:''Common names: pygmy rattlesnake, eastern pygmy rattlesnake, ground rattlesnake, leaf rattler, death rattler,

more More or Mores may refer to: Computing * MORE (application), outline software for Mac OS * more (command), a shell command * MORE protocol, a routing protocol * Missouri Research and Education Network Music Albums * ''More!'' (album), by Booka S ...

.'' Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates, a Division of Cornell University Press. (7th printing, 1985). 1,105 pp. (in two volumes). . (''Sistrurus miliarius'', pp. 1052-1061). ''Sistrurus miliarius,'' commonly called the pygmy rattlesnake, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

venomous snake Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow or g ...

in the subfamily

Crotalinae The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfa ...

(pit vipers) of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Viperidae The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs th ...

. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the

Southeastern United States The Southeastern United States, also referred to as the American Southeast or simply the Southeast, is a geographical region of the United States. It is located broadly on the eastern portion of the southern United States and the southern por ...

. Three subspecies are currently recognized.

Description

''S. miliarius'' is a small species, with adults usually growing to in total length (including tail). The maximum reported total length is ( Klauber, 1972). Snellings and Collins (1997) reported a specimen of ''S. m. barbouri'' measuring , but it had been in captivity for over 12 years. The largest ''S. m. barbouri'' reported by Gloyd (1940) was a specimen measuring from

St. Petersburg, Florida St. Petersburg is a city in Pinellas County, Florida, United States. As of the 2020 census, the population was 258,308, making it the fifth-most populous city in Florida and the second-largest city in the Tampa Bay Area, after Tampa. It is the ...

. Shine (1978) suggested that in some populations, males may be larger than females, but a later study by

Bishop A bishop is an ordained clergy member who is entrusted with a position of authority and oversight in a religious institution. In Christianity, bishops are normally responsible for the governance of dioceses. The role or office of bishop is c ...

''et al.'' (1996) did not find

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

of any kind in a population in Volusia County, Florida.Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publishing Associates. 870 pp. 1,500 plates. . At midbody, the rows of

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down t ...

usually number 23. The dorsal pattern consists of a series of oval or subcircular spots with somewhat regular edges. The spots on the flanks are mostly round and not much higher than they are wide. Belly pigmentation towards the rear is more limited to indistinct blotches found on pairs of adjacent scales. Juveniles' color patterns are similar to the adults, although they may be paler or more vividly marked, and the tips of their tails are yellow.

Common names

Common names for ''S. miliarius'' include pygmy rattlesnake, ground rattlesnake, hog-nosed rattlesnake, little rattlesnake, miliar(y) rattlesnake, North American smaller rattlesnake, oak-leaf rattler, pygmy ground rattlesnake, small rattlesnake, southeastern ground rattlesnake, southern ground rattlesnake, southern pygmy rattlesnake, spotted rattler, spotted rattlesnake, southern rattlesnake.U.S. Navy (1991). ''Poisonous Snakes of the World''. New York: United States Government / Dover Publications Inc. 203 pp. . Older common names might include bastard rattlesnake, nipple snake, Carolina ground rattlesnake, brick red rattlesnake, Carolina pygmy rattlesnake, Catesby's small snake, dwarf rattlesnake, eastern pygmy rattlesnake, grey rattlesnake, and ground rattler (

Garman Garman is a surname or first name. Notable people with the name include: Sports * Ann Garman, All-American Girls Professional Baseball League player * Judi Garman (born 1954), American softball coach * Mike Garman (born 1949), American baseball pla ...

, 1887).

Geographic range

''S. miliarius'' is found in the Southeastern United States from southern and eastern

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and ...

, south through peninsular

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

and west to

East Texas East Texas is a broadly defined cultural, geographic, and ecological region in the eastern part of the U.S. state of Texas that comprises most of 41 counties. It is primarily divided into Northeast and Southeast Texas. Most of the region cons ...

and Oklahoma. The type locality given is "Carolina". Schmidt (1953) proposed that this be restricted to " Charleston, South Carolina".

Habitat

''Sistrurus miliarius'' reportedly inhabits

flatwoods Flatwoods, pineywoods, pine savannas and longleaf pine-wiregrass ecosystem are terms that refer to an ecological community in the southeastern coastal plain of North America. Flatwoods are an ecosystem maintained by wildfire or prescribed fire and ...

sandhill A sandhill is a type of ecological community or xeric wildfire-maintained ecosystem. It is not the same as a sand dune. It features very short fire return intervals, one to five years. Without fire, sandhills undergo ecological succession and bec ...

s, mixed forests, and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s, and is also found near lakes and

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

es.

Conservation status

This species is classified as least concern on the IUCN

Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

(v3.1, 2001). Species are listed as such due to their wide distribution, presumed large population, or because the population is unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend is stable; it was assessed in 2007. This species is not protected by South Carolina or Georgia state law, but pygmy rattlesnakes are protected in North Carolina and Tennessee.

Behavior

''S. miliarius'' is usually seen in the summer sunning itself or crossing the road late in the day. The tiny rattle makes a buzzing sound that can only be heard from a few feet away. Some individuals are very aggressive and strike furiously, while others seem lethargic and do not even attempt to rattle. 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. . (''Sistrurus miliarius'', pp. 697-698 + Plates 625, 641, 642, 645). Conant R (1975). ''A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition''. (First Edition published in 1958). Boston: Houghton Mifflin Company Boston. xviii + 429 pp. + Plates 1-48. (hardcover), (paperback). (''Sistrurus miliarius'', pp. 232-233 + Plate 35 + Map 177). It does not dig its own burrows, but rather uses those dug by small

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

s or gopher tortoises (''

Gopherus polyphemus The gopher tortoise (''Gopherus polyphemus'') is a species of tortoise in the family Testudinidae. The species is native to the southeastern United States. The gopher tortoise is seen as a keystone species because it digs burrows that provide s ...

'').

Feeding

The diet of ''S. miliarius'' includes small mammals and

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s, lizards, insects, and

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

s, as well as other snakes. Pygmy rattlesnakes also include giant desert centipedes in their diet, which they hunt by active pursuit, grabbing and flipping the centipedes around while simultaneously injecting venom to prevent injury by the victim. They also ambush lizards such as skinks by using their tails as lures, as is common in many other species of vipers. Caudal luring becomes less effective for adults, as the prey size and type changes. Their feeding strategy becomes sit-and-wait, with individuals remaining in a coiled position for days at a time.

Venom

Since ''S. miliarius'' is unable to produce much

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a st ...

, it is unlikely to be able to deliver a fatal bite to a human adult.Norris R (2004). "Venom Poisoning in North American Reptiles". ''In'': Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publishing Associates. 870 pp. 1,500 plates. . This snake produces cytotoxic venom that is strongly

hemorrhagic Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...

and tissue toxic, but devoid of any neurotoxins. The venom was the basis for the development of the drug

eptifibatide Eptifibatide (Integrilin, Millennium Pharmaceuticals, also co-promoted by Schering-Plough/Essex), is an antiplatelet drug of the glycoprotein IIb/IIIa inhibitor class. Eptifibatide is a cyclic heptapeptide derived from a disintegrin protein ( ...

, which is used to prevent clotting during a heart attack. The venom is somewhat different in that it contains substantial amounts of serotonin and related

tryptamine Tryptamine is an indolamine metabolite of the essential amino acid, tryptophan. The chemical structure is defined by an indole ─ a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the f ...

compounds.Welsh, 1967

Subspecies

Gallery

File:Sisistrus miliaris.jpg, Carolina pygmy rattlesnake (''S. m. miliarius'') File:Dusky Pygmy Rattlesnake - Sistrurus miliarius barbouri, Okaloacoochee Slough State Forest, Felda, Florida.jpg, Dusky pygmy rattlesnake (''S. m. barbouri''), Hendry Co., Florida (3 May 2013) File:Western Pygmy Rattlesnake (Sistrurus miliarius streckeri) (20799317490).jpg, Western pygmy rattlesnake (''S. m. streckeri''), Wayne Co., Missouri (28 August 2015)