Brenda S Greene. Increase of gannets (Morus serrator) at Muriwai, Auckland. Notornis 46 (4): 423-433.

The growth of New Zealand’s second mainland Australasian gannet (Morus serrator) colony at Muriwai, north west Auckland is described from counts between 1975 and 1998. The colonies on Motutara Island, and the southern and northern colonies on Otakamiro Point have increased from 28 pairs in 1975 to 1393 pairs in 1998. The potential for future colony expansion on the northern cliff face, where human disturbance is highest, is discussed.

G. A. Taylor. Seabirds found dead on New Zealand beaches in 1996. Notornis 46 (4): 434-445.

During 1996, participants in the Beach Patrol Scheme patrolled 3071 km of the New Zealand coastline. There were 4649 dead seabirds of 58 species recovered by patrollers. In addition, beach patrollers found 165 birds of 32 non-seabird species. Unusual finds included one Chatham Island mollymawk (Diomedea cauta eremita), one New Caledonian petrel (Pterodroma leucoptera caledonica), two channel-billed cuckoos (Scythrops novaehollandiae) and two spine-tailed swifts (Hirundapus caudacutus). There was a moderate-sized wreck of sooty shearwaters (Puffinus griseus) on North Island west coast beaches in November. The highest annual totals of Pitt Island shag (Stictocarbo featherstoni) and Chatham Island shag (Leucocarbo onslowi) were recorded in 1996. The mean annual recovery rates of Buller’s mollymawks (Diomedea bulleri) and black-billed gull (Larus bulleri) were the highest recorded since the start of the Beach Patrol Scheme. Red-billed gulls (Larus novaehollandiae scopulinus) had their lowest annual recovery rate in 1996. Causes of seabird mortality are discussed in the paper.

J.W. Knegtmans & R.G. Powlesland. Breeding biology of the North Island tomtit (Petroica macrocephala toitoi) at Pureora Forest Park. Notornis 46 (4): 446-456.

The breeding biology of the North Island tomitit (Petroica macrocephala toitoi) was studies at two sites in Pureora Forest Park, central North Island, during the 1997/98 season, and compared with data from the Ornithological Society of New Zealand Nest Record Scheme. The nesting season at Pureora was from 26 September 1997 to 15-17 February 1998, one pair fledging three broods. Of 11 Pureora nests and 32 of the Nest Record Scheme, 63.6% and 28.1% respectively were among dead hanging fronds of tree ferns, and 18.2% and 34.5% respectively were in holes in trees, rocks, banks, the ground or in nest boxes. The mean height of 11 nests at Pureora was 3.4 m, and that of 34 nests in the Nest Record Scheme was 2.8 m. Mean clutch size for the combined data was 4.15 eggs (n=13). On all occasions, except one, females were incubating, with males feeding their mates at regular intervals. Both parents fed the chicks but only the female brooded them. Mean brood size at Pureora was 4.0 (n=4), but for the Nest record Scheme was 3.1 (n=21). All 15 fledglings in four broods appeared to reach independence. Of 11 nesting attempts at Pureora, 72.7% were successful, compared with 45.4% of 11 attempts on Nest Record cards. This greater success at Pureora compared with other mainland areas was attributed to aerial 1080 possum control at Pureora reducing predator densities to low levels, and so reducing the incidence of predation.

A.J. Beauchamp. Weka declines in the north and north-west of the South Island, New Zealand. Notornis 46 (4): 461-469.

Population trends in the western weka (Gallirallus australis australis) in Golden Bay and the Marlborough Sounds were examined by field surveys and reference to the literature. Weka declined on the southern margin of Kenepuru Sound in 1995-96, but they were still at 0.30 and 0.06 ha-1 at Big Bay, Endeavour Inlet, and Long Bay near St Omer, respectively. Weka numbers have declined in lowland Golden Bay to less than 0.01 ha-1 since 1986. The reasons for this decline is unknown, but it appears that high densities of mustelid peaks and climatic extremes are times when weka populations need close monitoring.

A.J. Beauchamp & G.R. Parrish. Bird use of the sediment settlement ponds and roost areas at Port Whangarei. Notornis 46 (4): 470-483.

The sediment ponds and tidal flats at Port Whangarei have been significant roost areas for waderes since they were created from dredge tailings in the late 1960s. In 1971, 11 species of waders fed or roosted in this area. New Zealand dotterel (Charadrius obscurus), white-fronted terns (Sterna striata), Caspian terns (S. caspia) and black-backed gulls (Larus dominicanus) bred there, and on six islands of mud and shell. Intensive observation in 1979-80 and 1995-98 found that the residency status of many species had changed. There were significant declines in the numbers of New Zealand dotterel, Caspian tern and skylark (Alauda arvensis) and significant increases in the numbers of red-billed gulls (L. novaehollandiae scopulinus) and house sparrow (Passer domesticus). These changes were associated with development of sedimentation ponds and increases in weed-stabilised communities and cover by mangroves. Future bird use of this area is very dependent on the management of the ponds, and the rate of encroachment of mangroves or ponds over the main mudflat roost area. A new island would safeguard wader roosting in the upper harbour.

R.G. Powlesland & P.J. Reese. Aspects of the breeding biology of black shags (Phalacrocorax carbo) near Lake Kohangatera, Wellington. Notornis 46 (4): 484-497.

The nesting activities and breeding success of black shags (Phalacrocorax carbo) near Lake Kohangatera, Wellington, were studied from 1993 to 1998. The colony was used during November-July by a mean of 67 birds per night, but in August-October numbers increased to a mean of 98 birds when fledglings were present. Courtship and nest-building began in March, and nesting continued until October-November when the last chicks fledged. Most clutches (83% of 185) were laid in April-May (early nests), the remainder being laid in June-September (late nests). The mean estimated laying date of early nests varied from 14 April to 3 May in 1995, the overall mean (1993-98) being 24 April. During the day typically the male took two incubation stints, including the first ,and the female one or two. The mean length of incubation stints by females was 3 h 46 min, over an hour longer than that of males. However, the mean time females and males were absent from the colony to forage, 2 h 39 min and 2 h 21 min, respectively, did not differ significantly. Three types of changeovers were seen during incubation are described as are the activities of adults and chicks during nestling rearing. Fledglings took their first flights when 49-60 days old, but continued to be fed by their parents for 40 to 80 days afterwards, the oldest fledged young seen fed being about 140 days old. Of 185 breeding attempts during 1993-98, 83% were successful, the majority resulting in one or two fledglings per nest. Mean brood size at fledging varied with year, from 1.1 in 1991 to1.7 in 1998. Overall, the mean brood size was 1.4 fledged young per nest, and 1.7 for successful attempts. Early clutches were more productive than late ones. We conclude that a pair of black shags would be unable to successfully rear two broods and complete their moult within a year, and that late nestings were replacement clutches.

Bourne, W.R.P. Albatross names.

Keedwell, R.; Sanders, M.D. Australian magpie preys on banded dotterel chicks.

Schweigman, P. Breeding age of royal spoonbills in New Zealand.