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.
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:
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.
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.
Most of us who studied “Macbeth” in high school know that the chanting witches in the story used many ingredients in their brew, from “eye of newt” to “toe of frog.” In fact, throughout history, amphibians—mainly frogs and toads—have been superstitiously considered either good luck symbols, or more commonly, signs of evil or the devil. Today, though all of the readers of this blog know how incredible frogs are, there are even phobias associated with the animals:
Batrachophobia: Fear of amphibians (frogs, newts, salamanders, etc.)
Ranidaphobia: Fear of frogs
Bufonophobia: Fear of toads
In honor of the spookiest holiday of the year, we’ve compiled a list of freaky frogs and frog facts that may just creep you out (though we suspect most of you will think, “wow, cool!”).
Say “AAAAAAHHHH!!!!”
A number of frog species, like the Luzon fanged frog here, have bony jaw protrusions that resemble fangs. (Image courtesy of Rafe M. Brown)
Most frogs that swallow their prey whole compress their eyeballs down into their heads to push the food down their throats to swallow it! In addition, there are a number of frog species that have bony jaw protrusions that resemble fangs, and they eat anything from rats to snakes to even birds! Scientists believe the “fangs” help the frogs hold onto quickly moving prey.
Speaking of teeth, there is also the vampire flying frog (Rhacophorus vampyrus), native to Vietnam. Adult flying frogs have webbed fingers and toes, which allow them to jump and glide from tree to tree. Though not really vampires, the adults are nocturnal and do like to come out at night. In addition, this species’ tadpole stage is the only one known to have “fangs,” which disappear as they mature.
The paper highlighting the discovery of the “fangs,” explains that they are not true fangs, but rather “keratinized hooks” on the sides of their mouths. It is highly unlikely that the tadpoles actually suck blood, and researchers are currently studying these so-called fangs because their function is unknown. Head researcher, Jodi Rowley, suspects that they may help the tadpoles anchor themselves underwater or somehow aid in eating.
For Whom the Frogs Scream…
Did you know that some species of frogs, like the smoky jungle frog and American bullfrog, scream? When a frog does so, it is considered a distress call, usually a high-pitched noise emitted when a predator snatches them up, or when they are stressed or handled. Nobody knows what the exact purpose of the cry is, but researchers believe it is a defensive mechanism that aims to startle or disorient a predator enough that the frog will be released and it can escape.
This practically frozen solid wood frog can quite literally come back to life. (Image courtesy of Janet Storey)
When it comes to the living dead, you may not believe your eyes when we show you the wood frog. These frogs can quite literally come back to life after being practically frozen solid. Native to cooler North American habitats, they can remain around 70 percent frozen for about four weeks in their burrows thanks to a natural antifreeze chemical in their blood, as well as a fluid balance mechanism within their bodies that moves water to areas less likely to be damaged by ice crystals. Their bodies then completely shut down, suspended in a cryostasis. When the weather gets warmer and the frogs begin to thaw, their organs will slowly begin functioning again—even the heart will begin to slowly beat—and within a day, the frog will be back to normal.
See a frozen wood frog thaw and hop away:
What on Earth is THAT? A Prehistoric Monster?
It appears this frog would be a good candidate for the monster mash. (Image courtesy of Sathyabhama Das Biju)
This isn’t a monster, but it may be just as unusual looking as one. The Indian purple frog (Nasikabatrachus sahyadrensis) is found in the Western Ghats in India. Only just discovered in 2003, it is rare and researchers believe it evolved separately from its closest relatives, the Seychelles frogs, for more than 130 million years. These frogs live mostly underground and come up only to breed during the monsoon season.
And THAT?
The turtle frog appears to be a turtle without a shell, but is actually a frog! (Image courtesy of Evan Pickett)
Is this the Blob? Nope! It is known as the turtle frog (Myobatrachus gouldii), found in southwestern Australia. It is called the turtle frog because it looks like a turtle without its shell! It spends its entire life almost completely underground in burrows in sandy soil, eating termites from within its own colony tunnels. The frogs only emerge to mate during rainy season, but lay eggs that hatch into froglets underground.
CreepinessContinued
Tadpoles grow within pockets on the back of female Surinam toads, then eventually emerge as toadlets. (Image courtesy of Peter Janzen)
The Surinam toad is another one of the creepier amphibians you will see—it is also one of the flattest, resembling road kill or plant debris. They live in the Amazon River Basin of South America in moist lowland forests, swamps and freshwater marshes.
Perhaps the most amazingly creepy thing about this animal is the way it reproduces. The female will lay eggs that the male attaches to her back. The eggs embed themselves into her skin, which grows to form a type of pocket around each one. The tadpoles grow within these pockets, then eventually emerge as toadlets, as in the photo shown.
Check out this video:
Another creepy reproduction method was unique to the two species of now-extinct gastric-brooding frogs (Rheobatrachus family), native to eastern Australia. Female frogs incubated their eggs and babies developed within their stomachs. When ready, the babies would crawl out her mouth.
These Frogs Eat Almost Anything!
These big-mouthed frogs have been known to eat all kinds of prey, ranging from rats to other frogs. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)
Perhaps some of the most frightening yet fascinating types of frogs are within the Ceratophrys genus. These are ‘horned’ frogs, possessing an elongated flap of skin that resembles a little horn on the upper eyelids. Also called Pac-man frogs, these large, aggressive, roundish frogs have insatiable appetites and will try to eat almost anything, even if it is bigger than they are. Examples of prey include insects, mice, rats, fish, other frogs, reptiles, etc. These frogs have even been known to eat their mates and go after smaller livestock!
In fact, one of the largest frog fossils ever discovered, a species that scientists call “Beelzebufo ampinga” or “devil frog,” was a close relative to these guys. Beelzebufo may be the biggest frog fossil ever found, dating to around 70 million years old, and grew to about 16 inches in length. It may have even gone after newly hatched baby dinosaurs.
Other well-known frogs that have quite an appetite are bullfrogs and green tree frogs. These have also been seen eating anything from rats to snakes to other frogs.
Glass frogs have such transparent skin that you can see their organs. (Photo by Mehgan Murphy, Smithsonian's National Zoo)
Glass frogs are not scary, but they are a little creepy. These adorable frogs lack pigment on the skin of their abdomens, which allow their organs to be perfectly visible through the skin!
In addition to glass frogs, you may have heard of ghost frogs. These frogs are obviously not spirits, but members of the Heleophrynidae family. Native to South Africa, these frogs live in streams and their name probably stems from the fact that many are found in a place called “Skeleton Gorge.”
Lastly, and this is TRULY scary:
The Epomis beetle eats its prey, including frogs, from the inside out. (Image courtesy of Gil Wizen)
Imagine going to take a bite of a nice delicious hotdog, only to find that as you open your mouth, it springs a set of pincers, clamps onto the inside of your mouth, and begins to eat you instead!
The Epomis beetle does just this, and may be the last thing a frog will ever try to eat—since the frog will almost always become a meal itself. The Middle Eastern beetles specialize in preying on amphibians—mainly frogs—in a most unique and horrifying way.
The larvae of these beetles lure a frog by waving its antennae and then wait for the frog to try to snatch it up. When it does, the larvae will latch onto the attacker’s mouth with its double-hooked jaws, and, turning the tables, it will eat its prey alive. The larvae have become very adept at this, as frogs are all they eat, though the adults will eat a variety of amphibians by biting the victim’s back, paralyzing the prey, and eating it at its leisure.
Cuban long-nosed toads (Bufo longinasus) are hard to come by. They are confined to three disparate areas of Cuba— Pinar del Province on the west end of Cuba, Sierra de Trinidad in the center and Sierra del Guaso in the east end. Nobody has actually seen a Cuban long-nosed toad in Sierra del Guaso, however, since the early 1900s.
Unfortunately, Cuban long-nosed toads have only ever been observed in forests, and always close to streams, placing them directly in the way of Cuba’s clear-cutting of forests, charcoaling, fires and agricultural expansion. They are considered endangered by the IUCN.
Cuban long-nosed toads are found in upland pinewoods and broadleaf forests of moderate moisture. These toads are terrestrial by day, but researchers believe they move up into the trees after the sun sets, perhaps to escape predators. While the toad here is posing on a rock, males have also been observed calling while floating on the surface of the water of streams!
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.
This incredible image is the winner of our Golden Frog Day photo contest. Congratulations to Harold Henry, who took this great photo of the gladiator frog. Nice work!
Gladiator frogs are aptly named. Males are known for their aggressive behavior toward one another both during mating season and while guarding clutches of eggs. In fact, males even have a small, sharp spike on each hand that grows out of their wrist by the base of their thumbs. They use this as tiny daggers while fighting, and they have been seen tearing at each other with them, often causing significant damage or death. The eyes and face are the easiest, most common targets, and many individuals bear battle scars.
The male frogs are nest-builders, either digging out small clay or sand basins on the edges of streams or ponds, or utilizing natural ones, such as footprints, where the female will lay her eggs. Some researchers believe this is the cause of the aggression—they compete to this extent because of the small size of available breeding areas. Males will even return to nest sites and guard the eggs until tadpoles have hatched. Interestingly, biologists have noticed that this fighting behavior was only prevalent in populations in Panama, but was not seen in Costa Rica, where there were larger areas for nest-building and egg-laying available. These frogs are most commonly found in Costa Rica and Panama, where their populations are decreasing, according to the International Union for the Conservation of Nature.
Photo by Harold Henry.
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.
The Smithsonian Channel documentary follows as three rescue project scientists search for the vanishing Toad Mountain harlequin frog. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)
We’re excited to announce that next week “Mission Critical: Amphibian Rescue” will be airing for the first time on the Smithsonian Channel! The documentary follows three of the project’s frog rescuers, Brian Gratwicke, Edgardo Griffith and Bob Chastain, into the Panamanian rain forest to collect the vanishing Toad mountain harlequin frog (Atelopus certus). Their adventure—including their triumphs and challenges—are captured on film, in addition to the promising recent developments in finding a cure for the deadly chytrid fungus.
The documentary will air on Smithsonian Channel at 8 pm (eastern) on Wednesday, Oct. 12. For information and a preview, check out the Smithsonian Channel’s website.
In addition, the Smithsonian’s National Zoo will be hosting a premiere for the documentary in its Visitors’ Center on Tuesday, Oct. 11. The reception starts at 6 p.m. and the movie will air at 7 p.m. and will be followed by a lively panel discussion with the stars of the documentary! Attendees will also have a chance to participate in an auction that includes frog artwork, books and more! If you live in the D.C. area and are interested in attending, please email Lindsay Renick Mayer at renickmayerl@si.edu.
Houston Zoo Amphibian Conservation Manager Paul Crump prepares to release Houston toads in the area of Bastrop State Park. The park was devastated by recent wildfires. (Photo courtsey of the Houston Zoo)
Sixty years ago John Wottring, an amateur herpetologist, and Ottys Sanders described Bufo houstonensis, the Wottring Toad, what is now popularly known as the Houston toad.
In the 1960s the toad disappeared from the Houston area as its historic range was taken over by tract housing and commercial development and an extended drought.
In 1973 it was included in the passing of the Endangered Species Act, likely one of the first amphibian species in the United States, maybe even in the world, to be recognized as declining.
Fast forward to the summer of 2011 and we find that the Houston toad is again threatened by an extended drought and a devastating wildfire that consumed thousands of acres in the toad’s primary habitat, a state park near Austin, the state capitol.
The partners in the Houston toad recovery project, the Houston Zoo, Texas State University, the Environmental Defense Fund, U. S. Fish and Wildlife Service, and the Texas Parks and Wildlife Department, are working to assess the impact from a wildfire in early September that incinerated almost 55 square miles near Austin, destroying more than 1,500 homes and taking two lives.
The level of destruction was shocking and stunning. Major wildfires had been seen in the area in the early 1900s. But none approached the scale of the fires in September.
The fires incinerated a major remaining habitat for the Houston toad, the 6,000-acre Bastrop State Park. The Houston toad is found in isolated populations across nine counties between Austin and Houston. But Bastrop State Park was the toad’s primary habitat.
It will be weeks before the recovery team has an estimate of the impact of the wildfire on the habitat and the toads.
As the wildlife impact is assessed this fall, the Houston Zoo Houston Zoo toad team will develop “assisted reproduction” techniques to get Houston toads to breed reliably and in large numbers. These procedures will then be used to keep the captive assurance colony alive and genetically healthy, and when the time comes, to produce hundreds of thousands of toads for reintroduction.
While the future of the Houston toad in the wild may have dimmed due to the wildfire impact, there is hope. Always hope. Segments of habitat remain and could be used to bolster the area’s toad population. As Texas State University biologist Dr. Michael Forstner told Houston Chronicle reporter Shannon Tompkins: “They’re pretty tough little guys. As a species, they’ve lived here a long time. This kind of thing has happened before and they’ve recovered. But it’ll be decades before we know all the impacts of this fire.”
(Editors note: To read Houston Chronicle reporter Shannon Tompkins’ September 18, 2011 story about the impact of the Bastrop wildfires visit http://preview.tinyurl.com/6ht82bu)
Despite its appearance, the giant burrowing frog (Heleioporus australiacus) is not a Hutt crime lord trying wreak havoc on Luke Skywalker’s life. Instead, this funny looking cutie is spends its time burrowing and calling to potential mates from partially flooded burrows at the banks of rivers. It also calls sometimes while hidden beneath dense vegetation. It’s not as large as its name may imply, but three and a half inches long is nothing to scoff at.
The giant burrowing frog is primarily restricted to southeastern Australia, residing in the eastern slopes of the Great Dividing Range, a region also known as the Sydney Basin. They exist primarily in montane sclerophyll woodland, montane riparian woodland, and wet, damp and dry sclerophyll forests. These frogs are well-adapted to Australia’s often unforgiving climates, laying their eggs in ephemeral pools, or permanent pools, if they exist.
These frogs are listed as vulnerable, and face a number of challenges in their mountainous environment. Intensive timber harvesting, fox and cat predation, cattle grazing and invasive terrestrial and aquatic predators are just a few of the trials confronting these amphibians. Unfortunately, chytrid was also detected in this species, specifically in Springwood, New South Wales. Giant burrowing frogs are, however, protected by state legislation and are the subject of two major studies in New South Wales, so they hopefully will survive and not be consigned to a galaxy far, far away any time soon.
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.
Dr. Vance Vredenburg swabs frogs to test for chytrid. (Photo courtesy of Vance Vredenburg, San Francisco University)
A new study published on Aug. 16 in the journal PLoS ONE found that Batrachochytrium dendrobatidis (Bd), the fungus that causes chytridiomycosis, is indeed present in Asia, but at significantly lower levels than anywhere else in the world. In fact, researchers found that just more than two percent of the individuals they tested were positive and that the fungus was present only in the Philippines, Kyrgyzstan, Laos, Indonesia, Malaysia and South Korea. Now scientists want to know why.
An international research team conducted this study between 2001 and 2009, examining more than 3,000 amphibians, most of which were frogs, from 15 Asian countries. It was the first large-scale investigation of the disease conducted in Asia.
We spoke with Dr. Vance Vredenburg of San Francisco University, one of the researchers from the study and a leading expert in this disease. Here’s what he had to say:
1) This was the first comprehensive survey of chytrid in Asia. Why do you think this hasn’t been done before?
I think expense is probably a huge hindrance on research. Our study was conducted in 15 countries and our data was collected by a large number of field personnel. The cost of analyzing the samples is not cheap–costs range from $5 to $30 per sample, depending on where and how they are analyzed. We ran nearly 3,500 samples.
2)What do your findings mean in the battle against chytrid, and what is your next step?
Our findings provide an important milestone because they are the first broad survey for Bd across a vast continent that harbors a large amount of amphibian diversity. Our hope is that researchers will now be able to return to many of these sites and see if the dynamics of the pathogen host system change and if so, in what direction. Our next step will be to follow up on as many sites as possible.
3)Were you surprised by the findings? Why or why not?
Yes. I was surprised by how low the prevalence was across what appears to be such perfect habitat for this pathogen.
This frog, Hylarana similis, is native to the Phillipines and is a species now infected by chytrid. (Photo courtesy of Rafe M. Brown, University of Kansas)
4) Why do you think that frogs in Asia aren’t being wiped out at the same rate as frogs in the neotropics?
There are only a few possibilities. We describe them in detail in the discussion [in the paper], but in short, either Bd is only just emerging in Asia and thus we haven’t seen mass die-offs due to chytridiomycosis yet, or it is endemic and there are either abiotic or biotic influences holding the pathogen at bay. We still don’t have the answer to this.
5) If this outbreak in Asia is relatively recent, where did it originate on the continent?
We discovered one–and only one–place out of 300 sites where an outbreak may be occurring, at a site in the Philippines.
6) The Philippines are a series of Islands. If you believe there is or is going to be an outbreak there, how did it get there and how can it spread to other places in the world?
We propose that human trade is involved, specifically that farms raising American bullfrogs could be the source of Bd that could then spread to wild frogs [if some escape]. We don’t know where it originated or how it spread for sure.
7) Are there Asian amphibians other than frogs that appear to be affected by chytrid?
Asia has a rich fauna of both salamander and caecilians, but to date we do not know if they are affected by Bd. Our study did not sample caecilians and includes only a small number of salamanders.
8) A few amphibian species, such as bullfrogs, are said to be carriers of Bd, but rarely seem to die from it. What exactly allows a species to be a “carrier,” or is there still not enough information known about that?
We don’t yet know how bullfrogs (Rana catesbeiana) are able to survive Bd infections without showing symptoms of chytridiomycosis.
9) Do you believe that these Asian frogs that seem to be less affected may be carriers as well?
We need more information to assess this. My guess is that there are probably some species that can sustain infections just like American bullfrogs and could act as carriers.
10) What other threats do frogs in Asia face and what is being done to address those threats?
The two major threats in Asia are habitat destruction and hunting and gathering amphibians to eat.
