Conserving Frogs and Identifying an Invader in Panama

A group of researchers at the Smithsonian Tropical Research Institute confirmed this frog's identity as the "greenhouse frog," Eleutherodactylus planirostris. (Photo courtesy of STRI)

A team of dedicated amphibian caretakers, volunteers and Smithsonian scientists assembled their field gear, chytrid swab kits and swamp boots. Preparation was imperative for the week-long field expedition to the remote tropical rainforest in the Darien Province of eastern Panama. The team’s intention was to survey the site, still relatively untouched by fungal amphibian disease, and to collect individuals of species targeted for conservation at the captive rearing and breeding facility at the Smithsonian Tropical Research Institute (STRI). As had been the case in the last expeditions to these little-studied places, there was also a high probability of finding new species.

But storms made it impossible to land a plane at the site, so the trip was canceled. Disappointed, the team went back to work at the captive-breeding facility.

At the same time, another group of researchers at STRI identified another species of frog. Instead of being “new” to biology, this was an invader, native to the islands of the Caribbean, but new to Panama. In late 2008, herpetologists heard unusual calls in the gardens of suburban Panama City. A lack of local knowledge and individuals for comparison made definite identification difficult at first, so a genetic technique called DNA barcoding was employed to finally confirm the frogs’ identity as the “greenhouse frog,” Eleutherodactylus planirostris. Since then, many more individuals have been collected, confirming their presence.

DNA barcoding complements the more traditional techniques of identifying species based on body shape and size. Barcoding uses standardized snippets of mitochondrial genes that vary between species but not within individuals of the same species. DNA from the greenhouse frog was compared to sequences available in large worldwide databases like GenBank, kind of like matching the picture of a criminal to one of the faces in a line-up of suspects.

In 2010, a group of scientists working at STRI published a paper on amphibian diversity established using DNA barcoding. The paper and study came in the wake of massive frog species die-offs in central Panama caused by the fungal disease chytridiomycosis. “This is the first time that we’ve used genetic barcodes—DNA sequences unique to a given species—to characterize an entire amphibian community,” said Eldredge Bermingham, STRI director and co-author. “STRI has also done barcoding on this scale for tropical trees on in our forest dynamics-monitoring plot in Panama. The before-and-after approach we took with the frogs tells us exactly what was lost to this deadly disease in this area—33 percent of their evolutionary history.”

Applying a technique like barcoding in new places results in new knowledge and also raises many more questions than it answers.  What will the effect of the loss of so many frog species be on the insects that the frogs ate and on the snakes and birds that ate the frogs?  How did an invasive frog species arrive in Panama City from the Caribbean?  More updates soon….from Panama!

–Charlie Hruska, Columbia University and Panama Amphibian Rescue and Conservation Project volunteer

The escape artist.

Giant barred frog (Mixophyes iteratus)

Giant barred frog (Mixophyes iteratus)

Cute Frog of the Week: Nov. 28, 2011

The Houdini of Australia’s rainforest, the great barred frog, is an escape artist who has plenty of tricks to help it elude predators. Growing up to 8 centimeters in length, these frogs are often dark brown in color, which helps them blend in with the fallen leaves. To further camouflage themselves, barred frogs will stiffen and flatten their backs to avoid detection on the forest floor. If spotted, they have webbed feet on their powerful hind legs that allow them to leap great distances into streams and rivers where they quickly swim away. Even the youngsters have special gambits. After mating, the females deposit eggs along the river bank. Usually the first rain washes the eggs into the stream where the tadpoles hatch. However, the rains don’t always come before the eggs hatch and the tadpoles must make their way to the water by wiggling down the rocks without any arms or legs. How’s that for a magic trick?

Photo by Frank Lemckert 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:

The Green Gobbler

North American Bullfrog (Rana catesbeiana)

North American Bullfrog (Rana catesbeiana)

Cute Frog of the Week: Nov. 21, 2011

The American bullfrog (Lithobates catesbeianus) is the largest frog species in North America. Males can reach up to 8 inches long and weigh in at nearly 2 pounds. And this guy takes pleasure in throwing his weight around. Bullfrogs are notorious for eating anything they can get their mouths around, including snakes, mice, birds, insects or even other bullfrogs. Because of their insatiable appetite, the frogs are sometimes considered a nuisance to places where they’ve reduced local populations of fish, turtles or other frogs. Although the males’ “mooing” mating call (which can be heard for miles) may be a siren song for the ladies, it should serve as warning to other critters that there’s a bully in the pond.

Photo by Joe Milmoe, U.S. Fish and Wildlife Service.

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:

Hitchhiking Frog Lands at Houston Zoo


A Savigny’s Tree Frog caught a ride from Syria to Texas and found a home at the Houston Zoo. (Photo courtesy of the Houston Zoo)

At the Port of Houston it is the job of U.S. Customs and Border Protection (CBP) agriculture specialists to intercept pests arriving in shipping containers from different parts of the world.  Not much surprises the CBP staff, but that changed on Sept. 16 when CBP agriculture specialists working at the Port of Houston’s Bayport Terminal opened up a shipping container that had arrived on a ship from the Middle East.

There, sitting quietly on a pallet of imported stone, was a tree frog.

The frog was captured quickly and delivered to U.S. Fish and Wildlife specialists who contacted the Houston Zoo looking for assistance to identify the little hitchhiker.  Houston Zoo Herpetology Curator Stan Mays and Senior Keeper Chris Bednarski identified the stowaway as a Middle Eastern tree frog, specifically a Savigny’s tree frog.

Stan was happy to make the Houston Zoo the frog’s new home.  “Our research indicates that only one other zoo has this animal–the Dierenpark Emmen Zoo in the Netherlands and at last count they had 23 of them,” says Stan.

The frog showed no ill effects from its long trip in the dark from the Middle East.  “From what we were told by CBP staff, the container in which it was found was sealed shut in Syria and had not been opened until it arrived in Houston,” says Stan.

Released by CBP to Stan and Chris, the frog was taken to the Houston Zoo’s quarantine building where it made short work of what everyone assumed was its first decent meal in some time.  “On its first day in quarantine the frog consumed six crickets,” says Stan.

The intrepid traveler was moved from quarantine Nov. 9 to an off exhibit area at the Houston Zoo’s reptile house.  “He’s doing fine.  He’s big and healthy,” says Stan.

While the little frog may have surprised the CBP specialists, the Savigny’s tree frog is quite common in Iran, Iraq, Israel, Jordan, Lebanon, the island of Cyprus, the Republic of Georgia and Turkey.  “They’re the only tree frog found in Egypt,” says Stan.

They are native to deserts and semi-deserts and are found near water bodies such as oasis, gardens, bush lands and the edges of mountain forests.  The snout-to-vent length ranges between 30 to 47 mm.  The Savigny’s tree frog is probably one of the most heat-tolerant species of all the tree frogs, living in very hot and dry regions. When it isn’t their breeding season, these tree frogs are fairly inactive by day. In fact, they may sit motionless for hours, becoming active only in darkness. In the evening twilight, the frogs become active and start to forage and come to water bodies to rehydrate.

They hibernate on land from October until the beginning of November to March or April.  When they hibernate, they burrow in the soil and other hiding places. As tadpoles, they feed on plant and animal matter in the ponds where they hatched.  As adults, they feed on all sorts of insects.

The male’s breeding call resembles a cicada chirping.

Brian Hill, Houston Zoo

Sound the bell.

Red-eyed stream frog (Duellmanohyla uranochroa)

Red-eyed stream frog (Duellmanohyla uranochroa)

Cute Frog of the Week: Nov. 7, 2011

If you are hearing bells, there’s a possibility that a wedding’s in your future or that Christmas carolers are about to knock on your door. But if you’re in the subtropics of Panama and Costa Rica, you are likely hearing the distinct bell-like mating call of the red-eyed stream frog. This call sounds like “boop, boop, boop,” and can be heard in May and June.

This cute little frog is typically found in the Caribbean slopes of the Provincia del Pocas del Torro, Panama and Costa Rica. This area is a subtropical habitat, and most frogs are active during the night, so keep an ear open for them.

The red-eyed tree frog is leafy green in color, with a yellow throat and belly, and apricot-colored thighs. Its fingers and toes are slightly webbed and, of course, it has bright red eyes. Some researchers have wondered why their eyes are such a striking color, and have come up with a possible theory that they call “startle coloration.” This is a type of protection that allows the frogs to abruptly glance at or open their eyes when a predator shows up. This can startle the predator enough that they pause momentarily, allowing the frog time, though brief, to leap to a safe place out of its reach.

This is a critically endangered species, and the largest threats to them are general habitat alteration/losses, climate change and disease.

Photo by Andreas Hertz 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:

With Winter Coming, Frogs Play it Cool

American toad

During the winter, amphibians such as the American toad burrow deep into the soil, safely below the frost line. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

I have always had a bit of a fetish for frogs and toads. I have a number of toads in my back yard every year. One has taken up residence under my grill for at least three years now.  My two terriers are great fans of this little guy!

Now that it is getting colder, I have been wondering what actually happens to these guys once the cold weather settles in.  So I did a little research.

While most of us would pack our bags and move to Florida, that’s a pretty long way to travel for frogs and toads. So instead, they find a living space called a hibernaculum that will protect them from weather extremes and predators. They “sleep” away the winter by slowing down their metabolism; their heartbeats and breathing slows and their body temperature drops to nearly match the outside temperature as they pass the time in a state of dormancy. When spring arrives, they wake up and leave the hibernaculum, immediately ready for mating and eating! I guess they are pretty energized after that long winter’s nap!

Different species of frogs and toads have different strategies.  Northern leopard frogs, for example, pass the winter at the bottom of deeper lakes, far beneath the ice. They settle on the lake bottom in deep water and stay concealed behind a log or other debris to escape predators.

Aquatic frogs hibernate under water and take in oxygen from the water through their skin. They spend most of the winter lying on top of the bottom’s mud or partially buried in mud. At times, they may even slowly swim around.

Terrestrial frogs and toads typically hibernate on land. Those frogs and toads that are good diggers, such as the American toad, burrow deep into the soil, safely below the frost line. Spring peepers are not adept at digging so they find deep holes or cracks in logs or rocks, or simply burrow down in the leaf litter as far as they can to stay protected.

A few species that live in especially cold climates can even survive being frozen solid.  Check out this video I found of a wood frog going through the freeze/thaw hibernation process. Amazing!

If you have a pond frequented by frogs and toads in your back yard, put some leaf little in it so they can nestle down for a good slumber.

So as we say goodbye to these wonderful amphibian creatures for the year, keep your fingers crossed that it will be an easy winter.

To learn more about hibernating frogs and toads, check out the following web sites:

Cindy Hoffman, Defenders of Wildlife

Play Hide-and-Seek? Gopher it!

Gopher frog (Lithobates capito)

Gopher frog (Lithobates capito)

Cute Frog of the Week: Nov. 7, 2011

This reclusive nocturnal frog tends to be very shy, and likes to live in holes, burrows and tunnels during the day. It does not dig its own tunnels, but rather utilizes those that have been dug by other animals, most often gopher tortoises.

This frog is short and stubby in appearance, with dark spots covering its body.  The gopher frog also has two very prominent ridges along the side of its back, one on each side, starting from behind the eyes.

Native to the United States, this species can be found along coastal plains from the southern half of North Carolina to southern Florida and west toward Alabama. It is unclear just how fast their numbers are declining because they are so reclusive and hard to find in general, but they are listed as near threatened by the International Union for Conservation of Nature. This is due to extensive habitat loss, which they do not adapt well to, caused mainly by agricultural, residential and commercial development, as well as the timber industry. Other threats include fire suppression and peat build-up, which increases acidity levels in the water; introduction of predatory fish into breeding ponds; and the declining population of gopher tortoises whose burrows are most often used by these frogs.

Photo by Kelly Jones 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: