Millie reports the news that is relevant to frogs (and their humans). Watch for frequent updates. 

The North American wood frog survives the winter with a heart-stopping strategy.  This frog, found from southern Ohio up to the Arctic Circle, puzzles researchers with its ability to literally "freeze and thaw" along with normal winter-spring weather patterns.

To survive winter's freezing temperatures, the frog doesn't fight the temperatures; it just freezes from the outside-in.

Jon Costanzo, a professor at Miami University in Ohio, studies amphibians that live in harsh climates, especially cold ones.  His research was featured on NOVA's "scienceNOW," a television magazine series on PBS.  The "Frozen Frogs" episode shows Costanzo holding a frozen frog in the laboratory, as well as identifying the frigid amphibians in their natural environment. 

At the first sign of ice in late fall or early winter, the frog freezes solid as a rock. 

"That touch of ice immediately sets off signals inside the frog that pulls water away from the center of its body, so the frog's internal organs are now wrapped in a puddle of water that then turns to solid ice," says Costanzo in "Frozen Frogs." 

The frog's heart stops beating, its kidneys stop functioning and its respiration ceases--for months.  The frogs endure this suspended animation by producing a type of antifreeze made with glucose, keeping the water in their cells in a liquid state at temperatures below 32 degrees Fahrenheit (0 degrees Celsius).

When warmer spring temperatures trigger the frog to thaw, its heart and brain thaw first, followed by its body, all in perfect synchrony.  Costanzo refers to this series of events as "a spontaneous resumption of function."  Within 10 hours, the frog is fully functional.

Costanzo and others are studying this amazing phenomenon in hopes of discovering new technology to preserve human organs that are destined for transplantation.

"Currently it's not possible to freeze human organs for transplantation," said Costanzo, "yet the wood frog and several other amphibians and reptiles have solved not only the problem of freezing individual tissues and organs, but also that of simultaneously freezing all organ systems."

According to the Scientific Registry of Transplant Recipients, more than 85,000 patients were on the national waiting list for an organ transplant as of June 2004.  At present, a heart can be persevered for only five hours before it must be implanted into a recipient; a kidney might last 72 hours.  If organs could be preserved longer, more time would be available for both the recipient and the associated surgical team, leading to improved transplantation success rates.

Costanzo's research on freeze tolerance and metabolic depression in hibernating animals is supported in part by the National Science Foundation's (NSF) Division of Integrative Organismal Biology. 

 

    In that same vein, a tree frog was found in the freezer of an Australian cafeteria. The human was going to trash the frog but a smart friend, another human said sometimes they can be frozen. Well, sure enough when the first human rubbed the frog's back it revived and started breathing. Of course the moral of this is that a frozen frog has not necessarily croaked. (sorry)
 

Nation

Frog species disappearing

But researchers are fighting for the little guys

MILWAUKEE — It's the frog version of the Ebola virus: a disease so rapacious it kills nearly every croaker it encounters.

Steamrolling its way south through Central America and across the Caribbean, the fungus known as chytrid is killing millions of frogs — wiping out entire species and tipping ecosystems out of balance as these amphibious keystone species are expunged from existence.

And while scientists don't know how to stop this fungal fury, they are — with help from three Milwaukee County Zoo employees — trying to bide time by collecting, disinfecting and housing the survivors, in hopes that a few will pull through and someday recolonize the cloud and montane forests the fungus has plundered.

The fungus, which probably originated in Africa, kills by thickening the frogs' skin, such that the inward flow of oxygen and outward expiration of carbon dioxide are restricted — in effect, suffocating the animal.

Berg and two other frog experts at the zoo — Craig Pelke and Shawn Miller — are helping researchers in Panama salvage the few remaining frogs, while simultaneously studying frogs from Grenada, where the fungus has yet to hit.

They hope that by understanding the behavior and biology of the frogs, as well as figuring out how to get them to breed in captivity, they might someday reclaim the forests for the frogs.

"It's kind of like what AIDS was in the 1980s," said Craig Berg, the zoo's reptile and aquarium curator, referring to the research community's urgent response to a new global threat. Indeed, just as doctors and epidemiologists raced to answer the most basic questions about HIV and AIDS — such as, how does the disease travel? Where does it live? And how did it get here? — so too are herpetologists and zoologists in the case of chytrid (pronounced KIT-rid).

Zoological epidemiologists say the earliest known evidence of the fungus can be found on a 1938 preserved specimen of a South African clawed toad, Xenopus laevis. Like the fruit fly or white mouse, Xenopus frogs are ubiquitous features of molecular biology laboratories around the world.

Frogs are critical parts of food chains. Not only are they eaten by larger animals such as birds and mammals, they also consume insects such as mosquitoes.

 

 

 

Scientists to discuss acacia link to Bornean frogs

 

Sabah and Sarawak are now considered the world's tropical hotspot for frogs. NST

KUCHING (NST) - A world-renowned American scientist will be in Bintulu next month to discuss the importance of acacia plantations in Sarawak to the conservation of Bornean frogs.

Professor Dr Robert Inger, the Curator Emeritus at Field Museum of Natural History in Chicago, will join scientists and researchers at the regional conference on "Biodiversity Conservation in Tropical Planted Forests in Southeast Asia" from January 15 to 17.

During his latest research in Sabah and Sarawak, Inger found 148 species of frogs, making the area one of the tropical world's hotspots for these animals.

In a statement on Thursday, the Sarawak Forestry Corporation said the conference would determine the effects of acacia on the frogs.

It said a survey was conducted recently on frogs living in acacia plantings and the secondary forests of the Planted Forest Zones (PFZs) of Sarawak.

In 89 days, 41 species of frogs were found in the PFZ, 29 of them in acacia plantings.

There will be three main sessions during the conference - planning and management, community participation and sustainable use, and biodiversity inventory and monitoring.

 
     

 

 

 

Flying Frogs

 

While many of New York’s snow birds head south to Puerto Rico for time in the sun, a recent batch of first-time fliers—born and raised in the city—are heading down for a different reason: to save their own species.

 

Tadpoles generally do not fly, unless they are part of a reintroduction program to save the Puerto Rican crested toad, according to the Wildlife Conservation Society (WCS).

 

Specifically, animal husbandry experts from WCS have successfully reared nearly 500 tadpoles at the Central Park Zoo and recently released them in Puerto Rico’s Guanica State Forest.

 

“The release went well, and we’re hoping that this new generation of toads can help secure a future for this species” said Bruce Foster, Collections Manager for WCS’ Central Park Zoo. “Puerto Rico is an island of great natural beauty, and protecting the natural inhabitants of the island is an important part of preserving that beauty.”

 

Researchers flew down to Puerto Rico and made a rendezvous with other participants at the release site: a manmade pond in Guanica State Forest. Combined with contributions from the other zoos, a total of 2,700 tadpoles were released into the pond.

 

Unlike the coqui, a small and widespread tree frog that is Puerto Rico’s most popular amphibian, the Puerto Rican crested toad—with its distinctive, upturned snout, warty skin, and gold-colored eyes—has declined dramatically in number.

 

Formerly a denizen of both Puerto Rico and the Virgin Islands, the toad is now only found in Guanica State Forest. The reasons for the decline: loss of habitat, and threats from introduced species such as the mongoose, rat, and the giant marine toad, the last of which competes with the Puerto Rican crested toad for the same resources. The species is now listed as Threatened on the U.S. Endangered Species Act, and as Critically Endangered according to the World Conservation Union (IUCN).

 

 

 

 

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