2 Venomous Snakes in Minnesota

There are 17 snakes in Minnesota. Of these, there are 2 types of venomous snakes. This article will discuss what they are and where to find them in Minnesota.

• Timber Rattlesnake (Crotalus horridus)
• Eastern Massasauga Rattlesnake (Sistrurus catenatus)

Pit Vipers

Minnesota’s 2 venomous snake species are both rattlesnakes. Rattlesnakes are pit vipers. Pit vipers belong to the Crotalinae subfamily of the Viperidae family. Other pit vipers in the United States are cottonmouths and copperhead snakes.

Pit vipers have heat-sensing pits on each side of the head between their nostrils and eyes. These pits are actually infrared receptors that detect body heat from warm-blooded animals. Pit organs enable pit vipers to strike their prey precisely, even in the dark. They can also detect body heat from up to 1 meter away.

All pit vipers have a distinctive triangular-shaped head.  Furthermore, they have cat-like pupils with vertical elliptical slits.

Pit vipers have hollow fangs connected to venom glands. They use their fangs to inject venom into their prey. This venom immobilizes the prey, making it easier for the snake to consume. They primarily consume small mammals, reptiles, amphibians, and small birds. These snakes play an important role in the ecosystem. This is because they maintain balance in rodent populations.

Rattlesnakes

The first thing people think about regarding Rattlesnakes is their iconic rattle. When they are disturbed, they vibrate their tails. This makes a buzzing or a rattle-like sound. Sometimes, rattlers strike without rattling. Sometimes, their rattles fall off. Rattlesnakes are ambush predators. They lie in wait for small animals to approach within striking range. They then bite the animal and wait for their venom to take effect. They then track the animal down, following its scent trail with their tongue, and eat it.

You must be aware of where you are placing your hands and feet when you’re in rattlesnake country. If you hear a rattling noise, do not move until you spot where it originated. Otherwise, you may accidentally move into the snake, provoking it to strike you.

Timber Rattlesnake

Scientific Name:	Crotalus horridus
Description:	Adult Timber Rattlesnakes grow between 36 and 60 inches (.91 to 1.52m) long. Their bodies are yellowish-brown with a dark chevron pattern. They also have a brown mid-dorsal stripe down their backs. Their tails are dark brown or black.
Habitat:	Timber Rattlesnakes prefer wooded areas and hillsides with rocky outcroppings.
Conservation Status:	The Minnesota DNR has listed the Timber Rattlesnake as a threatened species.

Timber Rattler and Canebrake Rattlesnake are both common names for the Timber Rattlesnake. Generally, in higher-elevation habitats, they are called Timber Rattlesnakes. On the coastal plain, though, they’re called Canebrake Rattlesnakes.

The average Timber Rattlesnake grows 36 to 60 inches (.91 to 1.52m) long. However, there have been reports of them growing up to 7 feet (2.13m) long. See

These snakes vary in color. Their general base coloration is a light brown to grey-brown, though. They have dark chevron-shaped bands on their back and sides against a lighter base color. Moreover, they have a rusty brown, pinkish, or yellow stripe down their backs. They have a black tail with a tan rattle at the end of their tail. There are also melanistic timber rattlers. These are dark and sometimes almost entirely black. In the dark color morph of these snakes, the tail is usually darker than the rest of the snake’s body.

Where Do Timber Rattlesnakes Live in Minnesota?

The Timber Rattlesnake can be found in southeastern Minnesota. They’re in Washington, Dakota, Goodhue, Wabasha, Olmsted, Winona, Fillmore, and Houston counties.

The Timber rattlesnake lives in various habitats. These include deciduous forests, pine forests, and agricultural fields. They can also be found in wetland habitats and river flood plains.

As we talked about, Timber Rattlesnakes are ambush hunters. When not on the move, they’re likely lying motionless in a potential ambush spot. They often employ ground debris as an additional layer of camouflage.

What Do Timber Rattlesnakes Eat?

Timber rattlers prey on small rodents such as mice, rats, squirrels, and chipmunks. They also eat small birds, other reptiles, and amphibians.

These snakes are excellent climbers. In fact, timber rattlers have been found in trees at heights of more than 80 feet. Source

In 2013, University of Maryland researchers conducted a study. This study has proven that timber rattlesnakes help control Lyme disease. This is because as they consume rodents, they’re also consuming ticks. A timber rattler will consume 2,500 to 4,500 ticks per year, depending on the location. See

Wintertime Brumation

Timber Rattlesnakes make a winter den in sheltered spots. They den underneath rocks and logs, as well as in fissures in rocky hillsides. An individual Timber Rattler might brumate alone in some parts of their range. But in other areas, they congregate in dens with other snakes through the winter.

Dens are usually placed on slopes facing south because they get more warmth from the sun. They don’t always share their dens only with Timber Rattlers. Sometimes, they share their dens with other species of snakes. These wintertime dens may hold up to 60 snakes. Source

In spring, snakes emerge from their winter dens. They then relocate to their hunting grounds, reaching peak movement in May. Conversely, during the fall, they return to their wintering areas. September is the peak month for this seasonal migration. In May and September, snake-human encounters are most likely to occur.

How Dangerous Are Timber Rattlesnakes?

Timber Rattlesnakes are among the most dangerous snakes in North America. This is due to their long fangs and high venom yield. 1% to 10% of untreated Timber Rattlesnake bites result in a fatality.

Fortunately, 40% to 60% of the time, they produce dry bites. In other words, although their fangs penetrate the body, they do not inject any venom. Source

This venomous species produces hemotoxic venom. A Timber Rattlesnake bite can sometimes cause serious complications. These include shock, seizures, coma, internal bleeding, blood clots, and deep tissue damage. Source

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Eastern Massasauga Rattlesnake

Scientific Name:	Sistrurus catenatus
Description:	Adult Eastern Massasaugas average 22 to 30 inches (55 to 75cm) long. Their body is light grey with dark brown blotches.
Habitat:	Wetland habitats such as swamps or marshy areas near lakes or streams.
Conservation Status:	The Minnesota DNR has listed the Timber Rattlesnake as an endangered species.

Eastern Massasaugas are sometimes called swamp rattlers. They are one of two rattlesnake species native to the Great Lakes states. The other is the Timber Rattlesnake.

An adult Eastern Massasauga rattlesnake grows to a length between 22 to 30 inches (55 to 75cm). Some individuals may exceed this length.

Their body is a light gray with dark blotches along the spine and the sides. They also have a dark stripe on each side of their face and across their eye and a white stripe on their heads.   Some melanistic snakes are almost entirely black in color.

Massasaugas have a high-pitched rattle sound, which is different from other rattlesnakes. In fact, it’s more like the buzzing of an insect. This is why they have the nickname Buzz Tail.

Western Fox Snakes and Eastern Milk Snakes are non-venomous snakes in Minnesota. Both have similar color patterns to the Eastern Massasauga. Sometimes, when these snakes are agitated, they mimic the tail shake of a rattlesnake. The effect can be quite convincing if their tail is vibrating against dry leaves. However, neither of these harmless species actually have rattles. They also lack the triangle-shaped head of a pit viper,

Where Do Eastern Massasauga Rattlesnakes Live in Minnesota?

There are very few Eastern Massasaugas living in the North Star state. According to the Minnesota Department of Natural Resources, the Eastern Massasauga is endangered. This is due to habitat loss.

The extant Eastern Massasaugas are in southeast Minnesota in Wabasha County. They inhabit wet habitats. These include forested swamplands, marshy grassy areas, and lake edges. They also inhabit dry prairie and woodlands.

Wintertime Brumation

Snakes do not tolerate cold winters very well. They are ectotherms, which means they cannot regulate their body temperature internally. Physiologically, ectotherms cannot hibernate. Yet, they go into a state of suspended animation called brumation for up to 7 months out of the year.

Most snakes spend the winter in communal dens. Eastern Massasaugas do not. These snakes spend the winter alone or in groups of two or three. They use places such as crayfish burrows or small animal burrows as hibernacula.

Only about 70% of adults and 38% of neonate Eastern Massasaugas survive from year to year. Many of the mortalities that occur take place over the winter. Source

What Do Eastern Massasauga Rattlesnakes Eat?

Eastern Massasaugas prey on smaller rodents such as mice and voles. They also eat frogs, toads, and small snakes.

How Dangerous Are Eastern Massasauga Rattlesnakes?

The venom of the Eastern Massasauga rattlesnake is cytotoxic. Cytotoxic venom destroys body tissue. Moreover, digestive enzymes in cytotoxic venom disrupt blood flow and prevent clotting. Massasauga bites to humans are rare. However, they do occur.

There are two documented deaths in Ontario from Eastern Massasauga bites. In each case, the victim did not receive antivenom in time. Source

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Also see:

Wild Cats in Minnesota – Krebs Creek

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Symptoms of Venomous Snake Bites

Some of the symptoms you may experience when a venomous snake bites you include:

• Discoloration in the area of the bite.
• Swelling in the area of the bite.
• Loss of muscle coordination.
• Tingling sensation in the area of the bite.
• Feeling nauseous.
• Having a faster heartbeat or rapid pulse.

What Should You Do if You Are Bitten?

If you or someone you are with has suffered a venomous snakebite, time is of the essence. Because the sooner a victim receives antivenom, the less chance the venom in their body has to cause harm. In other words, it is important to seek immediate medical attention.

Do not attempt to kill the snake for identification purposes. This gives the snake a chance to bite you again. Also, consider that severed snakeheads can still bite and envenomate and often do. If you have a phone, take a picture of the offending reptile. Otherwise, get started on your way to the nearest hospital.

First Aid for Snake Bite Victims

• The best thing you can do is remain calm and limit your movements. Do not run. If you must hike back to a vehicle, do it calmly and deliberately. Put as little stress on your heart as possible.
• Keep the area of the snake bite below the heart level and never above the heart level. Keeping the bite below the heart level will reduce the venom’s flow. However, holding the bite above your heart level will increase the venom’s flow.

• Remove all constricting items such as bracelets, watches, or rings before swelling occurs.
• Remember that using a cold compress on a venomous snake bite is not advisable. The cold may cause the local blood vessels to constrict and spread the venom faster.
• You can wash the affected area like any other wound with soap and water.
• You may cover the bite area with a moist dressing to reduce the swelling.

• Get prompt medical treatment. Call the hospital to tell them a venomous snake has bitten you. So they can have antivenom ready to give you when you arrive.
• A person whom a venomous snake has bitten may go into shock. If this happens, lay them flat and cover them with a blanket.

Dressing for Snake Country

• It’s a good idea to wear high-top leather boots and long pants.
• Also, wear loose-fitting denim. If there’s a gap before the snake’s fangs touch your skin, your chances of being envenomated are lower.
• In the absence of high-top leather boots, some people wear snake gaiters.

In Conclusion

Timber Rattlesnakes and Eastern Massasaugas are notable residents of Minnesota. Stay vigilant in snake-prone areas. Also, appreciate their role in nature and share this knowledge. Your awareness contributes to a safer coexistence. Thanks for exploring the world of venomous snakes with us!