The eradication of cattle from Enderby Island and subsequent ecological response

Cattle (Bos taurus) were liberated on 695 ha Enderby Island, the northernmost of the Auckland Island group, in 1894–96, after a previous liberation had died out. After reaching a peak population of c. 100 animals, they established a relatively stable population of 35–60 animals for the latter half of the 20th century. Eradication was mandated in the 1987 Auckland Islands Management Plan, but proposals for eradication were not universally supported due to the interesting traits of this long-isolated population and its adaptation to the subantarctic environment of the island. Therefore, retrieval of genetic material was permitted before the planned operation. Eradication of the cattle occurred between 1991 and 1993, with at least 47 animals shot in 3 weeks in February 1991, a further two in March–April 1991, and two in December 1991–January 1992. The only two surviving animals were removed alive in February 1993 for captive breeding. The ecological response is considered significant but unable to be completely differentiated from the effects of subsequent eradication of rabbits and mice. Attempts to preserve genetic material via ova, sperm, and live animals met with limited initial success but a small captive population has been established on mainland New Zealand.