Crotalus horridus
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Crotalus horridus Linnaeus, 1758 |
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Crotalus horridus is a venomous pitviper species found in the eastern United States. No subspecies are currently recognized.[3] This is the only rattlesnake species in most of the populous northeastern United States[4] and was featured prominently in the American Revolution, specifically as the symbol of the first Continental Navy in the First Navy Jack.
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[edit] Description
Adults usually grow to an average length of 91-152 cm (35.8-59.8 in).[4] The maximum reported length is 189.2 cm (74.5 in)(Klauber, 1956). Holt (1924) mentions a large specimen caught in Montgomery County, Alabama, that had a total length of 159 cm (62.6 in) and weighed 2.5 kg (6.7 lb).[5]
The dorsal scales are keeled[6] and arranged in 21-26 scale rows at mid-body (usually 25 in the south and 23 in the north). The ventral scales number 158-177 in males and 163-183 in females. Males have 20-30 in males subcaudal scales while females have 15-26. The rostral scale is normally a little higher than it is wide. In the internasal-prefrontal area there are 4-22 scales that include 2 large, triangular internasal scales that border the rostral, followed by 2 large, quadrangular prefrontal scales (anterior canthals) that may contact each other along the midline, or may be separated by many small scales. Between the supraocular and internasal, only a single canthal scale is present. There are 5-7 intersupraocular scales. The number of prefoveal scales varies between 2 and 8. Usually the first supralabial scale is in broad contact with the prenasal scale, although slightly to moderately separated along its posteroventral margin by the most anterior prefoveals.[5]
[edit] Common names
Timber rattlesnake, banded rattlesnake, American viper, bastard rattlesnake, black rattlesnake, canebraker, cane rattler, canebrake rattlesnake, canebrake rattler, chevron rattler, common rattlesnake, common (timber) rattlesnake, eastern rattlesnake, great yellow rattlesnake, mountain rattlesnake, mountain timber rattler, North American (horrid) rattlesnake, northern banded rattlesnake, northern rattlesnake, pit viper, rattlesnake, rattlesnake of the bottomlands, rock rattlesnake, Seminole rattler, small rattlesnake, swamp rattler, southern banded rattlesnake, velvet tail, velvet-tail rattler, yellowish brown rattlesnake, yellow rattlesnake.[2]
[edit] Geographic range
Found in the eastern United States from southern Minnesota and southern Maine, south to east Texas and north Florida. It also occurs in southern Canada in southern Ontario. The type locality given is "America", although Schmidt (1953) proposed that this be restricted to "vicinity of New York City" (USA).[1].
[edit] Conservation status
This species is classified as Least Concern (LC) on the IUCN Red List of Threatened Species (v3.1, 2001).[7] Species are listed as such due to their wide distribution, presumed large population, or because it is unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend is down. Year assessed: 2007.[8]
It is also listed as threatened or endangered in 18 states. It is endangered in Indiana, New Jersey, and Ohio, threatened in Illinois, Minnesota and Texas, and protected in Wisconsin and Massachusetts. In May 2001, the Canadian Species at Risk Act listed it as extirpated in Canada.[9]
Numbers have declined largely due to a history of bounty hunting and collecting (in the past). Today, loss of habitat is the primary concern over declining populations in several states protecting the species.
Environmentalists in the New Jersey Pinelands have fought development in rattlesnake sanctuaries. A controversy over the species in Evesham Township, NJ, was the inspiration for the 2006 novel, "Rattled," by Debra Galant (St. Martin's Press).
[edit] Habitat
Generally, this species is found in deciduous forests in rugged terrain. During the summer, gravid females seem to prefer open, rocky ledges where the temperatures are higher, while males and non-gravid females tend to spend more time in cooler, denser woodland with a more closed forest canopy.[10]
[edit] Feeding
Their prey is mainly small mammals, but may include small birds, frogs, or other snakes.[10]
[edit] Venom
Potentially, this is one of North America's most dangerous snakes, due to its long fangs, impressive size and high venom yield. Fortunately, this is to some degree offset by its relatively mild disposition.[11] Before striking, they often do a good deal of preliminary rattling and feinting.[12] Cist (1845) described how he lived in western Pennsylvania for many years and that the species was quite common there, but that in all that time he heard of only a single death resulting from its bite.[2]
There is considerable geographic and ontogenetic variation regarding the toxicity of the venom; something that can be said for many rattlesnake species. Four venom patterns have been described for this species: Type A is largely neurotoxic and is found in various parts of the southern range. Type B is hemorrhagic and proteolytic and is found consistently in the north and in parts of the southeast. Type A + B is found in areas where the aforementioned types apparently intergrade in southwestern Arkansas and northern Louisiana. Type C venom has none of the above components and is relatively weak.[11]
The neurotoxic component of the Type A venom is referred to as canebrake toxin, and is a phospholipase A2. It is analogous to the neurotoxins found in the venoms of several other rattlesnake species and, when present, contributes significantly to the overall toxicity. Other components found in the venom include a small basic peptide that works as a myotoxin, a fibrinogen-clotting enzyme that can produce defibrination syndrome, and a bradykinin-releasing enzyme.[11]
CroFab antivenin, while not specific for C. horridus, is used to treat envenomations from this species.[13]
[edit] Taxonomy
The subspecies C. h. atricaudatus (Latreille in Sonnini and Latreille, 1802), often referred to as the canebrake rattlesnake,[2] is currently considered invalid.[14]
[edit] See also
- List of crotaline species and subspecies
- Crotalus by common name
- Crotalus by taxonomic synonyms
- Crotalinae by common name
- Crotalinae by taxonomic synonyms
- Snakebite
[edit] References
- ^ a b McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
- ^ a b c d Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates. (7th printing, 1985). 1105 pp. ISBN 0-8014-0463-0.
- ^ Crotalus horridus (TSN 174306). Integrated Taxonomic Information System. Retrieved on 8 February 2007.
- ^ a b Conant R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition. First published in 1958. Houghton Mifflin Company Boston. 429 pp. 48 plates. ISBN 0-395-19979-4. ISBN 0-395-19979-8 (pbk.).
- ^ a b Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. 2 volumes. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.
- ^ Behler JL, King FW. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf. 743 pp. LCCCN 79-2217. ISBN 0-394-50824-6.
- ^ Crotalus horridus at the IUCN Red List. Accessed 13 September 2007.
- ^ 2001 Categories & Criteria (version 3.1) at the IUCN Red List. Accessed 13 September 2007.
- ^ Crotalus horridus at Species at Risk Public Registry. Accessed 28 March 2008.
- ^ a b Timber Rattlesnake Fact Sheet at NY State Dept. of Environmental Conservation. Accessed 8 February 2007.
- ^ a b c Norris R. 2004. Venom Poisoning in North American Reptiles. In Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.
- ^ U.S. Navy. 1991. Poisonous Snakes of the World. US Govt. New York: Dover Publications Inc. 203 pp. ISBN 0-486-26629-X.
- ^ Crotalus horridus horridus at Munich AntiVenom INdex. Accessed 27 March 2008.
- ^ Crotalus horridus atricaudatus (TSN 174307). Integrated Taxonomic Information System. Retrieved on 27 September 2006.
[edit] External links
- Crotalus horridus at the TIGR Reptile Database. Accessed 12 December 2007.
- Timber Rattlesnake (Crotalus horridus) at Center for Reptile and Amphibian Conservation and Management. Accessed 8 February 2007.
- Timber Rattlesnake Crotalus horridus at Center for Reptile and Amphibian Conservation and Management. Accessed 8 February 2007.
- Timber Rattlesnake - Crotalus horridus at Herpnet.net, Reptiles and Amphibians of Iowa. Accessed 15 June 2007.
- Account of severe C. horridus envenomation at venomousreptiles.org. Accessed 12 December 2007.
- Canebrake Rattlesnake photos at Handyman Services in Durham, NC. Accessed 7 August 2007.
- Canebrake rattlesnake (Crotalus horridus) at Virginia Department of Game and Inland Fisheries. Accessed 7 August 2007.
- Snakes of Louisiana at Kingsnake.com. Accessed 7 August 2007.