Smooth newts (Lissotriton vulgaris) are the least abundant species of newt in Scotland, despite beng the most common in the UK overall. With a atchy local distribution, these newts are encountered much less frequently than the closely related palmate newts.
Smooth newts measure around 7 - 11 centimetres in length from head to tail,the male being slightly larger than the female. Females and non-breeding males are pale brown or olive green. Both sexes have an orange belly, although it is paler in females, which is covered in rounded black spots. When on land they have velvety skin. During the breeding season, male smooth newts develop a continuous wavy (rather than jagged) crest that runs from their head to their tail, and their spotted markings become more apparent.
Male smooth newts seek out a female and waft glandular secretions towards her by fanning his tail in her direction. Males then deposit a spermatophore in front of their mate, who pick up the capsule in her cloaca - fertilization occurs inside the females. After a few days,spawn is laid as individual eggs, each of which is wrapped carefully in a leaf of pond weed, by the female newt. Females lay up to 300-400 eggs between March and June at the rate of 3-7 a day. After 2-3 weeks, the eggs hatch and the tadpole larvae begin to swim around after a few days. They are known as 'efts' and breathe through external feathery gills which sprout from behind the head. These larvae usually undergo metamorphosis between July and September to become air-breathing juveniles. They return to breed 2-3 years later.
Smooth Newts live, on average, 6 years. They are nocturnal and spend the day hiding under large stones or compost heaps. Unlike many other amphibians, the habitat surrounding the water body does not seem to be very important. They emerge from hibernation in February or March, when the temperature is above 0°C and conditions are moist, and head for the breeding sites. Outside of the breeding season (from late July to February), newts come onto land and are often found in damp places, frequently underneath logs and debris in the summer months. Adult newts shed their skin as often as once a week. Smooth newts eat invertebrates either on land or in water. On the land, they tend to feed on insects, worms and slugs by projecting their tongues to catch prey. In water, they only use their teeth to feed on shrimps, water lice, insect larvae, water snails and frog tadpoles.
Smooth Newts are protected in Britain under Section 9(5) of the Wildlife and Countryside Act (1981). This prohibits sale, barter, exchange, transporting for sale and advertising to sell or to buy. They are vulnerable to urbanisation, agricultural change and pollution of their habitat. They are also listed under Annex III of the Bern Convention.
Erik Paterson, CARG Secretary