Great Crested Newt Survey

Great crested newts are typically found in ponds, ditches, and other standing water habitats throughout all but the furthest northern and western extremities of Britain, though populations are often scattered and at low density. Though still relatively common across lowland Britain, their population has declined dramatically over the past 40 years, with an estimated 50% of breeding water bodies having been lost during the 20th century, and 80% of those remaining in poor condition. They are fully protected under UK and European law, making it an offence of kill, capture, or disturb them, or to damage their habitat. Appropriate survey licences are required to work with this species. 

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The appraisal is used to inform the emerging scheme design, enabling significant ecological effects within the zone of influence to be avoided, mitigated, or compensated for, where necessary. This ensures the continued favourable conservation status of great crested newts, post development, and ultimately compliance with nature conservation legislation and planning policy. 

 

There are three types of great crested newt survey, comprising Habitat Suitability Index's (HSIs), environmental DNA (eDNA) sampling, and presence/ likely absence surveys. HSIs involve assessing the potential of water bodies to be used by breeding great crested newts, based on ten indices. The resultant score represents varying degrees of habitat suitability, enabling an estimation of likely presence. If the index produces a low score, the feature can typically be scoped out of the study. However, a moderate or high score may necessitate further targeted survey. The index is not sufficiently precise to prove that a higher score confirms presence, or a lower score confirms absence.

 

eDNA sampling involves a rapid assessment of presence/ absence within water bodies, based on traces of great crested newt DNA within the water column, which typically persists for several weeks. If a negative result is returned, instant confirmation of absence can be established and the feature can be scoped out of the study, thereby expediting the survey process. However, if presence if confirmed, further survey will be required to establish the population size, which eDNA sampling alone cannot determine.

 

Presence/ likely absence surveys involve four sessions (two survey visits per session), utilising a combination of three survey methods (bottle trapping, torching, egg searching, or netting). Artificial refugia may be deployed in suitable terrestrial habitat to supplement the study. If a negative result is returned, the feature can be scoped out of the assessment. However, if presence is confirmed, two additional sessions will be required, to enable a population class assessment to be made. The field survey is typically supplemented by a desk study, utilising maps and aerial photographs of the surrounding area to identify ecological connectivity, and published records of great crested newts, purchased from the local records centre.

 

Requirements for any necessary avoidance, mitigation, or compensation measures will be identified, and opportunities for ecological enhancement will be outlined, to integrate on-site biodiversity net gain into the scheme at an early stage, where possible.​ If the proposals are deemed likely to adversely affect great crested newts, a European protected species mitigation licence may be required, prior to the commencement of works. Alternatively, if the site lies within an area covered by the district licensing scheme, an application can be made under the scheme licence, often resulting in a simpler and more timely (though often slightly more costly) resolution.

 

Great crested newt surveys are seasonally constrained, making it prudent to plan ahead and consider ecological issues early on in the planning process. A robust great crested newt survey at an early stage in project planning and design can therefore deliver significant benefits, avoiding potentially costly and time-consuming delays.​

 

When

 

HSIs can be undertaken throughout the year. eDNA sampling must be undertaken between mid April-late June inclusive, when the DNA is yet to dissipate from the water column. Presence/ likely absence surveys and population class assessments can be undertaken between mid March-mid June inclusive, with a portion of the surveys undertaken during the core breeding period of mid April-mid May inclusive.