13 Frog Species Zoos and Aquariums are Helping to Conserve in the Fight Against Extinction
By: Caitlin Ball, WAZA
Frogs are an integral part of the ecosystems they evolved in, serving as prey for some species and predators for others. Additionally, they are an indicator species for environmental health due to their skin’s indiscriminate absorption of everything in their habitat’s water. This characteristic makes amphibians especially vulnerable to global warming and the chytrid fungus outbreak, thrusting them into their own amphibian extinction crisis amidst the ongoing 6th mass extinction event.
We present to you 13x§ frog species that zoos and aquariums are helping to protect via in situ and ex situ conservation efforts. (Disclaimer – this is by no means an exhaustive list):
1. Mountain Chicken Frog
The mountain chicken frog is an unfortunate victim of chytrid fungus, which has devastated both its homes on the Caribbean islands of Montserrat and Dominica. The species was once found on other islands, including Guadeloupe and Antigua, but the chytridiomicosis disease, in combination with overhunting, drove it out and only around 100 individuals are estimated to remain in the wild. Captive breeding programmes have prevented the species’ complete extinction and now a few populations are in care at a number of zoos while work to eradicate chytridiomycosis from their habitat continues.
Fun fact: the mountain chicken frog does, indeed, taste like chicken and is so popular that it is on the official seal of Dominica.
2. Archey’s Frogs
Recognised by Edge of Existence as the world’s most Evolutionarily Distinct and Globally Endangered amphibian species, the Archey’s frog is often called a ‘living fossil’ because it is barely distinguishable from 150 million year old fossilized frog remains. Predation from mice and rats, in addition to the devastating chytrid fungus, have driven the species to be listed as critically endangered. Along with a breeding programme for Archey’s frogs, Auckland Zoo also assists the New Zealand Government’s Department of Conservation (DOC) with annual surveys and censuses of Archey’s frogs in Whareorino Forest.
Fun fact: the Archey’s frog has tail-wagging muscles, but no tails.
Archey’s frogs are impressively durable in a drought – studies show “that frogs dehydrated to 92% of their body weight could rehydrate to 99% of their body weight in only four hours when placed on wet foliage.”
3. Oregon Spotted Frog
The Oregon spotted frog is Canada’s most endangered amphibian, with a recent population drop of roughly 90% due to pressures from habitat loss and invasive species. The Oregon Spotted Frog Recovery Team, which includes a number of WAZA members, was created in 1999 to safeguard this species from extinction and between 2003 and 2017 released approximately 15,000 captive-bred tadpoles and juvenile frogs into previously inhabited areas.
Fun fact: The Oregon spotted frog is the most aquatic frog in the Pacific Northwest
4. Baw Baw Frog
The Baw Baw frog is only found on the Mount Baw Baw plateau, Victoria, Australia, and is predicted to go extinct in the wild within the next five – 10 years. Chytrid fungus has driven the population down by 98% since the late 1980s, but Zoos Victoria is spearheading the establishment of a self-sustaining captive insurance population.
Fun fact: Baw Baw tadpoles hatch much earlier than most and may be non-feeding, instead living off their own yolk sack before metamorphosing into frogs.
5. Panamanian Golden Frog
Chytrid fungus and human activity has driven the Panamanian golden frog, a cultural symbol of Panama, to extinction in the wild, but a number of WAZA members carefully maintain it in survival-assurance breeding groups. More than 1,000 adult individuals live at more than 50 participating institutions while scientists work to combat habitat deterioration and provide them with a future in the wild.
Fun fact: this is Panama’s national animal and is a symbol of good luck.
6. Corroboree Frog
The Corroboree Frog Recovery Programme was established in 1996 to halt the species’ decline caused by chytrid fungus and habitat loss. Successful captive breeding colonies at Taronga Zoo, Healesville Sanctuary, and Melbourne Zoo have allowed for the release of more than 2,000 individual frogs and more than 2,000 eggs in their natural Australian habitat.
Fun fact: corroborees do not jump like most frogs, but rather walk because their toes lack webbing.
7. Kihansi Spray Toad
The Kihansi spray toad is only found in the spray area of Kihansi Falls, Tanzania. In 2009, the species was listed as extinct in the wild after construction of the Lower Kihansi dam had devastated populations, but a coordinated breeding and reintroduction programme from Toledo Zoo and Bronx Zoo has released nearly 10,000 individuals as of last year.
Fun fact: Kihansi spray toad fertilisation is internal, unlike most of its peers, and eggs remain in the female’s body until developed into small toadlets.
8. Lemur Leaf Frog
Lemur leaf frogs are also victims of chytrid fungus and have faced drastic population declines, even going extinct in some areas throughout their range in Costa Rica, Panama, and Colombia. A coordinated conservation project involving multiple WAZA members aims to conserve this species by protecting it in the wild, studying it, and ensuring survival with a captive breeding programme.
Fun fact: these frogs can change color based on activity – they are green while resting during the day and turn brown when active at night.
9. Golden Mantella
The golden mantella is a critically endangered species found in east-central Madagascar’s high altitude swamps. Habitat loss caused by agriculture, timber, fire, and human developments presents the biggest threat to its survival so zoos have stepped up to breed them in captivity for reintroduction while efforts to secure their habitat continue.
Fun fact: Golden mantella frogs retain toxins from their insect meals so that they, too, are toxic, just like poison dart frogs.
10. Lake Titicaca Frog
The Lake Titicaca frog is the top endemic predator of Lake Titicaca, the largest entirely aquatic frog on Earth, and the main ingredient of Jugo de Rana (frog juice), a popular aphrodisiac that does not actually gain anything from the addition of frogs. High demand, in addition to lake water extraction, pollution, and introduced trout, has pushed the species to become critically endangered in recent decades. Denver Zoo maintains a population descended from frogs rescued from the Peruvian market and is working with the Heredia University in Lima, Peru, to protect and save these strange-looking frogs.
Fun fact: their ultra-baggy skin has earned them the nickname “scrotum frog” and the position of runner-up in 2013’s “world’s ugliest animal” contest run by the United Kingdom’s Ugly Animal Preservation Society. Also, they can grow to the size of a dinner plate.
11. Spike-Thumb Frog
Spike-thumb frog populations have declined by 80% in the last decade due to chytrid fungus and illegal deforestation. It is only found in one fragment of montane rainforest in northern Honduras’s Parque Nacional Cusuco, but this habitat has become infested with the fungus. A number of WAZA members work closely with the Honduras Amphibian Rescue and Conservation Center (HARCC) to conserve both species of spike-thumb frog (exquisite and cusuco) in captive populations.
Fun fact: the species earns its name from adult males’ bone spike, which looks like a second thumb and is used for territorial combat.
12. Yellow Spotted Bell Frog
This species was thought to have become extinct in 1979, before it was rediscovered 30 years later in 2009. An ex situ colony was established with tadpoles at Taronga Zoo soon after rediscovery. Only a few years after rediscovery the population at the site crashed due to high adult mortality and low tadpole recruitment associated with the La Niña weather event, and once again disappeared from the wild. In 2017, Taronga Zoo started successfully breeding this species, and have now undertaken the translocation of over 1,700 frogs to two sites in the wild with more planned in the near future.
13. Puerto Rican Crested Toad
Though to be extinct from 1931-1967, habitat loss and invasive species drove the Puerto Rican crested toad to a threatened listing on the IUCN Red List in 1987. Through a Species Survival Plan (SSP) established by the American Zoo and Aquarium Association (AZA) over 300,000 captive-hatched tadpoles have been reintroduced since 1992. The project is still ongoing and is based on a master plan that incorporates community education outreach and habitat protection, restoration, and creation.
Fun fact: studies of the last two wild populations in Puerto Rico showed that they have been genetically separate for up to a million years.
The World Association of Zoos and Aquariums (WAZA) is the global alliance of regional associations, national federations, zoos and aquariums, dedicated to the care and conservation of animals and their habitats around the world.