Using Dorsal Stripes to Identify Lissotriton Newt Efts

 

Smooth Newt eft, showing the indistinct dorsal stripe which quickly fades towards the tail

Palmate Newt eft, showing the distinct uniform dorsal stripe running the length of its back

Britain is home to two Lissotriton newt species, Smooth Newt Lissotriton vulgaris and Palmate Newt Lissotriton helveticus, both species are relatively widespread in eastern parts of Yorkshire. The area in which I live has both species, Palmate Newts are the most abundant of the two species on the acidic North York Moors uplands and upland fringes, including in the conifer plantations and forests. Smooth Newt become more abundant in low-lying areas like the Vale of Pickering, and most parts of East Yorkshire. Both species occur around Scarborough where I live, with Palmate Newts being common as far south as the chalk at Buckton Cliffs and the Wolds northern edge where they become much more scarce. Subsequently I come across both species fairly frequently with practice adults including females are straightforward to identify, especially during the breeding season, when males sport their elaborate breeding features. Efts are slightly more difficult to identify. 

The terrestrial juvenile stage of a newt is called an eft it is usually in this pre-breeding stage for 2-3 years until its first breeding season. At this stage they resemble a small adult female, and have the usual velvety terrestrial skin of adults outside of the breeding season. 

A good method of differentiating between the two species, which are similar at this age is the dorsal stripe. Not all individuals show this feature, but when it is present if it starts at the back of the head and fades out as it runs down the back it is likely to be a Smooth Newt. If it runs with uniform intensity along the entire back onto he tail it is likely to be a Palmate Newt. In Palmate Newts there is a tendency for the stripe to start slightly lower on the neck. Palmate Newts also have a tendency to show more of a mottled dorsal pattern adjacent to the stripe, with Smooth Newts being a more uniform line. Additionally you could check for a pink (Palmate) or cream (Smooth) throat, as with adults I also find the shape of the newt to be distinctive per species, with Palmate short and stocky (plumose) and Smooth less compact.