03/3/11

Celebrating Spring Peepers! Tiny Frogs with a Mighty Voice

Now that it’s March, it’s almost time for the peepers to usher in spring!

Renowned science writer Carl Safina describes spring peepers so beautifully in his new book The View from Lazy Point: A Natural Year in an Unnatural World. I enjoy reading anything by Safina, who usually writes about the ocean, sea animals, or birds. He’s won many awards for his work, including the MacArthur “genius award.” Safina’s writing reminds me of Rachel Carson’s—very lyrical, yet not sentimental. In this book, he writes mainly about a year he spent in a cabin on Long Island. In the chapter, “March: Out Like a Lamb, ” he writes this about spring peepers:

I open a window to let in the season’s lushest, most delicious sound. It’s from tiny tree frogs that come to water to go a-courting—Spring Peepers. So far, these little amphibians remain abundant. And for as long as they’ve been, and as long as they are, their singing makes the difference between the night of winter and the breath of spring…

Hearing them is easy. Seeing them takes some effort. But even after I step into the shallows as deep as my boots allow, even though I hear calls coming from the half-submerged vegetation right around me—well within the halo of my flashlight—they’re all but invisible. They’re smaller than the tip of your thumb, colored like dead leaves. The majority of my neighbors—even many who were raised here— have never seen one. Many people assume the callers are crickets. But the sound and the season are so different, one might logically assume the moon is just the sun at night.

Safina goes on to describe how as a teenager he taught himself how to find spring peepers by following the sound into the woods at night, but they were very elusive. He finally found one and

…when that tiny movement caught my eye, I saw the littlest frog I’d ever seen, his bubble-gum throat puffed almost as big as his body, calling his heart out. That mighty sound from that tiny body appealed to my teenage sensibilities. His was a strong, clear voice, defiantly undaunted about being so small a soul in so big a world.

Spring peepers Safina writes are a “strong and joyous life-affirming presence” and he would

…gladly suffer a chilly bedroom just to open a window in spring when the peepers are at their peak, and let the exuberant trilling chorus resonate in my chest. “We’re alive,” they seem to say, “and time is short.” No sound in our region is so welcome and welcoming, so revivifying, as peepers in full spring chorus. Or so seemingly unlikely. Out of dust, God is said to have made one man. But here, out of mud, such song!

To celebrate peepers and spring, Susan created a poster for Earth Day 2011, with a wonderful photograph by Richard D. Bartlett. Enjoy!

12/10/10

How Frogs and Toads Adapt To Winter's Chill

It’s mid-December and we’re inside keeping warm, while temperatures outside are below freezing (in parts of the northern hemisphere, that is). But what about our amphibian friends? How do they survive the winter? After all, they would seem vulnerable to temperature extremes with their thin skins and need to constantly stay moist.

Actually, we don’t need to worry about the frogs. They are well-equipped to deal with the cold weather, even with Arctic temperatures.

In the fall, frogs first need to find a place to make their winter home, a living space called a hibernaculum, that will protect them from weather extremes and from predators. The frog then “sleeps” away the winter by slowing down its metabolism. When spring arrives, it wakes up and leaves the hibernaculum, ready for mating and eating.

Aquatic frogs and toads such as the leopard frog and American bullfrog usually hibernate underwater. They don’t, however, dig into the mud like turtles—turtles are able to slow down their metabolism in a much more extreme way than frogs and can get by with almost no oxygen. Aquatic frogs need more oxygen—they lie just above the mud, or only partially buried in the mud, so they are near the oxygen-rich water. They may even occasionally slowly swim around.

Terrestrial frogs and toads typically hibernate on land. Those frogs and toads that are good diggers like the American toads burrow deep into the soil, safely below the frost line. Some frogs, such as the wood frog and the spring peeper, aren’t good diggers and so must scout out their winter homes in deep cracks and crevices in logs or rocks, or they might dig down into the leaf litter.

Yet these frozen frogs aren’t dead—they have a kind of natural anti-freeze in their bodies. Ice crystals form in their organs and body cavity, but a high concentration of glucose in the frog’s vital organs prevents freezing. A partially frozen frog will stop breathing: its heart will stop beating and it will seem dead. When spring approaches and their hibernaculum warms up above freezing, the frog’s frozen body will thaw, and it will come back to life.

As you go about your holiday, all bundled up for the cold, think of the frogs with their amazing adaptations for survival, safe in their winter homes, waiting for spring.

Here’s a video from YouTube about the hibernation of a wood frog. It’s pretty amazing—take a look!

Most of the information from this post came from an article in Scientific American, How Do Frogs Survive the Winter? Why Don’t They Freeze to Death? by Rick Emmer.

10/12/10

The 10 Weirdest and Most Unusual Frogs on Earth

You might be familiar only with the green frogs or brown toads that live in nearby ponds or woods. But frogs and toads are among the most incredibly diverse animals on earth. Here are just a few of the weirdest and most unusual frogs and toads:

Tomato frog (D. antongilli)

Tomato frog, photo courtesy of Charles Paddock Zoo, Atascadero, CA

This frog is definitely NOT green! Colored as red a ketchup, the Tomato frog’s bright color is meant to warn predators that it is not safe to eat. The frogs secrete a gummy substance that gets in a predator’s eyes so it will drop the frog, which can then make a quick escape. The Tomato frog is found only in Madagascar.

Glass frogs (family, centrolenidae)

: Glass frog. Image courtesy of iFrog.

Glass frogs are nocturnal tree frogs that live in the humid forests of Central and South America. Their name comes from the translucent skin on the underside of their bodies. In many species the glass frogs’ internal organs, even a beating heart, can be seen. This see-through skin helps them blend into the forest.

Ornate horned frog (Ceratophrys ornata)

Ornate horned toad. Image copyright American Museum of Natural History.

This frog is nicknamed the Pac-Man frog because of its enormous mouth and insatiable appetite. They are a sit-and-wait ambush predator and hide well-disguised on the ground or in leaf litter. Ornate horned frogs can swallow birds, insects, mice, or even other frogs whole. This species can be found in Uruguay, Argentina, and Brazil.

Turtle frog (Myobattachus gouldii)

This unusual-looking frog looks like a turtle that has lost its shell. It has a short, blunt snout, little beady eyes, and short, fat limbs. It lives underground in burrows in sandy soil and chambers in termite colonies, upon which it feeds. During a few rainy nights in summer they emerge, mate, then then burrow underground where the eggs are laid. Four to six months later the eggs hatch as fully formed froglets. The Turtle frog only lives in the coastal plains and woodlands of extreme Southwestern Australia.

Wallace’s Flying Frog (Rhacophorus nigropalmatus)

Wallace's flying frog. Image copyright Tim Laman, National Geographic.

These frogs leap and glide from tree to tree by spreading out their huge webbed feet like parachutes.They are rarely found on ground except to mate and lay eggs. Their oversized toe pads help them stick to tree trunks and to land softly. Flying frogs inhabit the dense tropical jungles of Malaysia and Borneo.

Water-holding frog (Cyclorana platycephala)

Unusual among frogs, water-holding frogs can catch prey—aquatic insects and small fish—underwater, lunging at the animals and stuffing them in their mouths with their arms. During the dry season they become inactive and burrow underground, secreting a mucous to line their burrows. This hardens around the body and enables the frog to retain water that might otherwise be lost due to evaporation. These frogs were traditionally used by indigenous people in Australia as a source of water. They would dig up the frogs, gently squeeze the water from them, and release them unharmed. Water-holding frogs live in grasslands, temporary swamps, and clay pans in arid areas of southern Australia.

Pinocchio-nose frog (no scientific name yet)

Pinocchio-nosed frog courtesy of Treehugger.com

The Pinocchio-nosed frog was discovered recently during a wildlife expedition to Indonesia’s remote Foja Mountains. This long-nosed frog, a tree frog, has a spike on its nose that points upward when the male is calling but deflates and points downward when he is less active. You can see the Pinocchio-frog and the other newly discovered species on the National Geographic site.

The hip pocket frog (Assa darlingtoni)

Hip Pocket Frog courtesy frogs.org.au

This is called a Male Marsupial frog because like a kangaroo it carries its young in pouches. It has two openings, one on each hip, where tadpoles develop. First the female lays eggs in damp sand, then they are guarded by the male, and finally they hatch into finless white tadpoles, which wriggle their way into the pouches. Only about half make it. They emerge 7 to 10 weeks later as froglets. Hip-pocket frogs are terrestrial and live among leaf litter in the forest (and like a few of our other unusual frogs, they are only found in Australia).

Southern gastric-brooding frog (Rheobatrachus silus)

Gastric brooding frog

This species was discovered in 1972 living in rocky creeks and ponds in the rainforest of Queensland, Australia. They have an amazing way of “bringing up baby.” First the female swallows her eggs, then her digestion slows down and she stops feeding and the tadpole develops in her stomach. After six to eight weeks, she opens her mouth, dilates her esophagus and the babies crawl out. Sadly, this extraordinary frog is most probably extinct. The last wild southern gastric-brooding frog was seen in 1981—the last known frog in captivity died in 1983.

Pipa or Surinam Toad (Pipa pipa)

Surinam toad

This Surinam toad is the world’s flattest amphibian—in fact, it looks like the victim of an unfortunate road accident. Yet this frog’s unusual shape helps hide it among the leaves and plant debris in the streams they inhabit in the Amazon River Basin of South America. Like some of the other frogs above, they have an amazing reproductive strategy: after the female lays eggs the male attaches them to the female’s back. They stick to her skin, which grows to form pockets over them, giving her a honeycomb appearance. The tadpoles grow within these pockets and emerge as toadlets after 20 weeks.

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We’ve designed a cool new 2011 calendar and poster: The Weirdest and Most Unusual Frogs on Earth. Get one for your kid’s room!

Note: I got most of the information for this post from The Golden Guide to Frogs and Toads:

Golden Guide to Frogs and Toads by Dave Showler, illustrated by Barry Croucher.

08/18/10

Back to School at FROGS ARE GREEN!

It’s back-to-school time and we’d like to introduce you to a few notable children’s books about frogs and other amphibians published recently:

THE FROG SCIENTIST by Pamela S. Turner, photographs by Andy Comins (Houghton Mifflin, 2009)

Dr. Tyrone Hayes, with his children, reads a book his mother gave him as a child, from THE FROG SCIENTIST. Photo copyright Andy Comins.

This book, part of the Scientist in the Field Series, is a biography of frog scientist Dr. Tyrone Hayes at UC-Berkeley, who has done groundbreaking studies about the effects of atrazine, a widely used herbicide, on frogs. While the book is mainly a biography of Hayes, it is also a good overview of the global amphibian crisis and it includes an easy-to-understand explanation of the scientific method. The book has a lively, engaging design and many wonderful photos. It would be ideal for kids who are at that age (around 10 or so) when they decide that “science is boring.”

Dr. Hayes is an engaging subject for a biography, and the anecdotes about him are refreshing for this type of book (which can often be dry). A whole unit could be planned around THE FROG SCIENTIST, covering such topics as a science as a career, African Americans in science, the global amphibian decline, the scientific method, to name just a few.

A PLACE FOR FROGS by Melissa Stewart, illustrated by Higgins Ford (Peachtree 2009).

A PLACE FOR FROGS by Melissa Stewart, illustrated by Higgins Bond

For younger children (@5-8), this nonfiction picture book introduces different species of frogs and places them in their habitats. Each oversized double-page spread features a frogs species, their habitat, and shows some of the ways that human action and interaction can affect frog populations.

For example, one spread describes the Sierra Nevada Yellow-legged frog and its habitat, and explains why adding trout to the frogs ponds caused their decline (the trouts devoured the tadpoles). When people removed the trout, the frog populations began to recover. The frog and its habitat is depicted in gorgeous realistic paintings and is described in easy-to-understand language.

A Place for Frogs could be used for teaching kids about animal habitats (this author/artist team also did A Place for Butterflies and A Place for Birds). It could also be used in a unit about endangered animals, a unit devoted to frogs and amphibians, or it could be read as a springboard to study a local endangered frog in more detail, depending on where the school is located.

Big Night for Salamanders by Sarah Marwil Lamstein, art by Carol Benioff (Boyds Mill, 2010).

Illustration from BIG NIGHT FOR SALAMANDERS by Sarah Marwil Lamstein, art by Carol Benioff

In this narrative nonfiction picture book, a boy waits for the Big Night, the first rainy night in late winter or early spring when the blue-spotted salamanders begin their annual migrations. The salamanders must travel from their forest burrows to vernal pools, where they breed and lay eggs. The problem is the salamanders must cross a busy highway to reach the vernal pools. The boy, along with other volunteers, helps the salamanders cross the road. A parallel text in italics describes the migration of salamanders.

This is a lovely simple story about how one boy helps an endangered species close to home. It is illustrated in richly-colored gouache. At the back is information about the life cycle of blue-spotted salamanders, as well as information about the Big Night and vernal pools.

Big Night for Salamanders would be a good read-aloud book for younger children. It could also be used in units about the life cycles of animals, and about species whose habitats are threatened. Teachers could read this book in the spring and plan a field trip to a local vernal pool.

Don’t forget about the FROGS ARE GREEN ART CONTEST FOR KIDS! Please download and print out this flyer to tell kids about the contest.

04/29/10

Big Chill Helps Mountain Yellow-Legged Frog

One of the most endangered amphibians in North America—the mountain yellow-legged frog—might have some hope this spring due to the collaborative work of researchers at the San Diego Zoo’s Institute for Conservation Research, along with the help of biologists at the U.S. Forest Service, U.S. Geological Survey, and the U.S. Fish and Wildlife Service.

Courtesy of UC Berkeley, www.crcd.org

As reported in the Press-Enterprise (Riverside, California), researchers from the San Diego Zoo’s Institute for Conservation Research, which has a captive breeding program for the frogs, discovered that three months hibernation in near-freezing water is what gets these frogs in the mood for love. In the wild, frogs hibernate in icy, high-elevation streams, not in 55-degree aquariums. To mimic these cool temperatures, they were placed in clear plastic shoe boxes called “Valentine’s Day retreats” and stored in the refrigerators.

When they were removed from the refrigerators in April, they displayed breeding behavior within a few days. According to the institute’s Research Coordinator Jeff Lemm, “It has been wildly successful, and as a result, we could reintroduce about 500 eggs into the San Jacinto Mountains.”*

Only 200 individual mountain yellow-legged frogs exist in the wild. Once common in Southern California’s mountain streams, the frog species is almost extinct due to fungal infections, pollution, habitat loss, and predatory trout introduced for fishing. Researchers hope to re-establish wild populations with the captive-bred frogs.

Kudos to students, researchers, and biologists who are helping to save the mountain yellow-legged frog from extinction!

Please see the video below to learn more about efforts to save the mountain yellow-legged frog. This frog species was also featured in the episode Yosemite in the recently rebroadcast PBS documentary The Thin Green Line, about the amphibian decline, which you can watch online.

*As reported on the University of California’s Natural Reserve System site.

04/7/10

Vernal Pools: Woodland Nurseries for Frogs and Salamanders

This past weekend, I went hiking with my family in Harriman State Park in New York. We’ve had a very wet spring—well, actually it sometimes seems as if we’ve been living in a rainforest. It’s possible that all this rain will means lots of frogs and toads this summer.

While hiking we found a swamp and listened to a wonderful chorus of spring peepers and (we think) Eastern American toads.

My son Jeremy listening to a chorus of spring peers, Surebridge Swamp, Harriman State Park, New York

My son Jeremy listening to a chorus of spring peepers, Surebridge Swamp, Harriman State Park, New York

We also saw lots of vernal pools, bodies of water that appear in the spring and last from two to three months before they dry up in the summer. Some types of amphibians, crustaceans, and other wildlife need these pools for breeding, hatching eggs, or as a nursery while they are young. Because they are temporary, vernal pools do not contain fish (which eat tadpoles and larvae).

When you hike by vernal pools, they don’t look like much. In fact, my sneakers got soaked as I tried to jump over one. Yet they are of critical importance to wildlife. I’ve noticed, however, a lot of comments on environmental blogs that read something like this, “Only treehuggers would want to save these mud puddles!” Yet wood frogs, some species of salamander, and fairy shrimp need these “mud puddles” in order to survive. Every year hundreds of acres of wetlands are lost (usually forever) to commercial or residential development. According to the Ohio Vernal Pool Partnership

These usually small, but very dynamic wetlands fill with water, blossom with life and host a cacophony of sounds and a plethora of life forms every spring, only to disappear into the forest floor every autumn…. A vernal pool is a place where a good naturalist can weave many fascinating stories about the amazing life forms, adaptations, and life histories of its inhabitants, and demonstrate it by a single swoop of a dip net! Vernal pool is a miniature, fascinatingly complex and fragile world, with all of its drama played out every year close to our homes, and yet most of us have never witnessed it. [Ohio Vernal Pool Partnership].

: Salamanders and woodfrogs migrate from their wintering sites to vernal pools for breeding when the conditions are right, courtesy of The Vernal Pool Association