Anura (Frogs and Toads)

A frog is any member of short-bodied, tailless amphibians of the order Anura. Frogs are widely distributed, from the tropics to subarctic regions, with the highest diversity concentrated in the tropical rainforest. Frogs account for around 88% of extant amphibian species and are one of the five most diverse vertebrate orders. Warty frog species tend to be called toads by the layman, and there is no official taxonomic distinction.

An adult frog has a stout body, protruding eyes, anteriorly attached tongue, limbs folded underneath, and tailless. Frogs have glandular skin, with secretions ranging from distasteful to toxic, an anti-predation characteristic. Their skin varies in colour from well-camouflaged dappled brown, grey and green to avoid detection to vivid colorful patterns to warn of would-be predators of toxicity. Adult frogs live in fresh water and on dry land; some species are adapted for living underground or in trees.

Frogs lay their eggs in water, and these hatch into tadpoles that have tails and internal gills. They have highly specialized rasping mouth parts suitable for herbivorous, omnivorous or planktivorous diets. The life cycle is completed when they metamorphose into adults. Compared to their omnivores young, adult frogs are carnivorous, and have a diet consisting of small invertebrates. There are a few species that are omnivorous, but these are rather rare.

Frogs are an important food source for predators and are extremely important to food webs of many of the world’s ecosystems. Their skin is semi-permeable, making them susceptible to dehydration and so usually found in moist places. Some do exploit drier habitats or seasonal dry habitats, by having behavioral adaptation such as burrowing themselves deep in the ground where there is moisture and only emerging when the rainy season arrives. Vocalisation are also extremely important to frogs, especially for communication during breeding season, when they exhibit a myriad of complex behaviors to attract mates, to fend off predators and survive.

Frogs are valued as food by humans and as environmental indicators due to their susceptibility of their skin. Declines in frog populations are often an indicator of environmental degradation, and populations have seen significant decline since the 1950s which is extremely alarming. Currently, more than a third of all frog species are considered threatened with extinction and over 120 species are believed to have become extinct in the past 40 years. Today, a new threat for frogs has emerged, a fungal disease chytridiomycosis cause malformation in frog population, which has spread globally.