Common Frog (Rana temporaria )
The Common Frog is easily our most recognisable amphibian. They’re found throughout Britain and Ireland, in almost any habitat where suitable breeding ponds are near by. Common Frogs have smooth skin and long legs for jumping away quickly. Garden ponds are extremely important for common frogs, particularly in urban areas.
|Identification||Adults males grow up to 9 cm in length and females up to 13 cm in length. Usually a shade of olive-green or brown (although can be yellow, pink, red, lime-green, cream or black). Dark patches on the back, stripes on the hind legs, and a dark ‘mask’ behind the eye. Oval, horizontal pupil. Call: soft repetitive croak.|
|Distribution||Native to the UK. Found throughout Britain and Ireland. Widespread and common across Europe but numbers thought to be declining.|
|Ecology||Breed in shallow water bodies such as puddles, ponds, lakes, and canals. Tend to be most active at night when they feed on a wide variety of invertebrates. During winter they hibernate under rocks, in compost heaps, or underwater buried in mud and vegetation. Deposit ‘rafts’ of spawn, often containing up to 2000 eggs. Each small black egg is surrounded by a clear jelly capsule around 1 cm across. Common Frog tadpoles are black when they hatch but develop light bronze speckles as they mature.|
|Predators and other threats||Threatened by degradation of habitats and the introduction of disease.|
A year in the life…Spring
Adult frogs emerge from their overwintering sites in early spring and head straight to a pond to breed; frogs reach breeding age at 2-3 years old. Males have a single vocal sac under the chin and may ‘piggy back’ to the pond on a female. Clumps of spawn (eggs) are laid in ponds anytime from January (in south-west England) onwards. Depending on local weather conditions, two to four weeks later tadpoles will hatch out. As they grow the tadpoles become faintly speckled with gold/brown, which distinguishes them from Common Toad tadpoles which are black. They feed on algae and water fleas. After around 16 weeks the tadpoles start to grow back legs, followed by front legs. When they have fully absorbed their tails they leave the water as tiny froglets, usually in early summer but sometimes as late as September.
When tadpoles have fully absorbed their tails, they leave the water as tiny froglets. Adult frogs may be seen around ponds or in damp areas of the garden as they attempt to cool off in the hot weather. Summer is also the time when the frog disease ranavirus is active. Find out more here.
Adults and tiny new froglets spend autumn preparing for hibernation. They feed on insects, slugs and worms. If the weather stays warm then ranavirus outbreaks may continue into autumn.
Common Frogs spend the winter sheltering under rocks, in compost heaps or at the bottom of ponds. They don’t hibernate as such, and may take advantage of milder patches of weather to come out and forage.