Our Guide to Frogs found in the UK
We’ve trawled the web to bring you all the information we can on the UKs Frog Species in one handy place. This article includes their food, mating and hibernation habits as well as their protected status.
Picture by our member Nick Shelley
The Common Frog – Rana temporaria
Common Frog, also known as European Common Brown Frog, is an amphibian that belongs to the genus of Rana. These frogs are found in major parts of Europe and Arctic Circle. These amphibians are more prone to jumping, instead of walking and can live up to 8 years.
The Common Frog has certain descriptive features;
Colour: The colour of this frog varies from brown to yellow. The backs and flanks have an olive green lining and are covered with asymmetrical dark marks. Frogs often have bands of darker striping on the back legs. Many individuals have irregular dark markings on the back. Colouration is extremely variable: yellow, pink, red, orange and black individuals have been reported to the Wildlife Information Service. Female Common Frogs have orange under bodies and brown eyes.
These amphibians turn greyish blue during their mating season.
Picture by our member S. Olwyn
Red eyes and yellow skin, possessed by the albino Common Frogs, distinguish them from their kind. The back of the neck bears a chevron-shaped spot and have either white or yellow underbellies. Length: The average length of these frogs ranges in between 6-9 centimetres.
Weight: The average weight of these amphibians is 22.7g.
Height: Male Frog is shorter than the females.
Ear Drum: These amphibians have a clear distinct tympanum.
Glands: Common Frogs have a slightly raised paratoid glands.
Tongue: These frogs use their gluey tongue to catch prey.
Legs: Common Frogs are equipped with long legs to jump great heights.
Teeth: These frogs possess small fish like teeth to eat their prey.
Common frogs have certain adaptation qualities that need to be mentioned;
Common frogs can breathe through their skin which enables them to hibernate for the coming months under the decaying leaves water and mud piles.
Due to their transparent inner eye lids, they can protect their eyes under water.
They have the ability to change their skin colour according to the environment.
Depending on the surrounding, Common frogs can breathe through their lungs.
They are compatible to live under water and also above the surface.
These frogs can absorb water through their skin hence they do not need to drink.
Picture by our member Tom Moore
Pool Frogs- Rana lessonae Protected Species & Habitat
The northern pool frog is Englands rarest amphibian. Pool frogs were presumed extinct in the wild in 1995 but their native status was actually debated for many years as similar ‘exotic’ species had been introduced from Europe. Research was carried out in the 1990s which showed pool frogs have regional ‘accents’ to their calls and further genetic studies revealed their true ancestry. It was determined that English pool frogs belonged to a distinct, and very rare, northern group of pool frogs, also found in Sweden and Norway. Pool frogs have since been reintroduced at a single site in Norfolk. They belong to a complex of species known as ‘green frogs’ which also includes marsh frogs and edible frogs.
Lifespan of these frogs ranges between 6 years and 12 years
Size: Their lengths vary between 2.5 and 3 inches. The females are larger in size than the males. Pool Frog tadpoles are 5 mm to 9 mm long when born, growing between 50 mm and 75 mm before metamorphosis.
Colour: The body colour ranges from olive green to brown with dark brown spots covering their dorsal side. A yellow line runs down the middle of their dorsal side. The ventral side or belly is off white or creamish in colour. They have golden coloration around their eyes.
Head: These frogs have a pointy snout. There are no dark patches around their eardrums behind the eyes unlike other frogs.
Eyes: This species of amphibians have horizontal pupils.
The Common frogs are largely terrestrial outside the breeding season, and can be found in meadows, gardens and woodland. It prefers to live on land when it is not breeding
The Pool frogs preferred habitat would be within a series of small ponds in woodland, called pingos. Pool frogs prefer small, sheltered, sunny ponds adjacent to woodlands, in woodland margins or in meadows.Requiring insolation they are usually found gregariously sunning on south-facing banks adjacent to the water body or on floating leaves and rafts of vegetation on the water body. On disturbance they leap into water with characteristic ‘plop’.
The common frog can breathe through its skin. This enables it to hibernate for several months. During the winter they hibernate in compost heaps, under stones and logs, or underwater beneath piles of mud and decaying leaves.
Pool Frogs Hibernation starts in fall and continues through spring (September to November). They also hibernate from March till May in some colder areas. These amphibians hibernate on land, inside tree cavities and frost-free holes.
The Common frog when its active, will feed on any moving invertebrates of a suitable size, such as insects, snails, slugs and worms, which they catch with their long, sticky tongues. Adult frogs feed entirely on land, whereas younger frogs will also feed in the water. Tadpoles are herbivorous and feed on algae but become carnivores when they mature into adult frogs.
Adult Pool frogs are carnivorous, feeding on various insects and invertebrates including wasps, hoverflies, dragonflies etc. Sometimes they also eat smaller amphibians. Tadpoles of this species generally eat algae while the juvenile frogs feed on large amounts of flies and fly larvae.
What should Common frogs be doing in WINTER?
Frogs normally overwinter in places like compost heaps, amongst dead wood or under decking/your shed/other objects. Some amphibians, usually frogs and sometimes newts, will choose to overwinter at the bottom of the pond; they bury themselves down in the silt at the bottom and take in oxygen through their skin. Frogs may choose to come out and forage during milder periods of weather so do not worry if you see them around quite late in the year or if you accidentally disturb them.
What should common frogs be doing in SPRING?
Frogs will emerge from hibernation when the weather starts to warm up (night time temperatures over 5’C) – this can be any time from January onwards. It really all depends on local weather conditions so there is no set time. They head straight towards water to breed and it’s common to see lots of them congregating in and around ponds. Males often start moving before females and will either wait at the pond for a potential mate to arrive or wait nearby and ‘piggy back’ on passing females. A pitch-black swelling on the nuptial pad of the male frogs is visible during the mating season. The throats of the male frogs turn white during mating. Actual spawning takes place at night. The females are bigger than the males and lay around 1000 to 2000 eggs after breeding.
Once spawning is over, most animals will leave the water and may not spend much more time actually in a pond at all.
What should common frogs be doing in SUMMER?
Adult frogs may be found near ponds in summer. Otherwise they will be found in damp, shady spots such as under dense foliage or under logs. Depending on when the spawn was laid, froglets and toadlets will leave the pond in summer (June-September). They leave the water all at the same time and for a couple of days the garden will be alive with tiny amphibians! They quickly disperse into surrounding areas and may not return to the pond until they’re old enough to breed themselves (2-3 years later).
If you come across large numbers of dead frogs which were thin and/or lethargic before death you may be witnessing an outbreak of ranavirus. Summer is the prime time for this, when it is active in warm temperatures.
What should common frogs be doing in AUTUMN?
Autumn is a fairly quiet time for amphibians. All froglets and toadlets should have left the pond by now so you may not see any around the water at all. As gets colder frogs will be feeding up on insects, slugs and spiders in preparation for winter.
Towards the end of Autumn frogs will be looking for places to spend the winter, such as log piles, compost heaps and rockeries.
What should Pool Frogs be doing in WINTER?
Pool frogs normally hibernate on land between October and April.
What should Pool Frogs be doing in SPRING?
Adult frogs emerge from their overwintering sites in late spring and head to a pond to breed. Males have a loud call generated by a pair of vocal sacs either side of the head.
What should Pool Frogs be doing in SUMMER?
Pool frogs lay clumps of spawn (eggs) in the pond during late spring/early summer; breeding coincides with the onset of warm nights in May/June. These clumps are typically smaller than those laid by the common frog; individual eggs are brown above and yellowish below. Pool frogs are very aquatic and spend much of the year in or near the water; they also tend to bask in sunshine even on very hot days.
What should Pool Frogs be doing in AUTUMN?
Adults and froglets prepare for winter by feeding up on invertebrates.
The Pool frog species have some unique behaviour patterns different from other similar species:
These amphibians are diurnal creatures, staying active during daytime.
They are most active in hot weathers.
Even during the hottest days these frogs can be seen basking in the sun. This habit is very uncommon amongst frogs.
They tend to dive into their pools when frightened or threatened.
These water frogs give a loud defensive call when trapped immobile.
They can travel a long distance from water for hunting.
The presence of humans does not bother them much.
Common Frog larvae generally experience a threat from dragonfly larvae, birds, fish and beetles. Adult frogs are generally eaten by terns, herons, pine martens, stoats, weasels, crows, gulls, ducks, polecats, badgers and otters. Frogs experience life danger from domestic dogs and cats. Every year a large number of frogs are killed by motor cars and vehicles. Slugs poisoned by slug pellets are often eaten by these frogs and hence stand as one of the main factors for their extinction.
The Pool frog predators include grass snakes, owls, hornbills and different aquatic birds like heron. Pool frogs are extremely sensitive to movement and when predators are nearby will stop calling, flatten bodies to ground relying on camouflage, slip underwater or dive into the water from their sunning areas with a mighty leap.
Primary Threat is Loss of habitat – drainage of fenland is thought to be primarily responsible for the species originally becoming extinct in the UK.
How to encourage Frogs into your garden;
They need ponds to breed, so adding a pond to your garden is the best way to encourage them. Where possible try to consider size, shape and location of your pond before starting work; avoid adding fish as they will feed on spawn.
If you do not have a pond (or space to create one), your garden can still benefit, they may make use of it if there are water bodies nearby. You could think about a bog garden or small water feature instead.
They spend the majority of their life on land and make use of a variety of habitats in which they forage, shelter and overwinter (hibernate). They will use log and stone piles, long grass, compost heaps and even nooks and crannies under your shed, decking or greenhouse. Habitats that provide them with shelter and stay damp will provide a good source of insects and slugs to feed on and this is particularly beneficial.
Role in the garden;
They feed on snails and slugs, making them popular with gardeners. They also feed on other invertebrates such as beetles, spiders, and caterpillars.
I’ve found an injured frog what can I do for it?
If the injury appears slight and the animal is active and able to move freely, then it’s best to just move the amphibian to a sheltered part of the garden, away from the view of predators (such as cats and birds) and extreme weather so it can recover on it’s own. Dense foliage, dead wood or a compost heap are good places. Make sure it has the option to move to another part of the garden, should it want to.
Injuries such as skin abrasions should heal fairly quickly, so moving the animal to a quiet place, where it can recover and forage easily, will increase its chances of survival. If you think that an animal is seriously injured contact your local vet – though unfortunately they’re often unable to help with treating injured amphibians unless they have a specialism or interest in this field. Most vets treat wild animals for free but ring to check first. Wildlife hospitals are more likely to be able to offer assistance – the RSPCA may be able to help locate your nearest wildlife hospital. Some links are provided below but further internet searches may prove useful.
Please remember that amphibians are small, vulnerable creatures and it is unlikely that a severely damaged animal will be treated successfully.
Useful Contact Numbers:
RSPCA helpline 0300 1234 999
Or contact your local vet/wildlife hospital and they may be able to offer help and this is usually Free of charge.
Conservation & Protected Status
Frogs and toads have little legal protection, though toads, as a Biodiversity Action Plan priority species, should be protected from any adverse effects of development.
All of the UK’s rare amphibians and reptiles (Natterjack Toad, Pool Frog, Smooth Snakes and Sand Lizard), as well as Great Crested Newts, are protected by law from intentional killing and injury; their habitats (ponds and terrestrial habitats) are also protected. Unfortunately the other widespread, more common species are only protected against trade/sale.
The Pool Frog has full protection under UK law. It is an offence to kill, injure, capture or disturb them, and to damage or destroy Pool Frog habitats. It is also illegal to sell or trade pool frogs. This law applies to all life-stages.