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Natural re-colonisation events are rare so it can be important to monitor newly establishing populations to understand and characterise such events. As re-colonising populations are often freed from spatial and competitive constraints, documenting the sex-ratio of offspring may provide insights in sex-allocation theory. We studied a re-establishing population of Black-winged Petrels (Pterodroma nigripennis) on Raoul Island, in the Kermadec Group, New Zealand, where all predators have recently been removed. We measured, and took DNA samples from 20 chicks in four new colonies in 2007, when the colonies first re-established, 25 chicks from seven colonies in 2008, and 25 adults captured across both years, including seven that were caught nearby at sea, and two adults caught at a colony where no chicks were sampled. We found the developmental stage of chicks to have no differences between sexes, and recorded no sexual differences in the morphometrics of chicks or adults. We report a significantly biased sex-ratio towards male offspring in the first year of re-colonisation. In contrast, the sex-ratios of offspring in the second year of re-colonisation and of adults in both years were even. We suggest that biases in offspring sex-ratios towards the more philopatric sex may be adaptive when under release from spatial or competitive constraints in re-colonising birds. Continued monitoring of the populations of Black-winged Petrels re-establishing on Raoul Island, as well as comparable data from adjacent islets with long-established breeding colonies of Black-winged Petrels will be critical to identify the realised ecological role of variation in offspring sex-ratio and of sex-biased natal philopatry.

Lightweight capillary tube depth gauges were attached to eight petrel species breeding at New Zealand colonies during the period 1998-2008. This paper presents the first information on the diving ability of Pterodroma petrels.Grey-faced Petrels, Pterodroma macroptera gouldi, recorded maximum dives down to 23 m. Males (6.3 ± 6.3 m SD) dived deeper on average than females (3.6 2.5 m) during the incubation period but not significantly so (P=0.06). Breeding birds dived significantly deeper on average than non-breeders, and breeding males dived significantly deeper on average than non-breeding males. The two small Pterodroma species sampled, Pterodroma pycrofti and Pterodroma nigripennis, only exhibited shallow dives down to 2 m but sample sizes were small. Sooty Shearwaters, Puffinus griseus, had mean maximum dive depths of 42.7 ± 23.7 m, with males (53.0 ± 17.3 m) diving significantly deeper on average than females (20.1 ± 20.4 m) during the incubation period. One male Sooty Shearwater dived to nearly 93 m, the deepest dive so far recorded in the order Procellariiformes. Flesh-footed Shearwaters, Puffinus carneipes, dived to 28 m, with a mean maximum dive depth of 13.6 ± 7.9 m. Hutton's Shearwaters, Puffinus huttoni, had a mean maximum dive depth of 23.0 ± 8.5 m (range 11.1-36.6 m). A single Fluttering Shearwater, Puffinus gavia, recovered with a dive gauge had dived to 29 m. Mean maximum dives made by Common Diving-Petrels, Pelecanoides urinatrix, of 10.9 ± 6.1 m (range 6.9-22.2 m) were shallower than results reported from other sites but may have been biased by gauge failures. Capillary gauges provide the best means we have at present to understand the diving capability ofsmall seabirds. While studies elsewhere have shown these gauges may overestimate diving performance by about 10-15%, other factors identified in this study indicate that sometimes diving performance will be underestimated using this simple technique.

Little Shearwaters, Puffinus assimilis assimilis, were thought to have disappeared from Lord Howe Island during the early 1900s. This study reports Little Shearwaters breeding on Lord Howe Island between 1990 and 2001. A survey in 2000 recorded 85 nestlings. It is unclear whether this species has persisted on Lord Howe Island in low numbers throughout last century or whether it is recolonising. Adults, ashore between April and October, often occupied burrows previously used by Black-winged Petrels, Pterodroma nigripennis. Observations at a single nest showed the incubation period to be 55 days and the nestling period to be 72 days. Chick mass increased at a mean rate of 5.2 g day–1 to a maximum of 272 g at 48 days old. The chick fledged on 5 November at 158 g after fasting for six days. During chick rearing, parents came ashore almost nightly, arriving just after sunset and remaining with the chick until shortly before dawn; occasionally they were ashore during the day.

The Black-winged Petrel, Pterodroma nigripennis, is a recent coloniser of Lord Howe Island, with adults present between late October and early May. Four nests were monitored during both the 1989-90 and 1990-91 breeding seasons. Eggs were laid at the end of December and hatching occurred in mid February after 45.3 ± 0.5 days' incubation (mean ± s.d.). Young (weighing 175.5 ± 8.7 g) fledged in early May, 84.8 ± 0.5 days after hatching and 10.3 ± 1.6 days after feeding stopped. On average, chicks were fed every 2.5 days, with each parent returning every 4.4 days. Provisioning rates remained constant throughout the period of chick rearing. Average meal size was estimated at 32.6 g. Inter-specifi c competition for nesting burrows with Little Shearwaters, Puffinus assimilis, was observed.

Seabirds were counted along the same cruise tracks in the eastern tropical Pacific (10°oN-10°oS and 140°o-90°oW) each spring and autumn for 8 years, 1984–1991. During spring, three species groups were apparent among eight species seen in five or more years: (1) Leach's Storm-petrel Oceanodroma leucorhoa and Wedge-rumped Storm-petrel Oceanodroma tethys, which feed on neuston by surface seizing; (2) Black-winged Petrel Pterodroma nigripennis and White-winged Petrel Pterodroma leucoptera, which feed on neuston and micronekton by surface seizing; (3) Juan Fernandez Petrel Pterodroma externa, Wedge-tailed Shearwater Puffinus pacificus and Sooty Tern Sterna fuscata, which feed on micronekton driven to the surface by foraging tuna. During autumn, only one group was identified from the seven species seen in five or more years: Leach's Storm-petrel associated with either Wedge-rumped Storm-petrel or Juan Fernandez Petrel and/or White-winged Petrel. Annual variability in assemblage composition was more extreme in the autumn and thus was similar to variation in physical and biological factors linked to the El Nino-Southern Oscillation cycle.

I describe and illustrate five new species of chewing lice in the genus Halipeurus, parasitic on petrels from the Pacific and the Atlantic Oceans. They are: Halipeurus confusus n. sp. from Pterodroma nigripennis; H. pricei n. sp. from Pterodroma brevipes and Pt. leucoptera; H. atlanticus n. sp. from Pterodroma cahow and Pt. madeira; H. pelagodromae n. sp. from five subspecies of Pelagodroma marina; and H. vincesmithi n. sp. from Oceanodroma matsudairae. I discuss the morphological similarities of the currently recognised subgenera of Halipeurus and propose to synonymise them—Synnautes Thompson, 1936 and Anamias Timmermann, 1965—under the nominate subgenus. I propose two new synonymies at species level: Halipeurus sawadai Nakagawa, 1959 and Halipeurus angusticeps fosteri Edwards, 1961 both as junior synonyms of Halipeurus angusticeps (Piaget, 1880). Also, I propose to merge H. subclavus Timmermann, 1961 and Halipeurus spadix Timmermann, 1961 as subspecies of H. spadix. I report several new host-louse records for other Halipeurus species, and present additional information and illustrations for H. raphanus Timmermann, 1961, H. fallacis Timmermann, 1960, H. nesofregettae Timmermann, 1961 and H. spadix subclavus Timmermann, 1961 based on their type material and other specimens. Lectotypes of Lipeurus pelagicus Denny, 1842 and Lipeurus languidus Kellogg & Kuwana, 1902 are designated.

Pterodroma nigripennis and P. longirostris were observed in the Northwest Pacific during several cruises on R. V. Hakuho Maru from May to November between 1980 and 1984 (the north of 7°N, the west of 180°E). It can be deduced that P. nigripennis and P. longirostris fly regularly every year in the Northwest Pacific, and during these observations there were no species of smaller petrels to migrate in these areas except the above species including P. hypoleuca. With regard to the season of migration of P. nigripennis to the Northwest Pacific, they migrate to these areas in June-July, and in August-September there are great numbers in the waters southesast of Honsyu, then they return to the breeding islands after November. The favoured water temperature of P. nigripennis is in the range 25°-28°C, so it is surmised that they do not move in the waters off Sanriku to the north of 38°N. P. longirostris migrate to the waters far east of Honsyu in May-June and concentrically distribute in the waters off Sanriku between late July and September, in this season they were feeding mainly at the waters in front of Kuroshio Current, and then they beign to return to their breeding islands. The three smaller petrels occurred in areas where surface water temperatures ranged from 16°C to 31°C in June-September, P. nigripennis favour in areas with the highest water temperature in these species and P. hypoleuca next, but when these species distribute in the Northwest Pacific, they devide a feeding area for keeping away from competition. In the Northwest Pacific P. hypoleuca and P. nigripennis formed mixed groups with sea birds which the breeding islands or distribution areas are same with them, on the other hand P. longirostris formed large flocks with the storm petrels in having same feeding areas.