The Herpetological Journal

pp.183-190

Authors: R. S. Oldham  And R. N. Humphries

Abstract: Published evidence from 178 great crested newt population translocations in the UK carried out between  1985 and 1994 emphasizes the need for continued monitoring following translocation. In more than half the cases, there was insufficient evidence for judging success, mainly due to lack of monitoring. Using the liberal criterion of the presence of a population one-year following translocation, 37% of all cases were successful and 1 0% unsuccessful. Most of the failures were predictable from existing knowledge of great crested newt requirements. Conflict between development objectives and great crested newt conservation at a site in northern England prompted a large-scale translocation of over 1 OOO individually photographed adults to a conservation area immediately adjacent to the development site. During the first year following translocation, adult newts showed a strong tendency to move towards their previous breeding site, some travelling 500 m in doing so, but none reaching home ponds 900 m away. At least 60% of the translocated newt population either escaped from - or attempted to leave - the conservation area. The remainder accepted the ponds in the conservation area, some of which were less than one year old, and bred successfully. Population sizes were extrapolated from the results of trapping both outside and within the conservation area. The estimated density of adults in the conservation area, at 150 ha·1, was high compared to that in the proposed development site (about 5 ha-1). Nevertheless, in the first year the population in the conservation area showed good production of metamorphs, and mortality consistent with that found in previous studies. Furthermore, most recaptured adults had grown (median of 18% gain in mass) during the season. This was probably the result of the increased habitat diversity in the conservation area, especially the aquatic habitat. It must be recognised that this translocation procedure can be applied only to the adult component of the population.

Keywords: Triturus cristatus, great crested newt, translocation, conservation, population size, survival, site fidelity