This is an updated repost of a Father’s Day post from 2009.
Most animal dads aren’t too involved with their offspring (human dads, excepted of course). But two species of frogs, Liophryne schlaginhaufeni and Sphenophryne cornuta, in the microhylid frog family are devoted dads, and in fact, carry their their brood of up to 25 froglets piggyback style through the rain forest of Papua New Guinea. The frogs were discovered by evolutionary biologist David Bickford.
While most frogs start their lives as tadpoles, these frogs undergo “direct development.” They bypass the tadpole stage and go straight from larvae to miniature versions of adults while still inside the egg. This is an adaptation that allows the frog to reproduce in regions without bodies of water nearby.
After the mother frog lays the eggs, she hops off while Dad watches over the clutch, warding off predators, and keeping the eggs moist for about a month.
copyright David Bickford
After the froglets hatch from the eggs, they hop on Dad’s back. He carries them by night through the leaf litter in the rain forest. The froglets have a free ride until they grow up a bit and can live independently (hmmm…sounds familiar).
This is an updated repost of a Father’s Day post from 2009.
We never stop being amazed by how amphibians are able to survive in the harshest environments. The Shovel-Nosed Chamber frog (Leptodactylus bufonius), for example, lives in the dry subtropical or tropical shrublands or grasslands of Paraguay, Argentina, Bolivia, and Brazil, in areas that have only intermittent freshwater lakes, marshes, and ponds. But this frog has evolved many incredible adaptations for overcoming the challenges of living in these mostly dry conditions.
Going Underground
Unlike most frogs, Shovel-Nosed frogs don’t have ponds or other aquatic areas in which to lay their eggs. They have only the muddy remains of ponds that have dried up. So with their shovel-like noses, they dig a chamber in the mud and then top it with a mud cone. Because no water can penetrate these chambers, the frogs produce a foam nest from the female’s albumin secretions to keep the tadpoles moist. But there is no food in the nest—scientists believe the tadpoles metabolize their own issues for food. Then the frogs wait for a big rainstorm that will wash away the burrow and create a predator-free pond (like a vernal pool) for the tadpoles to grow in. But the story isn’t quite over. After the Shovel-Nosed frogs vacate their burrow, a local toad reuses it as a hiding place.
Take a look at this amazing video of the Shovel-Nosed frog by FROGS ARE GREEN friend Joe Furman. We especially like the frogs’ little mating wiggle!
About the filmmaker:
Joe Furman lives in Houston Texas. He is a lifelong animal photographer and makes wildlife documentaries, mostly about reptiles and amphibians. He is also an artist and cartoonist and father of one.
Like most kids, Joe was attracted to frogs and toads and caught and kept them as pets for awhile, but then would release them back into the wild. He had, and still has, a neverending curiosity about tadpoles and the life cycle of frogs. In his twenties he got the chance to go to Costa Rica to look for the Golden Toads. This event set the course of his life ever since. He has traveled around the world with different organizations to study, film, and photograph reptiles and amphibians, and other wildlife. The kid has never left him. He still love frogs!
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 frogsand 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!
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 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
Here are some sites and articles I’ve found (you can also try putting “vernal pool” and the name of your state in google).
