Eastern Garter Snake
(Thamnophis sirtalis)
Description: Eastern garter snakes are small to medium-sized snakes (15 - 26 inches as adults, 5 - 9 inches as juveniles). They are usually black, or grayish brown with three bold yellow stripes along their backs (one dorsally and two laterally). The lateral stripes usually cover the first, second, or third scale row (or all three). Sometimes the lateral (or side) stripes blend in with the yellow belly scales, making them hard to distinguish. The belly is olive or yellowish gray. Garter snakes are members of the family Colubridae and the sub-family Colubrinae, which includes red-bellied snakes, brown snakes and water snakes.
Habitat/Ecology: Garter snakes can exist in almost any habitat that has a suitable amount of vegetation and moisture. This can include: grassy meadows or abandoned lots, golf courses, cemeteries, and even back yards. I have even found them in industrial parks on plots that have not been built upon yet. They seem to prefer to have a water source nearby (such as a pond or creek), and are often found near river backwaters, marshes, impoundments. Although they can tolerate somewhat dry habitats (I have found them on open bluff faces, for example), these habitats are usually in the vicinity of a water body (in this instance, the bluff faces were along the Mississippi). I have spent considerable time in some of the few remaining sand prairies in Wisconsin and garter snakes are nonexistent there.
Garter snakes emerge from hibernation very early in the spring (I have heard reports of them being seen when there is still snow on the ground). Mating occurs shortly after emergence in the form of a phenomenon called a "breeding ball". Breeding balls usually consist of a large aggregation of many garter snakes, heaped together in a pile. While in this large group, males will seek out females and mating will commence. Gravid females will hold their embryos internally and do not lay eggs. When development of the embryo is complete, they female gives birth to them live. Hatchling garter snakes are small (3 to 5 inches) and not often encountered in the wild due to their size. They move quickly and are generally gone before prying eyes can get close enough. They most likely over-winter in fissures near the banks of water sources, along bluffsides, or abandoned mammal burrows that go below the frost line.
They are known to eat earthworms, amphibians, fish, small mammals, and insects. Once, while fishing along the rip-rap of the Mississippi River, I happened to notice a garter snake eyeing the bait fish in my minnow bucket. I was intrigued (and the fish weren't biting) so I grabbed one of the minnows and slowly held it in front of the garter snake's nose. To my surprise, the snake took the fish from my fingers and did not flee. Incredibly amused, I continued to feed the snake in a similar fashion and finally stopped after he had taken seven! Then, I gave him a good scare so that he left and would no longer associate a fisherman's bait bucket with a free meal (a habit that would likely get him killed). These snakes frequently fall prey to predatory birds, such as Herons and Egrets.
Remarks: These are probably the most commonly seen snake in the La Crosse area (and the entire state of Wisconsin). The Myrick Park marsh has a large population and many times during the summer of 2000, as I strolled along the paths there, it seemed I could not walk for more than 50 yards without seeing a Garter Snake shoot through the grass at my feet. However, the flooding that occurred there during the spring of 2001 seemed to push them out of the area surrounding the major marsh trails and I did not see a single one until late August (this was a single individual some distance from where I had found them the previous year).
Although common, these snakes are wary and avoid people. They are quick moving and prefer to escape rather than bite. However, if escape is not possible, them will not hesitate to bite or defecate on their captor. Smaller snake bites will not break the skin, however, older adults can draw blood (albeit very little). Though frequently killed by misunderstanding humans, these snakes are harmless. Several other sub-species of Garter Snakes exist within Wisconsin (such as the plains garter snake and the endangered Butler's garter snake) but they generally are not found in La Crosse County. I have not witnessed either of these snakes in the area. For a list of snake species found in Wisconsin, but not La Crosse, CLICK HERE!
Aside from Myrick Park, I have encountered garter snakes in several locations including; Goose Island, near Green Island and Hixon Forest/Grand-dad's Bluff.
It is interesting to note that, as a child, I encountered garter snake "breeding balls" along the railroad tracks near my home in Stoughton, WI.. Furthermore, I can even recall a grade school encounter that a friend of mine and I had with a garter snake during the winter! We were playing outdoors in the snow near Stoughton, along a frozen creek-bed. Although it was extremely cold outside, it was a very sunny day and enjoyable playing weather. The snow and ice were very thick, and we were walking atop the frozen water, when we came upon a garter snake! The snake was cold and unresponsive, but still flicking its tongue. Searching the newly fallen snow, we were able to find the snake's "tracks", and follow them back to a muddy bank that was exposed to the sun. The sun had thawed the mud, very slightly, and we were able to find a hole in the bank where the snake appeared to have come from. Quickly we guided the little critter back into the hole and went on our way. At the time, it surprised me. Now, however, it completely astonishes me. Just think, that tiny little cold-blooded critter was able to withstand an undetermined amount of time, in the snow, during a Wisconsin winter. This truly lends credence to the fact that these snakes will make an attempt to emerge from hibernation very early in the spring.
|