Common Frog
Identification: Length up to 11 cm, mostly smaller. High, round snout. Pupil horizontal elliptical. Eardrum up to three quarters of eye diameter. Dark patch from the eye through the eardrum. Light stripe along the upper lip. Back brown, reddish brown, yellowish, olive brown or grey, often with dark spots and a dark V-shaped mark between the shoulders. Rarely with a vague, lighter coloured stripe over the middle of the back. Dorsolateral folds on the border of flank and back. Throat whitish, sometimes with a light central stripe. Belly whitish to grey, brownish or greyish marbled, spotted or speckled. Well-developed webbing on the relatively short hind limbs. Metatarsal tubercles soft and smaller than half of the length of the toe on which it is standing. Sexes difficult to distinguish. Males have thicker forelimbs and in the breeding season black nuptial pads at the top of the thumbs, the throat often has a bluish tinge. The males can be swollen in the breeding season because of an accumulation of lymph. In the breeding season, females often develop pearly granules on their flanks.
Range: Central and north Europe. Widespread in Britain and Ireland. UK's most familiar native amphibian. Also on Guernsey, Alderney and Sark.
Habitat: All kinds of moist landscapes with dense vegetation, such as woods and marshes. Also in small-scale agricultural land, parks and gardens. Often in relatively cool and shady places, but needs sunny, shallow bank zones for breeding. Not restricted in the choice of breeding water, they use all kinds of still or slowly running waters, large and small, nutritious or poor in nutrients. In the south of its range also found in the mountains, in the Alps up to altitudes of 2800 metres, in the Pyrenees up to 3000 metres.
Habits: Active from the end of February until October. In mild weather conditions they sometimes stay active until December. In the breeding season active by day and night, after this period mainly nocturnal. In spring, mainly in March, a massive migration to the breeding waters occurs during the night. Their calls can be heard from mid-March; sometimes hundreds of them call together. They stay for a few weeks at most in the breeding water and subsequently range long distances, sometimes up to 10 km. A female produces 700-4500 eggs in total, divided over one or two clumps of spawn on the bottom of shallow water; they later float to the surface. After 1-3 weeks the eggs hatch and the larvae are 6-9 mm long then. They metamorphose after 2-3 months, at a length of about 4.5 cm. The newly metamorphosed frogs are only 1-1.5 cm long and look like miniature adults. They are mainly diurnal. After 2-3 years they mature, but males sometimes mature after 1 year. Common Frogs feed on all kinds of small invertebrates like insects and spiders as well as earthworms and slugs. Sometimes the frogs travel to the breeding water in autumn and hibernate in the surroundings or even in it. Hibernates both on land and water and sometimes they are even seen moving about under ice.
How to find: Common Frogs are most likely to be seen during the breeding season, though sub-adults may frequent garden ponds throughout the summer months. A regular garden visitor, they often breed in garden ponds. It is best to go towards their call. In late summer in the evening in rainy weather they can be found foraging near water. Adult frogs will range far from their breeding ponds and may be found almost anywhere at this time, from open fields to the more expected damp areas close to standing water.
Call: Faint humming sound, not very penetrating, can be heard up to 10-20 metres away. Heard day and night during breeding, sometimes also in autumn. Occasionally they call under water.