Evaluation of translocation as a tool for mitigating development threats to great crested newts (Triturus cristatus) in England, 1990-2001

Great crested newts (Triturus cristatus) are protected under European and UK legislation, but are frequently the subject of conflict between development and conservation in England. When this occurs, the developer is legally obliged to instigate a mitigation plan to reduce the impacts on the newts. This usually involves the translocation of newts coupled with habitat enhancement and creation. We reviewed mitigation projects carried out in England between 1990 and 2001 by (1) analysing licensing information collected by the governmental licensing authorities; and (2) a questionnaire survey of a sample of mitigation projects. Over half of the licensed projects on file contained no report of the work undertaken. There was an increase in the number of new translocation projects from less than 10 a year in the early 1990s to over 80 a year by 2000. This translates into about £1.5 million per year currently being spent on great crested newt mitigation projects. Most of these projects involved in situ translocations of newts to areas within or adjacent to the development site. The number of newts translocated per project declined over the same period, and was related to the total area of habitat destroyed and work effort. About 27% of great crested newt terrestrial habitat was destroyed during the developments along with about half of all ponds. Although the number of new ponds created compensated for the number of known great crested newt ponds lost, there was a net loss in terms of overall area of aquatic habitat. Where follow-up monitoring of translocations was conducted, there was evidence of breeding at most sites one-year post-development, but it is unclear whether these populations were sustainable in the long-term.