Re-introduction of the natterjack toad in the UK

Summary

The natterjack toad (Epidalia calamita), which declined 70-80% in Britain since the early 20th century from habitat afforestation, urbanization, pond acidification and competitor invasion, has been the subject of sustained conservation translocation since the 1970s, now led by the Amphibian and Reptile Conservation Trust, aiming to restore the species' historical UK range and boost breeding female numbers from 2,500 toward 3,500 by 2010. Reintroductions have mainly used translocated spawn and tadpoles from existing native populations, supplemented in some cases by head-starting and captive breeding, with standardized near-annual monitoring in place since 1985 feeding a national site register; translocations at 29 sites since 1975 have grown the number of known UK natterjack sites from about 40 in 1970 to 69 today. Of 27 translocations old enough to judge, 19 (70%) succeeded at least in the short to medium term, with self-sustaining breeding populations established at some sites, though success rates differed sharply by habitat: only 57% on heathland versus 85% on coastal dunes and saltmarshes. Landmark successes include the first confirmed translocation success at Sandy heathland in 1980, a large 200-plus-adult dune population established at Holme in 1982, and a rapidly expanding population exceeding 50 adults from spawn transfers to Hengistbury in 1989-1991. Major difficulties included understanding the scale of historic heathland degradation needed for restoration, a shrinking pool of suitable unmanaged sites, and opportunistic rather than strategically planned progress due to funding and staffing limits. The project rates itself Successful, noting only a small, unexplained subset of heathland translocations have failed to establish lasting populations.