Remember the scene from Indiana Jones and the Last Crusade when Junior plummets from the rickety train catwalk into a horrifying crate of wriggling snakes? Well, there are many who share Indy’s fear of snakes, but there are also those who curiously seek out cold blooded critters. With the arrival of spring and warmer temperatures snakes begin seeping out of crevices where they’ve spent the winter hibernating. A few kilometres north of the Pelly, Saskatchewan, overlooking the Swan River a subterranean den filled with red-sided garter snakes awakens. Tens of thousands of snakes ooze from pores in the hill side – blanketing the forest undergrowth with a slithering carpet of scales and forked tongues.
Having spent the frozen winter months huddled together deep underground, the mass of snakes awake rather – frisky. The skewed gender ratio creates somewhat of a dilemma, leading to what can only be described as a gigantic snake orgy. The madness begins when the sought after females release a pheromone to indicate their breeding readiness. Dozens of males then wrap themselves around a single female creating an awkward ball of mating snakes – so involved in the task at hand, that these knotted mating balls often snowball down hills.
Interestingly, the males do not engage in any sort of combat for dominance nor do they establish territories like many other animals might. Scientists are still unsure as to what females consider attractive courtship. Males can be observed rubbing their chin’s against a female’s neck as well as quivering their entire body, but what exactly triggers a female to allow mating is a mystery. Upon successfully breeding, a male will ‘seal’ the deal with a copulatory plug: it’s a gelatinous plug covering the female’s cloaca and contains a pheromone which makes the female unattractive to other males. Though, the plug doesn’t last forever and it is possible a female will mate with more than one male – subsequent litters can be comprised of pups sired by as many as three different males.
A gathering of this many snakes is not a common occurrence and only takes place in a handful of special sites in North America. The red-sided garter snake is the most northerly living reptile in the western hemisphere and must endure winter temperatures below minus fifty degrees Celsius. In order to survive the harsh cold, the snakes hibernate well below the frost line – in subterranean dens called hibernaculums. In geologically-unique regions, such as here in eastern Saskatchewan and the more well known Narcisse site in Manitoba, there are a very limited number of dens and all the snakes living in the surrounding area are forced to gather in one or two hibernaculums.
Whether you love them or loathe them, the red-sided garter snake is completely harmless to people. Despite what you may have heard, these snakes do indeed have teeth – small ones, and prey primarily upon small frogs, insects and worms. The presence of this many snakes in one hibernaculum is a clear indicator of a healthy ecosystem and it’s an event you need to witness in person to comprehend the sheer number. The peak of the snake’s emergence is typically the second to third week of May, however cool or wet weather can delay their hibernaculum departure and warm dry conditions can speed it up.
If you’re planning a visit and have eager junior herpetologists coming along, please take a moment before arriving to explain how to properly respect the snakes. The following may sound a bit preachy, but it’s important to have as little impact as possible on the snakes and their environment. Use two hands to support a snake – not squeeze, and there’s no need to hold more than one snake at a time. It may be difficult to convey the seriousness of not disturbing mating snakes to a younger audience, but try to leave the gigantic heaps of breeding snakes alone. Finally, watch your step – in the time I spent watching the snakes, I observed far too many fatalities under the feet of excited children.