Palmate Newt

Palmate newts grow to a total length of 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 it is wide and has 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, these spots can sometimes form two irregular lines, and they may have a red stripe running along their 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. The skin is dry and velvety while the newts live on land, but it becomes smooth when they migrate into water. 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 palmate newt is found across Western Europe, from Great Britain (including Scotland) to northern Portugal and Spain. In the east, it ranges to the Elbe river in Germany and the Czech Republic and the lower and mid Alps in Switzerland. It is most common from 500–1,500 m (1,600–4,900 ft) elevation, but can be found from sea level up to 2,500 m (8,200 ft) (in the Pyrenees). Genetic analyses by Recuero and García-París suggest that the species was confined to the Iberian Peninsula during the Last Glacial Maximum and then expanded its range north of the Pyrenees. They were recently discovered in South Western Ireland, but it is unclear yet whether they are native or introduced to this region. The palmate newt is common over much of its range and is found in a variety of habitats, including forests, marshes and pastures. It is less abundant in cultivated areas, but it can adapt to gardens. For reproduction, newts tolerate different types of stagnant water bodies, preferably fish-free, acidic ponds. The smooth newt has a similar distribution, but in France it appears to prefer ponds in open land, whereas the palmate newt prefers forest ponds. Hybrids between the two species are rare.

The reproductive period usually extends from February to May, but it can start earlier or last longer in the southern part of 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 observed 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. The females lays 150–440 eggs individually on the leaves of aquatic 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). As they grow, their characteristics are affected by their environment. …