This is the largest and the least abundant species of newt in the UK.
As adults they can easily be distinguished from either the smooth or the palmate newt simply by size alone. Females are the larger of the two sexes averaging around 15cm in length, while the males average around 12 -13cm, although individuals frequently exceed these sizes.
The skin is rough and granular, leading to the alternative name of ‘warty newt’, to which they are often referred. The dorsal ground colour is essentially black, with fine white speckling along the flanks, usually extending onto the face and chin. The underside is a striking yellow or orange overlaid with a pattern of black markings. The pattern of black markings on the underside is unique to each newt and is often used by researchers to identify individuals.
When seen under torchlight at night, the usual black dorsal colouration often appears brown, with discernable large dark spots across the body
During the breeding season the males develop a high jagged crest stretching from the top of the head, along the back, to the base of the tail, followed by another running from the base of the tail to the tip. The fact that these are two separate crests with an obvious gap between them at the base of the tail is diagnostic of the species. The only other British species that grows a significant crest during the breeding season is the smooth newt, but in this species the crest is continuous from the top of the head to the tip of the tail. Additionally, the male crested newt develops a striking white line along the length of either side of the tail, which fades once the breeding season ends.
The females do not grow a crest and they lack the white stripe along the tail, both of which make them easily distinguished from the males during the breeding season. However should further distinguishing features be needed, the females are usually of a heavier build than the males, and during the breeding season are likely to be noticeably swollen with eggs. The females also have a continuous yellow or orange stripe running along the bottom edge of the tail. If the animals are captured it can be seen that this stripe runs through the cloaca therefore the cloaca of a female is yellow or orange, while that of a male is pigmented black and is noticeably more swollen than that of a female.
Outside of the breeding season, the ornamentation of the male disappears making them harder to differentiate from the females; however the females retain the continuous yellow stripe along the bottom edge of the tail, which the males never have.
On emergence from hibernation, crested newts return to their breeding ponds. The first arrivals, usually males, may appear as early as January, although the majority do not arrive until March. A few individuals may overwinter in the water, perhaps accounting for the earliest arrivals.
Courtship, followed by spawning begins within a week or two after arrival, each female producing in the region of 300 – 400 eggs, although a strange genetic anomaly, peculiar to great crested newts, renders about 50% of the eggs unviable, presumably conferring a significant disadvantage on the species.
The eggs are 4–5mm across and are white, differentiating them from the eggs of the other two species which are smaller and are brown or grey.
The species has a high fidelity to its natal pond, and has more stringent requirements of a breeding pond than do either the smooth or palmate newts. This is in part due to the behaviour of the larval stage of the newt. The larvae of both the smooth newt and the palmate newt are very secretive, spending their time hidden among the vegetation at the bottom of the pond. By contrast, those of the crested newt are described as ‘nektonic’, the term referring to their conspicuous behaviour, spending their time feeding and growing in the middle-depths of the water column in large expanses of open water. This makes them particularly vulnerable to predation by fish. Consequently, unlike the other two species, a crested newt population cannot usually persist in a water body shared with fish. Crested newts, therefore cannot thrive in most large lakes and canals, many ditches or rhynes and ponds on flood plains, which fish can quickly colonise during times of flood. Neither will they live in very small, shallow pools, lacking expanses of open water, although these may well suit the other two species. Ponds with a surface area of around 600m2 appear to be the optimal size for crested newts.
A habitat that seems to suit crested newts well is farm ponds, for example dew ponds and others of the type traditionally used to water livestock. These are usually large and deep enough to provide sufficient open water yet do not generally contain fish. Ponds that dry out during occasional drought years may be beneficial. The drying prevents colonisation of the pond by fish and crested newts can live for up to 15 years, so the population is able to absorb the occasional loss of an entire cohort of larvae, so long as drying does not occur too regularly.
The terrestrial habitat around the pond is important and must provide adequate cover and foraging opportunities. Most semi-natural environments such as rough grassland, scrub, hedgerows, woodland or even mature gardens are usually suitable, although intensively managed land such as arable is not favoured.
Unfortunately, pond loss has been a feature of the British countryside throughout the twentieth century. The advent of water troughs fed from the mains rendered livestock ponds redundant and many have now disappeared, either filled in or lost to neglect. While this has affected all species of amphibians it has had a disproportionate effect on crested newts due to their particularly stringent habitat requirements, and they have become a species of considerable conservation concern. They are afforded the greatest level of protection available to an amphibian in Britain, being listed under Schedule 5 of the Wildlife and Countryside Act 1981 and Annex 2 of the European ‘Habitats Directive’. Collectively these instruments protect the species from any intentional or reckless killing, injuring or disturbance; any collection or trade and any damage to or destruction of the species’ habitat.
The species is actually still relatively widespread in Britain, but beyond our shores its distribution extends across much of mainland Europe, where it has suffered considerably steeper declines than it has here. In fact, lowland England has now become the major remaining stronghold for this species, putting England in the enviable position of having the most important populations of crested newts in the world, justifying this high level of protection.
Predictably, this level of protection can be controversial, sometimes causing expensive delays for developers; and the media relish reporting on any conflicts that arise. However, reports are usually greatly exaggerated and development almost invariably proceeds, once steps have been taken to mitigate damage to the populations involved, which usually results in the newts being translocated to an alternative site.
In the nineteenth century, both Baker and Charbonnier described the great crested newt as ‘common in ponds and ditches’ in Somerset; a description that would not be entirely accurate today. Nevertheless, the species is not uncommon, either in Somerset or the unitary authorities, although their distribution is localised and patchy and they are absent from large swathes of the county. Where they do exist they can sometimes be found in significant numbers, often living sympatrically with one or both of the other native newt species.
In those parts of the Mendips where the crested newt has been intensively surveyed, it has been found to be widely distributed, but fragmented into small isolated pockets, too far distant from one another for any interaction to occur between them, each population often reliant on just one suitable breeding pond. This deprives the species of the meta-population structure in which they normally exist, leaving them vulnerable to local extinction. A comparable situation is likely to occur throughout many of those parts of the county where the species is found.
They are frequently encountered on the mid-Somerset hills and the Yeovil Scarplands where suitable ponds exist, but are not as common on the wetlands of the levels and moors as might be expected. The connectivity between the watercourses on the levels and moors together with the propensity for flooding, facilitate dispersal of fish, leaving few water-bodies fish-free. In the absence of fish-free ponds, crested newts exist only in very low densities, particularly on the peat moors. Closer to the coast, on the clay belt, flooding is less frequent and where clusters of discrete ponds do exist, they often sustain populations of crested newts.
The species is absent from Exmoor and the far west of the county. In Somerset the farthest west that they have been found is at Kittisford in the south, and Willett a little further north. They have not been found west of the OS easting grid line ST07, and their absence in the far west is not confined to Somerset. They are absent or rare, south-westwards throughout the west of Devon and the entire county of Cornwall.
Beyond Somerset crested newts are widely distributed across most of England, but are less common in Wales and Scotland and absent from Ireland. On mainland Europe they occupy northern and central France and the central countries of the continent as far north as Southern Scandinavia, but do not extend south into the Iberian Peninsula or to the Mediterranean. Their range extends east through Russia as far as the Ural Mountains and Western Siberia.