Mongabay is the world's most popular site about the rainforest. This section provides information about frogs.
There is are free app versions of this web site, which includes a quiz to test what you've learned. Download the Android app at the Google Play Store under Frog Slideshow or the iOS version at the Apple Store.
Frogs and toads are among the best known amphibians. Photo: Red-eyed tree frog
Warty frog species are often called toads, but the distinction between frogs and toads is informal, not scientific. All toads are frogs, but not all frogs are toads.
There are over 6,000 species of frogs worldwide. Photo: Strawberry poison-dart frog (Oophaga pumilio) in Costa Rica's Atlantic rainforest.
Frogs live in a wide-range of habitats from deserts to sub-arctic regions to the tropics. Photo: Black-spotted rock frog (Staurois natator) in Indonesian Borneo
While frogs are found all around the world, the greatest abundance and diversity is found in tropical rainforests. Photo: Lemur frog (Agalychnis lemur)
Brazil has the most species of frog, with more than 1,000.
Colombia has the second most species of frog, with about 800.
China, India, and Indonesia are the countries in Asia with the most species of frog.
Madagascar has more species of frog than any other country in Africa.
Frogs live in trees, under leaves, in lakes and creeks, and even underground Photo: Imbabura Tree frog
While some frogs spend most of their time in the water, all frog species breathe air and therefore must surface from time-to-time Photo: Green-and-black poison dart frog in Costa Rica
Frogs have semi-permeable skin, which makes them highly sensitive to toxins in their habitats. It also means they are susceptible to dehydration, so they either need to live in moist places or have special adaptations to deal with dry conditions. Photo: Panamanian golden toad
Frogs, like other amphibians, typically have a multi-stage life-cycle. Photo: Reed frog in Madagascar
Most frogs undergo the process of metamorphosis as they develop from their larval stage into their adult form.
Most frogs start life in eggs, which are usually laid in or near water.
After hatching, most frogs then enter into the larval stage as tadpoles.
Tadpoles have gills, enabling them to live fully underwater where they feed on microorganisms and algae. Photo: Three-striped poison arrow frog with tadpoles on its back
From the tadpole stage, frogs eventually develop into their adult form.
However some frogs develop directly from eggs into their adult frog form. Photo: Glass frog in Costa Rica's Osa Peninsula.
Frogs come in a wide range of sizes, from tiny species less than 0.3 inches (8mm) long that live in leaf litter in the rainforest ...
... to the giant Goliath frog, which can grow to 13 inches (32 cm) long and weigh up to 7.2 pounds (3.25 kg). Photo: Giant smooth-sided toad
Frogs are carnivorous. Most eat insects and other invertebrates. Photo: Giant monkey frog
However larger frogs, like cane toads of the bullfrog, may eat other frogs, lizards, fish, and even small mammals.
Frogs are eaten by a wide range of other animals, making them an important part of the food web. Photo: Gmelin's Bronzeback snake (Dendrelaphis pictus) eating a frog in Malaysia.
Frogs are even eaten by people.
In some cultures, frogs are valued beyond food as religious symbols.
Frogs typically communicate by vocalizations. These calls are highly diverse across species.
Frog use their calls to attract mates, defend their territories, and scare away predators.
Frogs have different strategies to protect themselves from predators. Photo: Rhaebo haematiticus frog
Some frog species rely on camouflage, disguising themselves as leaves, to hide from predators Photo: Leaf toad in the Amazon.
Other frogs take the opposite approach, advertising their toxicity or bad taste with bright warning coloration Photo: Blue poison dark frog from Suriname.
Poison dart frogs are the best example of warning coloration. Photo: Granular Poison Frog in Costa Rica
These brightly colored frogs derived their toxicity from the ants and other invertebrates they eat. Photo: Almirante strawberry dart frog (Oophaga pumilio)
Poison dart frogs are found widely in the Americas. Some frogs in Madagascar take a similar approach. Photo: Varadero morph of Ranitomeya imitator
While the bioactive skin molecules that protect many frog species can be toxic, some have been used to create medicines. Photo: Cristobal strawberry dart frog (Oophaga pumilio).
The giant monkey frog (Phyllomedusa bicolor) is known for its mind-altering skin secretions. Shamans in the Amazon rain forest have used this species in hunting rituals.
Because frogs typically spend parts of their lives in different habitats and are sensitive environmental changes, they are seen indicators of ecological health.
For example, frogs can be heavily affected by water pollution or the use of pesticides. Photo: the lemur frog is Critically Endangered.
Rising levels of environmental damage is causing a global decline in frog populations. Photo: the Kinhasi spray toad nearly went extinct when its habitat in Tanzania was destroyed for a dam.
Many frogs are endangered, or have gone extinct, due to the outbreak of a deadly fungal disease that has spread around the world since the 1970s. Photo: the endangered black-eyed frog
The Panamanian golden toad for example is now extinct in the wild. It now only survives in captivity.
More than 100 species are known to have gone extinct since the 1980s due to chytridiomycosis, the devastating fungal disease. Photo: Gliding Treefrog (Agalychnis spurrelli) in Costa Rica's rainforest
More than one third of the world's remaining species are considered endangered according to the IUCN Red List compiled by scientists. Photo: Rhacophorus dulitensi tree frog in Borneo
Tree frog being treated for disease by researchers in Panama. Frogs and other amphibians are declining worldwide.
The rest of this slideshow highlights some of the wonderful variety of frogs found around the world.
Spiny-headed tree frog (Anotheca spinosa) in Costa Rica.
Green-and-black poison dart frogs fighting in La Selva, Costa Rica
Hyla tree frog in Tambopata, Peru.
Red-eyed tree frog from the Central America rainforest.
A poison dart frog in a cup mushroom in Costa Rica.
Java Toad (Phrynoidis aspera)
Matecho Dendrobates tinctorius poison dart frog
Blueberry poison arrow frog (Dendrobates pumilio)
Strawberry poison-dart frog (Oophaga pumilio) in Costa Rica.
Gephyromantis webbi frog in Madagascar
Tree frog in Costa Rica's rainforest
Glass frog in Costa Rica.
Clown tree frog (Dendropsophus leucophyllatus) in the Colombian Amazon.
Green-and-black poison dart frogs fighting in Costa Rica
Hypsiboas crepitans treefrog
Mother Panamanian golden frog with green baby. The Panamanian golden frog is believed to be extinct in the wild. These individuals are part of the Bronx Zoo's captive breeding program.