The GCN knowledge gap

Amphibian and Reptile Conservation's consultancy arm ARCESL and University of Kent's DICE have teamed up to carry out research and development into predictive modelling of great crested newt (GCN) occurrence in England. The project, commissioned by Natural England, is a follow-up to the Evidence Enhancement Project which ran in 2013 and 2014, delivered by Hyder-Cresswell, CGO Ecology and other partners.

The new DICE/ARC project is running a SurveyMonkey questionnaire for practitioners and others who use GCN distribution and status information.

CGO Ecology's Director & Principal Ecologist has already submitted our response, and had this to say: "I am sceptical of the current drive for eDNA instead of traditional survey as a way to save costs. I am fully in support of predictive modelling however, but not for cost-saving purposes. The mandatory mitigation that SNCOs require is inordinately more expensive than presence-absence surveys, and often with limited benefits.  The Habs Regs offences are badly-designed, and need an overhaul. The cost of exclusion fencing and excessive capture effort is insupportable."

CGO Ecology has first-hand experience of the frustration borne by conservationists and developers alike when rigid mitigation policy backfires. At a minerals site we worked on, pond surveys suggested zero GCN presence, but subsequent reptile survey produced GCNs. An urgent and intensive terrestrial GCN survey had to take place, which showed a major GCN presence. The ensuing licensed mitigation took place at great and disruptive cost (£140k) to the developer.

Predictive modelling and eDNA would not necessarily have changed anything in this scenario. Modelling might have predicted GCN presence, but standard guideline-compatible survey efforts still would not have found GCN. Detection failure was partly due to a dry spring in this case - which can hamper breeding detection in any year - but this is an intrinsic flaw in any single-season GCN survey. The current Natural England policy of accepting negative eDNA as evidence of GCN absence adds yet another risk factor to the system.