Let the games begin!

Silverstoneia flotator

Frogs, including this Silverstoneia flotator, have all sorts of fascinating adaptations that can give them a “competitive” edge in the wild. (Photo by Brian Gratwicke, Smithsonian Conservation Biology Institute)

On July 27, 2012, the 30th Summer Olympiad opened in London. Thousands of the best athletes from almost 200 countries are competing against one another in friendly competition for two weeks. Billions around the world have tuned in to watch the sporting events.

Few people, however, tune in to the competition going on outside their own window. For a frog, winning the 100 meter dash to a hiding place isn’t a gold medal win. It’s a win for survival. As many athletes mention, there is no second place, unless the belly of a bird counts.

As natural selection demands, only the best survive. With the Olympics in full swing, it’s a good time to take a look at the best of the best in the frog world. What follows is a list of a few of those that live by the Olympic motto, “Faster. Higher. Stronger.”

1) Longest jump – The longest recorded jump by a frog (not to be confused with the human frog jump!) was completed by a frog called Santjie at a South African frog derby. The frog, of unknown species, jumped an astounding 33 feet, 5.5 inches. In the United States, the record holder at the famous Calaveras County Jumping Frog Jubilee is Rosie the Ribeter (American bullfrog, Rana catesbeiana), who jumped 21 feet, 5.75 inches in 1986. According to the rules, the leaps were the total measure of three jumps.

2) Weightlifting – Some of the largest athletes at the Olympics are the weightlifters. With the top weight class clocking in at more than 230 pounds and able to lift twice that, these competitors have some massive muscles. The largest frog, and by proxy probably the strongest, is the goliath frog (Conraua goliath). This behemoth, found in a narrow range of Equitorial Guinea and Cameroon, clocks in at 1 foot long and more than 7 pounds! They are listed as endangered by the IUCN because of overharvesting for frog legs.

3) Wrestling – While the single largest individuals at the Olympics have often been wrestlers, the champions of the frog world are much, much smaller. Many frogs will tustle over territory during mating season, but the tiny members of the family Dendrobatidae are the best known for it. You can watch a fantastic clip of a 30-minute wrestling match from David Attenborough’s Life in Cold Blood on YouTube. The frogs rumble and tumble for up to half and hour, with the winner keeping the prime territory and the adoration of the ladies.

4) Gymnastics – It wouldn’t be the Summer Olympics without high-flying gymnastics! In the frog world, this title would most likely belong to the flying frogs, which have independently evolved in three different genera. The most famous and one of the largest is Wallace’s flying frog (Rhacophorus nigropalmatus). All flying frogs have large, webbed feet and skin flaps that allow them to glide from the treetops to escape predators, catch food or head to the ground for mating. I’d like to see them go up against the USA’s Fab Five. Wouldn’t that be a match to see?

Though there are many other frogs out there, I hear the closing ceremonies beginning. Unless that bird catches up, see you again in four more years!

– Andrew Franks, Zoo New England

Frog Love

Valentine's frogs

In celebration of Valentine’s Day this week, we pulled together some of the most interesting breeding rituals in the frog world. Their wooing methods and reproductive techniques are as diverse as the animals themselves—and candy and flowers are not required for success!

1. The Underwater Ballet: Surinam toads (Pipa pipa) bring the romance of the ballet to their breeding habits, performing what looks like an “underwater ballet.” While they are joined in amplexus (when the male hangs on the female’s back, grasping her around the neck), they flip through the water together in arcs; a perfect dance. As the male and female swing in synchrony, the female releases eggs and the male fertilizes them.

Panamanian golden frog (Atelopus zeteki)2. The Sign for “I Love You:” Panamanian golden frogs (Atelopus zeteki) aren’t shy. If the males can’t get their point across to a potential mate through their low whistling call, they wave their hands in seduction. Some researchers believe they may even use this to greet one another!

3. That’s a Mouthful: Now thought to be extinct, the gastric brooding frog (Rheobatrachus silus) incubated its young inside its tummy! The female swallowed the eggs after they had been fertilized and the tadpoles developed in her stomach while the female’s entire digestive system would shut down to ensure she didn’t digest her children! After about six weeks, she would give birth to up to 25 young by opening her mouth widely so the fully formed frogs could emerge and hop away.

Nest of a foam nest tree frog (Chiromantis xerampelina)4. Whipping up a Frenzy: When two male foam nest tree frogs (Chiromantis xerampelina) find true love, they shack up in a nest of foam. But it’s up the female to build it and she whips up a foam nest out of skin secretions with her back feet before blending between 500 and 1,200 eggs into the froth. Sometimes this process includes more than one pair of frogs—or more than one male at a time!

5. Flying High: Wallace’s flying frog (Rhacophorus nigropalmatus) spend almost all of their time in trees, coming down only to mate and lay eggs. These frogs are very particular, however, about where they lay their eggs, preferring the smelly wallowing holes of the nearly extinct Asian rhinoceros! They seem to risk getting stepped on in exchange for at least some protection from potential predators who are scared off by the rhinos.

6. Paternal Instincts: In the case of the Darwin’s frog (Rhinoderma darwinii), it’s up to the father to rear the young. After the female lays the eggs, the male then guards them before picking up all of the survivors and carrying them around. The tadpoles develop in the male’s baggy chin skin, feeding off their egg yolk. When they are tiny froglets (about half an inch), they hop out and swim away, leaving pops on his own again.

7. Egg Mania: The female blue mountain tree frog (Litoria citropa) lays about a thousand eggs on the floor of a rocky pool of water during the spring and summer. When the eggs are fertilized, she kicks them so they disperse and have a greater chance of survival in the case of a targeted attack. The female frog can reproduce only at the age of 2 or 3 years old.

Banded horned tree frog (Hemiphractus fasciatus) 8. Hitchin’ a Ride: The eggs of the banded horned tree frog (Hemiphractus fasciatus) get pushed into a sack on the female’s back as the male fertilizes them. These frogs breed by direct development, which means that when they are born, they pop out as kid frogs instead of baby tadpoles. Then they stick around for awhile, taking a ride on mom’s back.

Lexie Beach, Smithsonian’s National Zoo

–Unless otherwise indicated, photos by Brian Gratwicke, Panama Amphibian Rescue and Conservation Project