Palmate newt  (Triturus helveticus)

Sale or commercial exchange of palmate newts is prohibited in Britian by the Wildlife and Countryside Act, 1981 (2).

The palmate newt is the smallest British amphibian, and earns its English name from the strongly webbed hind feet that males develop during the breeding season (3). Both sexes have smooth skin, with olive green or brownish coloured upperparts and a yellow belly featuring a scattering of small black spots. The throat is not spotted and is pinkish in colour (4). Males are slightly smaller than females and have a ‘boxy’ appearance as a result of two ridges that pass along the back. In addition to the webbed feet, they also develop a very low, smooth crest during the breeding season, which extends along the back to the tail, where it forms a deep ‘fin’ (2). The tail has an orange central line passing along its length, bordered by two rows of dark blotches (4). Female palmate newts are easily confused with those of smooth newts (Triturus vulgaris), but the unspotted pink throat is a good distinguishing feature (2). The larvae of smooth and palmate newts are extremely difficult to tell apart from each other (2).

This newt has a western European distribution, and is found from northern Germany through France to the north of Portugal and Spain. In Britain it has a widespread but rather patchy distribution. It is rare or completely absent from the Midlands, East Anglia, and parts of southern England and is most common in Wales and Scotland (2).

The palmate newt breeds in a range of still and occasionally running water, including ponds, puddles, woodland and heath pools and even mountain lake edges (4). It shows a marked preference for shallow soft-water pools on acid soils, which explains why the species is common on heathland in the south and west of England, and in moorland and bogs in the north (5). Ponds and ditches that do not support fish are preferred, and it is often found in garden ponds (2). All amphibians require good quality undisturbed terrestrial habitats around the breeding ponds (2).

Palmate newts are very similar in general habits and behaviour to smooth newts. They are crepuscular, with activity peaking at dusk and dawn. This secretive newt (4) spends most of the day in thick aquatic vegetation, coming out into open water only after dark (2). Their diet is very broad, and includes zooplankton, freshwater shrimps and hoglice; when they are on land they eat a wide range of invertebrates, the capture of which is aided by the possession of a sticky tongue (2).

Although this species is not threatened at present, there has been a dramatic and worrying global decline in amphibians. In Britain, widespread species, including the palmate newt have declined. It is thought that changes in agriculture are largely to blame, including the massive reduction in the number of farm ponds. In the last century, a staggering 70% of Britain’s pools and marshes have been destroyed. Furthermore, remaining ponds are often polluted with agricultural chemicals (2).

Although this species isn’t threatened with extinction at present, the long-term survival of all Britain’s native amphibians and reptiles remains in the balance (2). Interest in reptiles and amphibians has increased massively in the last 30 years and there are now conservation charities dedicated to these fascinating and often overlooked species, such as the Herpetological Conservation Trust (5). The ecology and habits of this species of this species are well understood, and effective monitoring is in place, which will enable the state of the palmate newt population to be tracked carefully. Any decline will therefore be apparent and informed conservation action can swing into action. Although sale of this newt is prohibited under the Wildlife and Countryside Act of 1981, it is unfortunate that the species is not yet fully protected by law in Britain (2).

For more on this species and other amphibians and reptiles of the UK see The Herpetological Conservation Trust:
http://www.hcontrst.f9.co.uk/
For more on amphibians of the world see Amphibia Web:
http://elib.cs.berkeley.edu/aw/index.html

• Crepuscular: active at twilight and/or just before sunrise.
• Hibernation: a winter survival strategy characteristic of some mammals in which an animal’s metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer. In insects, the correct term for hibernation is ‘diapause’, a temporary pause in development and growth. Any stage of the lifecycle (eggs, larvae, pupae or adults) may enter diapause, which is typically associated with winter.
• Larvae: stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
• Metamorphosis: an abrupt physical change from the larval to the adult form.
• Pheromone: a chemical produced by an animal, which stimulates a behavioural or physiological response by another member of the same species.

1. NBN Species Dictionary (January 2004). Available on-line from: http://www.nhm.ac.uk/nbn/
2. Beebee, T & Griffiths, R. (2000) The New Naturalist: Amphibians and reptiles- a natural history of the British herpetofauna. Harper Collins Publishers, London.
3. Buczaki, S (2002) Fauna Britannica. Hamlyn, London.
4. Arnold, E.N. and Burton, J.A. (1978) A field guide to the reptiles and amphibians of Britain and Europe. Collins, London.
5. The Herpetological Conservation Trust (October 2003): http://www.hcontrst.f9.co.uk/