The northern crested newt, great crested newt or warty newt (Triturus cristatus) is a newt species native to Great Britain, northern and central continental Europe and parts of Western Siberia. It is a large newt, with females growing up to 16 cm (6.3 in) long. Its back and sides are dark brown, while the belly is yellow to orange with dark blotches. During the breeding season, males develop a conspicuous jagged crest on their back and tail. The northern crested newt spends most of the year on land, primarily in wooded areas of the lowlands. In spring, it moves to aquatic breeding sites, mainly larger fish-free ponds. Males court females with a ritualised display and deposit a spermatophore on the ground, which the female then picks up with her cloaca. After fertilisation, a female lays around 200 eggs, folding them into water plants. The larvae develop over two to four months before metamorphosing into terrestrial juveniles (efts). Both larvae and land-dwelling newts mainly feed on different invertebrates. Several former subspecies of the northern crested newt are now recognised as separate species within the genus Triturus. Its closest relative is the Danube crested newt (T. dobrogicus). It sometimes forms hybrids with some of its relatives, including the marbled newt (T. marmoratus). Although it is currently the most widespread Triturus species, the northern crested newt was probably confined to small refugial areas in the Carpathians during the Last Glacial Maximum. While the International Union for Conservation of Nature lists the northern crested newt as a species of Least Concern, its populations have been declining. The main threat is habitat destruction, for example, through urban sprawl. The species is also listed as a European Protected Species.
Taxonomy The northern crested newt was described as Triton cristatus by Josephus Nicolaus Laurenti in 1768. As Linnaeus had already used the name Triton for a genus of sea snails ten years before, Constantine Samuel Rafinesque introduced the new genus name Triturus in 1815, with T. cristatus as type species. Over 40 scientific names introduced over time are now considered as synonyms, including Lacertus aquatilis, a nomen oblitum published four years before Laurenti's species name. Hybrids resulting from the cross of a crested newt male with a marbled newt (Triturus marmoratus) female were mistakenly described as distinct species Triton blasii, and the reverse hybrids as Triton trouessarti. T. cristatus was long considered as a single species, the "crested newt", with several subspecies. However, substantial genetic differences between these subspecies were noted, eventually leading to their recognition as a distinct species, often collectively referred to as "T. cristatus species complex". There are now seven accepted species of crested newts, the most widespread of which is the northern crested newt.
Description
The northern crested newt is a relatively large newt species. Males typically grow to a total length of 13.5 cm (5.3 in), while females can reach 16 cm (6.3 in). Rare individuals of 20 cm (7.9 in) have been recorded. Other crested newt species are more stockily built; only the Danube crested newt (T. dobrogicus) is more slender. Body shape is correlated with skeletal build: The northern crested newt has 15 rib-bearing vertebrae, only the Danube crested newt has more (16–17), while the other, more stocky Triturus species have 14 or less. The newts have rough skin, and are dark brown on their back and sides. They have black spots and heavy white stippling on their flanks. The female has a yellow line running along the lower edge of her tail. Their throats are yellow–black with fine white stippling and their bellies are yellow-orange with dark, irregular blotches. During the aquatic breeding season, the males develop a crest that measures up to 1.5 cm (0.59 in) high. This runs along the back and tail but is interrupted at the tail base. The crest is heavily indented on the back but smoother on the tail. During breeding season, the male's cloaca swells and it has a blue–white flash running along the sides of the tail. Females do not develop a crest.
Range The northern crested newt is the most widespread and northerly crested newt species. The northern edge of its range runs from Great Britain through southern Fennoscandia to the Republic of Karelia in Russia; the southern margin runs through central France, southwest Romania, Moldavia and Ukraine, heading from there into central Russia and through the Ural Mountains. The eastern extent of the great crested newt's range reaches into Western Siberia, running from the Perm Krai to the Kurgan Oblast. In western France, the species co-occurs and sometimes hybridises (see section Evolution below) with the marbled newt (Triturus marmoratus). In southeast Europe, its range borders that of the Italian crested newt (T. carnifex), the Danube crested newt (T. dobrogicus), the Macedonian crested newt (T. macedonicus) and the Balkan crested newt (T. ivanbureschi).
Habitat
Outside of the breeding season, northern crested newts are mainly forest-dwellers. They prefer deciduous woodlands or groves, but conifer woodlands are also inhabited, particularly in the northernmost and southernmost ranges. In the absence of forests, other cover-rich habitats, as for example hedgerows, scrub, swampy meadows, or quarries, can be inhabited. Preferred aquatic breeding sites are stagnant, mid- to large-sized, unshaded water bodies with abundant underwater vegetation but without fish (which prey on larvae). Typical examples are larger ponds, which need not be of natural origin; indeed, most ponds inhabited in the United Kingdom are human-made. Examples of other suitable secondary habitats are ditches, channels, gravel pit lakes, or garden ponds. Other newts that can sometimes be found in the same breeding sites are the smooth newt (Lissotriton vulgaris), the palmate newt (L. helveticus), the Carpathian newt (L. montadoni), the alpine newt (Ichthyosaura alpestris) and the marbled newt (Triturus marmoratus). The northern crested newt is generally a lowland species but has been found up to 1,750 m (5,740 ft) in the Alps.
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