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POP2025-04 Auckland Islands albatross and petrel research 2025–26 (PDF, 2,076K)
Summary
The white-capped albatross Thalassarche cauta steadi is the most bycaught seabird species in New Zealand fisheries and the third most at-risk species in the NZ fisheries risk assessment. There is uncertainty in both demographic and abundance estimate trends. Contrasting trends in abundance estimates show either a steep population decline, a shallow, non-significant population decline, or something in between. This project aimed to address the data gaps for this heavily bycaught species.
We aimed to estimate the population size of white-capped albatross on Disappointment Island, monitor adult survival, and describe their at-sea distribution. Secondary objectives were tracking work on Gibson’s albatross and white-chinned petrels.
Conditions for landing at Castaways Bay, Disappointment Island, were unworkable. We therefore focused on tracking and demographic work at Auckland and Adams Island. At Southwest Cape, Auckland Island, we deployed tracking devices on white-capped albatrosses and conducted drone surveys of some of the colony areas there. At Adams Island we deployed tracking devices on Gibson’s albatrosses and white-chinned petrels. Secondarily we focused on collecting demographic data for white-chinned petrels in an area where the birds were studied and burrows marked 2013–2018.
Tracking devices were deployed on all three focal species in December 2025 in the Auckland Islands. Of the three types of tracking devices on white-capped albatrosses at SW Cape, one collected the first flight altitude data for this species. Tracking devices were also deployed on white-capped albatrosses and white-chinned petrels in November 2026 at Kaikoura. Six out of the eight white-capped albatrosses from Southwest Cape have stayed in Australasian waters, while the other two migrated to waters off southern Africa. White-capped albatrosses caught at sea off Kaikoura showed a similar pattern with three of the four birds staying in NZ waters. GLS from the white-capped albatross study colony on Disappointment Isl 2023–24 provided year-round distributions for seven birds. Of these, four stayed in Australasian waters year-round, foraging in NZ waters, in the Tasman and up into the Great Australian Bight, while three spent time off southern Africa. Gibson’s albatross juveniles equipped on Adams Island in December, foraged primarily in the Tasman and in waters north of the Chatham Rise during the first six months. Trackers fitted on white-chinned petrels in the Auckland Islands and at sea off Kaikoura showed that over the December to May period, birds foraged mainly on the Campbell Plateau and off the South Island East Coast. As the breeding season ended, five of the birds so far have made the migration to their wintering areas in waters off South America.
Drone overflight on 10 March 2026, by a DOC team working nearby two months after us, allowed counts of the 988 white-capped albatrosses present on the eastern side of Southwest Cape (819 in the Gulch and 169 along the east-facing slopes of Southwest Cape). These are raw counts of birds present. Image quality was good at upper levels, but lower on the steep colony slopes image quality deteriorated. White-capped albatrosses on lower slopes could be identified, but nesting birds could not be reliably distinguished from those loafing in the colony. Ground-truthing data was not collected at the time of aerial photos, so we did not refine the raw count of birds present into an estimate of active nests on 10 March.
When trends for white-capped albatross numbers in their SW Cape breeding colony are modelled, we see that annual breeding pairs peaked in the late 2000s, but after a period of roughly stable abundance, there has been gradual decline since ~2013. The gradual decline over the last decade mirrors the trend seen for the population as a whole.
We investigated 335 white-chinned petrels burrows and could accurately determine the contents for 130. Burrow occupancy was 38% (50 occupied burrows out of the 130 known-contents burrows), lower than occupancy rates expected for white-chinned petrels in the Auckland Islands. Of the fifty occupied burrows, seven contained a banded bird and 43 did not.
Mark-recapture at the Disappointment Island white-capped albatross study colony was just starting to yield quality adult survival estimates at last visit, so recaptures and banding of new white-capped albatrosses remain priorities so trends in adult survival can be assessed. Access to Disappointment Island requires more vessel-standby days to improve the chances of workable conditions occurring. It is important to develop a quality DEM for Disappointment Island in advance, so that drone image quality is retained on lower parts of albatross slopes. During drone overflight, concurrent ground-truthing is vital to estimate the number of active nests. Aerial photography is useful, but mark-recapture is important to allow more detailed insight into the population health of the species.
Publication information
Parker, G., Philps, B., Rowley, L., Sagar, R., Simister, K., Rexer-Huber, K. 2026. Auckland Islands albatross and petrel research 2025–26. Conservation Services Programme, Department of Conservation, Wellington, Aotearoa New Zealand. 22 p.