Great crested newt eDNA: a detection tool, not a headcount

Technical summary · Updated 28 October 2026

The evidence

Biggs and colleagues (2015) compared environmental DNA with conventional great crested newt survey methods. In their known-occupied ponds, eDNA detected newts on 139 of 140 survey visits. A separate volunteer exercise produced false negatives at some occupied sites. Those are study results, not a guaranteed accuracy rate for every pond.

What it means in practice

An eDNA sample tests for genetic material in water. It can support an assessment of presence or likely absence, but it does not count animals or establish a population size class. Sampling coverage, contamination control and laboratory quality checks matter. An inconclusive result should not be presented as a negative.

Plan the right survey

The usual planning window is 15 April–30 June. A negative result needs to be interpreted with its sampling conditions and the wider site evidence. Pond access and laboratory turnaround should be arranged before that window closes. Additional population information or a different licensing route may change the survey scope.

Sources & further reading

This is an explanatory summary of the cited evidence, not an original research paper or a site-specific survey specification.