The Antipodean wandering albatross (Diomedea antipodensis) is endemic to Antipodes Island in the New Zealand subantarctic. A programme of regular census and population study was initiated on Antipodes Island in 1994 to determine the status of the species. This paper reports on field work carried out every summer from 1994 to 2005. Aspects of breeding biology are described and compared with those of other species of wandering albatross, particularly the closely related Gibson’s wandering albatross (D. gibsoni) on Adams Island. Average annual survival over 10 years was 0.957. Productivity was measured over 11 years and averaged 0.74 chicks per nesting pair. Survivorship was similar to that in the increasing Diomedea exulans population on Crozet Island, and productivity higher than recorded in all other wandering albatross populations. Between 1994 and 1997, the average annual number of pairs nesting on Antipodes Island was 5136. There is evidence of population decline during the 1970s but numbers are now increasing.
A previously unknown population of Coenocorypha snipe was discovered on Jacquemart Island, a rat-free 19 ha islet adjacent to Campbell Island in the New Zealand subantarctic, on 9 November 1997. This was the first evidence of Coenocorypha snipe occurring in the Campbell Island group, which is believed to have been infested by Norway rats (Rattus norvegicus) before the first naturalists visited in 1840. Rats were eradicated from 11,268 ha Campbell Island by the New Zealand Department of Conservation in July 2001. Two snipe were seen, and one caught, on Campbell Island adjacent to Jacquemart Island on 10 March 2005. The bird caught was a fully-feathered chick, indicating successful breeding on Campbell Island. The Campbell Island snipe remains undescribed and critically endangered.
Counts, mark-recapture estimates of abundance, and simulations were used to assess the population trends of Antipodean wandering albatross (Diomedea antipodensis) and Gibson’s wandering albatross (D. gibsoni). Estimates of population size based on mark-recapture analysis had much greater power to detect trends than did annual counts of nests. In fact, nest counts were so variable that significant trends would only be detected when populations had already changed by more than 25%. Population simulation models were constructed using survival and productivity data from the two species, and recruitment data from closely related species. The simulation models were sensitive to variation in recruitment data and suggested that the recruitment of Gibson’s wandering albatrosses is significantly lower than that of Antipodean wandering albatrosses. The sensitivity of the models to variation in the surrogate data compromises the usefulness of such models as predictive tools. After large, probably fisheries-induced declines during the 1970s and 1980s, Antipodean wandering albatross populations are now increasing at about 3.1% per annum, while Gibson’s wandering albatross populations are static.
New Zealand bellbirds (Anthornis melanura) disappeared suddenly from the northern New Zealand mainland and several large northern islands in the late 19th century. During the past 75 years, several unsuccessful attempts were made to reintroduce them. Between 1988 and 1991, four translocations (111 birds) were made to Waiheke Island near Auckland, sourced from Kaingaroa (21 birds) and Cuvier Island (90 birds). The birds were conspicuous immediately after release but became progressively less visible within six months and the translocations failed. While the cause(s) of failure are unknown, predation by mammalian predators, especially ship rats (Rattus rattus) is likely to have been a critical factor. Other possible reasons for failure of bellbird translocations are discussed, along with the reasons why original bellbird populations disappeared from northern New Zealand and subsequently failed to re-establish.