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The Eastern diamondback is one of the largest North American snakes, with a record length of 8 feet. However, they are usually 33 to 72 inches in length. The snake has a large head and a bulky body. It has a row of large dark diamonds with brown centers and cream borders down its back. The ground color of the body ranges from olive, to brown, to almost black. The tail is usually a different shade, brownish or gray, and banded with dark rings. At the end of the tail is a well-developed rattle. The head has a light bordered dark stripe running diagonally through the eye. The pupil is vertical (catlike). There is a large pit between the nostril and eye. The young are similar to the adults in color pattern. The tip of the tail of a newborn diamondback ends in a button, which is the first segment of the future rattle. Male and female rattlesnakes look alike. (Conant and Collins 1998, Ashton and Ashton 1985)
Average lifespan
Status: captivity: 22.8 years.
The Eastern Diamondback resides in the palmetto flatwoods and dry pinelands of the South. It generally avoids marshes and swamps, but on occasion will live near the borders of wetlands. Occasionally it may venture into salt water, swimming to the outlying Keys off the Florida coast. (Conant and Collins 1998, Ashton and Ashton 1985)
Terrestrial Biomes: chaparral ; forest
The Eastern Diamondback lives in the coastal lowlands, ranging from southeast North Carolina to eastern Louisiana, and throughout Florida, including the Florida Keys. (Conant and Collins 1998)
Biogeographic Regions: nearctic (Native )
The Eastern diamondback feeds primarily on small mammals, from mice to rabbits. It will also eat birds. Young diamondbacks feed primarily on rats and mice, while adults prefer larger prey like rabbits and squirrels. The snakes lie waiting for prey beside logs or near the roots of fallen trees. Diamondbacks locate their prey by odor, as well as by sensing the infrared waves (heat) given off by their warm-blooded prey. Once found, the prey is bitten. The prey is released after the strike, and is then allowed to crawl away and die. The snake will pursue the prey, eating it once it is dead. (Ashton and Ashton 1985, King 1996)
This snake is extremely beneficial to man. It preys on rats, mice, rabbits, and other small mammals, many of which are pests to humans. (Ashton and Ashton 1985)
Though not endangered, the Eastern Diamondback is clearly in trouble. The snake is rapidly disappearing from many areas in which it formerly occupied. Suburban housing and agricultural development destroys vast areas of habitat for the rattlesnake. Most snakes are killed on sight when found by humans. 'Rattlesnake roundups' held annually in several states of the U.S. further decrease their numbers. Crotalus adamanteus is regulated in North Carolina, a permit is required to
collect it, and in Florida a permit is needed to possess all vcenomous snakes. (King 1996, Georgia Wildlife Federation 1999, Levell 1997)
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
The Eastern Diamondback is a large, impressive, and potentially dangerous snake. It can strike up to 2/3 its body length; a 6-foot specimen may strike 4 feet. The venom of the diamondback is potent. When severely bitten, the mortality rate for humans is nearly 40 percent. The symptoms of diamondback venom include pain, swelling, weakness, breathing difficulty, weak pulse, heart failure, shock, and sometimes convulsion. This is a snake that should be left alone and not molested. (Ashton and Ashton 1985)
Eastern Diamondbacks mate in the late summer and fall. The size of the brood ranges from 6 to 21 young. The gestation period is six to seven months. Young are born live, in retreats such as gopher tortoise burrows or hollow logs. At the time of birth, the baby snakes are 15 inches long. The snakes can live 20 years or more. (Georgia Wildlife Federation 1999)
One of the largest of the snakes in North America, and the largest of the 32 known rattlesnake species, the eastern diamondback (Crotalus adamanteus) is endemic to the Southeastern United States.It inhabits coastal lowlands up to 500 meters (1500 feet) in elevation. The eastern diamondback currently occurs from southeast North Carolina to eastern Louisiana and throughout Florida. Historically its range was considerably larger and less patchy.
Eastern diamondbacks can reach lengths greater than 2.3 m (7 feet), though they usually range between 1-2 m (3-6 feet) long.A characteristic pattern of large, crisp, dark brown and cream-colored diamonds runs down its back.It has yellow stripes on either side of its head, running diagonally across the eye, and black and white bands adjacent to its rattle at the end of its tail.
Like most rattlesnakes, eastern diamondbacks live exclusively on the ground and rarely climb into vegetation. They inhabit upland forests, fields, scrub and hammocks, and less often swamps and marshes.Excellent swimmers, they have colonized the Keys and Atlantic and Gulf coast barrier islands. Eastern diamondbacks come out in mornings and afternoons, when they can frequently be found basking in the sun, and they hunt by night. These snakes sometimes actively forage but more often lie in ambush for small mammals including rabbits, rodents, squirrels and birds.They strike their prey with venomous fangs then wait until it is subdued before swallowing it, usually headfirst.In winter eastern diamondbacks hibernate in underground shelters, often using gopher tortoise or armadillo burrows.The same holes are reused multiple years.
Eastern diamondbacks mate in the late summer and fall, and females hold fertilized eggs internally while they develop, 6-7 months.The mother then gives birth to live-born young in gopher tortoise burrows or hollow logs. The brood usually numbers 16-21 babies. Newborn snakes are about 38 cm (15 inches) long. Just hours after birth they are self-sufficient. The young look very similar to adults, but instead of a rattle they have a “button” at the tip of their tail. This button is the first segment from which their rattle will develop. With each shedding of its skin, an eastern diamondback adds a subsequent segment to their rattle.
After birth, diamondback littermates aggregate together, piling on top of each other until their first molt, which occurs about 10 days later. This aggregation behavior may help newborns reduce water loss through their neonatal skin. Aggregation may also allow siblings to learn conspecific scents, which helps them follow trails to den localities later in life. Some evidence suggests that the mother stays with, or at least near, her litter for this time. After their first molt, young diamondbacks become independent.
Eastern diamondbacks can live more than 20 years.Young snakes, however, experience high mortality.Predators include birds of prey, owls, and other snakes such as the indigo snake (Drymarchon corais) and the eastern kingsnake (Lampropeltis getulus).
Humans are clearly the most significant enemy of the diamondback.These snakes are highly vulnerable to urban/suburban development, agriculture, tree farming and fire suppression, activities that have destroyed or altered the habitat and shelters upon which they are dependent. A history of hunting eastern diamondbacks for their skins and general persecution (e.g. “rattlesnake roundups” which include gassing of gopher tortoise holes) along with little legal protection has also decreased diamondback numbers considerably. Late maturity, low reproduction rate, and relative large ranges exacerbate their vulnerability to human activities.
Crotalus adamanteus is not usually an aggressive species, and defensively shakes its rattle tail to warn aggressors before it strikes.However, this snake is powerful and if provoked can deliver an extremely painful bite, potentially fatal to humans.Diamondbacks have long fangs that hold a large yield of venom.The venom includes the hemorrhagic protein crotolase, hemotoxins that cause tissue damage, and proteins that interrupts neurotransmission.Several effective antivenoms are available, including CroFab and Antivenin Crotalidae Polyvalent (ACP).
Eastern Diamondbacks are not listed as endangered, but their range and numbers have decreased sharply since the 1960s. This snake is rare or almost extirpated the edges of its range (especially North Carolina and Louisiana), although still locally common in suitable habitat in some areas of Georgia and South Carolina. Florida holds its largest population.
(Butler et al. 1995; Hammerson 2007; Hoss et al. 2010; National Geographic 1996-2016; Wikipedia 2016)
Eastern diamondback rattlesnake
Southeastern USA: along the Gulf Coast from southeastern Louisiana and southern Mississippi eastward through peninsular Florida, including the Florida Keys, northward along the coastal plain to southeastern North Carolina (McDiarmid, et al. 1999)
Types: None designated.
Type-locality: Not specifically stated in original description. Proposed by Schmidt, Check List N. Am. Amph. Rept., 6th ed., 280pp.[230] (McDiarmid et al., 1999).
The eastern diamondback rattlesnake (Crotalus adamanteus)[3][4] is a species of pit viper in the family Viperidae. The species is endemic to the Southeastern United States. It is one of the heaviest venomous snakes in the Americas and the largest rattlesnake. No subspecies are recognized.[5]
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The eastern diamondback rattlesnake is the largest rattlesnake species and is one of the heaviest known species of venomous snake, with one specimen shot in 1946 measuring 2.4 m (7.8 ft) in length and weighing 15.4 kg (34 lb). However, other venomous snakes may rival this species in weight such as the much longer but more slender king cobra and the shorter but even bulkier Gaboon viper.[6][7][8] Maximum reported lengths for the eastern diamondback rattlesnake are 2.4 m (8 ft)[9] and 2.5 m (8.25 ft).[10][11] However, the stated maximum sizes have been called into question due to a lack of voucher specimens.[12][13] Males are typically larger than females, which is rare among snakes (females are usually larger than males).
Specimens over 2.1 m (7 ft) are rare, but well documented. Klauber (1998) included a letter he received from E. Ross Allen in 1953, in which Allen explains how for years he offered a reward of $100, and later $200, for an 2.4 m (8 ft) specimen, dead or alive. The reward was never claimed. He did receive a number of 2.1 m (7 ft) range specimens and some 2.4 m (8 ft) skins, but said such skins can be taken from specimens as short as 1.8 m (6 ft).[3] A 2.2 m (7.3 ft) specimen was caught and killed outside a neighborhood in St. Augustine, Florida in September 2009.[14]
The average size is much less. Specimens are rarely found over 6 feet in length. Lengths of 1.1 to 1.7 m (3.5 to 5.5 ft),[15] and 0.8 to 1.8 m (2.75 to 6 ft) are given.[16] One study found an average length of 1.7 m (5.6 ft) based on 31 males and 43 females.[17] The average body mass is roughly 2.3 kg (5.1 lb).[18] The average weight of 9 laboratory-kept specimens was 2.55 kg (5.6 lb), with a range of 0.8 to 4.9 kg (1.8 to 10.8 lb).[19][20] Few specimens can exceed 5.12 kg (11.3 lb), although exceptional specimens can weigh 6.7 kg (15 lb) or more.[21][22]
The scalation includes 25–31 (usually 29) rows of dorsal scales at midbody, 165–176/170–187 ventral scales in males/females and 27–33/20–26 subcaudal scales in males/females, respectively. On the head, the rostral scale is higher than it is wide and contacts two internasal scales. There are 10–21 scales in the internasal-prefrontal region and 5–11 (usually 7–8) intersupraocular scales. Usually, there are two loreal scales between preoculars and the postnasal. There are 12–17 (usually 14–15) supralabial scales, the first of which is in broad contact with the prenasal, and 15–21 (usually 17–18) sublabial scales.[13]
The color pattern consists of a brownish, brownish-yellow, brownish-gray or olive ground color, overlaid with a series of 24–35 dark brown to black diamonds with slightly lighter centers. Each of these diamond-shaped blotches is outlined with a row of cream or yellowish scales. Posteriorly, the diamond shapes become more like crossbands and are followed by 5–10 bands around the tail. The belly is a yellowish or cream-colored, with diffused, dark mottling along the sides. The head has a dark postocular stripe that extends from behind the eye backwards and downwards to the lip; the back of the stripe touches the angle of the mouth. Anteriorly and posteriorly, the postocular stripe is bordered by distinct white or yellow stripes.[13] The rattle at the end of their tail is made of hard, loosely attached, hollow segments which break off frequently and are completely replaced when the snake sheds.[23]
Other common names for this snake species include eastern diamond-backed rattlesnake,[5] eastern diamondback,[4] diamond rattlesnake, diamond-back rattlesnake, common rattlesnake, diamond-back, diamond(-patch) rattler, eastern diamond-back (rattlesnake), eastern diamond rattlesnake, Florida diamond-back (rattlesnake), Florida rattlesnake, lozenge-spotted rattlesnake, rattler, rattlesnake, southeastern diamond-backed rattlesnake, southeastern diamond-backed rattler, southern woodland rattler, timber rattler, water rattle, water rattlesnake,[17] and diamondback rattlesnake.[3]
The eastern diamondback rattlesnake is found in the Southeastern United States from southeastern North Carolina, south along the coastal plain through peninsular Florida to the Florida Keys, and west along the Gulf Coast through southern Alabama and Mississippi to southeastern Louisiana. The original description for the species does not include a type locality, although Schmidt (1953) proposed it be restricted to "Charleston, South Carolina" (USA).[2]
This snake species is classified as Least Concern on the IUCN Red List (v3.1, 2001).[1] Species are listed as such owing to their wide distribution or presumed large population, or because they are unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend was down when assessed in 2007.[24]
In North Carolina, the eastern diamondback rattlesnake is protected by state law and considered endangered within the state.[25] It is likely extirpated in Louisiana, having last been observed there in 1995. In fact some scientists and conservationists believe it may even be extirpated in North Carolina, having last been observed there in the early 1990s.[26][27]
This species is currently under review for being added to the Endangered Species List by the United States Fish and Wildlife Service owing to its recent decline,[28] and the current population represents only 3% of the historical population.[29]
Threats to eastern diamondback rattlesnake include habitat loss, killing by humans, and highway mortality. Rattlesnake roundups are another threat to this species, as they are removed from the wild and killed for exhibition and entertainment. One common method of capture at these events involves pouring gasoline down a rattlesnakes supposed burrow, a practice which is harmful to both the snake and its environment. [30]
The eastern diamondback rattlesnake inhabits upland dry pine forest, pine and palmetto flatwoods, sandhills and coastal maritime hammocks, longleaf pine/turkey oak habitats, grass-sedge marshes and swamp forest, cypress swamps, mesic hammocks, sandy mixed woodlands, xeric hammocks, and salt marshes, as well as wet prairies during dry periods. In many areas, it seems to use burrows made by gophers and gopher tortoises during the summer and winter.[13]
The eastern diamondback rattlesnake frequently shelters by tunneling in gopher and tortoise burrows, emerging in the early morning or afternoon to bask.[31] Some research shows that these snakes spend less time underground during their active seasons.[32]
Like most rattlesnakes, this species is terrestrial and not adept at climbing. However, it has on occasion been reported in bushes and trees, apparently in search of prey. Even large specimens have been spotted as high as 10 m (33 ft) above the ground.[3]
It is also known to be an excellent swimmer. Specimens have often been spotted crossing stretches of water between barrier islands and the mainland off the Georgia coast, in the Gulf of Mexico and in the Florida Keys, sometimes miles from land.[3]
Individual disposition varies, with some allowing close approach while remaining silent, and others starting to rattle at a distance of 6–9 m (20–30 ft).[16] The rattle is well developed and can be heard from relatively far away. When threatened, it raises the anterior half of the body off the ground in an S-shaped coil, and can strike to a distance of at least a third of its body length.[33] Many will stand their ground and may strike repeatedly, but if given the opportunity, they will usually retreat while facing the intruder and moving backwards towards shelter, after which they disappear.[3][31][33]
One popular myth is that the eastern diamondback rattlesnake must rattle before striking. To the contrary, it is quite capable of striking while remaining completely silent.[34]
Hawks, eagles, and other snakes have been known to prey upon young and adolescent specimens of the eastern diamondback rattlesnake.
The eastern diamondback rattlesnake forages actively or lies in ambush for small mammals, especially rabbits and rice rats (Oryzomys). The diet also includes birds. Prey is struck and released, after which the snake follows the scent trail left by the dying prey.[31]
Because of their large size, adults have no problem eating prey as large as fully grown cottontail rabbits. As the juveniles are capable of swallowing adult mice, they do not often resort to eating slimmer prey, such as lizards. In fact, eastern cottontails and marsh rabbits (Sylvilagus) form the bulk of the diet in most parts of Florida. Squirrels, rats, and mice are also eaten, along with birds such as towhees and bobwhite quail. Other prey that have been reported include a king rail, a young wild turkey, and a mother woodpecker along with four of her eggs.[3] It also eats large insects.
Rattlesnakes, including the eastern diamondback, are ovoviviparous. Gestation lasts six or seven months and broods average about a dozen young. However, the young only stay with the mother 10–20 days before they set off on their own to hunt and find cover.
Females give birth to between 7 and 21 young at a time, usually between July and early October. Neonates are 30–36 cm (12–14 in) in length[35] and are similar in appearance to the adults, except for having only a small button instead of a rattle on the tip of their tails.[33]
The eastern diamondback can live beyond 20 years, but life expectancy in the wild is now typically shorter because of hunting and human expansion.
Adult wild-caught specimens are often difficult to maintain in captivity, but captive-born individuals do quite well and feed readily on killed laboratory rodents. The eastern diamondback requires a dry and well-ventilated cage with a hide-box, maintained at a temperature of 23–27 °C (73–80 °F) for normal activity.[31]
The eastern diamondback rattlesnake has the reputation of being the most dangerous venomous snake in North America.[35] While not usually aggressive, it is large and powerful. Wright and Wright mentioned a mortality rate of 30%, but other studies show a mortality rate of 10–20% (untreated).[17][36]
In proportion to its length, it has the longest fangs of any rattlesnake species, with calculations leading one to expect an 2.4-meter (8 ft) specimen would have fangs with a total length of over 25 mm (1 in). For comparison, a 1.5-meter (5 ft) specimen had fangs measuring 17 mm (2⁄3 in) in length.[3] It has a very high venom yield, an average of 400–450 mg, with a maximum of 858–1,000 mg.[37] Brown gives an average venom yield of 410 mg (dried venom), along with LD50 values of 1.3–2.4 mg/kg IV, 1.7–3.0 mg/kg IP and 14.5–10 mg/kg SC for toxicity.[38] The estimated human lethal dose is 100–150 mg.[37]
The venom contains a thrombin-like enzyme, "crotalase", capable of clotting fibrinogen, leading to the secondary activation of plasminogen from endothelial cells. Although the venom does not activate platelets, the production of fibrin strands can result in a reduced platelet count, as well as the hemolysis of red blood cells (see article on MAHA). Even with this defibrination, however, clinically significant bleeding is uncommon.[39] Nevertheless, the venom does exhibit high hemorrhagic activity.[40] It also contains a low-molecular-weight basic peptide that impedes neuromuscular transmission[41] and can in theory lead to cardiac failure. This peptide is similar to crotamine from C. durrisus terrificus, and makes up 2–8% of the protein found in the venom. In general, the venom can be described as highly necrotizing, mildly proteolytic and containing a large phosphodiesterase fraction. It stimulates the release of bradykinin that can result in severe pain, as well as profound, transient hypotension.[37]
Klauber described one case in which the symptoms included instant pain "like two hot hypodermic needles", spontaneous bleeding from the bite site, intense internal pain, bleeding from the mouth, hypotension, a weak pulse, swelling and discoloration of the affected limb, and associated severe pain. The symptoms were further described as strongly hemolytic and hemorrhagic.[3]
CroFab, ANAVIP, and Wyeth's ACP are effective antivenins against bites from this species, although massive doses may be needed to manage severe cases of envenomation. Generally, ACP is very effective at countering the defibrination syndrome that is often seen, but may do little for low platelet counts. Wyeth's ACP is no longer being manufactured.[37]
{{cite web}}: Cite uses generic title (help) {{cite journal}}: Cite journal requires |journal= (help) The eastern diamondback rattlesnake (Crotalus adamanteus) is a species of pit viper in the family Viperidae. The species is endemic to the Southeastern United States. It is one of the heaviest venomous snakes in the Americas and the largest rattlesnake. No subspecies are recognized.
