40 Fun Facts About Red-Eyed Tree Frog

What signal tells red-eyed tree frog embryos a snake is at their clutch, so they hatch days early?

Vibrations from the snake's jaws are the cue, and the embryos can tell them apart from the patter of a rainstorm. Hatchlings wriggle free and drop into the water below.

The Rainforest Alliance made the red-eyed tree frog its mascot because it is common in which country?

Costa Rica is where the group first worked to protect forests in the late 1980s, and the frog was a familiar sight there. Its seal now appears on coffee, tea, cocoa and bananas.

What is the gold-veined nictitating membrane that covers a sleeping red-eyed tree frog's eye?

A third eyelid, see-through and laced with gold, lets the frog rest while still noticing a predator's approach. Many birds, reptiles and sharks have one too.

What does a female red-eyed tree frog look for beneath a leaf before laying her eggs on it?

A pond or large puddle sits below the chosen leaf, so the tadpoles simply slide off and splash down. Each clutch holds roughly 40 eggs.

Red-eyed tree frog tadpoles graze on algae and plankton, but what else will they sometimes eat?

Each other is on the menu, since the tadpoles turn cannibal as well as scavenging carrion. Dragonflies, meanwhile, are among the hunters that eat them.

What lets a red-eyed tree frog cling to the underside of a leaf and climb almost any surface?

Adhesive toe pads grip so firmly that a mating female can hang from them under a leaf while the males wrestle nearby.

What is a group of red-eyed tree frogs called, the name National Geographic lists on its fact file?

An army is the collective noun, a grand title for an animal that would fit inside a teacup: even the larger females reach only about three inches.

What colour are the stripes on a red-eyed tree frog's flanks, hidden under its legs during sleep?

Blue and yellow bars line the flanks, and the sleeping frog folds its legs over them so only leaf-coloured skin shows. Females also judge a male by his stripes.

The red-eyed tree frog is native to the humid lowland forests of which region?

Central America is the frog's heartland, with a range that also spills into the north-western corner of South America. It needs humidity of 80 percent or more.

What do adult red-eyed tree frogs mainly eat, hunting among the leaves after dark?

Insects such as moths, crickets and flies make up most meals, though a big adult will now and then swallow a smaller frog.

Which process turns a red-eyed tree frog tadpole into a froglet after its spell of life in water?

Metamorphosis reshapes the swimming tadpole into a froglet, and its timing shifts with conditions in the water. Before then, a tadpole can last only up to 20 hours on land.

Wild red-eyed tree frogs are threatened by capture for which international business?

The pet trade takes frogs from the wild in several countries, which is why zoos urge buyers to choose captive-bred animals only.

Red-eyed tree frog eggs that fall into the water hatch early because the embryos run short of what?

Oxygen runs low once a clutch is submerged, and the embryos can then hatch at just three days old, about half the usual time.

Which red-eyed tree frog parent, if either, stays to guard the eggs once they are laid on a leaf?

Neither parent returns to the clutch, so the embryos must defend themselves, which they do by hatching in a hurry when attacked.

Which word describes the texture of a red-eyed tree frog's skin, which helps it pass for a leaf?

Smooth skin with almost no bumps lets the resting frog pass for part of a leaf. A coat of mucus on top slows water loss and helps fight infection.

How do male red-eyed tree frogs threaten rivals before they wrestle, a signal first decoded in 2010?

Shaking their perch sends tremors along the plant to a rival, and the male that keeps it up longest usually wins. No tree-dwelling vertebrate had been shown to signal this way before.

Besides snakes, which stinging predators raid red-eyed tree frog eggs and trigger early hatching?

Wasps raid the clutches alongside egg-eating snakes, and an embryo at one study site had a 50 percent chance of meeting one or the other.

Which stand-in rival did scientists build to pick fights with male red-eyed tree frogs?

A robot frog drew angry replies from real males, but only while its signals were switched on. When it sat still, they ignored it.

Which rival in the Bone Wars fossil feud first described the red-eyed tree frog, back in the 1860s?

Edward Drinker Cope named the frog while still in his early twenties, years before his fossil feud with Marsh began.

What is the red-eyed tree frog's defence of suddenly flashing its eyes, feet and flanks called?

Startle coloration buys the frog an instant: a bird or snake hesitates at the burst of colour, and the frog springs away.

Which IUCN Red List category covers the red-eyed tree frog, which copes well with altered habitat?

Least Concern reflects a wide range and a tolerance for disturbed forest, yet the IUCN still records many populations as shrinking.

What do red-eyed tree frog embryos release from their snouts to dissolve an exit hole in the egg?

Enzymes stored in cells on the snout are dumped all at once, so an escape takes seconds. Photographs showed the cells full before hatching and empty afterwards.

Which call does a male red-eyed tree frog make to attract a female when rainfall is at its highest?

Chack is how the call is written down, and females weigh it together with the stripes on a male's sides before choosing a mate.

Chytrid, a threat to red-eyed tree frogs and to frogs across the world, is which kind of organism?

A fungus is behind the disease, which has been linked to steep declines and extinctions among frogs on several continents. No effective control is known in the wild.

Frogs like the red-eyed tree frog are sensitive to pollution, making them which kind of species?

Indicator species show whether an ecosystem is healthy, which is why a conservation group put a frog on its seal for certified farms.

Adult red-eyed tree frogs sometimes hide inside which plants, pineapple relatives that hold water?

Bromeliads trap water between their overlapping leaf bases, making damp hideaways high above the ground. One such tank was found to hold a small frog among a crowd of other creatures.

Which country hosts the Smithsonian institute where red-eyed tree frog hatching is studied?

Panama is home to the only Smithsonian bureau outside the United States, and its frog research is based in the town of Gamboa beside the canal.

What do red-eyed tree frogs produce to glue their eggs together and guard them against drying out?

Sticky jelly holds the clutch together on its leaf, and the frogs may even fold the leaf over to hide the eggs from predators.

The wild range of the red-eyed tree frog reaches its southern limit in the north of which country?

Colombia marks the southern limit, so the species just crosses from the land bridge into a second continent. A look-alike found from Veracruz to Honduras was split off as its own species in 2019.

The leaf frog family of the red-eyed tree frog has its closest relatives in which distant land?

Australia and New Guinea hold the sister family, whose ancestors are thought to have left the leaf frogs' home continent by way of an Antarctica not yet frozen over.

Which way of travelling gives Agalychnis spurrelli, a cousin of the red-eyed tree frog, its common name?

Gliding is its trick: the frog spreads its heavily webbed hands and feet as it leaps, and they act as a parachute to slow the fall.

A red-eyed tree frog's neon colours may leave which effect in a predator's vision as it leaps away?

A ghost image may linger where the frog was sitting, because its vivid colours overload the keen eyes of nocturnal hunters.

How did Karen Warkentin first discover red-eyed tree frog escape hatching in Corcovado National Park?

She bumped into some eggs as a PhD student in 1991, and tadpoles burst out all over her. Until then, most biologists thought hatching ran like clockwork.

What is the mating clasp called, in which a female red-eyed tree frog carries the male for hours?

Amplexus comes from the Latin for embrace, and the male holds on while the female lays her eggs on a leaf for him to fertilise.

Which diet pigments, the kind that colour flamingos, turn young red-eyed tree frogs redder?

Carotenoids eaten soon after a froglet leaves the water deepen its skin colour and help females grow faster and lay more eggs. Captive frogs fed too few can fade.

The nictitating membrane over a red-eyed tree frog's eye is named from the Latin for which action?

Blinking is the root meaning, from the Latin nictare. Cats, polar bears, seals and aardvarks have a full membrane too, while many other mammals keep only a small remnant.

Red-eyed tree frog embryos have been found to aim their escape from the egg towards which cue?

Light draws the hatching embryo, a study found, which suggests it reads brightness and darkness to choose which way to burst out.

About how long after laying do undisturbed red-eyed tree frog eggs hatch and drop their tadpoles?

One week is the usual wait, at six or seven days, but embryos under attack can leave up to 30 percent sooner.

A red-eyed tree frog's lime-green skin can shift with its mood to dark green or which other colour?

Reddish-brown is the frog's other mood colour, and young froglets go further, changing their skin tone with the time of day.

What is the main reason red-eyed tree frog numbers are falling, though the frog is not endangered?

Deforestation strips away both the treetops the adults live in and the shaded pools they breed beside, which is why parks across the range matter to the species.