Frogs & Toads

Baby "Riot Frogs"

The calls of the Mission golden-eyed tree frog are among the loudest of all frogs. They always take place three times in a row and the noise level is comparable to that of a car horn. In 2021, new individuals came from Zurich Zoo to Zoo Vienna. Now, after a break of a few years, there are offspring of these “riot frogs” once again at the Zoo.

“Mission golden-eyed tree frog is particularly exciting because it lives in the treetops of tropical rainforests in the Amazon region. It uses water-filled tree cavities at a height of up to 30 meters to lay its eggs. The people there hardly ever see him, they only know him from his loud calls. The males have two extraordinarily large acoustic sacs,” explains Anton Weissenbacher, Head of the Zoological Department.

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Meet Olaf, the IVF Toad

Olaf side

You aren’t going to see this guy on the big screen any time soon, but he and others just like him may end up in their native habitat very soon. This tiny toad is the world’s first Puerto Rican crested toad hatched from in-vitro fertilization (IVF) utilizing frozen semen collected from the wild.

Olaf front view

The Fort Worth Zoo and its partners from Mississippi State University came together at the Fort Worth Zoo this summer to continue their efforts with assisted reproduction technology (ART) for critically endangered amphibians. For the first time ever, they were able to successfully conduct IVF using the eggs from two Zoo females and frozen semen from six wild males. To celebrate this conservation success, the first egg to be fertilized and hatched has been named Olaf! (Yep, just like that Olaf.)

This is a significant advancement for the critically endangered species as it will allow zoos, researchers and other conservationists to expand their population genetics used to increase the overall population while keeping the toads in their wild, natural habitat. These ART efforts will help maintain a genetically diverse, self-sustaining population of toads in the managed population without removing animals from the wild!

Since 2006, Zoo staff has coordinated and managed a Puerto Rican Crested Toad conservation program, under the direction of Fort Worth Zoo Curator of Ectotherms Diane Barber. Through this cooperative program, thousands of Puerto Rican crested toad tadpoles are released into the wild each year. As the longest continuous reintroduction program for any amphibian species, the Puerto Rican crested toad project has released over 510,000 tadpoles at six reintroduction sites since 1992 – the Fort Worth Zoo alone has released 70,988 of those tadpoles.


Vancouver Aquarium Releases Endangered Tadpoles

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More than 1,600 endangered Northern Leopard Frog tadpoles, raised at Vancouver Aquarium, an Ocean Wise initiative, were released into a natural habitat in the Kootenays on June 6, 2018.

This is the sixth consecutive breeding year for the conservation program that aims to boost the wild population of the Northern Leopard Frog (the most endangered amphibian in British Columbia) and the second largest number of tadpoles produced in a single year. In collaboration with the Northern Leopard Frog Recovery Team, Vancouver Aquarium has raised and released more than 7,100 Northern Leopard Frog tadpoles since 2013.

“This year was a banner year for our Northern Leopard Frog conservation program and we couldn’t be more pleased. We added two large frog ponds to the existing three and, as a result, saw improved breeding, more fertilized egg masses, and more tadpoles,” said Kris Rossing, senior biologist at Vancouver Aquarium. “We know that changes in environment impact Northern Leopard Frogs and their reproductive cycles both in the wild and here at the Aquarium; this results in varying numbers of egg masses and tadpoles produced. Every year we learn more and more about these frogs and their reproductive needs which helps us continually refine our propagation practices and maximize the impact of our conservation efforts.”

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3_2018 Northern Leopard Frog Release - New Ponds - Credit Ocean Wise

4_2017 Northern Leopard Frog Release_Mark Yuen for Vancouver Aquarium_IMG_1118Photo Credits: Vancouver Aquarium/Ocean Wise (Image 3)

For the past six years, Northern Leopard Frogs produced at the Vancouver Aquarium have been dedicated to re-establishing a population in a natural habitat near Brisco, B.C. For the past two years, the Recovery Team has heard adult males calling at this release site; this is a positive indication that the frogs are surviving winter and reaching sexual maturity, and that the program is successful in helping the vulnerable Rocky Mountain population.

Early morning on June 6, the tadpoles were diligently transported to the Kootenays, first by car to YVR then by plane to Cranbrook, B.C. Received by members of the Recovery Team, the tadpoles were then transported by car for an additional two hours, and then by kayak to their new home in the marshy wetlands along the Columbia River near the Alberta border.

Vancouver Aquarium was the first aquarium to breed the amphibians as part of an assurance population and is part of a worldwide effort, along with other zoos and aquariums, to conserve this and other amphibian species under the Amphibian Ark (AArk) project.

A key component of the propagation process involves collaboration with Dr. Vance Trudeau at the University of Ottawa and the use of a hormone treatment he created called Amphiplex. The treatment, which is a painless injection into the frogs, has been used to help induce spawning and spur the animals into amplexus — when the male mounts and holds the female frog to induce ovulation and then fertilizes the eggs as they are laid.

Beginning in the 1970s, populations of Northern Leopard Frogs (Lithobates pipiens) across western Canada declined by the millions, making them one of the most at-risk amphibian species, especially in B.C. Research continues into the cause of these sharp declines in the Rocky Mountain population of the Northern Leopard Frogs. The Rocky Mountain population that occurs in B.C. is listed as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and is on the provincial Red List.

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Dyeing Dart Frog Eggs Hatch at Stone Zoo

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April is National Frog Month, and Stone Zoo is celebrating their first successful hatching of Dyeing Dart Frog eggs.

The eggs require special care to reach the tadpole stage. The water conditions must be just right. The first little tadpole (in photo below) has been named Thad. He shares his aquarium with a snail named Chad.

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DyeingDartFrogTadpole2Photo Credit: Stone Zoo

The tadpoles breathe with gills underwater. They gradually develop legs, then lungs. and they metamorphose into adult Frogs. Along with Toads and Salamanders, Frogs are Amphibians. Amphibians are known as indicator species, because they can absorb environmental toxins through their skin. Ecosystems with large numbers of Amphibians are generally healthy.

Dyeing Dart Frogs are a type of Dart-poison Frog. These Frogs live in the moist forests of Guyana, Surname, Brazil, and French Guiana, where they feed on ants, mites, and termites.  Chemicals from their prey are accumulated in the Frogs’ skin glands, rendering the Frogs poisonous to the touch.

There are more than 170 species of Dart-Poison Frogs.  About four of those species have been documented as being used to create poisonous blowdarts. To create these poisonous darts, indigenous peoples apply the Frogs’ skin secretions to the darts’ tips.

In the video above, a Magnificent Tree Frog, native to Australia, munches on crickets. Zoo keepers use the crickets to lure the Frogs from their hiding places each morning, allowing the staff to account for each Frog under their care.

Stone Zoo is a partner in the Panama Amphibian Rescue and Conservation Project, which works to protect existing amphibian populations and introduce captive-bred Frogs into the wild.

 


Aquarium Breeds Endangered Frogs to Boost Wild Population

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The Vancouver Aquarium is helping one of the world’s most at-risk amphibians by raising and releasing hundreds of healthy Northern Leopard Frog tadpoles into the wilds of British Columbia, Canada. 

The release is part of the Northern Leopard Frog Recovery Team’s efforts to restore a species that was once widespread across Canada. Beginning in the 1970s, millions of frogs died, leaving just one small group of Northern Leopard Frogs remaining in western Canada. The Rocky Mountain population of this species is listed as Endangered in Canada.

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2017 Northern Leopard Frog Release_Mark Yuen for Vancouver Aquarium_IMG_1376Photo Credit: Mark Yuen for Vancouver Aquarium

Vancouver Aquarium was the first aquarium to breed the Frogs in captivity as an assurance population in case the wild population completely collapsed. A collaboration with researchers at the University of Ottawa utilizes hormones to induce spawning and mating behavior in the captive frogs.

Each year, tadpoles and young frogs bred at the aquarium are released back into the wild in suitable habitats to reestablish the species. By rearing the young in captivity, a process called “headstarting,” the odds of survival to adulthood are increased. Over the last five years, the aquarium has released thousands of Northern Leopard Frog tadpoles.

Headstarting programs are emerging as an important tool for rebuilding wild animal populations, and zoos and aquariums are perfectly suited for such projects. Zoos and aquariums have the expertise and facilities to care for and breed amphibians such as these frogs.

“We’re beginning to see the impact of our efforts to repopulate B.C.’s most at-risk amphibian, and have found animals that have survived the winter and are being located again year after release,” said Kris Rossing, senior biologist at Vancouver Aquarium. “Frogs are an important indicator species of environmental health. Overall, we’ve seen our conservation efforts make a difference, as we collectively move the needle a little bit every year through this vital program.”

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Endangered Tadpoles Set for Release to the Wild

1_Wyoming toad - Jennie Miller

The Detroit Zoological Society’s (DZS) conservation breeding program for the Wyoming Toad continues to make strides for this federally endangered amphibian. Seven hundred tadpoles have been produced in the Detroit Zoo’s National Amphibian Conservation Center and were scheduled to be shipped to Wyoming on July 5 for eventual release into the wild.

“It’s exciting to share our continued success with this program. We’ve had recording-breaking years in the past and are committed to ensuring the survival of this species as well as many others,” said Scott Carter, DZS chief life sciences officer. “Amphibians are the most endangered animals in the world, with more than 40 percent of all species at risk.”

The tadpoles were scheduled to be released into a protected Wyoming wetland in the Laramie Basin, where they will hopefully metamorphose into toadlets. The metamorphosis usually occurs in mid-July, and takes approximately four to five weeks.

Wyoming tadpoles 1 - Jennie Miller

Wyoming tadpoles 2 - Jennie Miller

Wyoming tadpoles 3 - Jennie MillerPhoto Credits: Jennie Miller / Detroit Zoo

The Wyoming Toad (Anaxyrus baxteri) is a dark brown, gray or greenish amphibian with small, dark blotches. The average length is 2.2 inches, with the females slightly larger than the males.

Once abundant in the wetlands and irrigated meadows of Wyoming’s southeastern plains, the Wyoming Toad was listed as extinct in 1994, meaning populations are no longer producing offspring that survive to adulthood in the wild. The cause of the decline is not well understood, but it is likely that more than one factor contributed to the situation in the past, with habitat loss and infectious diseases suspected as major drivers.

In 2007, the DZS’s collaborative breeding program for the Wyoming Toad was “No.1” on the Association of Zoos & Aquariums’ list of the Top 10 wildlife conservation success stories. The breeding partnership has successfully released more than 8,000 tadpoles, toadlets and toads in Wyoming since the program’s inception in 1995. Once released, these latest tadpoles should add to that number.

The National Amphibian Conservation Center opened at the Detroit Zoo in 2000 and was distinguished as the first major conservation facility dedicated entirely to conserving and exhibiting amphibians. It houses a spectacular diversity of frogs, toads, salamanders, newts and caecilians – including the Wyoming Toad. Dubbed “Disneyland for toads” by The Wall Street Journal, this award winning, state-of-the-art facility is world renowned for amphibian conservation, care, exhibition and research.


Titicaca Frogs Hatch for First Time in North America

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Denver Zoo is thrilled to announce the February 14th hatching of the first batch of Lake Titicaca Frog Tadpoles in North American history. The roughly 200 tadpoles are the offspring of two of the 20 frogs that arrived from the Huachipa Zoo, in Lima, Peru, in November 2015.

Currently, Denver Zoo is the only institution in the northern hemisphere to house this critically endangered species. Zookeepers have been watching the tadpoles carefully since their hatching and say they are doing great. Most of the tadpoles can now be seen at the Zoo's Tropical Discovery building.

It has been more than 20 years since a Lake Titicaca Frog has resided in the United States. Since the initial arrival of the Zoo’s Lake Titicaca Frogs, Zoo staff members have studied their behavior and looked to increase their population. The Zoo’s goal has been to raise awareness of the plight of these amphibians while also gaining important insight into the care of the species. Eventually, when the tadpoles develop into frogs, some will stay at Denver Zoo while many will be rehoused at other Association of Zoos and Aquariums (AZA) accredited institutions, furthering the message of conservation and awareness for this neglected species.

“In the time we’ve had the Lake Titicaca Frogs, we have gained so much insight to this unique species,” said Assistant Curator of Reptiles and Fish Tom Weaver. “We feel very proud that we are able to provide that opportunity.”

Since 2007, Denver Zoo has worked with partners in Bolivia and Peru to conserve the species and is currently the only zoo in the United States to support research in Peru. In addition, Denver Zoo also has staff based in Peru who are working with other zoos, local government, and in the field to further conservation efforts for the Lake Titicaca Frog.

“This hatching and the research we’ve done with Lake Titicaca Frogs at the Zoo and in Peru speaks to our role as a true conservation organization,” said Director of Conservation Education Matt Herbert, “Our work is raising much-needed awareness for the plight of this frog for our guests, children and adults, and will soon do the same for those who visit the other institutions which will soon be a home for the species.”

LT Tadpoles 2Photo Credits: Denver Zoo

The Lake Titicaca Frog (Telmatobius coleus), the world’s largest entirely aquatic frog, lives only in its namesake lake and the surrounding rivers and streams of the catchment. Lake Titicaca is one of the world’s highest navigable lakes, lying about 12,500 feet above sea level and straddling the Peruvian and Bolivian border.

The frogs can grow up to 20 inches long and weigh more than 2 pounds. The species’ saggy, seemingly excessive, skin absorbs oxygen, allowing it to remain submerged indefinitely while still breathing and able to respire.

The Zoo’s first population of frogs hatched as tadpoles in March of 2015 at Huachipa Zoo, in Peru. Their parents were the offspring of wild-born frogs that were confiscated by authorities on their way to a market for consumption purposes.

Although illegal, local Peruvians and Bolivians routinely harvest the frogs. In Peru, the frogs are consumed in a shake-like drink that is believed to enhance virility, among other benefits. This, along with disease, pollution and the introduction of invasive species, are main reasons the species faces extinction. According to the International Union for the Conservation of Nature (IUCN), the Lake Titicaca frog’s population has declined 80 percent over the last three generations and it is now classified as “Critically Endangered.”

While there is much conservation effort in Peru, there is little work being done on amphibians of the high Andes, which makes this project so important. Denver Zoo, working with local governments, leads conservation efforts in support of the frogs, such as conducting research and raising awareness about them, while also empowering local communities to prevent their extinction. Educators teach school children about the importance of the species and support local communities in their efforts to earn a living from the frog through handicraft sales and tourism.

Due to these efforts, the Lake Titicaca frog has recently transformed into a symbol of pride for the people of Puno, the largest Peruvian city that borders the lake. In 2012, the Regional Government of Puno issued an ordinance declaring the frog a tourist attraction in the Lake Titicaca region.


Zoo Keepers Make It Rain For Endangered Frog

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Paignton Zoo Environmental Park has bred a Critically Endangered frog for the very first time.

Keepers from the charity’s Lower Vertebrates and Invertebrates Department used artificial rainstorms to help set the mood for the Lemur Leaf Frog, a species found mainly in the rainforests of Costa Rica and Panama.

Paignton Zoo is one of only four collections in the UK working with this species. Keeper Andy Meek, from the Lower Vertebrates and Invertebrates Department, explained, “We have a total of 18 tadpoles, a number of which have now become full froglets. We also have 10 adults. The species is Critically Endangered. There is a studbook currently being set up to manage this species in Europe. This is a first for Paignton Zoo, so I’m really pleased.”

The keepers prepared a rain chamber using a water pump and a timer system to make it rain every few hours during the day. The rainfall and the humidity together helped to replicate the sort of conditions the frogs would encounter at the start of the wet season, which is when they breed.

This is a tiny but welcome success in the face of the huge extinction crisis facing amphibians.

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3_2016 09 PZ adult lemur leaf frog 1Photo Credits: Paignton Zoo

The Lemur Leaf Frog (Agalychnis lemur) is a slender, lime-green frog with bulging eyes and no webbing on hands and feet. It is a nocturnal tree frog associated with sloping areas in humid lowland and montane primary forest.

Their eggs are usually deposited on leafs; the larvae wash off or fall into water.

This endearing little frog also has a trick up its sleeve: it can change color. Light green during the day, and it turns a less obvious reddish-brown at night when it is active.

It was once considered to be reasonably common in Costa Rica, but most populations have now disappeared. The species is classified as “Critically Endangered” on the IUCN Red List of Threatened Species. The huge declines are probably due to the chytrid* fungus, which is decimating amphibians around the world.

(*Chytridiomycosis is an infectious disease in amphibians, caused by the chytrid Batrachochytrium dendrobatidis, a nonhyphal zoosporic fungus. Chytridiomycosis has been linked, by experts, to dramatic population declines and extinctions of species in western North America, Central America, South America, eastern Australia, and Dominica and Montserrat in the Caribbean.)


Cotswold Wildlife Park Breeds Mossy Frogs

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Meet the ultimate camouflage artist --- a brand new species to Cotswold Wildlife Park, the Vietnamese Mossy Frog (Theloderma corticale).

Reptile keepers are thrilled with the first successful breeding of this species at Cotswold Wildlife Park. Eight Mossy Froglets are currently under the watchful eye of the dedicated Reptile Team, along with several tadpoles yet to metamorphosise. At this delicate stage of their development, the froglets remain off-show in the Reptile Incubation Room. Visitors will be able to see the new species later this year. Updates will be posted on the Park’s Facebook and Twitter pages: (www.facebook.com/cotswoldwildlifepark and @CotsWildTweets).

Curator of Cotswold Wildlife Park, Jamie Craig, commented, “We treat the rearing of any amphibian to adulthood as a success. The metamorphosing stages can be very tricky and we are delighted to have had repeatable successes with our Mossy Frogs. They are growing well and we hope to create a new display for them in the near future.”

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4_Mossy Froglet close up on 20p piecePhoto Credits: Cotswold Wildlife Park

In scientific terms, these remarkable amphibians are a relatively recent discovery. Their first recorded sighting was in 1903, originating from the steep mountain slopes of Northern Vietnam. Due to their remote location, they have been out of reach for scientists and researchers for decades, and very little is known about this species in the wild. They are currently protected by the Vietnamese government.

Their camouflage has been described as one of the best in the amphibian world. Rough, bumpy skin, combined with complex green and black coloring, makes them almost indistinguishable from a lump of moss or lichen, enabling these tiny frogs to blend in perfectly with their surroundings and avoid detection by predators. When frightened, they curl into a ball and remain motionless, mimicking death to avoid further harm.

In the wild, this species breeds by larval development in rock cavities containing water and also in tree holes. It takes approximately one year for a tadpole to become a fully developed adult. Researchers have discovered that Mossy Frog tadpoles can exist in water for months without developing, but they metamorphose into froglets within days when the water dries up.

Frogs have appeared in legend and folklore in many cultures throughout history. Chinese legends involving frogs date back to 4 B.C. - 57 A.D. Special temples were built specifically for frogs. In these temples, live frogs were encouraged to stay with offerings of food and water. When the amphibians wandered away from their appointed homes, they would be brought back to the temple accompanied by drums and music. In ancient Egypt, carvings and religious statues were made in the image of frogs. Archaeologists have also discovered embalmed frogs in some Egyptian burial sites.

In the wild, the Mossy Frog’s population numbers are under threat from habitat destruction and demand by the global pet trade, and they are also known as the Tonkin Bug-eyed Frog.

Check out the great photos of Mossy Frog adults--below the fold!

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Newly Described Poison Dart Frog Hatched in Captivity

Photo Jorge GuerrelSmithsonian Tropical Research Institute

Smithsonian Conservation Biology Institute (SCBI) and Smithsonian Tropical Research Institute (STRI) scientists, working as part of the Panama Amphibian Rescue and Conservation Project, hatched the first Andinobates Geminisae Froglet born in captivity.

Photo Jorge GuerrelSmithsonian Tropical Research Institute (2)

Adinobates geminisae tadpole_3_Photo Brian GratwickeSmithsonian Conservation Biology Institute

Adinobates geminisae tadpole_Photo Brian GratwickeSmithsonian Conservation Biology InstitutePhoto Credits: Brian Gratwicke (Images: 3,4,5,6) ; Jorge Guerrel (Images: 1,2 7,8)

The tiny poison dart frog species only grows to 14 millimeters and was first collected and described last year from a small area in central Panama. Scientists collected two adults to evaluate the potential for maintaining the species in captivity as an insurance population.

“There is a real art to learning about the natural history of an animal and finding the right set of environmental cues to stimulate successful captive breeding,” said Brian Gratwicke, Amphibian Conservation Biologist at SCBI and Director of the Panama Amphibian Rescue and Conservation Project. “Not all amphibians are easy to breed in captivity, so when we do breed a species for the first time in captivity it is a real milestone for our project and a cause for celebration.”

Scientists simulated breeding conditions for the adult frogs in a small tank. The frogs laid an egg on a bromeliad leaf, which scientists transferred to a moist petri dish. After 14 days, the tadpole hatched. Scientists believe adult Andinobates Geminisae Frogs may provide their eggs and tadpoles with parental care, which is not uncommon for dart frogs, but they have not been able to determine if that is the case. In the wild, one of the parents likely transports the tadpole on his or her back to a little pool of water, usually inside a tree or on a bromeliad leaf.

After the tadpole hatched, scientists moved it from the petri dish to a small cup of water, mimicking the small pools available in nature. On a diet of fish food, the tadpole successfully metamorphosed into a froglet, after 75 days, and is now the size of a mature adult.

Panama Amphibian Rescue and Conservation Project scientists are unsure if Andinobates Geminisae Frogs are susceptible to the amphibian-killing chytrid fungus. However, since it is only found in a small area of Panama and is dependent on primary rain forests, which are under pressure from agricultural conversion, they have identified it as a conservation-priority species.

The Panama Amphibian Rescue and Conservation Project breeds endangered species of frogs in Gamboa, Panama and El Valle, Panama. The Panama Amphibian Rescue and Conservation Project is a partnership between the Houston Zoo, Cheyenne Mountain Zoo, New England Zoo, SCBI and STRI. This study was supported by Minera Panama.

More amazing photos, below the fold!

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