The desert tree frog (''Litoria rubella''), or little red tree frog, is a species of

tree frog A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia suborder have given rise to treefrogs, although they are not clos ...

native to Australia, southern

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

, and

Timor Timor (, , ) is an island at the southern end of Maritime Southeast Asia, in the north of the Timor Sea. The island is Indonesia–Timor-Leste border, divided between the sovereign states of Timor-Leste in the eastern part and Indonesia in the ...

. It is one of Australia's most widely distributed frogs, inhabiting northern Australia, including desert regions and much of temperate eastern Australia. It is one of the few Australian tree frogs to inhabit arid, tropical, and temperate climates.

Description

It is rotund, with a small, flat head. It has short arms and strong, short legs. Adults are in snout-vent length. Its ventral surface is white, and the dorsal surface ranges from light grey to dark red and has small black flecks. Adult specimens from

Cooktown Cooktown is a coastal town and locality in the Shire of Cook, Queensland, Australia. Cooktown is at the mouth of the Endeavour River, on Cape York Peninsula in Far North Queensland where James Cook beached his ship, the '' Endeavour'', for ...

, Queensland, often show a pronounced metallic sheen on the dorsal surface, ranging in colour from bronze to gold. A dark band runs from the snout, across the eye, and along the flanks of the frog. The throats of males in breeding season are a dark grey colour. The groin is lemon-yellow, and the tympanum is visible. Baby frogs have an almost transparent abdomen, allowing a clear view of their abdominal organs.

Ecology and behaviour

The wide distribution and the large range of habitats it inhabits create a large variation in breeding habits. Populations that live in temperate or tropical zones breed annually during the

wet season The wet season (sometimes called the rainy season or monsoon season) is the time of year when most of a region's average annual rainfall occurs. Generally, the season lasts at least one month. The term ''green season'' is also sometimes used a ...

or summer. However, the populations in desert regions will breed whenever rain occurs. Tadpole development is dependent on the temperature of the water. Small amounts of water heat to higher temperatures, which triggers the tadpoles to develop faster; some develop in just 14 days. Unlike most desert frogs, it does not burrow to avoid heat and

desiccation Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container. The ...

. It will seek out shelter under rocks, trees, or leaf litter. They are commonly found around human dwellings where water is available and can be found in sinks, toilets or drain pipes. Compared to other desert frogs of a similar size, they have a relatively low rate of evaporative water loss, and do not dry out as quickly as expected under hot and dry conditions. Their low rate of evaporative water loss can partly be attributed to adopting a water-conserving posture, where frogs tuck their limbs close to their body and close off ventral skin from the outside environment. One study found that frog species like desert tree frogs that use water-conserving postures tended to have a higher resistance to evaporative water loss. Desert tree frogs can also change their color from dark brown to bright white, which serves to increase

solar reflectance Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

off the skin and decreases their heat intake, and, unlike most

amphibians Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

, when exposed to dry air they will change color regardless of previous background color.

References

{{Taxonbar, from=Q2275306 Litoria Amphibians of Queensland Amphibians of New South Wales Amphibians of South Australia Amphibians of Western Australia Amphibians of the Northern Territory Amphibians of Indonesia Amphibians of Papua New Guinea Amphibians described in 1842 Fauna of Timor Fauna of Timor-Leste Frogs of Australia Taxa named by John Edward Gray