There are over 6,000 species of amphibians alive at present. This class of animals includes frogs, toads, newts, salamanders, and caecilians – a group of amphibians that resemble worms or snakes. In the UK, the most common amphibians are frogs, toads, newts and salamanders.
Most amphibians have a thin, moist skin that helps them breathe. No other group of animals has this unique skin. Nearly all amphibians undergo a unique change from larvae to adults, known as metamorphosis. All amphibians are cold-blooded, a characteristic they share with invertebrates, fish, and reptiles. Below are some examples of UK based amphibians.
Common Frog
Probably our most recognised amphibian, the Common Frog is found throughout Britain and Ireland and can be seen in most habitats where suitable breeding ponds can be found. Garden ponds are now very important for Common Frogs and several populations in built-up areas rely on them.
Adults can grow to nearly 8cm and are commonly some shade of brown or olive brown in colour with a dark area behind the eye and bands of darker colour on the back legs. Most individuals have irregular black markings on the back and two slender light stripes running down each side of the back. Coloration is variable and in recent years yellow, pink and orange individuals have been seen.
The life cycle of the Common Frog is known to most people; spawning happens usually in March, the tadpoles grow throughout the summer and appear as froglets in wet weather in August or September. Well-grown tadpoles are slightly dotted with gold, which distinguishes them easily from the black tadpoles of the Common Toad. Common Frogs eat a variety of invertebrate prey that is mostly caught at night. The frog’s skin is smooth and needs to be damp at all times, which restricts them to habitats near fresh water or habitats that remain damp throughout the summer.
Common Toad
The Common Toad is found throughout Britain although is missing in Ireland. It can grow to 8cm long, and is normally brown or olive brown and young specimens are usually brick coloured. The skin is warty and often seems dry. Glands in the skin contain a strong poison and possible predators soon learn not to try to eat toads. The Common Toad is found in almost any habitat and is common in gardens. They prefer large bodies of water in which to breed and, because the poisons are also found in the skin of the tadpoles, they can breed in ponds and lakes containing fish that learn to avoid the tadpoles. Common Toads meet at breeding ponds in early April but for the rest of the year will move away from water, as they are far more tolerant of dry conditions than the Common Frog.
Common Toads eat any moving prey small enough for them to swallow. They are mainly active at night when they will wander looking for food. If they find a good source of food they can become inactive. Their life cycle is similar to that of the Common Frog, spawn is laid in strings and the tadpoles are black and often move about together. The toadlets emerge in August usually after rain and in big numbers. At this point in their lives they are really small and speckled with gold.
Smooth Newt
Our most common newt, the Smooth Newt, is found all over Britain and is the only newt species found in Ireland. It can grow to 10cm long and is normally found during their breeding season in ponds. The Smooth Newt is brown, the female being fairly plain whilst the male is spotted and develops a continuous curvy crest along its back in the breeding season. The belly is yellow to orange with black spots and the spots on the throat offer a good way of telling this species apart from others. Outside the breeding season newts come onto land and live in moist places; they are usually found under logs and debris at this time in their yearly cycle. Newts found in these conditions are occasionally mistaken for lizards.
Newts eat small invertebrates either on land or in the water. A newt tadpole is known as an eft. Unlike frogs and toads, the efts develop their front legs before their back legs. Newt efts breathe through feathery gills that sprout from behind the head. Spawn is laid as individual eggs which are carefully wrapped in a leaf of pond weed by the female newt. |
