''Underwoodisaurus milii'' is a species of

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 throughout the world. They range from . Geckos ar ...

, a

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

in the family Carphodactylidae. The species is commonly known as the thick-tailed or barking gecko, referring to its distinctive plump tail and sharp, barking defensive call. The genus is also often called thick-tailed geckos as a group, along with the species '' Uvidicolus sphyrurus''.

Taxonomy

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''milii'', is in honor of French sailor and naturalist Pierre Bernard Milius.

Description

''U. milii'' is reddish-brown with bands of white and yellow spots, and a paler underbelly. It usually grows to a total length (including tail) of . The original tail is black with several pale bands, however the regenerated tail has little pattern.

Distribution and habitat

''U. milii'' is found in southern regions of Australia. Its distribution in Western Australia is throughout the southwest, the goldfields, wheatbelt, and Nullarbor regions to the east, and to

Shark Bay Shark Bay (Malgana: ''Gathaagudu'', "two waters") is a World Heritage Site in the Gascoyne region of Western Australia. The http://www.environment.gov.au/heritage/places/world/shark-bay area is located approximately north of Perth, on the ...

in the north. It is also found at the Houtman Abrolhos and the Archipelago of the Recherche. ''U. milii'' is found in rocky outcrops, and is slightly more cold-tolerant than many other Australian gecko species. It is nocturnal, and shelters underneath rocks or in burrows during the day.

Diet

''U. milii'' feeds on insects and small vertebrates.

Behaviour

Unusually for reptiles, ''U. milii'' forms aggregations in its retreat sites during the day. The reasons for this are unknown. However, it has been shown that this behavior results in a higher aggregate thermal inertia (they stay warmer) than would be found in solitary geckos of this and related kinds in similar circumstances.Lancaster J, Wilson P, Espinoza RE (2006). "Physiological benefits as precursors of sociality: Why banded geckos band". ''Animal Behavior'' 72: 199-207. In the same source, it was suggested that aggregating for physiological benefits may precede the development of other kinds of social behavior. When threatened, ''U. milii'' will arch its back and "bark". It also does this in breeding season. This species, and some other species of geckos have the unusual habit of licking their eyes after eating, presumably to keep the eyeshield clean.

Conservation status

The species ''U. milii'' has been assessed by the IUCN Red List and is listed as Least Concern. It has not been assessed by the Australian EPBC Act, and may be kept as a pet with the appropriate license in at least some states of Australia.