Great Crested Newt
Triturus cristatus (Laurenti, 1768)

Family: Salamandridae - Old World Salamanders

Order: Caudata - Salamanders

Class: Amphibia

Phylum: Chordata - Vertebrates

Kingdom: Animalia

Red List status: Least Concern

Great crested newt in captivity. Buckinghamshire, United Kingdom.

Adult length: 150 mm, occasionally to 200 mm

Hatchling length: 50 - 80 mm

 

Tadpole length: 50 - 90 mm

RANGE

Europe north of the Alps and east to central Asia. The species is absent from Ireland and much of Scandinavia.

            Range            Description            Habitat            Behaviour            Biology            Taxonomy            Status            References

Other common names: Northern crested newt, crested newt, warty newt

 

 

DESCRIPTION

 

Adult: A large newt with coarse, 'warty' skin and a dark purplish-brown or olive (often appearing black when on land) upper surface. The upper body is patterned in black spots, and there is a distinct, thick row of small white spots along the lower margin of the flank. The underside is very bright yellow or orange, with an irregular pattern of grey to black spots and blotches, occasionally dense enough to appear completely black. The throat is very heavily stippled with dark pigment.  The toes are strikingly marked, being banded black and orange, and brighter in males than females. In females, the tail base is orange.

 

Male crested newts in breeding condition are highly distinctive. The tail is rather short with well-

developed fins and without a sharply-pointed tip, and a thick central whitish-blue band which is highly visible in torchlight. The dorsal crest is tall and jagged and is not continuous with the tail, giving the appearance of a deep 'notch' between the rear of the crest and the tail. The maximum height of the crest is equal to the depth of the tail.

Great crested newt underside. Note the belly, throat and toes.

 

Larvae: Newt larvae can be recognised by the feathery gills they develop, and by the development of the forelimbs earlier than the hindlimbs in development (the reverse is true of frog tadpoles). After 4-6 weeks, at around 20 mm in length, great crested newt larvae develop a distinctive tail filament and black spots on the tail. Younger tadpoles can be difficult to distinguish from those of other species, but always possess a stripe down the length of the dorsum. Newt tadpoles tend to prefer open water habitats.

 

Eggs: Eggs are laid singly, characteristically in the leaves of submerged vegetation which the mother folds over to wrap the egg in a distinctive parcel. The eggs themselves are whitish in colour and about 4.5-6 mm in diameter, and are surrounded by a jelly capsule. A female may lay up to 700 eggs in a season, but more typically will produce 200-400.

 

Similar species: The species' common English name testifies to the animal's large size, which makes it easy to distinguish from other British and many mainland European newts. Other distinguishing features include its darker colour and less distinct dorsal spots, the lack of a sharply-pointed tip to the tail the stippling of the throat and the patterning of the underside (which rarely forms the regularly-sized, discrete

Profile view showing the characteristic 'notched' crest

spots of the smooth newt). Crested males cannot be confused with any other European species

                                                 except for other members of the crested newt complex; all other crested species have smooth crests that are normally continuous with the tail. The marbled newt (Triturus marmoratus) is typically larger, has extensive green colouration on the upper body (never present in crested newts), and is restricted to areas of southern France and the Iberian Peninsula where crested newts are absent. The alpine newt (Triturus alpestris) has an unpatterned belly and lacks white stippling on the flanks. Dark terrestrial animals with black bellies might conceivably be confused with the alpine salamander (Salamandra atra); this species lacks a crest or tail fins, and the digits are entirely black.

Note the warty skin and row of white spots.

 

The three other species of crested newt either lack white stippling altogether, or it is much reduced. Other characters distinguishing these species are less consistent; however, the colouration and patterning of the throat and the size and arrangement of spots on the belly can be used to tell species apart.

 

 

 

HABITAT

 

Like most newts, the great crested newt occupies terrestrial habitat outside the breeding season, sometimes several hundred metres from water, although occasional individuals may be encountered in water throughout the year. Animals favour wooded terrestrial sites where they take refuge in leaf litter, vegetation or mammal burrows, and may occur at high densities. Nevertheless, the species is tolerant of some forms of terrestrial habitat modification and will often be found in agricultural areas. Large cover objects are most likely to be used in February/March and May/June, but newts make relatively little use of such refugia.

 

Reproductive habitat: Great crested newts have relatively exacting breeding habitat requirements, favouring large, deep and clear semi-permanent ponds with emergent vegetation and exposure to the sun. They are most likely to occur in a landscape with multiple ponds connected by suitable terrestrial habitat with extensive low-lying vegetation. However, apparently unsuitable habitat such as ditches will also be used. Larvae of this species are especially susceptible to fish predation, and are typically excluded from waterbodies where fish are present.

 

Elevation: Generally below 1,000 m, but southern populations may be encountered as high as 1,750 m.

 

 

BEHAVIOUR

 

The great crested newt is a predominantly nocturnal species. Animals often disperse throughout the local landscape when not in breeding condition; newly-metamorphosed juveniles are drawn to ponds where they can smell adult great crested newts.

 

Courtship and reproductive behaviour: Males gather in open water to display to females, often staking claim to suitable areas and defending them from other males. Animals may mimic females to lure other males away from favoured spots. Courtship behaviour resembles that of the smooth newt, although the larger crest of the great crested newt facilitates oxygen intake and allows it to display for longer before surfacing. Males may directly compete for mates, with one animal occasionally poaching a female from a male that is in the process of displaying to her.

 

Defensive behaviour: When threatened animals may play dead, typically curling themselves round objects in the process. Adult newts are somewhat toxic, and can exude a whitish substance to deter predators with its taste and smell.

 

Diet: In contrast to some other newt species, great crested newts are predominantly bottom-feeders; their lower position in the water column can be a useful way to distinguish them from smooth and palmate newts during nocturnal surveys. Prey items include molluscs, leeches and other invertebrates, although great crested newts will also feed on the larvae of other amphibian species. On land animals forage for invertebrates among thick vegetation. Juveniles feed on protozoa and unicellular algae, taking small arthropods and worms as they develop.

 

 

BIOLOGY

 

Life cycle: Unusually, a chromosomal condition in crested newts ensures that only 50% of the eggs laid will produce viable embryos, as a consequence of which these animals have a fairly low reproductive output for salamanders. The remaining eggs develop within 1.5-3 weeks. Larval metamorphosis typically takes a further 3-4 months, although in colder climates where development is delayed the tadpoles may overwinter without metamorphosing. In some populations, neoteny has been recorded. Sexual maturity is reached after 2-3 years in males, when animals are 120-130 mm long; females may mature later.

 

Lifespan: Animals have been recorded living up to 8 years in the wild; in captivity, great crested newts may survive for up to 27 years.

 

 

TAXONOMY

 

Three formerly-recognised subspecies of the great crested newt, collectively known as crested newts, are recognised as separate species with ranges adjoining that of T. cristatus. See Similar species.

 

 

STATUS

 

Although this species' Red List status is justified by its wide distribution and its tolerance of a degree of habitat disturbance, populations are in decline throughout its range and are often localised in occurrence. Tritirus cristatus is included in Appendix IV of the European Habitats Directive and corresponding national legislation throughout the European Union. This affords it strict protection from disturbance, handling, the destruction of its habitat and the possession and trade of animals. Licences are required by people surveying for or translocating newts. In the United Kingdom, the great crested newt is a priority species for conservation, with requirements for habitat creation or disturbance mitigation to be taken into account during land development, and a Biodiversity Action Plan devoted to this species.

 

 

REFERENCES

 

Arnold, N. and Ovenden, D. (2004) Collins Field Guide: Reptiles and Amphibians of Britain and Europe HarperCollins, London: 288pp

Arntzen, J.W., Kuzmin, S., Jehle, R., Beebee, T., Tarkhnishvili, D., Ishchenko, V., Ananjeva, N., Orlov, N., Tuniyev, B., Denoël, M., Nyström, P., Anthony, B.,  Schmidt, B., Ogrodowczyk, A and Ogi, M. (2006). Triturus cristatus. In: IUCN 2008. 2008 IUCN Red List of Threatened Species

Jarvis, L. Advanced British Amphibians Field Studies Council course, Epping Forest, Essex, UK.

Langton, T.E.S., Beckett, C.L. and Foster, J.P. (2001) Great Crested Newt Conservation Handbook Froglife, Halesworth: 55pp

Wareham, D.C. (2008) The Reptiles and Amphibians of Dorset British Herpetological Society: 120pp

Triturus cristatus. Epping Forest, Essex, United Kingdom.