Reptile populations occur sporadically throughout the UK where they occupy a broad range of habitats. This patchy distribution is particularly vulnerable to the effects of development, which can lead to the direct killing of reptiles or the isolation of populations through habitat fragmentation. All species of native reptile receive legal protection against reckless killing and injury under UK law. In order to prevent an offence occurring, developers frequently commission the trapping and translocation of reptiles to a place of safety outside the development footprint, and occasionally offsite altogether. Although this fulfils the legal obligation of the developer, the long-term future of the translocated population is uncertain. Despite translocation being advocated as a last resort, it continues to be a frequently employed mitigation strategy for reptile – development conflicts.
Translocations are often considered to be a success if the population persists into the following year or show evidence of successful breeding. However, post development monitoring is undertaken sporadically and rarely extends beyond one year. It has been suggested that longer term monitoring programmes may be required to identify significant deviations from typical population trends. There is a paucity of long-term research; however, a long-term study (>10 years) of a population of Anguis fragilis indicated that body condition deteriorated following translocation. Reduction in body condition is likely to indicate a decline in population fitness and an increase in the risk of local extinction. From this perspective, translocations cannot be considered to be a success. The A. fragilis report is the only long-term study of its kind and more work is needed before making decisions on the appropriateness of using translocation as a mitigation tool for reptile-development conflicts.
- To undertake a rigorous investigation in to the long-term effects of translocation using A. fragilis, Zootoca vivipara, Natrix natrix and Vipera berus;
- To calculate Population Viability Analyses (PVA) for each study (translocated) population; and
- To develop sophisticated Capture Depletion models to test the efficiency and effectiveness of translocation programmes.