Baw Baw frog | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Amphibia |
Order: | Anura |
Family: | Limnodynastidae |
Genus: | Philoria |
Species: | P. frosti |
Binomial name | |
Philoria frosti Spencer, 1901 | |
Range of the Baw Baw Frog |
The Baw Baw frog (Philoria frosti) [2] is a critically endangered species of Australian frog as categorised on the IUCN Red List [1] and listed under the Flora and Fauna Guarantee Act (1988) , endemic to Baw Baw National Park. It has suffered a decline in population, mostly due to infection caused by chytrid fungus. Zoos Victoria has undertaken a breeding program to ensure survival of the species which commenced in 2010, and in October 2018 successfully collected the first eggs laid in captivity.
The species was described as Philoria frosti by Walter Baldwin Spencer in 1901, [2] honouring Charles Frost, an Australian naturalist. [3] The specimens used in the species description (type series) were provided by Frost, an amateur herpetologist, who recovered five individuals that had been regurgitated by a tiger snake Notechis scutatus . [4]
Adult length is between 42 and 55 millimetres (1.7 and 2.2 in). Adults are dark brown and often have brown to dark brown, yellow flecked bellies. The Baw Baw Frog has a prominent parotoid gland on the shoulders. Unlike most frogs the Baw Baw frog as unwebbed toes. The species is confined to a small region of safeguarded mountain gully habitat, situated at an altitude ranging from 1000 to 1300 meters, located on the Mt Baw Baw Plateau in the Central Highlands of Victoria, Australia. [5] At hatching, the tadpoles are creamy white and unpigmented, acquiring some colouration and eye pigmentation as they mature. Tadpoles have large yolk sacs and residual mouths, and do not feed until metamorphosis. In contrast to the typical behavior of tadpoles in other frog species, these developing tadpoles do not swim or feed; rather, they rely on nourishment from a yolk sac. [6] Metamorphlings have different colouration to the adults. [ citation needed ] During winter, they inhabit the space beneath the snow and exhibit higher activity levels compared to many other frogs during colder periods. Egg-laying occurs post-snowmelt, typically in mossy nests or within various crevices, occasionally as deep as one meter below the surface among rocks. [6]
The breeding environment depends on moist soil saturation and underground water flow beneath plant cover, fallen timber, and rocks, with breeding taking place on a yearly basis. [7] Egg clusters typically consist of 50 to 185 eggs, appearing white and lacking pigmentation. Hatching usually commences approximately 10 days after the eggs are laid and may continue for a duration of up to 5 days. [7]
Population estimates have reduced from 15,000 to 10,000 breeding males in 1983 to around 750, or according to Frogs Victoria less than 250 individuals. The decrease is likely caused by chytridiomycosis, which is attributed to the chytrid fungus. This disease can has been related to the diminish of many amphibian populations throughout the world.
In order to save the frog from extinction, a self-sustaining captive breeding program was commenced, with Zoos Victoria taking the lead. When the program was started in 2010 almost nothing was known about managing the frogs in captivity. [8]
Zoos Victoria has been researching the effects of food sources and temperature are larvae's growth development. The larvae they raised was at either a low temperature of 12 degrees Celsius or a high temperature of 17 degrees Celsius, with or without substrate that regulated food availability. The researchers measured both body size and the duration until metamorphosis. [9] The research concluded that changing the temperature and food sources could increase the birth rate. [9]
An artificial environment was created in a shipping container named "the Baw Baw Bunker" [10] and the first eggs were collected from the wild in 2011 but were unviable. In 2013, 96 metamorphs were raised from collected eggs. Eleven females were captured from the wild in 2016 for the first time, [lower-alpha 1] and on 22 October 2018 the first eggs were laid in captivity. Researchers planned to place the eggs on a chytrid fungus-free part of Mt Baw Baw within four weeks. [11]
In November 2020, at which time it was estimated that about 1,000 of the frogs remained in the wild, 25 male and 25 female adult frogs were released with radio transmitters on their backs in various specially selected areas on Mt Baw Baw. Researchers hope that the release of the adult frogs, the first time this has been tried, would create a more robust population of the frogs more quickly than by releasing eggs alone. [12]
Corroboree frogs comprise two species of frog native to the Southern Tablelands of Australia. Both species are small, poisonous ground-dwelling frogs. The two species are the southern corroboree frog and the northern corroboree frog. They are unique among frogs in that they produce their own poison rather than obtain it from their food source as is the case in every other poisonous frog species.
Chytridiomycosis is an infectious disease in amphibians, caused by the chytrid fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans. Chytridiomycosis has been linked to dramatic population declines or extinctions of amphibian species in western North America, Central America, South America, eastern Australia, east Africa (Tanzania), and Dominica and Montserrat in the Caribbean. Much of the New World is also at risk of the disease arriving within the coming years. The fungus is capable of causing sporadic deaths in some amphibian populations and 100% mortality in others. No effective measure is known for control of the disease in wild populations. Various clinical signs are seen by individuals affected by the disease. A number of options are possible for controlling this disease-causing fungus, though none has proved to be feasible on a large scale. The disease has been proposed as a contributing factor to a global decline in amphibian populations that apparently has affected about 30% of the amphibian species of the world. Some research found evidence insufficient for linking chytrid fungi and chytridiomycosis to global amphibian declines, but more recent research establishes a connection and attributes the spread of the disease to its transmission through international trade routes into native ecosystems.
The giant burrowing frog or eastern owl frog is a large frog species that occurs in coastal south-east New South Wales and Victoria in Australia. It is also known as the owl frog, southern owl frog, spotted owl frog, burrowing owl frog.
The green and golden bell frog, also named the green bell frog, green and golden swamp frog and green frog, is a species of ground-dwelling tree frog native to eastern Australia. Despite its classification and climbing abilities, it does not live in trees and spends almost all of its time close to ground level. It can reach up to 11 cm (4.5 in) in length, making it one of Australia's largest frogs.
The mountain yellow-legged frog, also known as the southern mountain yellow-legged frog, is a species of true frog endemic to California in the United States. It occurs in the San Jacinto Mountains, San Bernardino Mountains, and San Gabriel Mountains in Southern California and the Southern Sierra Nevada. It is a federally listed endangered species, separated into two distinct population segments (DPS): a northern DPS, listed endangered in 2014, and a southern DPS that was listed endangered in 2002.
The Wyoming toad, also known commonly as Baxter's toad, is a species of toad in the family Bufonidae. The Wyoming toad is an extremely rare amphibian that exists only in captivity and within Mortenson Lake National Wildlife Refuge in Wyoming in the United States. The Wyoming toad was listed as an endangered species in 1984, and listed as extinct in the wild since 1991. As with black-footed ferrets at the Tom Thorne and Beth Williams Wildlife Research Center at Sybille in Wheatland, Wyoming, the effort to save the Wyoming toad has been a cooperative effort among state and federal agencies and private landowners. The Wyoming toad was common from the 1950s through the early 1970s, but its distribution was limited to the Laramie Basin in Albany County. The population crashed around 1975 and was extremely low by 1980. The Wyoming toad was federally listed as endangered in January 1984. To prevent extinction, a captive-breeding program began in 1989 at the Thorne Williams Unit that produced enough offspring in its first few years to supply seven zoos, and in 1998 the Saratoga National Fish Hatchery received captive-breeding stock. Nearly 46,000 offspring were produced at the Thorne Williams Unit from 1995 until 2006, when the remaining captive stock was moved to the Red Buttes Environmental Biology Laboratory south of Laramie, and then released back into the wild. Before the sharp declines occurred, this toad had been originally classified as Bufo hemiophrys baxteri, a subspecies of the Canadian toad, by Kenneth Raymond Porter in 1968.
Holdridge's toad, formerly Bufo holdridgei, is a species of toad endemic to Costa Rica. In October 2008, it was declared extinct by the International Union for Conservation of Nature in its Red List since the species had not been seen since 1987, despite years of extensive searches. However, the species was rediscovered in 2010 by a Costa Rican herpetologist and is now classified as critically endangered. It is believed that the species is most threatened by the presence of the chytrid fungus in its habitat.
Philoria is a genus of frogs native to eastern and southern Australia. These frogs are all confined to mountain areas, with 7 species occurring in the mountains of northern New South Wales and southern Queensland. One species occurs in Victoria. All species are listed as endangered, except the Baw Baw frog, which is listed as critically endangered. They are small to medium-sized frogs that live in water saturated sites, such as sphagnum bogs and seepages on rocky slopes. The eggs are laid in foam nests hidden from light. The tadpoles remain within the nest and live entirely on the yolk.
The boreal toad is the nominate subspecies of the western toad. They are commonly found in the western U.S. and western Canada. Boreal toad populations have declined recently due to an emerging amphibian disease, chytrid fungus. The boreal toad is currently listed as an endangered species by Colorado and New Mexico. It is known in Colorado as the only alpine species of toad.
The Booroolong frog is a species of stream-dwelling frog native to the Great Dividing Range in New South Wales, Australia. It is a member of the Hylidae, or the "tree frog" family. The Booroolong frog is classified by the IUCN as a Critically Endangered Species.
Amphibians of Australia are limited to members of the order Anura, commonly known as frogs. All Australian frogs are in the suborder Neobatrachia, also known as the modern frogs, which make up the largest proportion of extant frog species. About 230 of the 5,280 species of frog are native to Australia with 93% of them endemic. Compared with other continents, species diversity is low, and may be related to the climate of most of the Australian continent. There are two known invasive amphibians, the cane toad and the smooth newt.
Spicospina is a genus of ground-dwelling frogs in the family Myobatrachidae. It is monotypic, being represented by the single species, Spicospina flammocaerulea, also known as the sunset frog. First discovered in the year 1994, it is native to south-western Western Australia. It is known from only 27 sites, all occurring east and northeast of Walpole.
The Panamanian golden frog, also known as Cerro Campana stubfoot toad and other names, is a species of toad endemic to Panama. Panamanian golden frogs inhabit the streams along the mountainous slopes of the Cordilleran cloud forests of west-central Panama. While the IUCN lists it as Critically Endangered, it may in fact have been extinct in the wild since 2007. Individuals have been collected for breeding in captivity in a bid to preserve the species. The alternative common name, Zetek's golden frog, and the epithet zeteki both commemorate the entomologist James Zetek.
Agalychnis lemur, the lemur leaf frog or lemur frog, is a species of frog in the subfamily Phyllomedusinae. It is found in Costa Rica, Panama, and adjacent northwestern Colombia. It is classed as Critically Endangered and threatened by the fungal disease chytridiomycosis.
The green-eyed treefrog is a species of Australasian treefrog in the subfamily Pelodryadinae that occurs in the Wet Tropics of Australia.
The Kroombit tinker frog, also sometimes referred to as Pleione's torrent frog, is a species of frog in the family Myobatrachidae. It is endemic to Central Queensland in Australia. It lives among rocks and leaf litter near small flowing streams.
The Mississippi gopher frog, also known commonly as the dark gopher frog, the dusky gopher frog, and the St. Tammany gopher frog, is a critically endangered species of frog in the family Ranidae. The species is endemic to the southern United States. Its natural habitats are temperate coastal forests and intermittent freshwater marshes. This secretive frog is on average 3 in (8 cm) long, with a dark brown or black dorsal surface covered in warts. It is a federally listed endangered species of the United States.
The Sierra Nevada yellow-legged frog or Sierra Nevada Mountain yellow-legged frog is a true frog endemic to the Sierra Nevada of California and Nevada in the United States. It was formerly considered Rana muscosa until a 2007 study elevated the more central and northern populations to full species status, restricting R. muscosa to the southern Sierra Nevada and southern California.
The golden toad is an extinct species of true toad that was once abundant in a small, high-altitude region of about 4 square kilometres (1.5 sq mi) in an area north of the city of Monteverde, Costa Rica. It was endemic to elfin cloud forest. Also called the Monte Verde toad, Alajuela toad and orange toad, it is commonly considered the "poster child" for the amphibian decline crisis. This toad was first described in 1966 by herpetologist Jay Savage. The last sighting of a single male golden toad was on 15 May 1989, and it has since been classified as extinct by the International Union for Conservation of Nature (IUCN).
Leptodactylus fallax, commonly known as the mountain chicken or giant ditch frog, is a critically endangered species of frog that is native to the Caribbean islands of Dominica and Montserrat. The population declined by at least 80% from 1995 to 2004, with further significant declines later. A tiny wild population remains on Dominica where there are efforts to preserve it, but few or none survive in the wild on Montserrat and its survival now relies on a captive breeding project involving several zoos. The initial decline was linked to hunting for human consumption, along with habitat loss and natural disasters, but the most serious threat now appears to be the fungal disease chytridiomycosis, which was the primary cause of the most recent rapid decline. On Montserrat it is known as the mountain chicken, while on Dominica it is known as the crapaud, which is simply the French word for "toad".