The densities of Chatham Island Pipits (Anthus novaeseelandiae chathamensis) and Skylarks (Alauda arvensis) on the south coast of Chatham Island were estimated at 7 individuals km2 and 10 ind. km2, respectively. Foraging behaviours used by Pipit differed significantly between rough fenland, pasture and beaches. Foraging behaviours also differed significantly between Pipits and Skylark on pasture, and Pipits moved on average 10 times further per minute than Skylark. The make-up of Pipit foraging behaviour on fields and beaches on Chatham Island also differed significantly from those at Wellington, North Island, during autumn.
The establishment since 1984 of small of Takahe (Porphyrio mantelli) on four predator-free islands has been an important component of the conservation strategy for the birds. However, initial productivity of birds in these habitats has been lower than expected due largely to low hatching success of early clutches. This study aims to describe behaviour associated with courtship, incubation and post-hatch care to assess possible behavioural causes of low productivity in Takahe on islands. No unusual behaviour associated with breeding was observed that might result in low productivity, although only two complete copulations were observed during the study. One incomplete copulation involving a yearling male was also observed. Territorial behaviour was recorded to compare with later years when densities of island populations increase. Six territorial interactions between neighbouring pairs were observed, three when pairs were between nesting attempts and ranging widely, and three when two pairs nested in close proximity. Monitoring of aggressive behaviour may be important as it may interfere with successful reproduction.
In 1960, a census of the Spotted Shag (Stictocarbo punctatus punctatus) population on Banks Peninsula found 9,787 breeding pairs (Turbott & Bell 1995). Here we report the results of a comparative census conducted on Banks Peninsula during the 1996 breeding season. Thirty-six years after the original census, the number of breeding pairs was found to have more than doubled to 22,123 pairs. We speculate that the population was formerly limited by food availability and that a reduction in fishing effort around Banks Peninsula, especially in the late 1980s, may have contributed to the observed growth in the shag breeding population.
During 1995, participants in the Beach Patrol Scheme patrolled 3,498 km of the New Zealand coastline. There were 7,625 dead seabirds of 55 species recovered by patrollers. In addition, beach patrollers found 156 birds of 28 non-seabird species. Unusual finds were the third specimen of a beach-wrecked Lesser Frigatebird (Fregata ariel) in New Zealand and five Kermadec Petrels (Pterodroma neglecta). Australasian Gannets (Morus serrator) wrecked in larger numbers than in any year since the start of the Beach Patrol Scheme. There were 648 birds recovered at an average rate of 22.2 birds per 100 km. A large wreck of Sooty Shearwaters (Puffinus griseus) occurred on Stewart Island in May 1995. Causes of seabird mortality are discussed in the paper.
The rare reversed sexual bill dimorphism of the extinct New Zealand endemic bird species, the Huia (Heteralocha acutirostris: Callaeidae) occurs in two Australian riflebird (Ptiloris) and three New Guinea sicklebill (Epimachus [Drepanornis]) birds of paradise (Paradisaeidae). While less extreme than that of the Huia, the female bill length proportionate to tarsus length is 7-18% longer than in males. In this proportionate bill length, females are longer-billed than males in most typical (polygynous) birds of paradise. More marked examples of reversed sexual hill dimorphism in the Paradisaeidae occur in species with greater proportions of wood-dwelling arthropods in their diets. Ecological studies of these species might provide insights into the way Huia lived and how their bill dimorphism evolved.
We present results of the final stage of the Fiordland Crested Penguin (Tawaki) survey for the area north of Milford Sound. A total of 1,260 nests was counted: 389 south of the Hope River in August 1995, and 871 north of the Hope River between 1992-1994. A further 150 are estimated to occur on the Open Bay Is. The estimated breeding population for Tawaki, based primarily on counts of confirmed nests, now stands at 2,260 nests. A realistic estimate of the total number of nests is 2,500-3,000.
The diet of the Wrybill (Anarhynchus frontalis) and the Banded Dotterel (Charadrius bicinctus) was investigated on two New Zealand braided riverbeds using faecal analysis. There was high overlap in terms of taxonomic composition between the two species’ diets, but large variability between individuals. Foods of aquatic and terrestrial (but near-aquatic) origin were consumed; mostly adult beetles (Coleoptera), bugs (Hemiptera) and flies (Diptera). Availability of these prey species relies on a suitable river flow regime.
Large breeding colonies of Sooty Shearwaters or Titi (Puffinus griseus) occur on offshore islands around New Zealand and several smaller colonies occur on headlands and near-shore islands around southern New Zealand; their population trends are unknown. Twelve mainland colonies around Otago had between 11 and 620 burrows in the 1992/93 breeding season. The largest of three near-shore island colonies in Otago had at least 1,050 burrows. Sooty Shearwater burrows have been recorded from 39 mainland sites in the South Island, but only 11 (28%) of these have been checked in the last 40 years: many may now be extinct. OSNZ Beach Patrol data suggest that the overall number of Sooty Shearwaters has changed little over a 26 year period. Methods for monitoring Sooty Shearwater colonies need to be standardised to evaluate population trends in the future.