The palmate newt (Lissotriton helveticus ) is a species of newt found in Western Europe, from Great Britain to the northern Iberian peninsula. It is 5–9.5 cm (2.0–3.7 in) long and olive or brown with some dark spots. The underside is yellow to orange, and the throat, unlike in the similar smooth newt, always unspotted. A dark stripe runs along the head and through the eyes. Breeding males develop a distinct filament on the end of their tail, strongly webbed hind feet, and a low, smooth crest on their back.
Habitats include forests, marshes, pastures or gardens. While on land, the newts are mainly nocturnal. After emerging from hibernation in spring, they move to stagnant, fish-free water bodies for breeding. After a courtship display, the male deposits a spermatophore that is picked up by the female. Larvae develop over after 1.5–3.5 months before metamorphosing into land-dwelling juveniles (efts). Sexual maturity is reached after two to three years, and the newts can reach a total age of up to 12 years in the wild. The species is overall common and has been assessed as Least Concern by the IUCN.
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal",...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Oviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
Animal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migrati...
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy charac...
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starts withPalmate newts grow to about 5–8.5 cm (2.0–3.3 in) total length in males, while females are somewhat larger and can reach 9.5 cm (3.7 in). The tail is slightly shorter than the snout–vent distance. The head is longer than wide, with three longitudinal grooves on the snout. Both sexes have an olive or brown base colour, and males and some females have dark spotting on their backs. In females, the spots can sometimes form two irregular lines, and they can have a red stripe running along the back while living on land. In both sexes, a dark stripe runs along the head through the eyes. The underside is yellow or light orange and more whitish on the sides; the belly can have some dark spots, while the throat is always unspotted. While the newts live on land, the skin is dry and velvety, but it becomes smooth when they migrate into water.: 224–225
Males can be distinguished from females by the larger and darker-coloured cloaca. During the aquatic breeding season, the cloaca swells, and other sexual differences develop: Males grow a low, smooth skin seam (a crest) on their back, which is higher on the tail. Their tail has a blunt end with a distinct, 4–7 mm long filament. They also have ridges (dorso-lateral ridges) running along their sides, giving them an angular, square shape in cross-section, and their hind feet have well-developed, dark webbing. The lower half of the tail is blue in breeding males and orange in females. Females do not develop a crest, tail filament or webbed feet.: 224
Sometimes confused with the smooth newt (Lissotriton vulgaris ) which is found in much of the same area, the palmate newt can be distinguished by its unspotted throat. It also resembles Boscá's newt (L. boscai ) from the Iberian peninsula, which has only a single groove on the snout and no dark eye strip.: 222
The reproductive period usually extends from February to May, but can start earlier or last longer in the southern range on the Iberian Peninsula, depending on elevation. The newts can use magnetoreception over larger distances and the calls of frogs over shorter distances to find their breeding ponds. Once in the water, they are active during day and night. Breeding involves a ritualised courtship display as in other closely related newts: The male attempts to attract a female by swimming in front of her and sniffing her cloaca. He then vibrates his tail against his body, sometimes lashing it (but less violently than in the smooth newt), thereby fanning pheromones towards her. In the final phase, its a packet of sperm (a spermatophore). He then guides her over the spermatophore so she picks it up with her cloaca.: 225
The females lays 150–440 eggs individually on water plants. These are 1.3–1.8 mm in diameter (2.2–3 mm with capsule) and very similar to those of the smooth newt. Larvae hatch after 8–21 days, depending on temperature, at a size of 8–14 mm. The young larvae are yellow–brown, with two black stripes, and have two appendages (balancers) on the sides of the head, which are later resorbed. The colour then becomes more cryptic, and the larvae grow to 3–4 cm (1.2–1.6 in). They metamorphose into land-dwelling juveniles (efts) after 1.5–3.5 months, but some larvae instead overwinter in water. Paedomorphism, where adults keep their gills and stay aquatic, is also known.: 224–225
The young efts live on land until maturity, which is reached in the second or third year. Activity on land occurs mainly during humid nights. The palmate newt usually hibernates on land but sometimes in the water, and in the Iberian peninsula, it is often active year-round. Larvae, efts and adults mainly feed on various invertebrates, but cannibalism also occurs, mainly by larvae preying on eggs. An age of up to 12 years can be reached in the wild.: 224–225
