Comox Valley Naturalists Society
Knowing Nature . . .
Spying a Snake: A Sign of Spring
March 31, 2006
When spring arrives, there is a special moment of realization. A few days ago I had one such moment. It was a sunny day, and I heard the buzz of a newly arrived Rufous Hummingbird. At the same time, I saw a handsomely striped garter snake winding it’s way through the grass. For me, these events marked the beginning of spring.
Seeing the snake got me thinking about snakes. Snakes have a bad reputation, always depicted as evil in myths and folklore. Movies make snakes seem even worse. Remember those scenes where the hero and heroine are trapped in the snake pit? Even in Harry Potter, all the bad kids belong to the “House of Slytherin”. Contrary to popular belief, snakes are fascinating creatures.
Snakes belong to a group called reptiles that also includes creatures like turtles and lizards. Most reptiles live in the tropics, but there are forty species of reptiles in Canada, and eighteen species in BC, nine of which are snakes.
One of the common misconceptions about snakes and reptiles are that they are cold blooded. A better choice of words for this condition is ectothermic. This means that unlike humans, snakes cannot maintain their body temperature. Snakes are very sensitive to temperature changes in their environment. They heat up when basking in the sun, but cool down in the shade. Mammals need food to generate enough energy to maintain body heat but snakes, being solar heated, require far less calories for survival.
Another misconception is that all snakes are dangerous and poisonous. It is true that some snakes constrict their prey to death by coiling around them. It is also true that some snakes kill prey by injecting them with venom. It is reassuring to know that the four species of snakes on Vancouver Island are all harmless. Snakes here are nothing to be afraid of, unless you are a worm, a slug, a baby bird, a small rodent, a tadpole or a fish; all favourite foods for snakes.
Snakes are predators and they eat their prey live, and swallow it whole. They cannot see well, but can detect movement. They have no ears but can sense vibrations. The most well developed sense is the sense of smell. Snakes have a specialized structure, called a Jacobsen’s organ, on the roof of the mouth. Chemical signals are picked up when the snake’s tongue is flicked out and brought into contact with the organ. In addition to their senses, snakes have a streamlined, limbless body, and are quick to capture prey.
In the winter months, snakes, like many animals, hibernate. Finding crevices, snakes hibernate together in hibernacula. Hibernation is necessary, because they cannot withstand very cold temperatures. During the first warm days of spring, snakes begin to leave the hibernacula. Males generally leave before females. Mating occurs soon after the females emerge, and sometimes numerous males will court a female, forming a mating ball of snakes.
The majority of snakes lay eggs, but all of the snakes in our area bear live young. A female may have from 2 to 85 baby snakes, depending on the species. Baby snakes are independent from birth and have no nurturing from the parents. Young snakes rely mostly on a diet of worms until they hone their hunting skills. As snakes grow they occasionally moult. They loosen their skin by rubbing against a rock, and then shed the entire skin inside out.
On Vancouver Island, there are three species of Garter Snakes, and the Sharp-tailed Snake. The Sharp-tailed Snake is quite rare, and only found on southeastern Vancouver Island and the southern Gulf Islands. The Sharp-tailed, unlike the Garter Snakes, lays eggs that hatch into young.
The Northwestern Garter Snake is terrestrial, and is most often seen in gardens. This snake varies greatly in colour and pattern, but usually has some yellow or red striping. The main body colour is usually brown or black. The head is quite small, and not much wider than the neck. A pale upper lip, and blunt snout distinguish this snake from others. The Northwestern is our smallest garter snake.
The Western Terrestrial Garter Snake has a large head that is distinct from the neck. It has yellowish stripe down the back that is usually somewhat wavy, and can be distinguished from the other garters by the two rows of dark brown or black diamond-like blotches between the stripes on each side of the body.
The Common Garter Snake is often found swimming in water. The head is larger than the neck, like the Western Terrestrial. The Common Garter has yellow stripes, and may have a red stripe along the side with some red blotching. The body colour is grayish to black.
If handling snakes, always do so very gently. Snakes release a mix of smelly musk and feces when handled. If extremely threatened, Western Terrestrial Garter Snakes may bite. Snakes do not survive long when collected as pets, so it is best to admire them in their natural environment.
Vancouver Island is a safe place to enjoy snake watching, and Garter Snakes are easily found in the spring. Their intricate stripes and patterning deserve a second look. With a little understanding, perhaps snakes can be better appreciated, and not viewed as something negative.
Click on a link below to view the CVNS newspaper column.