Timber Rattlesnake (Crotalus horridus): Facts, Range and Dens

What does a timber rattlesnake look like?

The timber rattlesnake has a broad, triangular head, a thick body and rough, keeled scales, meaning each scale has a raised ridge down its center. Like all pit vipers, it has vertical pupils and a heat-sensing pit on each side of the face between the eye and the nostril. The tail is solid black, giving it the old nickname “velvet tail”, and ends in a rattle of hollow keratin segments.

The back is marked with dark, jagged crossbands that often form V or M shapes, pointing toward the head. The background color varies widely, and biologists describe two main color phases in the North:

• Yellow phase: a yellow, tan or light brown background with dark brown or black bands.
• Black phase: a dark gray to nearly black background, sometimes so dark that the bands are hard to see.

In the Southeast, timber rattlesnakes, often called canebrake rattlesnakes, are usually paler gray, tan or pinkish, with a reddish-brown stripe down the middle of the back. A snake keeps the same color and pattern throughout its life.

How big do timber rattlesnakes get?

Adults usually measure 91–152 cm (36–60 in) in total length, and most are under about 115 cm (45 in). The record length is about 189 cm (74.5 in). Males grow larger than females.

In the Northeast, the timber rattlesnake is the largest venomous snake.

Where do timber rattlesnakes live?

The timber rattlesnake lives only in the eastern United States today. Its range stretches from southern New Hampshire, Vermont and New York west to southeastern Minnesota, southwestern Wisconsin and southeastern Nebraska, and south to east Texas and north Florida. It once also lived in southern Ontario, but it has disappeared from Canada, as well as from Maine and Rhode Island.

Habitat changes from north to south. In the Northeast, Appalachians and Midwest, timber rattlesnakes live in rugged, wooded hills with rocky ledges and talus slopes, especially on sunny, south-facing hillsides. In the southeastern Coastal Plain and the lower Mississippi Valley, they live in lowland hardwood forests, river floodplains, cane thickets, swamp edges and pine woods.

Within its range it is patchy. It is common in some large forests of the Appalachians and the South but has vanished from many areas near cities and farmland. Our guide to venomous snakes in the US shows how it fits among the country’s other pit vipers.

What do timber rattlesnakes eat?

Timber rattlesnakes are ambush predators that eat mostly small mammals. Studies of their diet show that white-footed and deer mice are the most common prey, followed by voles, chipmunks, rabbits, cotton rats and squirrels. Birds, especially ground-dwelling species such as bobwhite quail, are taken occasionally.

A hunting snake uses its tongue to pick up the scent trails of rodents and then coils beside a fallen log or along a path where prey passes often. It may wait in the same spot for hours or even days. A well-known hunting posture is a coil beside a fallen log with the chin resting on top of it, ready to strike anything that runs along the log. When prey comes within range, the snake strikes, injects venom, lets go and then follows the scent trail of the dying animal before swallowing it whole, head first.

Winter dens and summer travels

In the northern and mountain parts of the range, timber rattlesnakes spend the winter in communal dens, usually deep crevices in rock outcrops or talus slopes that stay above freezing. A den may hold from a handful to several dozen rattlesnakes, often alongside copperheads and rat snakes. Most snakes return to the same den every year, and in the North they may stay there for up to seven months.

In spring the snakes emerge, bask near the den and then disperse into the surrounding forest. Many travel 2–4 km (1.3–2.5 mi) from the den, and some males roam up to about 8 km (5 mi) in search of females. In fall they return, often along the same routes. Newborn snakes appear to find the den by following the scent trails of adults. For more, see Where do timber rattlesnakes spend the winter?.

Reproduction and life cycle

Timber rattlesnakes reproduce extremely slowly. Females usually take about 5 to 13 years to mature, depending on the region and food supply, and in a long-term study in New York’s Adirondack Mountains the average age at first birth was nearly 10 years. After that, a female typically breeds only every 3 to 5 years, partly because she needs more than one active season to build up the fat reserves needed for a litter.

Mating takes place from midsummer into fall. Males follow the scent trails of females and sometimes engage in combat dances, rearing up and wrestling to push each other down. Females store the sperm over winter, and fertilization and development take place the following spring and summer.

Like all rattlesnakes, the timber rattlesnake gives birth to live young. Litters of about 4 to 14, usually 6 to 10, are born from late August to early October. Newborns have working fangs and venom and a single “button” at the tail tip. They stay near their mother for about one to two weeks, until their first shed, then disperse. Each shed adds a new rattle segment, but the end segments break off, so rattle length is not a reliable guide to age, as explained in Can you tell a rattlesnake’s age by its rattle?.

Venom and safety

The timber rattlesnake’s venom is potent, and because the snake is large with long fangs and a high venom yield, a bite is a serious medical emergency. Venom composition varies by region. Most northern snakes have venom that mainly damages tissue and blood, while some southern populations have a strong nerve-acting component known as canebrake toxin.

Despite this, timber rattlesnakes are famously mild-tempered. They rely on camouflage, usually lie still or crawl away when people pass, and often rattle long before any threat of striking. Most bites happen when someone steps on a snake, reaches into a crevice or tries to handle or kill one. In New York, the state wildlife agency reports no recorded human deaths from wild rattlesnakes in recent decades.

Keep at least 2 m (6 ft) away from any rattlesnake you see and let it move on. If anyone is bitten, call 911 or seek emergency medical help immediately.

Lifespan, predators and threats

Young timber rattlesnakes face high mortality, but adults are long-lived. Many adults live 15 to 20 years, some exceed 30 years in the wild, and captive snakes have lived about 37 years.

Young snakes are eaten by predators such as hawks, foxes, coyotes and snake-eating kingsnakes. Adults have few natural enemies. People are the main threat: through habitat loss and development, roads, illegal collecting for the pet trade, disturbance of dens and deliberate killing, which was once encouraged by bounties in places such as northern New York, where some counties paid for rattles until 1971. Snake fungal disease, an infection of the skin, has also been found in some northeastern populations.

Conservation status

The IUCN Red List classifies the timber rattlesnake as Least Concern (assessed in 2007), because it still has a very large range and many healthy populations, especially in the South and central Appalachians. It is not listed under the US Endangered Species Act.

At the edges of its range, the picture is very different. It is listed as endangered or threatened in about a dozen states, mostly in the Northeast and Midwest, and has been lost from Maine, Rhode Island and Canada. State-by-state details are in Are timber rattlesnakes endangered?.

Myths and facts

• Myth: Rattlesnakes chase people. Fact: timber rattlesnakes do not pursue or attack people. A snake that seems to come toward someone is usually trying to reach its cover, and the person happens to be in the way.
• Myth: A rattlesnake always rattles before it strikes. Fact: timber rattlesnakes often stay silent and motionless, trusting their camouflage, so a snake may not warn at all before someone steps close. See Do rattlesnakes always rattle before striking?.
• Myth: The canebrake rattlesnake is a different species. Fact: it is the same species; the name simply refers to the paler, southern lowland form.

Timber rattlesnakes in American history

Few snakes are as tied to American history. The coiled rattlesnake of the 1775 Gadsden flag, with its motto “Don’t Tread on Me”, is usually taken to be a timber rattlesnake, the species most familiar to the colonists of the eastern seaboard. In the same year, an anonymous essay in the Pennsylvania Journal, widely attributed to Benjamin Franklin, praised the rattlesnake as a symbol of America because it never attacks first but is dangerous when stepped on.

In 2008, West Virginia named the timber rattlesnake its official state reptile, after a campaign by middle school students. Rattlesnake symbols appear on other early American flags too, a reminder that the snake was once common across the region where the nation began.