Darwin's Frog is a frog native to the forest streams of Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

 and Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. It was first described by French Zoologist André Marie Constant Duméril

André Marie Constant Duméril

André Marie Constant Duméril was a French zoologist. He was professor of anatomy at the Muséum National d'Histoire Naturelle from 1801 to 1812, when he became professor of herpetology and ichthyology...

 and his assistant Gabriel Bibron

Gabriel Bibron

Gabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...

, and is named after Charles Darwin

Charles Darwin

Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

 who discovered it in Chile during his world voyage on the HMS Beagle

HMS Beagle

HMS Beagle was a Cherokee-class 10-gun brig-sloop of the Royal Navy. She was launched on 11 May 1820 from the Woolwich Dockyard on the River Thames, at a cost of £7,803. In July of that year she took part in a fleet review celebrating the coronation of King George IV of the United Kingdom in which...

.

The most striking feature is the way the tadpole

Tadpole

A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...

s are raised—inside the vocal sac

Vocal sac

The vocal sac is the flexible membrane of skin possessed by most male frogs. The purpose of the vocal sac is usually as an amplification of their mating or advertisement call...

of the male.

Characteristics

The frog is brown or green with a size of 2.5–3.5 cm. Its front feet are not webbed, but some of the toes on the back feet usually are. It eats insects and other arthropods.

Darwin's frog not only has to hunt, but also must hide from predators wanting to eat it. Its most reliable technique to avoid its hunter is camouflage. It lies on the ground looking like a dead leaf until the predator passes by.

Mouth brooding

The female lays about 30 eggs and then the male guards them for about two weeks, until they hatch. Then the male takes all the survivors and carries around the developing young in his vocal pouch. The tadpoles develop in their baggy chin skin, feeding off their egg yolk. When the tiny tadpoles have developed (about half an inch) they hop out and swim away.