over one another to emerge from their lairs, forming a carpet of quivering snakes.

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National Geograpic/YouTube

Source: Government of Manitoba


It’s also peak breeding time. The males eagerly look for a female to mate with in the areas surrounding the dens.

source
National Geographic/Youtube

Source: The New York Times


In the huge heap of snakes, it can be tough for the males to recognize the females, even though they’re longer and wider.

source
National Geographic/YouTube

Source: Government of Manitoba


This is made even more interesting by the fact that the ratio of males to females is 10,000 to 1.

source
National Geographic/YouTube

Source: Government of Manitoba


The male-biased sex ratio is a result of the males pouring out of the den first and awaiting the females, who typically emerge over the course of a few weeks.

source
National Geographic/Youtube

Sources: Government of Manitoba, National Center for Biotechnology Information


Once the males are lured by a female’s pheromones, several try to court one female by rubbing their chins along her back. This is called a “mating ball.”

source
National Geographic/YouTube

Source: The New York Times


The male closest to the female copulates with her, leaving a gelatinous plug inside her body that blocks her reproductive tract for about two days, warding off other males.

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Reuters

Source: Robert Mason and Christopher Friesen of Oregon State University


Then, the female can slither away from the carpet of snakes, where she’ll feed and give birth later in the summer. One female can give birth to 40 to 50 young at once.

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National Geographic/YouTube

Source: Robert Mason and Christopher Friesan of Oregon State University


But if the female rejects the male, then she can prevent his sperm from fertilizing her eggs, a mechanism called “cryptic female choice.” She simply waits for the smelly plug to dissolve and then mates with another male.

source
National Geographic/YouTube

Sources: The New York Times, Government of Manitoba


In September, the snakes return to their dens for the winter, where scientists think they spend the next eight months in hibernation once again.

source
National Geographic/YouTube

Source: The New York Times