Common frog  (Rana temporaria)

Undoubtedly Britain's most well-known amphibian, the common frog is often found in garden ponds (2). They are typically brown or greyish in colour, but some individuals may be yellow or reddish. The flanks are usually yellow, the underside white, and the upper surfaces feature variable blackish markings (5). The large hind legs feature webbed feet; they power strong jumps and an excellent swimming ability, and are covered with dark bands, which provide camouflage (5). Males tend, on average, to be slightly smaller than females, and they can be identified by whitish swellings on the inner digits of the front feet, which support dark pads during the breeding season that allow the male to effectively grasp a female (5).

Found throughout Britain and Ireland (2). Elsewhere, the common frog occurs in most of Europe, with the exception of Portugal, most of Spain, Italy and Greece (4).

Found in a wide range of habitats, and breeds in puddles, ditches, ponds and large lakes as well as urban and rural garden ponds (5). They have even been recorded breeding in running water (5).

Common frogs hibernate through the winter, either at the bottom of ponds (breathing through their skin) or on land under refuges such as compost heaps (5). During the rest of the year they hunt on land on damp nights; they feed on snails, slugs, worms and a range of insects (5).

In spring, males arrive at breeding areas before females, and it is thought that individuals return to their natal ponds by following scents (5). There is typically heavy competition amongst males for females, involving much croaking and wrestling. Males grab a female and remain clasped to her body for days or weeks before spawning takes place. All of the frogs in a pond tend to spawn roughly within a few days of each other. The female releases 1000 to 2000 eggs, the male then releases sperm. The eggs are coated in jelly, and are popularly known as 'frogspawn'. After 10-14 days, the tadpoles hatch, becoming free-swimming a few days later, and undergoing metamorphosis into adults 10-15 weeks after hatching. Tadpoles are vulnerable to predation by a range of aquatic creatures, including water beetles, newts and fish (5).

For several decades up until the 1970s, this frog suffered a serious decline in Britain. Since the increase in popularity of garden ponds, however, it has experienced a welcome recovery. It is not currently threatened, but populations are vulnerable to the destruction and pollution of water bodies (4). Inbreeding in garden ponds caused by isolation is thought to be a serious problem in some areas, leading to reduced immunity and an increase in disease (5).

It is illegal to sell common frogs under the Wildlife and Countryside Act, 1981 (2).

For more on this species and other amphibians and reptiles of the UK see The Herpetological Conservation Trust:
http://www.hcontrst.f9.co.uk
For more on amphibians of the world see Amphibia Web:
http://elib.cs.berkeley.edu/aw/search/index.html

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact
arkive@wildscreen.org.uk