Dwyer's snake (''Suta dwyeri'') also known as the
"Balling as a defence mechanism for snakes", ''Journal of the Herpetological Society of Queensland'', Spring 2005 variable black-naped snake,
"''Suta dwyeri'' ". The Reptile Database. www.reptile-database.org. is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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 sti ...

ous

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Elapidae Elapidae (, commonly known as elapids , from , variant of "sea-fish") is a family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus '' Emydocephalus ...

. The species is

endemic Endemism is the state of a species being found only 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 foun ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, where it is found from

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

to South Queensland.
Snake Tracks Species List While closely related to Australian

sea snakes Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, w ...

, ''S. dwyeri'' is a terrestrial

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

.
Elapid Land Snakes (Family Elapidae, Subfamily Elapinae): South-east Queensland

Etymology

The Specific name (zoology), specific name, ''dwyeri'', is in honor of

Australian Australian(s) may refer to: Australia * Australia, a country * Australians, citizens of the Commonwealth of Australia ** European Australians ** Anglo-Celtic Australians, Australians descended principally from British colonists ** Aboriginal Aus ...

herpetologist Herpetology (from Ancient Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is a branch of zoology concerned with the study of amphibians (including frogs, salamanders, and caecilians (Gymnophiona)) and reptiles (in ...

John Dwyer John Dwyer may refer to: * John Dwyer (Australian judge) (1879–1966), Australian judge * John Dwyer (baseball) (active 1882), American baseball player * John Dwyer (field hockey) (born 1928), Australian Olympic hockey player * John Dwyer (medici ...

Taxonomy

There has been a great amount of instability of the nomenclature of many Australian snake

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

, particularly concerning the generic classification of the smaller

, some of which have been placed in several different

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

in the span of just a few decades. Accordingly, Dwyer's snake, which was originally named ''Denisonia dwyeri'' by Worrell in 1956, has been variously called ''Unechis dwyeri'' by Cogger in 1983, ''Suta dwyeri'' by Valentic in 1998, ''Suta spectabilis dwyeri'' by Cogger in 2000, and ''Parasuta dwyeri'' by Greer in 2006.

Description

Adult ''S. dwyeri'' males average 31 cm (12 inches) in length from the tip of the snout to the

uro Uro or URO may refer to: * Aurochs, the predecessor of modern cattle * Uro Bonsai technique; see deadwood bonsai techniques * Uro, Delta, Nigeria * ''Uro'' (film), directed by Stefan Faldbakken * Uro (trucks), a Spanish truck manufacturer * '' ...

genital A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting ...

vent. Females are slightly smaller at around 29 cm (11 inches) in snout-to-vent length (SVL).
Size and Breeding Information for Australian Snakes ''S. dwyeri'' has a cylindrical brown body with a slender to medium build. The head is short and somewhat widened so as to be distinct from the neck. The tail is short as well, and the

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

are smooth. The eye is medium-sized, with a vertically elliptical

pupil The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company. It appears black becau ...

.
Clinical Toxinology Resources

Reproduction

Animal husbandry, Breeders of exotic reptiles advise letting pairs of ''S. dwyeri'' mate when they reach a length of about for males and for females. This species is

viviparous In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juve ...

rather than egg laying and successfully births about three offspring per brood. Newborn ''S. dwyeri'' young are about long.

Defense mechanisms

Like other snakes in the

, ''S. dwyeri'' is

ous and has hollow

fang A fang is a long, pointed tooth. In mammals, a fang is a modified maxillary tooth, used for biting and tearing flesh. In snakes, it is a specialized tooth that is associated with a venom gland (see snake venom). Spiders also have external fangs, ...

s fixed at the front of the upper

jaw The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth ...

. These fangs are connected via ducts to venom

gland A gland is a Cell (biology), cell or an Organ (biology), organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. A gland may also funct ...

s near the eyes. Like the majority of Australian elapids, Dwyer's snake is inoffensive and shy. In addition,

Herpetologist Herpetology (from Ancient Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is a branch of zoology concerned with the study of amphibians (including frogs, salamanders, and caecilians (Gymnophiona)) and reptiles (in ...

s at the

Queensland Museum The Queensland Museum Kurilpa is the state museum of Queensland, funded by the government, and dedicated to natural history, cultural heritage, science and human achievement. The museum currently operates from its headquarters and general museu ...

describe Dwyer's snake as "weakly venomous", and do not include it among their list of eight snake species in the

Brisbane Brisbane ( ; ) is the List of Australian capital cities, capital and largest city of the States and territories of Australia, state of Queensland and the list of cities in Australia by population, third-most populous city in Australia, with a ...

area considered capable of inflicting potentially fatal bites. A 25-year-old man in

Western Sydney Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US * Western Creek, Tasmania, a locality in Australia * Western Junction, Tasmania, a locality in Australia *Western world, countries that ...

mildly describes a

snakebite A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may ...

from this species by saying that he was:

... bitten on the finger by a ''Suta dwyeri'' once. The bite did not hurt at all. But little did I know he had left his fang in my finger. A couple of days later it got a tiny bit infected and hurt for a couple of days ... nothing major though.
Aussie Pythons & Snakes (aussiepythons.com)

When threatened ''P. dwyeri'' prefers to coil into a tight ball as a

defense mechanism In psychoanalytic theory, defence mechanisms are unconscious psychological processes that protect the self from anxiety-producing thoughts and feelings related to internal conflicts and external stressors. According to this theory, healthy ...

for protection from larger

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

s. This enables the snake to protect its head and more vulnerable areas of its body.

Behaviour and habitat

''S. dwyeri'' is a secretive,

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

snake that seeks shelter under rocks, debris, and ground litter, and may make its home in

burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...

s made and abandoned by other creatures. Open

woodland A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunli ...

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

, and rocky areas are its preferred natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

Diet

''S. dwyeri'' feeds mainly on small

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s such as

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates. They range from . Geckos are unique among lizards ...

s and

skink Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one o ...

Images

Dwyer's snake

Dwyer's snake