timber rattlesnake
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What is a timber rattlesnake?
The timber rattlesnake (Crotalus horridus) is a venomous snake inhabiting low mountain ridges and upland woods in the eastern United States.
Adult timber rattlesnakes average 0.8 to 1.5 meters (2.6 to 5 feet) in length, but the largest males can reach 1.9 meters (6.2 feet). Their color can be golden yellow, grayish olive, or brown, and some are entirely black. They have brown or black wavy bands or chevrons across their bodies, and their tails are black.
Timber rattlesnakes are forest snakes that prey on small mammals and ground birds. They are listed as a species of least concern, but their populations are declining in some areas due to hunting and habitat loss.
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Where do timber rattlesnakes live?
The timber rattlesnake (Crotalus horridus) lives in low mountain ridges and upland woods in the eastern United States. Their territory stretches from New Hampshire, down the Appalachian Mountains to northern Florida, and westward from southeastern Minnesota to southeastern Texas. Timber rattlesnakes were last seen in southern Ontario, Canada, in 1941.
These snakes are forest dwellers, found basking on south-facing rocky slopes during the spring and fall. They also forage in fields, pastures, and farms, and near old stone fences. In late summer and fall, they gather on mountain slopes to hibernate in rock crevices.
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What do timber rattlesnakes eat?
The timber rattlesnake (Crotalus horridus) preys on small mammals and ground birds. They forage for food in fields, pastures, and farms, and along old stone fences.
Timber rattlesnakes use their forked tongues to perceive scents. They station themselves with their heads resting on their coils or on logs that serve as mammal runways, ready to ambush passing animals. In the heat of summer, they hunt at night, locating prey with the aid of their pit organs. Pit organs are a pair of sensory receptors at the sides of their heads that can detect infrared radiation given off by the body heat of their victims.
Young and small rattlesnakes feed largely on lizards.
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How does a timber rattlesnake use its rattle?
The timber rattlesnake uses its rattle as a warning device. The rattle is located at the tip of its tail and makes a buzzing sound when vibrated. This specialized structure is made up of loosely connected, hollow segments, with a new segment added each time the snake sheds its skin. Though it was once believed that you could tell the age of a rattlesnake by the number of segments, rattlesnakes typically shed multiple times a year. When threatened, the timber rattlesnake rapidly vibrates its tail, creating a distinctive rattling sound to deter potential predators.
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Why is the timber rattlesnake considered venomous?
The timber rattlesnake (Crotalus horridus) is considered venomous because it uses a bite to inject toxins. As a pit viper, it has large venom glands that give its head a triangular shape. Its fangs, similar to curved hypodermic needles, are connected to venom ducts. When threatened or hunting, the timber rattlesnake can deploy these fangs to inject venom into its prey or any potential threat. Though timber rattlesnake bites are rarely fatal, they should be assessed by a medical professional.
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What challenges threaten timber rattlesnakes in the wild?
Timber rattlesnakes face several challenges in the wild. Although the International Union for Conservation of Nature and Natural Resources (IUCN) considers them a species of least concern, local populations are declining due to hunting and collecting, habitat loss, and vehicle strikes. The snakes are becoming increasingly scarce in the northeastern United States, and populations near agricultural, residential, and urban areas are declining due to habitat loss and human persecution.
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timber rattlesnake, (Crotalus horridus), species of venomous North American snakes classified in the family Viperidae that inhabit low mountain ridges and upland woods in the eastern United States. Its range extends from New Hampshire along the Appalachian Mountains to northern Florida and, on its western edge, from southeastern Minnesota to southeastern Texas; the snake’s range once extended into southern Ontario, Canada, but was last observed there in 1941. Bites from a timber rattlesnake result in envenomation of the victim about 50 percent of the time; however, they are rarely fatal.
Natural history
The average adult length ranges from about 0.8 to 1.5 meters (about 2.6 to 5 feet), though the largest males can grow as long as 1.9 meters (6.2 feet). The head is broadly triangular due to the presence of large venom glands and their associated muscles. The neck is narrow, the body stout, and the tail blunt, ending in a rattle. Small scales cover the head, and the eyes have vertically slit pupils. Body coloration may be golden yellow, grayish olive, or brown; some snakes are entirely black. The head usually has no markings; however, the heads of some individuals may be accented by a dark diagonal line. The snake has markings across the body, with brown or black wavy bands or chevrons, some of which may be edged in pale yellow. The tail is black. A southern variant called the canebrake rattlesnake, which is classified by a handful of taxonomies as the subspecies C. horridus atricaudatus, has the same body pattern with the addition of an orange, yellow, pinkish, brownish, or reddish stripe along the back and a dark diagonal stripe on the sides of the head.
The timber rattlesnake is a forest snake. In spring and fall it may be found basking on south-facing rocky slopes. It preys on small mammals and ground birds, foraging in fields, pastures, and farms and along old stone fences. It perceives scents with its forked tongue and stations itself with its head resting on its coils or on logs that serve as mammal runways, ready to ambush passing animals. In the heat of summer it hunts at night, locating prey with the aid of its pit organs, a pair of sensory receptors at the sides of its head that can detect infrared radiation given off by the body heat of its victims.
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In late summer and fall, large numbers of timber rattlers gather on mountain slopes to hibernate in rock crevices. Most mating occurs during this time, but some may occur when the snakes emerge in spring. The timber rattlesnake is ovoviviparous, meaning that fertilized eggs are retained within the female’s body and young are born alive. Females become sexually mature between ages 7 and 13—which is significantly later than males, which become sexually mature between ages 4 and 6—and bear up to 20 live young every 2 to 6 years. Young timber rattlesnakes, which are generally 19.5–32 cm (7.7 to 12.6 inches) long, are born between July and October, and they remain with their mother for about one week before dispersing. Timber rattlesnakes can live as long as 30 years in the wild and as long as 37 years in captivity.
Snakebites
Although the snake is considered dangerous, it is not aggressive. It rarely bites, unless startled or stepped on, preferring to give prolonged warning rattles instead. Defensive bites delivered to human beings can introduce a mix of toxins that can result in death in up to 10 percent of untreated victims. So tenacious is the snake’s bite that the snake became a national symbol in the United States. Flags of the American Revolution and later the Gadsden flag portrayed a coiled timber rattlesnake with 13 segments on its rattle and the motto “Don’t tread on me.”
Conservation status
The International Union for Conservation of Nature and Natural Resources (IUCN) considers the timber rattlesnake to be a species of least concern. Although ecologists estimate that the entire timber rattlesnake population numbers more than 100,000 adults and that its range is very large, studies have shown that local populations throughout its geographic range are declining because of hunting and collecting, habitat loss, and vehicle strikes. Since the 1990s the timber rattlesnake is becoming more scarce in the northeastern United States; populations in New York, for example, fell by 80 to 85 percent between the 1940s and 1980s. Although the snake was listed as a threatened species in New York in the early 1980s, the population’s recovery since then has been slow or nonexistent, with some studies noting that populations continue to fall, albeit slowly, in many areas of the state. The southern parts of the snake’s range are characterized by populations of mixed success, with subpopulations in some areas thriving and those near agricultural, residential, and urban areas declining from habitat loss and human persecution.