The Zoo has two White's tree frogs. They were captive hatched in 2007 and arrived at the Zoo on June 14, 2008. One frog is on exhibit in the Reptile and Amphibian House; the second frog, named Dalby, is housed off-exhibit and used for education programs.
The skin of a White's tree frog has a waxy cuticle that helps prevent water evaporation allowing the frog to survive in arid conditions. The frog's skin has many perforations of skin glands that also keep it moist. White's tree frogs are bright green in color or a mixture of green and bronze, often with scattered white spots on the sides. The ventral surface is white. Often white stripes or series of spots are found from the angle of the mouth to the forearm. There is smooth skin on the upper surface, but the skin is coarse and granular on the sides and ventral surface. The parotid gland is large, and it has a noticeable tympanum. Its pupil is horizontal and the iris is pale. The upper part of the lower eyelid is transparent and colorless. Its fingers are one-third webbed with the second finger longer than the first. Its toes are about one-half webbed.
White's tree frogs live in rainforests but can also survive in arid areas. They also can be found in gardens and frequently around human habitation in water tanks, troughs, windmills, down-pipes and even toilet bowls. These frogs like to nest in tree hollows during the day.
Longevity
In zoos, the average life span of a White's tree frog is 16 years. One is recorded to have lived 20 years in a zoo. In the wild, their life span tends to be much shorter.
Reproduction
This frog breeds during the wet season in the summer. In the rainforest, it would not be unusual to find creeks and ponds with tree frog tadpoles in them. The White's tree frog lays a large amount of eggs, generally ranging from 150-300. The eggs are laid in a mass of sloppy jelly, which serves to protect them. Eggs are quickly hatched to produce free-living, aquatic tadpoles. The maturation period, during which the tadpole metamorphoses into a frog,usually takes two to three weeks.
Behavior
Males have a loud rasping call. This is often magnified by the echo chamber effect that occurs when the call is made from the hollow limbs of trees. During the dry season the frogs become dormant after surrounding themselves in a cocoon of skin and mucus. The White's tree frog's predators include birds of prey, snakes and lizards.
Adaptations
White's tree frogs are arboreal, or tree dwellers, and largely nocturnal. They have large adhesive pads on their fingers and toes. This makes them excellent climbers. They have very good balancing skills and are able to sit on different surfaces including wet vertical ones. White's tree frogs are also strong jumpers.
Amphibian Conservation
Conservation at a Glance
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Amphibians are an important component of the global ecosystem, as indicators of environmental health and contributors to human health.
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Amphibians provide vital biomedicines and are considered an indicator species for endocrine disruptors and unsafe environmental conditions
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They are also vital components of their ecosystems - in areas of the world where amphibians have declined, there has been an increase in invertebrate pests that damage crops and carry human diseases.
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Today, one third to one half of all amphibian species worldwide are threatened with extinction.
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The World Association of Zoos and Aquariums (WAZA) has joined with two branches of the IUCN Species Survival Commission (IUCN/SSC) - the Conservation Breeding Specialist Group (CBSG) and the Amphibian Specialist Group (ASG) - to form the Amphibian Ark (AArk).
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As an integral part of the Amphibian Conservation Action Plan, AArk was formulated to ensure that select species which would otherwise go extinct will be maintained in captivity until they can be secured in the wild.
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AArk keeps constant attention on the obligation to couple ex situ (in a captive setting) conservation measures with necessary efforts to protect or restore species in their natural habitats.
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AArk’s goal is to save as many species as possible by providing global coordination, technical guidance, training, necessary linkages to other IUCN groups, communications, and guiding publicity and capital campaigns.
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AArk’s goal is 100% participation of WAZA zoos and aquariums and the regional associations.
To learn more about the conservation efforts at the Philadelphia Zoo, click here.