Great Crested Newt Survey

Great crested newts and their habitats in water and on land are protected under the Wildlife and Countryside Act 1981 (as amended by the CRoW Act 2000), and under the Conservation of Habitats and Species Regulations 2017. In addition, great crested newt is listed as a Species of Principal Importance under the provisions of the NERC Act 2006.

Great crested newts can be surveyed between March and June using standard methods, and between 15th April and 30th June using eDNA sampling. Following Natural England guidelines, a standard ‘presence/absence’ survey requires four visits to potential breeding open water habitat. These surveys are carried out between April and June, with at least two surveys being carried out between mid-April and mid-May and two additional surveys required to determine population size.

Surveys methods include torchlight surveys, netting, terrestrial search, egg search (on suitable vegetation) and bottle trapping. The latter involves placing plastic bottles set at approximately two metres apart around the margins of the waterbody which are left overnight then checked in the morning by a licensed surveyor. Using bottle traps allows ecologists to record biometric information such as gender and life-stage, before releasing the newts back into the waterbody.

‘eDNA sampling’ is now being used to detect microscopic fragments of DNA biomarkers belonging to great crested newts within waterbodies, where such fragments can persist for one to three weeks, depending on environmental conditions. This method can be used to determine species occupancy in ponds and can increase survey efficiency, saving time and money.

The great crested newt (Triturus cristatus) is the largest of Britain’s three indigenous newt species. They are black in colour with an orange and black spotted belly, and they have characteristic ‘warty’ skin, hence their other English name of Warty Newt. During the breeding season (April-June), male great crested newts develop an enlarged ‘crest’ along the back and a silver streak in the middle of the tail, which they wave and flick to attract females during courtship displays.

Great crested newts are found in a variety of habitats and prefer open water for mating displays, and typically require marginal aquatic vegetation for egg-laying. The female carefully deposits the eggs within leafy vegetation and then folds and seals it using an adhesive-like secretion. Once the eggs have hatched, the larvae will swiftly develop and metamorphose into ‘efts’ (juveniles) over a period of three to six weeks. By August, the immature newts will emerge from the pond and continue to develop in the terrestrial environment.

Great crested newts are carnivorous and will feed upon a range of aquatic invertebrates and the larvae of other organisms. Major habitat loss can cause reduced breeding and recruitment (e.g. fewer young, maturing and adults joining the breeding population leading to fewer breeding adults); fewer foraging opportunities; fewer refuges, leading to exposure to predators or harsh conditions; unsuccessful hibernation; and population fragmentation.