Newborn Timber Rattlesnakes, often born well away from the overwintering den, follow the scent trails of adult snakes back to the den for hibernation (Brown and MacLean 1983, Reinert and Zappalorti 1988).
There are approximately 205 extant dens known in the state, but when interacting and potentially interacting populations are taken into consideration, the number of occurrences will be in the range of 35 to 60. Indiscriminate killing and unregulated collecting, including a past bounty system in some portions of the range, has resulted in many populations becoming extirpated or depleted in numbers in most areas where the species was once numerous. Bounties on Timber Rattlesnakes were outlawed in New York State in 1971, but even in areas without bounties, rattlesnakes were collected or severely persecuted by local residents in many areas. These factors, combined with a low reproductive potential, and current threats such as development, illegal collecting, and other disturbance factors will likely prevent or slow population recovery.
Declines and extirpation of some Timber Rattlesnake populations have been documented within the past 25 years and will likely continue to some degree given current threats.
Timber Rattlesnakes have been subjected to substantial reduction due to specimen collection and persecution during the past century and it is believed that denning populations in New York have been reduced by 50% to 75% of their historical numbers (Brown 1984, 1988). Management efforts focused on habitat protection and public education have somewhat stabilized the remaining populations, but loss of habitat continues to be a threat to the species.
Loss of habitat, habitat fragmentation, mining, road mortality, illegal collecting, persecution, and pathogenic organisms are all considered threats to Timber Rattlesnake populations.
Habitat fragmentation from development, logging, and illegal snake collecting and persecutions have impacted Timber Rattlesnake populations in New York. Fragmentation can be reduced by planning development that leaves contiguous undisturbed areas that includes dens, basking, gestating, and foraging areas. If contiguous habitat is not possible, then corridors would provide means for snakes to move between seasonally used habitats. Public education materials or public meetings in residential areas near rattlesnake habitat that informs residents of rattlesnake biology to help reduce misconceptions, fear, and accidental encounter advice. Nuisance response efforts aimed at moving rattlesnakes out of areas where they may be harmed are in effect in some areas and these efforts may be useful in other locations where homes are located within the summer foraging habitat. Logging should occur during the winter months when the snakes are hibernating. Some logging may be beneficial by opening basking and gestating habitats and remaining brush piles may provide cover and improved foraging opportunities (NatureServe 2019). There are still people that want to either illegally collect or harm rattlesnakes. Land managers should avoid disclosing known rattlesnake areas, especially dens, basking, and gestating areas. Recreational use trails should be routed to avoid these seasonally-used concentration areas. Some snakes may be sensitive to frequent visits by researchers (NatureServe 2019). Continuous disturbances may lead to abandonment. Studies should be carefully planned to minimize negative effects of site visits. Additionally, roads act as barriers by preventing snakes from moving freely in suitable habitat and reducing genetic exchange. Mortality increases as the volume of cars increase. Mortality can be decreased by reducing speed limits during active seasons, adding fencing that leads to culverts for safe passage under roads, and road closures when possible (Choquette and Valliant 2016). Vegetation thinning at den, basking, and gestating areas may be needed in areas that have become overgrown (NatureServe 2019).
Standardized survey protocols need to be developed and implemented at all known and potentially suitable sites to document the character, quality, and extent of occupied habitat. Additional research is needed to determine long-term effects of pathogens and ways to reduce irreversible population decline.
In the Northeast, this species inhabits mountainous or hilly deciduous or mixed deciduous-coniferous forests, often with rocky outcroppings, steep ledges, and rock slides (Petersen and Fritsch 1986, Brown 1993). Dens, or hibernacula, are located in rocky areas where underground crevices provide retreats for overwintering (Brown 1993). New York dens are often located in accumulations of talus below ledges or in fractures within or underneath ledges or rock outcrops. Rattlesnakes use open canopy, rocky areas for basking, shedding, gestating, and birthing. Foraging areas are generally located within forested habitat surrounding the den.
Although widespread in the state as a whole, Timber Rattlesnakes are now found in isolated or semi-isolated populations in southeastern New York, the southern tier, and the peripheral eastern Adirondacks. Populations were once found on Long Island and in most mountainous and hilly areas of the state, except for the higher elevations of the Adirondacks, Catskills, and the Tug Hill Plateau.
The Timber Rattlesnake ranges from central New England south to northern Florida and west to eastern Texas, central Oklahoma, eastern Kansas, southeastern Nebraska, southern and eastern Iowa, and southeastern Minnesota. The distribution is spotty along the western and northern edges of the range. Sizable populations still occur in the Appalachian Mountains from Pennsylvania though the Virginias, across eastern Kentucky and Tennessee to northeastern Alabama, in the Ouachita and Boston mountains of Arkansas and extreme eastern Oklahoma, in heavily wooded sections of the southeastern Coastal Plain from North Carolina to northeastern Florida and west to Louisiana and southern Arkansas, and in the Piedmont in the Uwharrie National Forest of central North Carolina and Pine Mountain of west-central Georgia (Martin, in Tyning 1992). The overwintering dens occur at elevations of up to about 5,000 feet in the southern Appalachians, 2,200 feet in southern New England, and about 1,300 feet in northeastern New York, Wisconsin, and Minnesota and individuals may range to higher elevations during the summer (Martin, in Tyning 1992).
This is a heavy bodied snake of forested uplands. The young measure approximately 12 inches at birth and adults range from 36 to 60 inches in length (Conant and Collins 1998). The coloration and pattern is highly variable geographically (Conant and Collins 1991) with two main color variations, yellow or black, found in New York. The yellow variation has a yellow head and body with black or dark brown crossbands and the crossbands, which may be "V"-shaped, may break up anteriorly to form a row of dark spots down the back and along each side of the body (Conant and Collins 1998). The black variation has a black head and body with black crossbands and a reddish mid-dorsal stripe may be present. Some individuals that are considered to be the black variation have black heads, yellow bodies, and dark crossbands. In some locations, completely black specimens are not unusual (Conant and Collins 1998). The scales have longitudinal keels giving the snake a rough textured appearance. Timber Rattlesnakes, like other pit-vipers, have a two heat-sensitive openings, or pits, situated below and between the eye and nostril. This sensory organ aids the snake in the detection of prey. As the name implies, rattlesnakes also have a rattle at the end of the tail that is made up of loosely attached segments. A new segment is added each time the snake sheds it skin, which is about 1.5 times per year. When disturbed, a rattlesnake will vibrate its tail, causing the loose segments to create a buzzing sound.
The presence of a rattle is the most useful diagnostic characteristic.
Adults may be easier to identify than newborn rattlesnakes, but in general the coloration and pattern of adults and young are similar, although newborn timber rattlesnakes may be more gray in color. Newborn timber rattlesnakes have a single rattle segment called a button.
In New York, Timber Rattlesnakes hibernate in communal dens, often with copperheads (also venomous), and other non-venomous snakes. Depending on the latitude and local weather conditions, hibernation generally begins from mid-September through late-October and continues through the winter until late-March through mid-May. During the active season, rattlesnakes will generally use forested habitats up to 2.5 miles (4 km) or greater from their overwintering dens for foraging and other activities. Mating takes place during late-July to early-August and the young are born in August or September of the subsequent year.
Timber Rattlesnakes mainly prey upon small rodents such as mice, chipmunks, and gray squirrels, but they will also take songbirds on occasion.
In general, Timber Rattlesnakes are active from late April until mid-October. In some locations, rattlesnakes may start to enter dens in mid-September and may not emerge until late-May, especially at more northern locations.
The time of year you would expect to find Timber Rattlesnake present and reproducing in New York.
Crotalus horridus Linnaeus, 1758
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This guide was authored by: Shaw, Hollie Y.
Information for this guide was last updated on: June 28, 2019
Please cite this page as:
New York Natural Heritage Program. 2020. Online Conservation Guide for Crotalus horridus. Available from: https://guides.nynhp.org/timber-rattlesnake/. Accessed March 31, 2020.