The mating behavior of snakes is not so easy to see. The mating displays usually occur immediately after the snakes leave their hibernacula (this term is used for winter shelters, where snakes brumate of sleeping, similarly to hibernation of other animals such as mammals) places, where they sometimes congregate in large clusters. But getting to such a hibernacula without a special purpose and without knowing the peculiarities of the ecology of snakes is almost impossible.
But then one day at the end of April, on a forest path, the rustling of foliage attracted my attention. I did not immediately understand where the rustle came from, but looking around I spotted an extraordinary sight. On the dry foliage of last year, covering the first shoots of the breaking green growth, an unusual ball rolled, from which for a moment heads or tails appeared on the surface … Yellow stripes on the body made it possible to immediately identify the species – it was a mating procession of a Common Garter Snake (Thamnophis sirtalis). One larger snake was distinctive from another dozen and half snakes of smaller size that are literally hovered around it. Squirming, first merging into one large ball, then stretching in a chain, the snakes continued their movement along the invisible pass in the dry foliage. But as soon as I took a step towards this extraordinary procession, the ball instantly became alert, assessing the situation, and began to disintegrate. Individual snakes crawled on the sides, looking for cover under the foliage, in the cracks between the hard rocks and between the roots of trees. Nevertheless, about a dozen of the most persistent continued to follow the largest snake. The presence of a small rock in the forest indicated that the snake hibernacula was somewhere nearby: snakes usually hibernate in cavities under rocks or in natural depressions formed under the roots of dead trees, where they can gather from several tens to several hundred or even thousands of individuals.
The common garter snake is widespread in Ontario. In the forests around Ottawa, it is the most common snake species. The slender body of garter snakes with a light stripe running along the keel from head to tail, with yellow or reddish longitudinal stripes on the sides and an elegant narrow head that smoothly merges into the body, allow anyone to immediately unmistakably identifies this species. The average length of a snake with a tail is 50-70 cm. Sometimes there are specimens that are larger – up to a meter in length, but they rarely can be found. Females are much larger than males. Only one female, accompanied by more than a dozen males, led the mating procession that I observed. This feature of the biology of the species directed to the fact that there are much more males in the population than females. Garter snakes are also remarkable by the reproduction features: they can both lay eggs, from which small snakes then hatch, and give birth to alive little snakes. Usually, individuals living in the north latitudes give birth to live offspring, and more southerly occurring counterparts lay eggs. In Ontario, garter snakes give birth to live young. During the season, the female can give birth from ten to forty offspring. But only a few individuals survive to adulthood since snakes are a desiring prey for both four-legged and feathered predators. In addition, a significant number of snakes are killed on the roads, under the wheels of cars in populated areas with a dense road network. In Ontario, there are two subspecies that are externally different: in the south, the nominative subspecies of Eastern Garter snake has the bright yellow stripes on the sides of the body, and in the northern subspecies, the red-sided garter snake has reddish-orange stripes.
Garter snakes are found in a wide variety of habitats, both in forests and in meadow communities as well as around wetlands. In the Ottawa Greenbelt and around, it is definitely a forest species, inhabiting light deciduous and mixed forests. The main food items for snakes are amphibians and earthworms, but on occasion these snakes can catch small rodents and passerines, as well as small fish. Hunting strategy includes two types of behavior. Sometimes, garter snakes wait for prey, attacking approaching animals. But more often they actively pursue their prey, effectively catching fast tadpoles and small fish.
Garter snakes are harmless to humans. But this does not mean that anyone can catch them. It must be understood that the capture of any living creature is a huge stress for the latter. Therefore, if you notice a garter snake near the forest path, walk by, or watch the snake from the side without trying to catch it.
If you wish, you can also join one of the programs of Ontario Nature such as Ontario Reptile and Amphibian Atlas or Youth Circle for Mother Earth, and contribute to wildlife monitoring and conservation.