Great Crested Newt Surveys

As an amphibian, the Great Crested Newt (GCN) it is dependent on standing water as a breeding habitat but lives on land for much of the year.

They usually remain within 250 m of their main breeding site but occasionally roam up to 500 m away. The GCN is nocturnal and spend the day sheltering beneath rubble, logs and large stones and inside mammal burrows, using similar places to hibernate through the Winter.

The GCN is a European Protected Species. Planning authorities must consider whether a European Protected Species is likely to be affected by a proposed development. They are legally obliged, therefore, to refuse planning permission until the presence or otherwise of GCN, and the extent that they may be affected by the proposed development, is established by survey.

At Castell Ecology we have almost 20 years’ experience of surveying for Great Crested Newt and mitigating the impacts of development on this species. There are a number of methods to survey for GCN and, depending on the information required, one or all of the techniques outlined below may be used. We can advise on the most appropriate survey method for your project. There are seasonal constraints to GCN surveys - for more information please see our Survey Calendar >>>

Habitat Appraisal

The general suitability of a pond for GCN is evaluated by undertaking a Habitat Suitability Index (HSI) survey. HSI for GCN examines ten features of a pond and its surroundings that are known to affect this species. The assessment grades the suitability of the waterbody as “unsuitable”, "poor”, “below-average", "average", "good" or “excellent”.

The HSI for GCN is a measure of habitat suitability. In general, ponds with high HSI scores are more likely to support GCN than those with low scores. The process, therefore, can provide some indication of the likelihood of GCN being present in a pond but cannot confirm if the species is present or absent.

Presence or Likely Absence Survey

Pond Surveys: This is the "traditional" method and uses nocturnal torch survey, bottle trapping, egg searches and netting to physically detect newts in the pond in Spring. The technique allows for the size of the population to be estimated which is essential information when applying for a development licence should one be required.

eDNA Testing: This technique involves taking water samples from ponds in Spring and sending them to a laboratory to test for traces of the species' DNA in the water. eDNA can only provide a positive or negative result for the presence of GCN. If a positive result is returned it cannot provide any indication of the size of the GCN population but is useful for scoping ponds out of future survey by confirming absence.

If GCNs are found, then a mitigation strategy may well be required depending on the nature and extent of proposed works. If any of the proposed works are likely to result in an unlawful act, a licence must be sought from the relevant statutory body, e.g. Natural England. The license ensures that works are undertaken in a controlled and legal manner. The licence application should be completed by an experienced ecologist on behalf of the licensee (the developer).

District level licensing schemes operate in certain parts of England to better protect GCN populations. If you are a developer proposing to develop land, you can pay to join a district level licensing scheme. If you join a scheme, you do not need to carry out surveys or carry out mitigation work.

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