Birds of the Auckland Islands, New Zealand subantarctic

The Auckland Islands are the largest island group in the New Zealand subantarctic region, and have the most diverse avifauna, including eight endemic taxa. We present the first comprehensive review of the avifauna of the Auckland Islands, based on a database of 23,028 unique bird records made between 1807 and 2019. At least 45 species breed (or bred) on the islands, with a further 77 species recorded as visiting the group as migrants, vagrants, or failed colonisers. Information on the occurrence of each species on the different islands in the group is presented, along with population estimates, a summary of breeding chronology and other reproductive parameters, and diet where known. The frequency at which 33 bird species were encountered during visits to the seven largest islands is compared graphically to facilitate comparison of each island's bird fauna in relation to habitat differences and the history of introduced mammals. Disappointment Island (284 ha) is the least modified island in the group. However, it lacks forest, and so has a very restricted land bird fauna, lacking ten species that breed on other islands in the group. Auckland Island (45,889 ha) is the only major island in the group where introduced mammals are still present. As a result, it also has a depauperate bird fauna, with at least 11 species completely absent and a further seven species reported at lower frequencies than on the next largest islands (Adams and Enderby Islands).