BRITISH AMPHIBIANS
 
Smooth newt Triturus vulgaris, palmate newt Trituris helveticus,
common frog Rana temporaria, common toad Bufo bufo
 
Smooth newt, common frog and common toad are common amphibians throughout much of Britain and can be found in ponds and wetland habitats of all shapes and sizes, they are also familiar visitors to garden ponds in the breeding season. The palmate newt has a more limited distribution than the other common amphibian species and is usually associated with shallow acidic ponds and pools that are found in the heathlands of southern Britain and the mountain and moorland bogs in the north of the country. The palmate newt is perhaps less common than the fully protected great crested newt but is common in the rest of Europe and receives no special protection in the UK.
common frogs
   
Natterjack toad Bufo calamita  
   
The natterjack toad is slightly smaller than the common toad and is a very rare species associated with heathland and sand dune systems. The natterjack toad is an attractive species which varies in colour from yellowish-green to olive-green, a yellow line runs down the middle of its back and this instantly distinguishes it from its common relative. Natterjack toads dig burrows in soft sand and emerge at night to hunt insects and other invertebrates. They breed in shallow ephemeral pools that are often devoid of vegetation and in some summers may dry out completely before the tadpoles have had time to complete metamorphosis into toadlets. Winter hibernation takes place buried deep in sand that protects the toads from extreme winter temperatures to which they are particularly susceptible.
Natterjack toads at a breeding pond in Dorset
   
Pool frog Rana lessonae  
   
The status of the pool frog in Britain has been the subject of considerable research and there is now a growing body of evidence to suggest that it was once a native species associated with the East Anglian Fenlands. One population survived near Thetford in Norfolk until 1995. Sadly its conservation significance was not fully recognised until the population died out following changes in the hydrology of its breeding pools. The last remaining male died in 1999. As an introduced species it is present at a number of sites across eastern and southern England.
   
Great crested newt Triturus cristatus  
   
The great crested newt is our largest species of newt and can reach over 15cm in length. Like other British amphibians it is terrestrial and is normally only present in water during the breeding season although this can often be as early January. It is a long lived species and in captivity has been reported to reach 27 years of age. It feeds on a range of small invertebrates.

Typically great crested newts use terrestrial habitats within 500 metres of their breeding ponds but they can sometimes be found considerably further than this. A wide range of terrestrial habitats are utilised and great crested newts can be found in hedgerows, ditches, woodland and rough grassland. A range of different water bodies is used for breeding but generally share one common theme in that they lack fish. Unlike other newt  species great  crested newt efts (larvae) are active swimmers and often float in mid-water which makes them particularly susceptible to fish predation.
Male great crested newt in breeding pond
   
   
Although the great crested newt occurs elsewhere in Europe it has suffered a massive decline in numbers throughout its range. Britain is thought to hold the largest population in the world.
     
Introduced Amphibians
     
A number of introduced species occur in the UK, the majority of these are localised and have failed to spread significantly from their original release sites. Well known and long established populations of introduced amphibians occur near Newdigate in Surrey where alpine newt Triturus alpestris, italian crested newt, Triturus carnifex, pool frog Rana lessonae, marsh frog Rana ribibunda and the hybrid edible frog Rana esculentaare have been known for many years. Of these species marsh frog and edible frog are now well known from other parts of Britain, for example, Romney Marsh in Kent supports a very large marsh frog population. Small colonies of the midwife toad Alytes obstetricans are established in one locality in England. Other amphibians that have formed short lived populations in Britain include tree frog Hyla arborea, mountain toad Bombina variegata and american bullfrog Rana catesbeiana. None of the introduced species receive any legal protection and species such as marsh frog are voracious feeders on native wildlife including other amphibians and as such are a serious ecological problem in areas where they are well established.
Privacy || Disclaimer
Copyright © 2003, Herpetosurveys. All rights reserved.