Antipodean albatross population assessment
The Antipodean albatross is endemic to New Zealand, nesting on Antipodes Island. The sub-species is classified as Nationally Critical under the New Zealand Threat Classification and is recognized as Endangered on the IUCN Red List at the species level. The species is listed on Appendix 1 of the Convention on Migratory Species, and the Antipodes Island population is recognized by the Agreement on the Conservation of Albatrosses and Petrels as a priority population for conservation management. Threats to the population include incidental mortality in fisheries (in New Zealand and in international waters) and climate change. These birds forage throughout the southern WCPFC area (south of approximately 25°S). Here we report an updated population assessment made in 2021. A Bayesian integrated population model was developed to estimate the main demographic parameters of the population. The model used field data from a study population that has been monitored since 1994. The model considered detectability of individuals, inter-annual variability, and movements in and out of the study area; it was fitted using the software Stan. From the model, the annual survival rate for females was estimated to decline from 0.947 (95% c.i.: 0.914 – 0.974) in the period from 1994 to 2004, to 0.882 (95% c.i.: 0.814 – 0.94) after 2005. Estimated survival for males was 0.946 (95% c.i.: 0.913 – 0.972) and 0.927 (95% c.i.: 0.887 – 0.961) for the two periods. Breeding success also declined between the two periods, from 72.4% (95% c.i.: 65.8% – 78.6%) from 1994 to 2004 to 63.7% (95% c.i.: 53.4% – 73%) subsequently. This study also developed a tool to explore the potential impact of threats and the demographic outcomes of management strategies. Using the tool, simulations of the demographic impact of different scenarios may be carried out so that management strategies can be assessed and prioritised. Under the current scenario, simulations suggest a significant decline of the population, with an annual growth rate of -4.84% (95% c.i.: -6.07% – -3.65%). Their current population is estimated at around 3200 breeding pairs, but under the projected decline, only about 400 pairs may remain in 2050.
Richard, Yvan (2021). Integrated population model of Antipodean albatross forsimulating management scenarios, 31 pages.
Technical report prepared for Departmentof Conservation – June 2021.