Frogs and Drought

Cane toad (Rhinella marinus)

The cane toad is an example of an amphibian that has adapted to survive extreme environments.

On this blog, we’ve discussed the challenges facing tropical frogs, especially those susceptible to chytrid fungus. Little discussed, however, are the amazing amphibian survivors in drier climates like deserts, grasslands and savannahs.

These frogs and toads have adapted to survive in an environment that’s very different from the tropical rainforest. Unlike the rainforest, frogs in a dry environment have to seek out rare pools of water to breed. They also have to find ways to prevent massive water loss through their thin skin during extended dry spells.

There are several species of frogs and toads that have developed amazing adaptations to survive in some pretty extreme environments. One of the most common adaptations is called aestivation (also “estivation”). During aestivation, an animal becomes dormant during a dry period to better conserve water or keep cool. Think of it like the dry weather counterpart to cold weather hibernation.

The water-holding frog (Litoria platycephala) of western Australia is a prime example of aestivation. Western Australia is prone to dry spells lasting months or even years. When rain does come, it’s usually in the form of tropical moisture, which means a lot of it and all at once. The water-holding frog takes advantage of this short breeding period to lay their eggs in the pools that form. Once all the water is gone, they bury themselves underground and shed several layers of skin that are thick enough to not only prevent dehydration but also store water. A convenient hole in the skin near the nostrils allows the frog to breathe slowly waiting out the next rainy period.

Aborigines discovered that these frogs could be used as an emergency source of water by squeezing the frog and emptying the almost fresh water for drinking. This doesn’t immediately kill or harm the frog, but it does make it harder for them to survive to the next rainfall.

Around the world, there are other species of frogs that aestivate in the same or similar manner to the water-holding frog. These include the African bullfrog (Pyxicephalus adspersus), cane toad (Bufo marinus) and plains spadefoot toad (Spea bombifrons). All three species are currently listed as “Least Concern” by the IUCN.

Despite their incredible ability to survive dry seasons, there is a limit to how much stress these frog species can handle. Climate change is likely to increase weather extremes, both floods and droughts. Increased drought length or severity could push some of these frogs to the edge where parasites or diseases could severely impact an already weakened population. In order to save all frog species, we’ll have to look high, low and even underground in some pretty dry places!

Andrew Franks, Zoo New England

Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute

References:

Black-eyed beauty.

Morelet's tree frog (Agalychnis moreletii)

Morelet's tree frog (Agalychnis moreletii)

Cute Frog of the Week: January 14, 2013

Also known as black-eyed leaf frogs, the Morelet’s tree frog is striking with its lime-green body, jet-black eyes, and vibrant orange underbelly. Found in moist, subtropical lowland rainforests and wetland habitats of Belize, Brazil, El Salvador, Guatemala, Honduras and Mexico, this small frog species thrives in pristine sub-tropical habitats with permanent bodies of water in which they can breed. During the summer months, they will breed and deposit clutches of 50 to 75 eggs on vegetation or rocks over water. When the eggs hatch, the larvae fall into the water to complete their development into frogs.

Sadly, the Morelet’s tree frog used to be abundant in Central America, but because of chytrid, the species is currently listed as critically endangered by the IUCN.

Photo by Victoria Ogilvy via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Genetic Matchmaking Saves Endangered Frogs

Marsupial frog

The casque headed tree frog (Hemiphractidae: Hemiphractus fasciatus), is one of 11 species of highest conservation concern now being bred in captivity in Panama. Females carry eggs on their backs where the young complete development hatching out as miniature frogs. DNA barcoding data suggest that populations of H. fasciatus may comprise more than one taxonomic group.

What if Noah got it wrong? What if he paired a male and a female animal thinking they were the same species, and then discovered they were not the same and could not produce offspring? As researchers from the Panama Amphibian Rescue and Conservation Project race to save frogs from a devastating disease by breeding them in captivity, a genetic test averts mating mix-ups.

At the El Valle Amphibian Conservation Center, project scientists breed 11 different species of highland frogs threatened by the chytrid fungus Batrachochytrium dendrobatidis, which has already decimated amphibian populations worldwide. They hope that someday they will be able to re-release frogs into Panama’s highland streams.

Different frog species may look very similar.

“If we accidentally choose frogs to breed that are not the same species, we may be unsuccessful or unknowingly create hybrid animals that are maladapted to their parents’ native environment,” said Andrew J. Crawford, research associate at the Smithsonian Tropical Research Institute in Panama and professor at Colombia’s Universidad de los Andes. Crawford and his colleagues make use of a genetic technique called DNA barcoding to tell amphibian species apart. By comparing gene sequences in a frog’s skin cells sampled with a cotton swab, they discover how closely the frogs are related.

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a unit of the Smithsonian Institution. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems.

Beth King, Smithsonian Tropical Research Institute

Photo by Edgardo Griffith.

Caught red-handed.

Riggenbach’s reed frog (Hyperolius riggenbachi)

Riggenbach’s reed frog (Hyperolius riggenbachi)

Cute Frog of the Week: January 7, 2013

The Riggenbach’s reed frog is distinct for its striking red fingers and leopard-like pattern. Native to Nigeria and Cameroon, this species is thriving in West African wetlands and montane grasslands. These terrestrial frogs call at dusk for mates from within stems of waterside plants. Females will then proceed to lay their eggs in still freshwater ponds. Due to habitat loss, this species is currently listed as vulnerable by the IUCN.

Photo by Vaclav Gvozdik via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Frog Poetry and the Washington Post

Washington Post

On Dec. 30, the Washington Post ran a front-page story about the rescue project.

The year ended on a high note for the Panama Amphibian Rescue and Conservation Project. William Booth, a science writer for the Washington Post, joined rescue project researchers on a field expedition and his story about the rescue project came out on the front page of the Post on Dec. 30. The story inspired one reader, Tim Torkildson, to share a lovely poem about frogs and the disease that is wiping them out.

Booth also did this NPR interview about his recent trip to Panama.

If you saw the story and are interested in making a donation to the rescue project, please follow this link to the National Zoo’s website.

THE FROG
by Tim Torkildson

The frog is an amphibian
Who thrives most ev’rywhere,
From the dry Namibian
To just off ol’ Times Square.
The ones who have a bumpy skin,
With warts and pits and nodes,
Are the closest Phylum kin;
We simply call them toads.
The bullfrogs in the early spring
give ponds reverberation
With their raucous verbal fling,
Attempting procreation.
The have a courtship ritual
that’s called, I think, amplexus,
Which gives them fits conniptual
Between the two odd sexes.
A little boy will manage to
Corral a tadpole, yes,
And give it quite a slimy view
Right down his sister’s dress!
And did you know the urine from
a pregnant lady will
cause some frogs to lay a scum
of eggs, with no male thrill?
And so they’re useful critters,
As the French will tell you so;
Their legs taste good in fritters,
Are mistaken for turbot.
And what of cane toads, mind you,
Where, if you lick the skin,
The psychedelics blind you
To sorrow, grief and sin?
But frogs, those little gargoyles,
Which are funny in cartoons,
Are engaged in lethal broils
That leaves their lives in ruins.
A fungus known as “Bd” kills
The frogs down in Belize,
Then jumps the valleys and the hills
So others it may seize.
The Costa Rica Golden Toad
Is now extinct, alack.
More are headed down that road,
Since habitat is slack.
Toxins give some frogs three legs,
Which doesn’t help them jump.
Instead they are like clumsy kegs
Who in the water flump.
Scientists preserve some frogs
In habitats in labs.
Dressed in their starched, stiff white togs
They keep meticulous tabs.
To save the frogs, oh please donate
A dollar or a yuan,
So the polliwog birth rate
Will someday be a shoo-in!

Say cheese!

Axolotl (Ambystoma mexicanum)

Axolotl (Ambystoma mexicanum)

Cute Amphibian of the Week: December 31, 2012

The axolotl (Ambystoma mexicanum), native to Mexico, is a salamander of variety; its skin can be either grey and dull or albino-like and fleshy.  This species is native to the ancient system of water channels and lakes in Mexico City. This salamander is quite particular–it requires deep water lakes (both natural and artificial canals) with abundant aquatic vegetation. The axolotl should be renamed “Hoover,” since they can suck food into their stomachs with vacuum force, including their own species, should the desire arise.

Their most interesting feature, however is their healing ability, which allows them to regrow whole limbs through the generation of stem cells from the remaining cells left of the limb, making this species virtually “indestructible.” The desiccation and pollution of the canal system, as well as the traditional consumption of the species by locals, is threatening the survival of the axolotl. The species is listed as critically endangered by the IUCN.

Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Feelin’ festive.

Small tree frog (Rhacophorus lateralis)

Small tree frog (Rhacophorus lateralis)

Cute Frog of the Week: December 24, 2012

The small tree frog species sports its holiday cheer with its vibrant red and green coloration. However, this frog is as mysterious as Santa Claus himself. The species was discovered in the late 1800s, but it had not been seen until 2000 when a research team rediscovered it living in the Western Ghats region of India. Found only in tropical rainforests and deciduous forests of this region, this arboreal tree frog breeds on vegetation overhanging small pools where the tadpoles eventually develop. Researchers have noted that the small tree frog can change color within 5 seconds (bright brown and/or coffee-colored spots) when handled. Because of habitat loss, the species is currently registered as endangered by the IUCN.

Photo by Sunil Sachi M.J. via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

What a “bewdy!”

Northern corroboree frog (Pseudophryne pengilleyi)

Northern corroboree frog (Pseudophryne pengilleyi)

Cute Frog of the Week: December 17, 2012

The striking Northern corroboree frog (Pseudophryne pengilleyi) is only slightly different from the more common corroboree frog (Pseudophryne corroboree) in that its stripes are a greener shade of yellow and are also a little narrower. Found in the bogs within the northern Australian Alps of New South Wales, these frogs are a prized Australian amphibian species. In some areas, ‘corroboree’ is an aboriginal word for a gathering or meeting—where traditionally the attendees are adorned with yellow markings not unlike those of this rare frog. Sadly, this stunning species is registered as endangered by the IUCN. Their decline has been the result of chytrid, erosion, habitat loss and the introduction of plant species such as blackberry and monkey rusk that are destroying the frog’s breeding grounds.

Photo by Lydia Fucsko via Arkive.

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Just like Daredevil. Only cuter.

Olm (Proteus anguinus)

Olm (Proteus anguinus)

Cute Amphibian of the Week: December 10, 2012

The olm (Proteus anguinus) native to Bosnia and Herzegovina, Croatia, Italy, and Slovenia and introduced in France, is unique because of its pigmentation, which resembles human skin. This species generally occurs in large subterranean aquatic karst systems formed in limestone and dolomite rocks, and may be found in cave entrances and abandoned mine workings. This salamander is the old man of the bunch having a maximum lifespan of over a century.

Just because it’s blind does not mean the olm is defenseless. With its super-hearing abilities the olm can receive sound waves in the water as well as vibrations from the ground. Interestingly enough, this salamander will never have to ask for directions; instead it uses the earth’s magnetic field to orient itself. The main threats to this species are changes to the forested and pastoral land above the subterranean systems, largely through tourism, economic changes, and increasing water pollution. At the current time the species is listed as vulnerable by the IUCN.

Photo credit: AJ Cann

Every week the Panama Amphibian Rescue and Conservation Project posts a new photo of a cute frog from anywhere in the world with an interesting, fun and unique story to tell. Be sure to check back every Monday for the latest addition.

Send us your own cute frogs by uploading your photos here: http://www.flickr.com/groups/cutefrogoftheweek/

Superhero Qualities in Frogs

Red-eyed tree frog

Frogs are helping researchers answer important questions about health and medicine.

In many Native American cultures, frogs are valued for their medicinal properties and are considered to have healing powers.

Modern day science certainly backs this up. For instance, most frogs produce skin secretions of amino acid compounds called peptides that protect their sensitive and porous skin from bacterial and fungal infections. The presence of these peptides even discourages predators, which find the peptides unappetizing. Scientists have discovered an Australian tree frog with peptides that can kill bacteria resistant to conventional antibiotics.

Poison from a South American poison dart frog is being analyzed for use as a painkiller. One such chemical is a painkiller 200 times as potent as morphine.

The gastric brooding frog swallowed their eggs and gave birth through their mouths. During this time, the frogs’ stomachs temporarily stopped producing hydrochloric acid. This condition could have provided insight on the treatment of stomach ulcers in humans; unfortunately, both species of brooding frog are believed to be extinct.

Frogs seem to have some pretty powerful superhero properties. Not only are they full of amazing traits that can be explored for medicinal purposes but they also help keep pest populations under control.  Without frogs, our lives would be a lot different, and not in a good way. So show some love for our fellow frogs. They have our best interests at heart. We should do the same for them.

Cindy Hoffman, Defenders of Wildlife

(Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)