Amphibians & Reptiles
The Great Crested Newt
The Great Crested Newt (Triturus cristatus Laurenti, 1768) is the largest and most distinctive of the three native newts.
Females, which are slightly larger than males, can reach up to 170 mm in length. They are characteristically very dark, almost black, in colour, and are rather reminiscent of miniature dinosaurs. During the breeding season (March to June), males develop a large and jagged crest along their back and tail. They have a distinctive bright orange belly spotted with large black blotches. This 'belly pattern' is unique to each individual newt, rather like a human's fingerprint, and can be used to recognise individuals.
Although widespread across Britain, Great Crested Newts tend to be localised and their numbers are declining in many areas. This is mainly due to habitat loss, such as the infilling of ponds and development surrounding habitats. However, they are particularly sensitive to even slight changes in habitat conditions. For this reason the animals, and their sites, are 'strictly protected' under both British and European Law, including full protection under schedule 5 of the Wildlife and Countryside Act (1981).
Like all amphibians, the Great Crested Newts need both aquatic and terrestrial habitats. They prefer large, well-established ponds, with circum-neutral, relatively nutrient-rich water. The larvae are particularly vulnerable to fish predation. Terrestrial habitat usually consists of rough grassland, scrub, and woodland. Of the British amphibians, Great Crested Newts spend the largest proportion of their life on dry land, and it is essentially that both terrestrial and aquatic habitats are considered if this species is to be conserved.
They spend the autumn and winter on land, feeding and hibernating, and in the spring, they migrate back to the ponds to breed. The larvae can take a couple of months to develop, eventually metamorphosing into the adult form, and leaving the pond in late summer. In general males mature at 2 to 3 years of age, females a year later, depending on food availability and other environmental conditions. Great Crested Newts, like many amphibians, are long lived. Although the average life span is just seven years, some individuals in the wild are known to be at least 14 years old.
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The Natterjack Toad
This rare toad is smaller than the familiar Common Toad. Its legs are shorter and it tends to run rather than walk or hop, hence its former Latin name, Bufo calamita which means “Running toad”.
Its most obvious difference is, however, a thin but bold yellow stripe down the middle of the back. In Britain the Natterjack is almost exclusively found confined to coastal sand dune systems, coastal grazing marshes and sandy heaths, though a single colony has been found on an upland fell site in Cumbria. It likes sandy habitats because any ponds that form tend to be shallow and very warm and the Natterjack needs warm water in which to breed.
It is found on about 60 sites in Britain and occurs on a small number of sites in south-western Ireland. Surprisingly some of the best areas for the Natterjack are in northern England and Scotland, notably on the sand dunes along the Merseyside coast, the coast on Cumbria and on the Scottish Solway. The Natterjack used to be quite common on the heaths of Surrey and Hampshire and also around the coast of East Anglia but sadly only one or two colonies now survive. Re-introduction programmes have now started to restore the range of this animal.
The Natterjack gets its common name from the loud rasping call made by the male from the edge of a pond at night during the breeding season (April - July) in an effort to attract a mate. Spawn is laid in strings as with the Common Toad and the tadpoles are small and black. They develop quickly and the yellow dorsal stripe is clearly visible on the young toadlets.
Threatened by habitat loss and the scrubbing up of its open habitats (often caused by changes in management such as the reduction in grazing) and suffering from competition from the commoner amphibian species the Natterjack is threatened in Britain
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The Adder
The adder(Vipera berus)is the only poisonous snake native to Britain. Adders have the most highly developed poison injecting mechanism of all snakes, but they are not aggressive animals. Adders will only use their poison as a last means of defence, usually if caught or trodden on. No one has died from adder bite in Britain for over 20 years.
With proper treatment, the worst effects are nausea and drowsiness, followed by severe swelling and bruising in the area of the bite. Most people who are bitten were handling the snake. Treat adders with respect and leave them alone. Adders are relatively common in areas of rough, open countryside and are often associated with woodland edge habitats. They are less inclined to disappear into the surrounding undergrowth when disturbed and so are probably the most frequently seen of the three British snakes.
The best time to see them is in early spring when they emerge from their hibernation dens. By mid April, the males have shed their dull winter skin and are ready to mate. There is a lot of frenzied activity on warm days, with males looking for females and occasionally wrestling with other males for supremacy. The 'dance of the adders' was thought to be a mating display, but it is a larger male attempting to drive off a smaller one. The snakes writhe around each other in an impressive way, often covering the ground at great speed.
Adders usually eat small rodents, such as the short-tailed vole. They will also eat lizards, frogs and newts, and have been seen taking young from the nests of ground nesting birds. When hunting, adders strike swiftly at the prey, injecting a lethal dose of poison. They then wait until the prey dies before starting the often lengthy swallowing process. Like all snakes, adders eat their prey whole, their teeth are designed to grip the prey as it is swallowed. Their jaws are linked by extensible connective tissue so each of the four main bones can move independently.
This means they are able to swallow items much larger than the width of their head. The lower ends of the ribs are not joined as in most animals and can also open out considerably. The adder's digestive fluid is amazingly powerful and will digest the flesh and bones of their prey almost completely. Only the hair and teeth of rodents pass through intact.
Young adders are threatened by a variety of predators, including birds of prey such as the common buzzard and sometimes adult snakes. Others may be killed and eaten by rodents while in hibernation. Adders are protected by law against being killed or injured through human activity.
Most adders are distinctively marked with a dark zigzag running down the length of the spine and an inverted 'V' shape on the neck. Males are generally white or pale grey with a black zigzag. Females are a pale brown colour, with a darker brown zigzag. But some adders are entirely black and can be mistaken for some other species.
Most of the woods managed by the Forestry Commission are suitable for adders. The way we manage the woods - cutting down older trees and planting young trees - provides excellent habitat. For the first 10 years as the young trees grow, adders can build up large populations unseen. Then as the tree canopy closes overhead, the snakes seek out the light and warmth that is available at the woodland edge.