It’s a bird! It’s a plane! It’s a…marbled treefrog?

Marbled tree frog (Phrynohyas venulosa)

Marbled tree frog (Phrynohyas venulosa)

Cute Frog of the Week: March 28, 2011

Marbled tree frogs distinguish themselves from their equally cute tree frog relatives by their uniformly colored flanks and green bones, and the lack of dark vertical barring on the lip. Additionally, males have paired lateral vocal sacs, one of either side of the head behind the angle of their jaw. But that isn’t all that makes this frog so unique. These cuties have a highly developed ability to parachute from the trees of their forest habitats in central and northern South America. They have even been observed gliding for 27 meters after being dropped from a height of 43 meters! When they aren’t showing off their parachuting skills, this nocturnal frog is typically found perching on tree branches and vegetation while foraging at night. It finds shelter in tree holes, under tree bark, or in banana sheaths during the dry season.

Even though this frog is undeniably cute, approach with caution. These guys produce sticky, insoluble, noxious secretions that can cause severe reactions ranging from irritation and swelling to temporary blindness if the secretions end up in the eyes. In Belize, they even call this frog the “pepper tree frog” because it is also thought to cause sneezing! Ah-choo!

Photo credit: 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:

Seeking things to smile about.


Palmer's tree frog (Hyloscirtus palmeri)
Palmer’s tree frog (Hyloscirtus palmeri)

Cute Frog of the Week: March 21, 2011

Although this cutie isn’t related to or owned by the world-famous golfer Arnold Palmer, he does enjoy spending time on the green—just not the putting green. This species of tree frog prefers the green, humid rainforests and riverbanks of Colombia, Panama, Ecuador and Costa Rica. These guys like to spend their time in the trees soaking up the sun and splashing around in the rocky streams where their tadpoles develop. But don’t be fooled by the seeming luxury of a tropical habitat—they don’t spend their lives on one long vacation. The homes of Palmer’s tree frogs are continuously threatened by deforestation, illegal crops, logging, human settlement, and pollution resulting from the spraying of illegal crops.

Photo credit: Brian Gratwicke, Panama Amphibian Rescue and Conservation Project.

Banded horned tree frog (Hemiphractus fasciatus) ALL-NEW frog ringtones: Download the palmer’s tree frog’s call!

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:

Toad Trackers

Houston Zoo's Toad Trackers

Students that are part of the Houston Zoo's Toad Tracker program measure a coastal plains toad. (Photo courtesy of the Houston Zoo.)

As we’ve mentioned in this blog before, the Panama Amphibian Rescue and Conservation Project partners are not just trying to save species of frogs in Panama, but also in their own backyards. Here is an account of one local project that partner the Houston Zoo has taken on.

In the spring of 2010, the Houston Zoo piloted a new conservation education program called Toad Trackers. In the first year of this one-of-a-kind, interactive program, the Houston Zoo ‘tracked’ 39 coastal plains toads (Bufo nebulifer) and ‘discovered’ 88 new amphibian enthusiasts.

Led by the Zoo’s Conservation Programs Manager Rachel Rommel and assisted by the Zoo’s Education Department, Toad Trackers expands on the idea of “citizen science,” such as Frog Watch USA and the North American Amphibian Monitoring Program, introducing students to field research methods and tools used by conservation biologists and wildlife professionals, such as Kestrel meters, calipers, GPS units, microchips and scales to track, monitor and assess the health of toad populations.  Toad Trackers was made possible by a grant from the Texas Parks and Wildlife Department’s Community Outdoor Outreach Program.

On select nights (warm and wet) on Zoo grounds, the supervised students conduct a ‘toad round-up,’ collecting every toad that can be found for processing and data collection.

The coastal plains toad has adapted quite well to living amongst humans and has survived despite a shrinking and fragmented habitat.  The large population of this particular toad and its ability to thrive in urban areas makes it a perfect candidate to study, both from a convenience and an environmental impact perspective.

When the toad round-up begins on sticky Houston summer nights, the kids weigh, measure, determine gender, note any mutations of each toad and record its GPS coordinates.

One of the Zoo’s conservation biologists, oftentimes Paul Crump, the Houston Zoo’s Amphibian Conservation Programs Manager, then inserts a pit tag into each toad (like the microchips in your cat or dog) and the students then release the toad where it was initially captured.

Subsequent toad round ups during the same or following year will provide valuable information (through the ability to individually recognize toads) on growth rates, reproductive events, and movement patterns.

In addition to encouraging a new generation of wildlife biologists, Toad Trackers also provides a forum in which students can learn about amphibian ecology, global amphibian extinctions and why monitoring local amphibian populations is important to detecting declines in our own region.

Houston Zoo's Toad Tracker program

A student involved in the Toad Tracker program holds one of the toads she caught. (Photo courtesy of the Houston Zoo)

Additionally, the data collected through Toad Trackers will be used to publish a peer-reviewed paper on native toad populations based on the world of citizen scientists.

In 2010, the Toad Trackers program was incorporated into the Houston Zoo’s home schooling program; Camp Zoofari, the Zoo’s summer day camp program; Zoo Crew, the Zoo’s teen volunteer program; and with one community outreach group, the Hispanic Women’s Network of Texas.

In 2010, Toad Trackers captured a total of 39 Bufo nebulifer. Of those, 77 percent were female, 21 percent were male.  The gender of two percent of the toads could not be determined due to life stage.

The average SUL was 69.22 mm for female toads and 60.1 mm for male toads, well within normal range for the species.  The average weight was 38 grams for females and 27.44 grams for males. Our citizen scientists also detected Rio Grande chirping frogs and green tree frogs on Zoo grounds on most field evenings.

Students reported one recapture of a female toad.  Named “Emily,” the toad traveled .02 miles from her last location, had grown 1.7 mm and increased her weight by 2 grams.

All but one animal (too small) was AVID microchipped.  The proportion of animals marked in the first sampling in 2010 that are recaptured in the second sampling this year can be used to calculate an estimate of the overall population size of the toads on Zoo grounds.

The students made some interesting observations in 2010.  One female Bufo nebulifer was found approximately 24 inches off the ground sitting inside a tropical plant by the Zoo’s reptile house. Neill and Grubb (1971) found Coastal Plain toads from 2 to 5 meters above the ground in oak trees; they can be considered arboreal in that individual toads will find tree holes and may use them repeatedly for periods of weeks.

On numerous occasions, students observed female Bufo nebulifer vibrating and chirping upon capture.  With this particular species, females are not generally known to display release calls as this is considered a male behavior.

Brian Hill, Houston Zoo

Look, but don’t touch!

Granular Poison Dart Frog (Oophaga granulifera)
Granular Poison Dart Frog (Oophaga granulifera)

Cute Frog of the Week: March 14, 2011

The bright colors of these frogs scream “Don’t eat me, I’m poisonous!” without the frog having to say a word. This cutie issues the warning with the color red, but you can find bright orange or olive-colored granular poison dart frogs too! Although they’re only the size of a paperclip, their skin contains deadly toxins. To survive, this little frog must find even smaller insects or spiders in the undergrowth of the stream-banks where it lives. Named for its bumpy exterior, the granular poison dart frog can be found in the forests of Costa Rica and Panama. This little frog may be in trouble, however, as it is experiencing continued loss of its forest habitat and chytridiomycosis-related declines.  It is considered threatened by the International Union for Conservation of Nature.

Photo credit: Brian Gratwicke, Panama Amphibian Rescue and Conservation Project.

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:

Science Project: A Cure for Chytrid

The author with Brian Gratwicke at the SCBI autumn conservation festival

One autumn day in 2010, I was at the Smithsonian Conservation Biology Institute, (SCBI) and I met Brian Gratwicke. Brian is a frog expert, a herpetologist, and is working in Panama to save frogs from a deadly fungus. The fungus is called chytridiomycosis, or chytrid. Brian told me of one cure for the chytrid fungus. It is a bacterium, called Janthinobacterium lividum. J. liv. for short. He said that the cure can come off the back of some redback salamanders, (Plethodon cinereus) which I realized, live in my back yard in northern Virginia. He said that it was kind of rare to discover the salamanders that have the bacteria on them. You need to swab the salamanders, and streak the bacteria on their backs onto agar plates. He said that if the salamanders carry J. liv., a milky purple spot will appear on the plate, that you can’t miss it. I told him I am very interested in herpetology, and that I could the do the experiment by the winter. So that is when I decided to try and find Janthinobacterium lividum. Brian said it was a great idea, but he would be very surprised if I found J. liv.

Searching for chytrid cure on the backs of salamanders - Tommy's 6th grade science fair project

I started with a question. My question was; is J. liv really on the backs of the redback salamanders in my backyard? To perform the experiment, I needed some supplies. I got petri dishes, agar, sterile swabs, distilled water, gloves, a plastic terrarium, my camera, and an instruction book (on how to prepare and streak petri dishes). Soon I had my lab set up. I microwaved the agar until it was completely liquid. Then I carefully lifted up the lids of the petri dishes, and poured the liquid agar in. I labeled them from one to ten. I put my gloves on, and got the terrarium. I was ready to catch some salamanders.

Isolating Janthinobacterium lividium with a sterile swab

Isolating Janthinobacterium lividium with a sterile swab

Soon I was outside on the lookout for anything that was small, and that crawled. I went to my backyard and started looking. I looked under logs, rocks, and bricks. After many false alarms with large earthworms, I came across a redback salamander. I picked it up with my gloves, and put it in my terrarium. Then I ran back inside. I set down the terrarium and began my work. I used my supplies to swab the salamander, and photograph it. I then returned it to its log, and started looking for another salamander. After the next few weeks of hard looking, I had done this for all my ten of my petri dishes, with salamanders, collected from different locations. I just needed to wait for the bacteria to grow. I waited for about three days. By then, the color started to appear on the petri dishes. On dish number one, there were orange and clear colors, but no purple. It was the same for all the next eight. On petri number ten, things were different. It took much longer to culture bacteria on it.

Pure cultures of purple bacteria, the purple comes from the anti-fungal chemical violacein.

Pure cultures of purple bacteria, the purple comes from the anti-fungal chemical violacein.

After three additional days, I saw it. In a small spot in the middle of the petri dish, was a milky purple spot. I couldn’t believe what I was seeing. I had found the bacteria. I took photos of all the petri dishes, and wrote the dates that the color appeared on them. I took many photos of the purple J. liv. colony. I was so happy.

It was very lucky that I had found J. liv. After I found the bacteria, I bought two more petri dishes. I took the original J. liv. culture and swabbed it. I then streaked the new agar plates with J. liv. I waited. Within three days, the color started to appear. The whole agar plates were covered in the milky purple J. liv. I wrote down my observations. I could culture and grow J. liv. in gigantic amounts. I found Janthinobacterium lividum, and I was proud of myself. I couldn’t wait to tell Brian Gratwicke!

–Tom McCarthy, 6th grade Chesterbrook Elementary School in McLean VA.

My bones are green too!


Powdered glass frog (Cochranella pulverata)

Powdered glass frog (Cochranella pulverata)

Cute Frog of the Week: March 7, 2011

Powdered glass frogs (Cochranella pulverata) are distinguished by their covering of white, irregularly sized spots on a lime-green body, looking like they’ve had a smattering of talcum powder. Their forward-facing eyes set them apart from other tree frogs, providing them with binocular vision and the most adorable anthropomorphic facial expressions that few other frogs can rival. Scientifically known as Cochranella pulverata, these amphibians live in forest-lined streams of Central and South America and are most active in the evening where males call to females while battling for the prime leaves overhanging rivers. They need these special sites to lay their jelly-like egg masses where tadpoles develop, eventually hatching and plopping down into the stream below as fully formed tadpoles.  They’re faring better than some of their froggie friends—the International Union for Conservation of Nature considers powdered glass frogs of least concern.

Photo credit: 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:

In the Field, In Search of a Cure

Rocket frog with tadpoles

Researcher Denise Küng is using emerald glass frogs and rocket frogs (shown here with tadpoles) in Panama to see if she can develop a treatment for chytrid. (Photo by Brian Gratwicke, Panama Amphibian Rescue and Conservation Project)

What comes to your mind when you think about bacteria? They are generally feared as disease agents among humans, but they do much more than cause infections. It seems like mutualistic microbial communities are common in invertebrates as well as vertebrates. Humans, with more than 600 types of bacteria residing only in their mouth, are no exception. Several cooperating bacteria can develop biofilms and create a matrix of living cells and bacterial products, and the community structure of microbes on a host could be connected with resistance to disease. Let’s say a bacterial community is disturbed by antibiotics and its competitiveness is thus reduced, then pathogens can exploit this and establish themselves in a host.

The skin of amphibians is host to a diverse microbiota. They live in damp or aquatic habitats which are potentially pathogen-rich environments. As protection against infections, amphibians developed skin defenses, such as antimicrobial peptides secreted by glands in their skin and microbial communities with antimicrobial activity. By doing bacteria removal and additional experiments, scientists found evidence for enhanced or decreased amphibian health depending on alterations of the microbial community structure on the skin. In some amphibian species, antimicrobial peptides seem to provide protection from infectious diseases such as the fungus Batrachochytrium dendrobatidis and may help to prevent population declines.

Denise with Colostethus

Denise hopes to find a treatment for frogs in nature so they can safely coexist with chytrid. (Photo by Brian Gratwicke, Panama Amphibian Rescue and Conservation Project)

To find out more about the bacterial communities and antimicrobial peptides on the skin of amphibians, I’m currently in Panama working with the Panamanian rocket frog, Colostethus panamensis, and emerald glass frog, Centrolene prosoblepon. I’m going to look at their skin microbiota and how it changes after several weeks living in captivity. Will it stay the same or are some members of the bacterial community getting lost?

By giving some of the rocket frogs a bath in a solution with bacteria, I’m trying to increase the density of a particular bacterium on their skin. This bacterium has been shown to decrease the growth of the chytrid fungus Batrachochytrium dendrobatidis in the lab. If it’s possible to amplify its density on amphibian skin over a long period of time, this might be a possible treatment for frogs in nature to allow them to coexist with the pathogen in infected environments.

The emerald glass frogs seem to be able to survive in environments infected with Batrachochytrium dendrobatidis. They must have found a form of protection from the fungus on their skin. I am taking a closer look at the antimicrobial peptides on their skin. I also bathed them in water every day for a week and then used their skin washes to treat another group of the rocket frogs with the hope that whatever protects the glass frogs from the fungus will go in the water and from there onto the skin of the rocket frogs. Analyzing the skin swabs of the frogs in the lab will show whether this treatment changed the rocket frog skin microbiota, antimicrobial petides or both.

Denise Küng, University of Zurich