VENOMOUS SNAKES OF CANADA
While India and Australia are known for their many species of poisonous snakes, and America has its rattlesnakes to boast, Canada can boast of its four venomous species, as well.
Hypsiglena chlorophaea, the North American Desert Night Snake, travels from sea level in Sonora, Mexico all the way up to 8,700 feet and through British Columbia, twisting and turning its way all through California, Oregon, and Washington. It gets it name from the Greek “hypsi,” meaning “on high,” “glena,” meaning “eyeball,” which probably refers to the oblong pupil and the fact that their eyes set up just a little higher than other snakes, and from “chloros,” meaning green, and “phae,” meaning dusky or dark grey, referring to the range of colors that the snake may be.
Although some resources list this snake as “Not Dangerous” or non-poisonous, its saliva is mildly venomous. It is not poisonous enough to kill a person, and so is considered “harmless” to most humans. Its venom is strong enough to kill the large range of animals that it eats, however. It is known to eat terrestrial vertebrates, such as lizards, lizard eggs, small snakes, frogs, and salamanders, anywhere between dusk and dawn, as it is a nocturnal snake. It is an oviparous snake, laying its eggs between April and September. It can be found under surface objects, boards, tree branches, and rocks, in arid areas where it prefers hiding in sagebrush flats, and chaparral. It can also now be found in suburban areas, gardens, meadows, and grasslands, areas with a lot of groundcover.
This is a relatively small snake, averaging between twelve and sixteen inches, though it has been seen at lengths of twenty-six inches. Its hatchlings are about seven inches long. It has a narrow flat head, smooth scutes in rows of twenty-one, and elliptical pupils. Its color varies from light grey to tan, and has dark brown or gray blotches down its back and sides. It also often has a dark bar running through or directly behind the eyes. Its underside is either white or yellow and unmarked.
Sistrurus catenatus, Massasauga, is found in midwestern North America, from Ontario to Mexico, and in small pockets throughout the United States. It is considered endangered, and in Pennsylvania, it is considered “critically imperiled” with only two counties with two locations found in the whole commonwealth.
The snake has many nicknames, ranging from the Mexican vivora de cascabel and massasauga rattler, to grey rattlesnake, swamp rattlesnake, and the Michigan point rattler. The Ojibwa term “massasauga” means “great river-mouth,” referring to the areas in the Ojibwa territory that the snake inhabits. As with all rattlesnakes, the massasauga is considered a pit viper because of its heat-sensing pits located between each eye and nostril pair. Adult massasaugas are not very large, ranging from twenty-four to about thirty inches in length. Their ground color is grey or tan, with a row of large brown and/or black splotches down the center of their backs and three rows down each of their sides. There have been full-black versions, melanistics, found, as well as those with splotches that meld the back and sides together. The young are lighter in color, but have bold patterning like the adults. They have small heads, and their scutes are keeled.
Their diets are like many snakes, that is, opportunistic for small vertebrates like rodents, lizards, and other snakes. In some areas, mostly in the northern and eastern regions, frogs make up a large part of their diet. In fact, they eat more frogs than any other rattlesnake.
Massasauga venom is cytotoxic. It destroys tissue and contains specialized digestive enzymes that make blood clotting impossible. Severe internal bleeding will make their prey die, and they often bite their victim and back away from their sharp teeth and claws and wait for the animal to die—and become partly digested in the process. They are very shy and avoid humans to the extent that that is possible. Most Ontarian snakebites were from cases where the humans either stepped, unaware, on the snake, or were handling or bothering the snake. They use their venom for prey, so they prefer not to “waste” it on human bites, but will if they are provoked. The only two deaths attributed to massasauga in Ontario were of people who had not been treated in the proper manner. The Ontarian hospitals are not known to carry the massasauga-specific venom, as it is expensive and hard to come by.
The Northern Pacific Rattlesnake, Crotalus oreganus, resides on the West Coast, from Santa Barbara, California, to British Columbia, Canada, though in Oregon and Washington it prefers the inland areas. It gets its name from the Greek words “krotalon,” meaning rattle, and “oreganus,” meaning belonging to the state of Oregon and the Columbia River. These snakes choose habitats that are rocky, woodlands, or sagebrush flats, in order to easily blend in, camouflaged from predators and prey.
Adult snakes are approximately twenty to thirty-six inches, with several specimens found up to forty-eight and sixty inches long. They have very robust bodies, a thin neck, and a large triangular head. Of course, they also have the rattle at the end of their tails, which is made up of loosened interlocking hollow segments, so that it can move. This is their warning signal. Each time the snake sheds, it gains a new bead in the rattle.
Northern Pacific Rattlesnakes tend to have a ground coloration that matches their environment. They can be grey, brown, reddish, yellow, or olive-green. They do have unique dark brown or black splotches, with darker edges and lighter borders. Their marks run down their backs about two-thirds of the length of their body, and also in stripes down their sides. The splotchy marks turn to dark bars further down the body, and eventually into ringed stripes on the tail. They often have a lighter-colored stripe running down from the corner of the eye to the mouth. The young have the same coloring, but have a bright yellow tail. Although they do have a “rattle,” it is only one bead and does not make a sound.
These snakes are very venomous, listed as “dangerously venomous,” and a bite from one of them can be quickly fatal if appropriate medical treatment is not sought immediately. This is the only rattlesnake found in its range, which may help with the antivenin sought by the treatment center. *Note: even a dead snake can “bite” if its fangs or jaws are handled after death, so it is best not to directly handle a dead rattlesnake.
These, like most snakes, are mostly nocturnal. They turn a very dark color when they get hot in the daytime sun, but they are sometimes seen in the daytime when the temperature is more bearable to them. They are not active during the colder temperatures of winter, instead “denning up” with other snakes in a period known as brumation. During this period, they are awake and alert, but slow, lethargic, and chilled.
Northern Prairie Rattlesnakes eat a wide variety of animals, from birds and lizards to rats and hares. Interestingly, the adult common ground squirrels in California are totally immune to rattlesnake venom, and are the only animal known to stand and fight against them. The snakes will either actively move about, searching for prey, sensing it with its heat pits, or will lie in ambush along lizard or rat trails, waiting for one to come along. It strikes and then releases its prey, so as not to get scratched by claws or bitten by sharp little teeth. It then follows the dying animal, and when it has finally passed, the rattlesnake will swallow it whole.
These rattlesnakes are ovoviparous, meaning that the mother will retain the developing soft-shelled eggs within her body, and eventually gives birth to live hatchling rattlesnakes. Breeding will take place in the spring, when the males avidly pursue the females, and fight among themselves to take precedence with a female. The young hatchlings are born in batches of about six to twelve snakes from August to October.
Crotalus viridis, the Prairie Rattlesnake, inhabits a wide range, appearing in northern Coahuila and northwestern Chihuahua, Mexico, and living in all of the middle, prairie, states of the United States, all the way up to Alberta and Saskatchewan, Canada. It tends to live in areas where there is a lot of prey. They like rocky areas, where they can inhabit caves and dens, but they will also take over other animals’ burrows, and live in brushy areas. The prefer dry and moderate conditions to live in, overwintering in their brumation phase in caves or “denning up” with many other snakes. The Prairie Rattlesnake grows to about three-and-a-half feet long, though there have been specimens found up to five feet long. In Montana, where they have abundant prey and prime conditions, they often will grow to four feet. A special characteristic of these rattlesnakes is that it has four internasal scales, unlike the other rattlesnake species. Their background color is usually light brown with darker brown splotches dorsally. They will usually have a color band at the corner of their eye, along with the large triangular head and heat-sensing pits seen in pit vipers.
Because of their wide distribution, these snakes eat a wide variety of prey, ranging from prairie dogs to birds, and sometimes even amphibians and other reptiles, though it is usually the younger snakes that rely on small snakes for food.
Prairie Rattlesnakes are viviparous, giving birth to about eight young, though litters of up to twenty-five have been seen. The babies are about eight inches long, and are venomous from the moment they come out. They do not require any care from their mother, usually immediately striking off in search of food.
Although these snakes live on the land, they have been known to stretch out and bask on sagebrush bushes, climb trees, and hide in crevices of rocky outcrops. They are a diurnal snake, though they prefer more moderate temperatures and will hide from brutally hot sun. They are active from spring to about October or November, depending upon the temperature that particular year.
They are dangerously venomous, as well, and inject approximately 25-55% of their venom load in one bite. The venom is hemotoxic, has tissue destruction properties, and is also a neurotoxin, so a bite by this snake must be treated immediately, also. These snakes will defend themselves if surprised or injured, so extra care must be taken when walking in areas where they are known to live. Their rattle is their warning call to hikers or predators in their space.
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VENOMOUS SNAKES OF CANADA
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