The yellow-faced whip snake (''Demansia psammophis'') 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), ...

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 ...

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 ...

, a family containing many dangerous snakes. ''D. psammophis'' is endemic to Australia, found throughout the continent in a variety of habitats from coastal fringes to interior arid scrubland.

Taxonomy

The yellow-faced whip snake is part of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Demansia ''Demansia'' is a genus of venomous snakes of the Family (biology), family Elapidae. Members of the genus are commonly known as whip snakes or whipsnakes, as are members of several other Genus, genera. Description All species of the genus ''De ...

'', a group of venomous snakes in the family Elapidae. This genus is composed of whip snakes, characterized by their large eyes and whip-like tail. The genus ''Demansia'' is commonly found in the Southern hemisphere around Australia and equatorial countries such as Papua New Guinea. 15 species are assigned to the genus ''Demansia''.

Description

''D. psammophis'' is a thin snake with a narrow head. It grows up to a total length (tail included) of , averaging around , females being slightly smaller than males. Characterized by its narrow yellowish head, pale ring around the eyes, and a dark marking curving along the upper lip, ''D. psammophis'' becomes distinguishable from other ''Demansia'' snakes. Juveniles can be distinguished as a white-edged dark line is seen across the snout. The large prominent eyes surrounded by a pale ring, account for its ability to be a successful diurnal species, having the largest eyes of any Australian snake assisting in prey capture. The colour of the yellow-faced whip snake varies, ranging from olive green, to grey and brown; however, a common characteristic in colour is a "red flush along the anterior third of its back". To accurately identify this species, there must be a clear view of the head, 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 ...

at the snake's mid-body must be counted. ''D. psammophis'' has 15 mid-body dorsal scale rows and 165–230

ventrals In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that cont ...

, with the

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving ...

and

subcaudals In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Comstock Publishing Associates, a Division of Cornell University Press. (7t ...

divided. ''D. psammophis'' is commonly confused with the eastern brown snake (''

Pseudonaja textilis The eastern brown snake (''Pseudonaja textilis''), often referred to as the common brown snake, is a species of extremely venomous snake in the Family (biology), family Elapidae. The species is native to eastern and central Australia and souther ...

''), due to their similar appearance.

Distribution and habitat

''D. psammophis'' is distributed throughout the Australian continent, with presence in every state except Tasmania. Although the distribution of ''D. psammophis'' is wide, it is endemic to Australia. Found in a variety of habitats across Australia, ''D. psammophis'' ranges from coastal

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

s to arid

scrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

s and

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 ...

s in Australia’s interior. It is not uncommon to find more than one ''D. psammophis'' as they are community dwellers. Habitats in rock crevices and under logs are common community habitats with communities often aggregating in winter months.

Behaviour

''D. psammophis'' is a diurnal reptile, fast-moving with a nervous disposition, always alert and fleeing quickly when disturbed. The yellow-faced whip snake is subject to

brumation Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be clo ...

, or slowing down its movements, in the winter months, usually only moving to seek sun and water.

Reproduction

''D. psammophis'' is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

, laying

clutches A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the ...

of 5–6 and 15–20 amniotic eggs. Communal egg laying is also common in this species, with some nests having 500–600 eggs present. ''D. psammophis'' females experience

vitellogenesis Vitellogenesis is the process of yolk protein formation in the oocytes during sexual maturation. The term ''vitellogenesis'' comes from the Latin language, Latin ''vitellus'' ("egg yolk"). Yolk proteins, such as lipovitellin and phosvitin, provid ...

between September and November, ovulating in late spring or summer. Eggs are laid in February and March, and each hatchling has an approximate snout-to-vent length (SVL) of .

Diet

Small diurnal lizards, and lizard eggs are the main source of food for ''D. psammophis''. Although diurnal, it forages during the night, catching

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 ...

forms such as geckos, lerista, and frogs. Demansia psammophis Berowra Creek

Predation and venom

Small reptiles such as

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 ...

s and other lizards are predated on by ''D. psammophis'' during the day. Juvenile ''D. psammophis'' have been observed to constrict their prey. However, as they become adults, constriction becomes uncommon, with the species occasionally creating a single body loop to restrain its prey. To immobilize and kill prey, ''D. psammophis'' lashes out and injects toxic venom, slowing and eventually killing its prey. Although this venom is deadly to other reptiles and amphibians, it is not considered dangerous to humans. If bitten, the bite will be painful, and the injection of venom will cause localized pain and swelling, ranging from moderate to severe, with some bites causing systemic symptoms such as paralysis and bleeding. Medical treatment should be sought following any snake bite.

Conservation

The yellow-faced whip snake is currently classified as "

least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

" under the

IUCN Red List 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 an inventory of the global conservation status and extinction risk of biological ...

and is considered stable. The species is secure under the status of "least concern" in the majority of states and territories in Australia, including Queensland and the Northern Territory. However, it is considered "near-threatened" in Victoria. ''D. psammophis'' is not found in Tasmania due to the Tasman Strait that separates it from mainland Australia and the climatic conditions of Tasmania.

References

Sources

* Weigel, John (2002). ''Australian Reptile Park's Guide to Snakes of South-east Australia''. . (''Demansia psammophis'', p. 50). * Cogger, Harold G. (2018). ''Reptiles and Amphibians of Australia, Updated Seventh Edition''. Clayton, Victoria, Australia: CSIRO Publishing. 1,080 pp. . * "''Demansia psammophis'' ". Integrated Taxonomic Information System. www.itis.gov. ITIS
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