Tuesday, July 19, 2011

What do you know about garter snakes?

     Today, on a very hot and humid day, I stepped out of the garage door to walk out to the street to get our mail. There in the center of our fairly large cement garage apron was an adult garter snake. She was slowly moving toward the edge of the cement but seemed to be in no hurry. She was about 2 feet long and I thought she had a bit of a swelling in her mid section. Maybe she is pregnant or else has eaten recently -- I don't know which. I took a couple of quick steps toward her and she raised her head as though to strike, her tongue flicking in and out. One more quick step toward her and deciding flight was the better choice, she slithered very quickly, even throwing her tail section ahead of her middle section to get the heck out of there. Earlier this summer while mowing, my husband said he saw a snake on our lake bluff. I find this interesting because we have lived here for 13 years and I have never seen a garter snake before. I am used to them, however; there were always garter snakes in our yard where I grew up. My mother had the typical fear of them and if one was seen and she had anything to do with it, she would get the garden hoe and that snake was no more. Actually she was doing the wrong thing. Garter snakes are harmless and they help us by eating rodents which can be quite destructive in our yards. We have a lot of moles and voles, and chipmunks and field mice. Sounds like a smorgasbord for garter snakes to me.

     I decided to read up on these creatures now that I know we are sharing our 3 acre lot with them. They are the most common snake in North America and range from very northern locations such as Alaska, to Central America. There are several different species; some may be different races with variations in the markings. These snakes hibernate during northern winters and may migrate fairly long distances to join others of their kind in a hibernacula (sleeping den for the winter). They emerge fairly early in the spring, sometimes while there is still snow on the ground. The males emerge first, warm up and get active, and are waiting when the females emerge, in order to mate. The females are producing pheromones that are highly attractive to the males. Often a single female will be surrounded by as many as 25 males in what is called a "mating ball." Interestingly very early in the spring, as the males are waking up, some males may produce some of this female pheromone which attracts other males to attempt to mate with him. This false copulation allows the attractant male to steal heat from the other males, allowing him to come completely out of hibernation more quickly.
     The female snake does not have to mate every year. She can store sperm for several years and fertilize her own eggs without ever seeing a male that year. She incubates and hatches the eggs internally and therefore gives live birth to from 3 to 80 juvenile snakes that are from 3-5 inches long. The juveniles are on their own immediately after birth and many fall victim to predation by birds, other snakes, raccoons and many other creatures. Herons and egrets often will take juvenile and even adult garter snakes.
     The success of the garter snake probably relates to its broad diet. It will eat almost anything, even carrion in some cases. Its usual prey are grubs, earthworms, leeches, frogs, toads, other smaller snakes, birds, rodents, and sometimes other creatures' eggs. Though some species and subspecies seem to prefer to live near bodies of water, many live in drier locations. In mid summer, they especially like the cool damp locations under vegetation, in wood piles, in stone walls, and stone foundations. Even so, they are on the endangered list since 1969, probably threatened by water pollution, vehicles on our roadways, and humans. Many of we humans still kill garter snakes when they are observed. It is no wonder that generally these snakes are timid, avoid humans, and are not seen.
     It was always thought that the garter snake was non venomous. But recently a mild neurotoxin has been found secreted from glands that are located behind the snake's eyes. The snake does not have fangs to deliver the toxin in a bite, but it is thought that the toxin enters the saliva and may enter prey through bite marks. The garter snake does have a tooth but the toxin is not delivered through it. Usually a garter snake will choose to flee like my friend did, but if captured it might bite. Such a bite in a human might draw a pinprick of blood, and might get a little red and itch a little much like an insect bite. When captured the snake also defecates and secrets a very strong musk odor from glands near its anus to try to drive its captor away.
     If a snake gets in one of our homes, it is totally by accident. It probably was hibernating under the foundation and in spring went the wrong way, into the basement or house. If this becomes a regular occurrence at your residence, you can reduce the likelihood of this happening by reducing the vegetation that extends all the way down to the ground, making certain that your foundation is well sealed, and get rid of other places that snakes like, such as woodpiles, stone piles, and loose stone walls with lots of chinks in them. You can also enclose the space under your deck with fine wire mesh that needs to be buried into the ground several inches to keep snakes from living there. But if you just see a snake now and then as we have, you probably don't need to do any of these things.
     Well that's all I know about garter snakes. I was kind of happy to see this lady on my cement driveway today because it means that my garden is an inviting place for another species of wildlife. I just have to make sure my baffles are securely attached to my bluebird house poles to avoid heartbreak there. 


  1. Helpful. New perspective on the garter snakes that frequent my hot tub. Thank you.

    1. Thank you for commenting and following my blog. I just posted a new piece on the Birds of Central America. check it out. Looks like you are a Midwesterner like me.

  2. Will feeding birds attract snakes due to the chipmunks ?

  3. Will feeding birds attract snakes due to the chipmunks ?