Smooth newt Lissotriton vulgaris males and females are a similar size, up to 10 cm in length. The dorsal surface is an olive brown or greenish brown, with pale lower flanks and belly. An orange stripe along the belly is usually wider and more colourful in the males but varies with the physical condition of the animal. Both the dorsal surface and the belly have black spots, more numerous and larger in the male, but varying considerably between individuals and populations.
In the breeding season the aquatic males have a crest, less jagged than a Great Crested Newt’s Triturus cristatus and without a gap between the back and the tail. The lower edge of the tail develops orange and blue stripes, which vary in intensity. The hind feet are flanged, like a Coot’s Fulica atra. Aquatic females are plainer, lack the crest, and have an orange lower edge to the tail, where Great Crested Newt females have a yellow stripe. Both sexes have a pale throat which is usually, but not always, strongly spotted. On land both sexes have a velvety skin and the males lose their crests. Breeding colours are also lost but the spots remain visible (Beebee and Griffiths, 2000).
Variations found in our region are mainly in the amount of spotting. Occasional individuals or populations have a sandy yellow-brown dorsal surface instead of the usual brown, or can be completely “blond” above and below. Other individuals or populations can be quite dark in colour. These variations have been noted more often in the North East than most books would suggest.
Eggs are laid singly in a folded leaf and are about three mm across, compared with Great Crested Newt eggs which are about four to five mm. The aquatic efts, or larvae, are very difficult to distinguish from Palmate Newt Lissotriton helveticus efts. Efts have over-wintered in the aquatic phase in recent mild winters. Terrestrial efts are similar to terrestrial adults but smaller and with fewer black spots on the underside.
Smooth Newts are widespread in the region except in acidic ponds in the upland areas. They are very sparse in western Northumberland and Durham, the A68 being the general westerly limit. West of this, they are largely replaced by the Palmate Newt. Smooth Newts were recorded on Lindisfarne in 1984 but not more recently. They are quite frequent in the Tees Valley area, including Redcar and Cleveland, up to the edges of the North York Moors. They are the most frequent newt found in garden ponds and in agricultural areas (Durkin, 2010A).
The Natural England Site of Special Scientific Interest (SSSI) criteria assessment is that less than 10 Smooth Newts netted or counted by torchlight is a “Low” population, 10 to 100 is a “Good” population, and more than 100 is an “Exceptional” population (Nature Conservancy Council, 1998). A great number of our populations would be “Good” on this basis, which could mean that this criterion is slightly too generous.
Smooth Newts have the least distinctive communities of the three newt species. Palmate Newts share about 40% of the ponds where Smooth Newts occur and Great Crested Newts share about 20%. All three species occur in about 10% of the Smooth Newt ponds. Smooth Newts occur as the only newt species in about 30% of their ponds. They are the only newt present in the majority of garden ponds and seem to have a stronger ability to colonise new garden, urban and lowland ponds than our other newt species. Common Frogs Rana temporaria are usually also present in Smooth Newt ponds. Common Toads Bufo bufo are usually present in the larger ponds used by Smooth Newts and less often in the smaller ponds.
by John Durkin