White’s Tree Frog
Order: Anura (toads and frogs)
Family: Hylidae (tree frogs)
Scientific Name: Litoria caerulea
Description: White’stree frogs can reach4inches in length. Theyare usually a brightgreen color, butcan alsoappear blue-green, bluish, or brown. The underparts are white. They are sometimes known as “Australian dumpy frogs”, because of their plump “buddha” appearance. They have large ridges above the eyes, and they may have additional folds of skin elsewhere on their body. Their toes and fingers have circular disks that act as suction cups, allowing the frog to climb up smooth surfaces. They have teeth in their upper jaw. The nostrils and eyes are on the top of the head, so that the frog can see and breath while submerged. They have a large conspicuous eardrum (tympanum) behind each eye. Males are usually smaller than females and have a throat patch of loose gray skin, which expands when the male is calling.
Home Range: Northern and eastern Australia, islands in the Torres Straits, and New Guinea and New Zealand (introduced)
Habitat Type: Usually temperate and tropical rainforests; often live near human habitations and have been found in houses, bathrooms, water tanks, and drainpipes
Reproduction: Australian WTF’s usually reach sexual maturity in their second year. In the wild, they breed in the summer (November to February in the Southern Hemisphere) in grassy rain-filled meadows. Males call to females with a harsh, bark-like courtship call. Mating usually occurs in a pool of still water, with the male grasping the female tightly in a position called amplexus. Fertilization is external. Females lay up to 3,000 eggs into a cloud of sperm. The clump of eggs sinks to the floor of the pool, and hatches within a few days. The newly hatched tadpoles are brown and green. They enter an inactive stage, resting on the bottom of the pool. They begin to show limited activity within 2 days of hatching, and will begin searching for food 3 or 4 days later. During their 4th week, they will emerge from the water as froglets. At this stage, they need plants to climb on or other access to land, or they will drown. Metamorphosis will be complete when they are about 6 weeks old.
Diet in the Wild: Insects and other invertebrates, and occasionally other animals such as mice or smaller frogs. They absorb water through their skin, instead of drinking it.
Diet in the Zoo: Crickets gut-loaded with vitamins
General Information: Like other amphibians, WTF’s are large-mouthed and have teeth which lack roots and are replaced continually. Their tongue is attached to the roof of the mouth. Adults have lungs for breathing air on land, and they can also absorb oxygen directly through their skin. They are the most primitive vertebrates to have a middle ear cavity for transferring sound vibrations from the eardrum to the inner ear. Along with this ear development is the appearance of a larynx, or true voice box, and an expandable vocal sac. The male’s voice is a deep “wark-wark-wark”.
WTF’s are crepuscular to nocturnal. They spend most of their time on high perches, and rarely have to travel far to find food and mates. They are very tolerant of drought conditions. Their loose skin allows them to take in a large amount of water when it is available, so that they can survive the following dry season. During hot, dry spells, they aestivate until the rains begin again, retaining their skin rather than sloughing it, which provides them with a dry coating to prevent water loss.
This species is of considerable interest in medicine. Their skin secretes a toxin called caerulein, which has been produced synthetically to treat high blood pressure. Their skin also produces several anti-bacterial and anti-viral chemicals.
Conservation Status: WTF’s are not thought to be threatened, and they are protected in most Australian states. They are becoming increasingly popular as pets, and breed well in captivity.
Predators: No information found
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