Some say the common frog, our most familiar amphibian, is no longer quite so common.
While the common frog (or Rana temporaria to use its formal scientific name) is distributed throughout the UK and Ireland and can be found almost anywhere with suitable breeding ponds nearby, its habitat is shrinking and facing pressures such as development, lack of habitat management and disease.
Garden ponds are increasingly important for common frogs and many populations in suburban areas depend on them. These help to compensate for losses in the UK countryside where ponds have decreased by a third in the last century to under 500,000.
Now, to mark World Frog Day on Wednesday 20 March – yes, it really exists – the country’s leading charity for amphibians and reptiles is calling on people to ‘care for the common frog’.
Jim Foster, Conservation Director of Amphibian and Reptile Conservation (ARC), said: “An awareness-raising event such as World Frog Day will often focus on eye-catching or exotic species such as tree frogs or the poison-dart frog.
“But we want to take the opportunity to highlight our own much-loved common frog, which will become less common if we do not conserve its habitat.
“Anyone can help by taking simple steps to make sure their garden ponds are amphibian-friendly: create gently sloping sides so frogs can move easily between water and land, use a good mix of native water-plants and have a deeper area – at least 60cm – in the centre so that frogs can sit out icy spells at the bottom. If you don’t have space for a pond, no problem – frogs can still use your garden to rest and feed.”
ARC produces free advice on how to make your garden frog-friendly. The leaflet Dragons in your Garden tells you how to create ponds and manage the rest of your garden to benefit amphibians.
The UK’s common frog may not be the poster-boy for World Frog Day but it is far from the uniform olive-green or brown of popular imagination. The common frog has a dark patch or mask behind the eyes and often darker striping on the back legs and irregular dark markings on the back. In fact the colour of the common frog is highly variable: yellow, pink, red, orange and black individuals are often seen.
Adult common frogs can grow to 9cm long. They are often found close to fresh water in habitats that remain damp throughout the summer, but outside the breeding season they can roam hundreds of metres from a breeding pond.
Spawning takes place during early spring, starting in the south of Britain as early as January. Tadpoles take up to 16 weeks to grow back legs, then front legs before they metamorphose into tiny froglets, ready to leave the water in early summer – often June, but in some ponds this may be as late as September.
Common frogs feed on a variety of invertebrate prey including slugs and snails which makes them especially popular with gardeners.
In Great Britain and Northern Ireland, the common frog (and its spawn) is protected by law from trade and sale.
Jim Foster added: “It may seem surprising to raise the prospect of shrinking numbers for a species which appears to be as common as the common frog, but the UK has already lost another native species of frog.
“The pool frog (Pelophylax lessonae) went extinct in the UK in the 1990s yet it has now been reintroduced successfully by ARC and partners in Norfolk , using frogs from Sweden.”
Common frog facts
- Frogs do not drink with their mouths; they drink by absorbing water through their skin
- Male frogs make a low purring sound in the breeding season to attract females, who are largely silent
- Frogs moult and they usually eat the skin
- Frogs swallow using their eyes – they retract them into the head to help push food down their throats
- Frogs in parts of Cornwall may breed as early as November, though spring is more usual for the rest of the country.
- Frogs in different areas can have different personalities – research shows that common frogs vary in boldness depending on where they originate, for example
- Frogs are a common theme in British folklore, often being associated with medicine and fertility
- Frogs don’t rain from the sky, as some stories suggest, but it is a fact that frogs can emerge from underground retreats in huge numbers during rain showers.