Translocation of a population of great crested newts (Triturus cristatus) : a Scottish case study

摘要

In the UK, translocation is increasingly being used to resolve conflict between great crested newt (Triturus cristatus) conservation and land development. Due to a lack of objective study on the translocation procedure, there remains little evidence of the success of employing this strategy despite widespread implementation. Reviews of translocations highlight the need for case studies that include longer term pre and post translocation monitoring. To allow redevelopment of the Gartcosh Industrial Site, the decision was taken to translocate the resident great crested newt population to the purpose built Gartcosh Nature Reserve around the periphery. This provided an opportunity for in-depth analysis of the largest project of its kind in Scotland. This project was designed to test the effectiveness of translocation in producing a self-sustaining, viable population. The key aims were: to ascertain if the population was successfully re-established in the receptor site at a level comparable with the donor site; to assess whether the newly created habitat was suitable for supporting a population of great crested newts; to determine what constitutes a successful translocation and how best to achieve this within the Scottish context. The following points summarise the projects findings: • Simple counts of adults are being maintained at a level comparable to or greater than pre translocation counts. • The favourable status of the adult population is supported by a capture-mark-recapture study. Population estimates are on a par with numbers of adults translocated to the Gartcosh Nature Reserve. • Juvenile lifestages indicate declines. Further monitoring is required to determine if this is an effect of the translocation or a natural fluctuation. • Survival rate of adults is measured at 43%. • There is significant recruitment of ‘new’ adults. • Good quality terrestrial and aquatic habitat has been produced, with an overall loss of land and pond surface area but increased number of ponds. • Increased individual growth rates of adults are indicative of a habitat capable of meeting adult resource requirements. • The nature reserve is internally fragmented into zones preventing movement through the site and is isolated within the wider landscape. For the population to be viable, connectivity requires improvement. • To ascertain long-term success of the Gartcosh translocation it is recommended that post monitoring extends beyond simple adult counts and continues capture-mark-recapture study specifically within the Railway Junction area. • Guidelines have been produced detailing best practice in translocation, monitoring and habitat creation.