Ecology of the Great Crested Newt
Great crested newts (Triturus cristatus Laur.) are the most distinctive of the three native species of newt in this country. It is the largest species, with males reaching 140 mm to 150 mm and females being slightly larger, reaching up to about 170 mm.
The skin is bumpy or granular and coloured a very dark brown to black when on land. The sides of the body and head can often be stippled with small white specks. When in the water the newts can appear paler (orangey-brown) with a number of black spots dotted irregularly over the back and sides of the body and the front end of the tail. The belly is yellow to orange with large black spots. The pattern of spots is unique to each individual newt, rather like a human's fingerprint.
Adult males have a white iridescent stripe along the side of the tail that becomes much more obvious during the breeding season (March to June). They develop a striking large and jagged crest along the back, extending from the middle or back of the head to the base of the tail and a smoother crest along the tail. Males also have a darkly pigmented and bulbous cloacal vent. Females have no crest, their yellow/orange belly colour extends along the underside of their tail and their cloacal vent is smaller and less conspicuous.
Great crested newts, like many amphibians, are long lived. There are records of a captive male living 25 years and a female for 27 years. Surveys have identified individuals in the wild that are at least 14 years old. In general males are thought to mature at 2 to 3 years of age, and females a year later. This may vary from site to site - growth is highly dependent on food availability, habitat quality and environmental conditions.
Although widespread across Britain, great crested newts tend to be localised and their numbers are declining rapidly, mainly due to habitat loss. Great crested newts are especially sensitive to habitat conditions; they do not adapt well to small garden ponds; they are particularly vulnerable to fish predation because their larvae are active swimmers; they often occur in large quarry ponds and old clay and sand pits and are therefore threatened by landfill and other destructive activities. Other threats to great crested newts, and amphibians in general, include pollution (amphibians have absorbent skins and are therefore at particular risk from some pollutants), direct human effect (e.g. motor traffic, road gully pots, collection of eggs, tadpoles and adults), and disease.
Other newt pages:
Conservation status of the Great Crested Newt
Amphibian research at Little Wittenham
Amphibian pond survey
