Author Archives: Susan

08/25/12

Frogs Are Blue!

Most people think frogs are green, right? And it’s true, most frogs are a greenish, brownish, yellowish color, the better to hide from predators among grass and other vegetation.

But frogs can be many different colors, even bright crayon colors like sky blue.

This three-centimeter-long blue tree frog in a tree in Chofu, western Tokyo. Courtesy of Toba Aquarium, Japan.

Why would a frog species evolve such a bright vivid color that would make it stand out? In most cases the frog, such as the colorful dart frogs, are giving a strong warning to predators: Don’t eat me! I’m poisonous! Either through instinct or through learning the hard way, predators will avoid them. These brightly colored frogs contain poisons that can kill or paralyze an animal that comes into contact with it.

The frog’s skin is not actually blue. The color comes from layers of chromotophores, or pigment-containing and light-reflecting cells between the dermis and epidermis (inner and outer skin layers). A blend of the three types of chromatophores creates the color, or in some cases, even transparency:

melanophores: contain pigments that appear black or brown from melanin

xanthophores: contain yellow colored pigments

iridophores: contain reflective or iridescent pigments

So although most of the time, frogs are green, sometimes Frogs Are Blue!

08/15/12

Live Bullfrog Trade Helping to Spread Deadly Fungus

A Frogs Are Green reader alerted us to a recent Dot Earth (New York Times) blog post by Andrew C. Revkin, “Genetic Study Finds Bullfrog Trade is Prime Pathway For Devastating Amphibian Fungus.”

University of Michigan mycologist Tim James and colleagues conducted a genetic analysis and have found that the global trade of live bullfrogs is helping to spread the deadly chytrid fungus, which has devastated worldwide amphibian populations. The results were published in the journal Molecular Ecology.

As Revkin notes, it isn’t clear why the fungus is devastating to amphibians in some areas, but seems to be harmless to those in other areas. For example, although there are deadly strains in the Northeast, there are no chytrid-related declines reported. Environmental conditions or other issues might account for this.

The researchers examined the role of bullfrog farming in spreading the chytrid fungus between the forests and frog farms of Brazil and then to the United States and Japan. They collected and analyzed bullfrogs sold at Asian food shops in seven U.S. cities and found that 41 percent of the frogs were infected with chytrid fungus, which is harmless to humans. Frogs in these shops are imported live primarily from farms in Taiwan, Brazil and Ecuador and sold as food for their legs.

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“A lot of the movement of this fungus is related to the live food trade, which is something we should probably stop doing,” James said. “We don’t need to have millions of live frogs being shipped from foreign countries into the United States.”

For more information: Press release from the University of Michigan

08/7/12

A Green Frog (at Frogs Are Green)

At Frogs Are Green, we’ve posted about tomato red frogs, blue frogs, and yellow-and-black spotted frogs, but I don’t think we’ve ever written about the Green Frog (Rana clamitans).

Green frog camouflaged in grass. Photo by Mary Jo Rhodes

Recently I visited my sister, who lives in the woods in Connecticut. On our first night, there was heavy downpour. When I woke the next morning, I heard what sounded like someone plucking a loose banjo string. Coming from the city, I was thrilled: it was my welcome call from a Green Frog outside! My sister has built a couple of frog/koi ponds on her property. Although fish and frogs aren’t supposed to co-exist (fish eat the frogs’ eggs), somehow it has worked out.

Frog pond in CT

The Green Frog is mainly aquatic, but they often rest by the side of the pond, leaping in when danger approaches. Males have a tympanum (external hearing structure) twice the diameter of the eye and a bright yellow throat.

Green Frog. Notice the large eardrum behind his eye. Photo by Mary Jo Rhodes.

Green frog in reeds. Photo by Mary Jo Rhodes

You might see Green Frogs in ponds, lakes, and swamps—they are one of the most common frogs in the eastern U.S.

Just in case you’re out in the country this summer, here is what it sounds like:

07/25/12

Guest post: A Herpetologist Chases Frogs with Tails

We were so pleased to receive a guest post from Sara E. Viernum, a herpetologist with over 10 years of experience chasing snakes and salamanders around the U.S. When she’s not chasing reptiles and amphibians in the field, Sara is blogging about them on her website The Wandering Herpetologist, which is devoted to all things reptile and amphibian related. She currently resides in San Antonio, Texas, with her wonderful husband and her pet milk snake, Nyarla The Crawling Chaos. Sara also has a Facebook page.

For two field seasons in 2010 and 2011 I had the pleasure of hunting for aquatic amphibians in the Tillamook State Forest in Western Oregon. I was helping a friend with her graduate research focusing on the effects of fish passable culverts on aquatic amphibians. We spent many, many fun-filled hours crawling around in streams in the forest looking for Pacific giant salamanders (Dicamptodon tenebrosus), Columbia torrent salamanders (Rhyacotriton kezeri), and Pacific tailed frogs (Ascaphus truei).

Male Pacific tailed frog showing his "tail". Photo courtesy Sara Viernum.

The tailed frogs were such interesting amphibians. I had never seen these strange little frogs before we started the stream surveys. The tadpoles have specialized sucker mouths that they use to hold onto the rocks in the fast-flowing currents of the streams. They will also adhere to a collection bucket and your hand. If that’s not strange enough the adult males have a little “tail.” The “tail” is actually an extended cloaca that is used for internal fertilization. The Ascaphus frogs are the only frog species that have internal fertilization.

Pacific tailed froglets showing color variations. Photo courtesy Sara Viernum.

Tailed frogs are members of the Leiopelmatidae family (Tail-wagging frogs). There are only two species in this family found in North America – the Pacific tailed frog and the Rocky Mountain tailed frog (Ascaphus montanus). The family is considered to be one of the most primitive. The frogs cannot vocalize (call) and they do not have an external ear or a middle ear bone. Their closest relatives are the Leiopelma frogs from New Zealand which are also considered to be primitive frogs too.

Pacific tailed frog tadpole suctioned to Sara's hand. Photo courtesy Sara Viernum.

The Pacific tailed frogs could be quite common in some of the streams and were always a treat to find, although it was sometimes difficult to get to tadpoles to let go of your hand.

Pacific tailed frog tadpole showing its sucker mouth. Photo courtesy Sara Viernum.

07/13/12

A Prince Becomes a Frog: The Prince Charles Frog

The Prince Charles frog. Courtesy of Amphibian Ark.

At Frogs Are Green, we’ve always loved the fact that one real live prince – Prince Charles of England – seems to care a lot about frogs. We’ve posted stories here about the Prince of Wales’s efforts to help rainforests; in his princely fashion, he has used frogs as symbols of his campaign to protect the rainforests, particularly the rainforests of Brazil and Indonesia.

Now HRH is being honored for his work: a rare species of Ecuadorian stream frog has been named Hyloscirtus princecharlesi or the Prince Charles Stream Tree Frog in recognition of his efforts to safeguard the world’s rainforests.

Amphibian Ark recently coordinated a special event to reveal the scientific name of the Ecuadorian frog. The event took place at the prince’s Highgrove House estate and included presentation of a commemorative medallion and a glass sculpture of a frog.

The handsome brown-and-orange frog was first spotted by Dr. Luis A. Coloma among other specimens collected for a museum in 2008. The Ecuadorian scientist was part of an expedition that later found a few living members of the species in the Cotacachi-Cayapas National Park in Ecuador.

According to the Royal Forums website, while posing for photos, His Royal Highness joked, “The things I do for frogs. I’m very touched. It’s very nice. I have a lump in my throat, it must be a frog.”

The Prince Charles Stream Tree frog is a nocturnal frog – it climbs on branches during the night and lives near very fast running streams, close to cascades. The frog is endangered – its rainforest habitat in under threat due to the impact of farming.

07/3/12

Frogs Are Green 2012 Kids' Art Contest: Now Open for Submissions!

Artwork by Valeriy Karabchukova, 7 yrs old, Belgrade, Serbia.

Artwork by Valeriy Karabchukova, 7 yrs old, Belgrade, Serbia.

We are very excited to announce that the 3rd annual Frogs are Green Kid’s Art Contest is now open for submissions!

Contest theme: IT’S EASY BEING GREEN!

Your artwork can be about frogs and how we can help them, or it can also be about ways we can be green at home, at school, or in the community.

We will award winners based on age in these age groups: 3-6, 7-9, 10-12. The winners will receive a Frogs Are Green poster of their choice from our store. All kids who enter the contest will receive a certificate of participation that can be downloaded from our site.

We’re looking for drawings, paintings, sculpture, collage, mixed media, or whatever format helps you express yourself.

Deadline for submissions is November 30, 2012, and the winners will be announced January 15, 2013. The winners will be featured in a post.

This year we have a new contest area using Flickr, where you can enter yourself. You must add a caption/ description with your Name, Age, and Country or your submission will not be added. Please see the contest page for more details.

Teachers: Please print out the attached flyer to post in your school.

We can’t wait to see your artwork!