The broad-headed snake (''Hoplocephalus bungaroides'') is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

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 ...

in 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 ...

Elapidae Elapidae (, commonly known as elapids ; grc, ἔλλοψ ''éllops'' "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 Emydoce ...

. The species is restricted to the Sydney Basin in

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

, Australia. It is one of three snakes in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

Hoplocephalus ''Hoplocephalus'' is a genus of venomous snakes in the family Elapidae. The genus is endemic to Australia. Three species are recognized. Description Snakes of the genus ''Hoplocephalus'' have a pair of large grooved venom fangs, which are foll ...

'', all restricted to eastern Australia. It is currently endangered in New South Wales and is listed as vulnerable under the Commonwealth Legislation.

Taxonomy

German naturalist

Hermann Schlegel Hermann Schlegel (10 June 1804 – 17 January 1884) was a German ornithologist, herpetologist and ichthyologist. Early life and education Schlegel was born at Altenburg, the son of a brassfounder. His father collected butterflies, which stimula ...

described the species in 1837 as ''Naja bungaroides''.

Description

The broad-headed snake is a small to medium-sized species of venomous snake, which attains an average total length (including tail) of , although some records show that it can grow as long as . It is black with numerous irregular yellow markings arranged in narrow cross-bands, Boulenger GA (1896). ''Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ) ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I–XXV. (''Hoplocephalus bungaroides'', pp. 348–349). which for inexperienced people can easily lead to confusion with a young

diamond python ''Morelia spilota spilota'' is a subspecies of carpet python (''Morelia spilota''), popularly known as the diamond python. It is a medium to large snake, found in coastal areas and adjacent ranges of south-eastern Australia. It is the most sou ...

, which is superficially very similar and found in the same habitat.

Distribution and habitat

The broad-headed snake is found in the

Sydney Basin The Sydney Basin is an interim Australian bioregion and is both a structural entity and a depositional area, now preserved on the east coast of New South Wales, Australia and with some of its eastern side now subsided beneath the Tasman Sea. ...

in New South Wales, Australia. The snake's choice of habitat depends on temperature, age, gender, and breeding status. In the colder months, adult and juvenile snakes reside in the crevices of sandstone outcrops on exposed cliff edges to maximise warmth from the sun. When the temperature rises in spring, adult males and non-breeding females move to adjacent woodlands and forests, inhabiting hollow trees during the summer months. Juvenile snakes and

gravid In biology and human medicine, gravidity and parity are the number of times a woman is or has been pregnant (gravidity) and carried the pregnancies to a viable gestational age (parity). These terms are usually coupled, sometimes with additional t ...

females remain in the rocks and move to cooler, shaded areas. Their habitat has been degraded by urbanization, illegal rock removal, vandalisation and indiscriminate reptile collecting. The sandstone rocks that the snakes occupy are valued for landscaping purposes. Their removal has led to a

loss of habitat Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

for both the snakes and their prey.

Behavior

Diet

The broad-headed snake feeds infrequently on small reptiles and mammals. Snakes in captivity are able to maintain or gain weight when fed one to two newborn rats per month. In one documented case, a snake survived a fast lasting twelve months. Juveniles feed mostly on Lesueur's velvet gecko ('' Amalosia lesueurii)'' and occasionally on small

skinks Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Ski ...

. Adults feed on Lesueur's velvet gecko, but also prey on other lizards, small snakes, and mice.

Breeding

Male broad-headed snakes reach maturity after five years whereas females require six. Mating occurs from autumn to spring, and mature females produce a litter every two years. Unlike most of its venomous counterparts, the broad-headed snake gives birth to live young. Birth occurs between January and April, with each litter resulting in 4–12 offspring born in mucous sacks. Unfertilized

oocytes An oocyte (, ), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The female g ...

and stillborn offspring are common.

Conservation status

The broad-headed snake was once commonly found in parts of Sydney including around Sydney Harbour; however, it is currently listed as an endangered species in New South Wales and vulnerable under the national Commonwealth Legislation. Its declining numbers are the result of a combination of factors including habitat loss through urbanisation, bush rock removal and irresponsible collecting.

Sources

Wildlife of Sydney Fact FileDEH Species Profiles - ''Hoplocephalus bungaroides'' - Broad-headed Snake