Notornis, 39 (1), 1-15
Article Type: paper
The seasonal change in Yellow-eyed Penguin numbers using a landing site (or part of the beach where penguins moved to or from the sea) at Middle Bay, Campbell Island, was monitored between November 1987 and September 1988. Numbers were low during the incubation phase of nesting (November) and rose to a peak during the chick-rearing period (December- March) when most breeding birds were travelling to sea each day. Numbers were low during the moult (April) as most birds were ashore. Peak numbers occurred in May but declined subsequently because of sea lion disturbance and pre-breeding behaviour. A census of 172 landing sites on Campbell Island during May-July 1988 found 1625 penguins, which may have represented a total of 2000 birds, or 490-600 breeding pairs. Decreases in penguin numbers at several landing sites between 1988 and 1990 suggest the population may have declined by about 45%. A census of 115 landing sites on part of the Auckland Islands in November-December 1989 found 934 penguins, which may have represented a population of 420-470 breeding pairs. Allowing for a possible sparse population on the east coast of Auckland Island, 520-570 pairs is a very conservative estimate for the islands. The total Yellow-eyed Penguin population in 1988-1989 was approximately 5930-6970 birds, with at least 56% in the subantarctic.