Wallace's Flying Frog

## About

A Wallace's flying frog in flight.

The Wallace's flying frog ***(Rhacophorus nigropalmatus)*** or Abah river flying frog, is an extremely unique frog species native to areas of southeast Asia and Indonesia, discovered and named after English naturalist Alfred Russel Wallace in 1855. Wallace's flying frogs are one of the few species of amphibian that is able to glide, and they achieve this by spreading their webbed feet, which act as parachutes. This flying ability is unique to the genus Rhacophorus, which includes 40 species of flying and parachuting frogs. Wallace's flying frog are a vivid green hue on their backs, with more yellowish-white stomachs, with largely pronounced back-arches. The webbed feet of the frog are unique among other species of frogs in that they are bright orange and deep black. The webbing of their feet are also lined with orange stripes. Wallace's flying frogs have considerably more pronounced webbing between their toes when compared to other species, which is a noticeably characteristic of all members of the Rhacophorus genus. As the frog's name suggests, the species is able to glide or 'parachute' through the air and how they do this is credited to their webbed feet. The frog's enlarged feet act as parachutes and work in sync with lateral skin flaps located on their limbs in order to glide large distances, and retain maneuverability while airborne. Flying frogs have also evolved a lightweight body plan, with reduced body mass and stronger and longer limbs. Wallace's flying frogs are relatively small, growing to a length of 10.6cm (4in) while the recorded weight varies. The length of the frog alone, makes it one of the largest flying frog species.

## Diet

The Wallace's flying frog is a carnivore, eating insects in addition to small invertebrates, according to the ADW. This diet is expected and common for the species classified under the order Anura.

## Conservation Status

Wallace's flying frogs are listed as least concern by the IUCN, but have not been assessed since 2004. The Wallace's flying frog population is large but considered to be decreasing however, they have been documented in a large and vast range. Deforestation and further habitat fragmentation/degradation threatens the frog and decreases their range yearly. A more infrequent threat to the frog is the pet trade, with frogs being wild caught and housed in usually unprofessional environments. The frog exportation happens on such a small scale however, it is not considered an immediate threat to the species. Other than this, not a great amount of information is known about the frog's threats, and the IUCN document requires revision.

## Range and Population

The population of the Wallace's flying frog is thought to be large but it is unknown as to how many individuals there are. The frogs live in areas of Borneo, Sumatra, mainland southeast Asian regions, and peninsular Malaysia, where they prefer to live far off the ground in tree canopies in tropical regions. Because of their specialised habitat, Wallace's flying frogs are typically seldom seen and quite elusive, making population surveys very difficult. Wallace's flying frogs can glide to an astounding distance of 15.24m (50ft), which is an extremely useful in their arboreal lifestyle. This gliding allows the frogs to easily evade predators such as tree snakes.

## Behaviour

The Wallace's flying frog exhibits not only strange adaptive behaviour among frogs, but also strange breeding behaviour. During the rainy season (November to March) gatherings of Wallace's flying frogs known as armies, will congregate on the ground in foliage near a water source such as a wallow and mate. During this interaction, female Wallace's flying frogs will excrete a liquid which they turn into foam by beating it quickly with their hind legs, they will then lay their eggs in the resulting nests. Whilst the eggs are being laid, male frogs will fertilise the eggs. Interestingly, the nest will be attached to a tree branch above the wallow, and once the hatchlings inside reach the larval stage, the foamy nest will collapse sending the larvae into the wallow below. The tadpoles appear brownish grey in colour and reach a length of 50mm (2in), they will then spend their lives in this wallow until adulthood. This mating interaction stands as the only time in the frog's life, that it will climb down from the trees.

### Relationship with Humans

Wallace's flying frogs are not particularly aggressive towards humans, not biting or defending themselves in any way when handled. If given the change however, a Wallace's flying frog caught by a human will attempt to escape by gliding to the nearest available foliage.

## In Captivity

Today only one zoo exhibits a Wallace's flying frog. The Biosphere Potsdam, is a zoo located in Potsdam, Germany that specialises in the care of cold blooded animals such as reptiles and amphibians. The zoo is also part of a larger botanical garden.

## Sources

* IUCN Red List of Threatened Species - https://www.iucnredlist.org/species/59008/11866922
* Wallace's Flying Frog | ZOOINSTITUTES - https://zooinstitutes.com/animals/wallaces-flying-frog-2066/
* Flying Frogs | Australian Museum - https://australian.museum/blog-archive/science/aerodynamic-amphibians/
* Wallace's Flying Frog | Animal Diversity Web, University of Michigan, Museum of Zoology - https://animaldiversity.org/accounts/Rhacophorus\_nigropalmatus/
* Wallace's Flying Frog | Active Wild - https://www.activewild.com/wallaces-flying-frog/