Species Guide: Common Frog (Rana temporaria)
Family: Ranidae
APPEARANCE
Generally brown with smooth skin, but their color varies to an olive green or grey, due to their ability to adapt their skin color to blend into their surroundings. Interestingly, during the breeding season, females can exhibit a reddish shine, whilst males can exhibit a blueish shine. They have partially webbed feet and long hind legs for hopping on land and swimming in water. They also feature a dark band around their eyes. Females are significantly larger than males, but males are also distinguishable by a nuptial pad nuptial pads (rough patch) on their thumbs, which they use for gripping onto females when they mate.
Diet
They are carnivorous animals, with a diet that consists of invertebrates such as slugs, snails, and flies. They use their long, sticky tongue to catch their prey and eat it whole.
HABITAT
Common Frogs can be found across the UK and much of Europe. They seek out standing water such as ponds and lakes, but are opportunistic, and are just as happy in flooded areas in meadows and forestry land. They can also be found across both highland and lowland habitats.
Note that this map is for a rough illustration of animal distribution across the UK, whereby light green indicates established populations.
Behavior
Common Frogs are terrestrial and generally nocturnal, although you may encounter them during the day, especially during the breeding season. Depending on the climate, they often hibernate during the winter months, though they are one of the first amphibians to commence breeding, which often occurs as early as February.
During the breeding season, males will attempt to claim females by clinging to their backs. Females lay upwards of 4,500 eggs in a clump in the water, after which the male will fertilize them. The eggs form into tadpoles after around 3 weeks and then hatch. The tadpoles are born with tails, but no legs, and are fully aquatic. They spend approximately 16 weeks in the water, eating algae and pond plants. During this time, a gradual metamorphosis occurs. The tadpoles lose their gills and develop lungs, their tails shrink, and they grow legs, transforming into frogs.
Common Frogs have a pleasant repetitive croaking call which lasts for around 2 to 5 seconds.
Common Frog Call:
Simon Elliott, xeno-canto.org
During the winter, the Common Frog will hibernate in shelters such as compost heaps and under logs. They will even hibernate underwater in ponds. Frogs have quite a unique ability, as they can breathe through their skin! Their skin is permeable and allows oxygen to diffuse directly into their bloodstream from the water.
Biometrics
Key biometric features of the Common Frog are:
| Total Length | Up to 11 cm |
| Body Weight | Up to 22 grams |
| Longevity | 5-10 Years in the wild |
NATURAL PREDATORS
Common Frogs are on the menu of a variety of predators. Some of the mammals include otters, badgers & Pine martens. They are also hunted by birds, including herons and even ducks. Their main reptilian predator is the grass snake. Even their youngsters don’t get an easy time; the eggs and tadpoles are frequently taken by aquatic predators such as fish, newts, and even some insects, such as diving beetles and dragonfly larvae.
Conservation Status
Loss of habitat has played a large part in the reduction of the numbers of Common Frogs. A large part of this habitat loss is the development of housing on sites that were historically used by them. They are still, however, classified as Least Concern from a conservation viewpoint. 1
Global
Conservation Status
CITATIONS
- IUCN Redlist [Accessed 16/03/2025] ↩︎
References
Speybroeck, Jeroen, et al. Field Guide to the Amphibians and Reptiles of Britain and Europe, Bloomsbury Publishing Plc, 2016. ProQuest Ebook Central. [Accessed 16/03/2025]
Dorcas, Mike, and Whit Gibbons. Frogs : The Animal Answer Guide, Johns Hopkins University Press, 2011. ProQuest Ebook Central. [Accessed 16/03/2025]
Frogs: Biology, Ecology and Uses : Biology, Ecology and Uses, edited by James L. Murray, Nova Science Publishers, Incorporated, 2011. ProQuest Ebook Central. [Accessed 16/03/2025]
