Foraging strategies and migration of southern Buller's albatrosses Diomedea b. bulleri breeding on the Solander Is, New Zealand

Foraging strategies of southern Buller's albatrosses Diomedea b. bulleri br eeding on the Solander Is, New Zealand, were studied by satellite telemetry in 1997 (4M 6F, 1-34 foraging trips per bird, total of 125 trips). During incubation, birds made long trips to the Tasman Sea (mean duration 10.4 d, range 1417 km), west coast (females, 10.4 d, 533 km) or east cease of the S outh Island (one male, 9.5 d, 656 km). During chick-rearing, foraging trips were of three distinct types: brief (0.7 d, 69 km) and extended short trip s (2.1 d, 266 km), and long trips (4.0 d, 571 km). All birds alternated bet ween 1-4 brief and 1-3 extended short trips during the guard-stage and post -guard stage to late May. In one pair tracked subsequently, male and female resumed long trips in alternation with both types of short trips during th e first half of June. After mid-June, the male reverted to short trips only , and probably made its final visit ashore on 24 June; the female fed the c hick until at least 18 July, alternating between 1-4 brief and 1-2 long tri ps. Males foraged mostly eastwards from the Solander Is (27 out of 32 short trips, two long trips), females mostly westwards (44 out of 55 short trips , seven long trips). Male and female of an unsuccessful pair migrated to Ch ile after mid-June, crossing the Pacific in 8.9 and 10.0+ d (mean speed 47. 2 and 35.9 km/hr respectively) and in two bouts of fast travel (up to 2758 km in 32.5 hrs) alternating with slower flight. Sexual differences and trip sequences during the post-guard stage were unlike those of Snares Is breed ers tracked in 1996. Foraging area partitioning between adults from the Sol ander and Snares Is was not consistent with the hinterland model.