Publications Archive

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.

In the 1980’s Little Spotted Kiwi (Apteryx owenii) were transferred to Long, Red Mercury and Hen Islands to establish new populations beyond their stronghold on Kapiti Island. Recent surveys indicate that all three populations are increasing at between 4% and 8% per annum. Recently, a fifth population has been established successfully on Tiritiri Matangi Island in the Hauraki Gulf, and has grown at a rate of about 11% per annum. Little spotted Kiwi now appear to be secure with five viable populations on predator-free islands. Aerial poisoning of rats using brodifacoum baits does not appear to have had any long-term adverse effect on the populations of Little Spotted Kiwi on Red Mercury and Tiritiri Matangi Islands.

Avifaunas from Pleistocene and Holocene fossil deposits in the Hodges Creek Cave System in northwest Nelson, New Zealand, are described. At least 20 species of birds are present in glacial-age deposits from these sites at about 900 m above sea level. A sample of 12,000 year old Finsch’s Duck (Euryanas finschi) bones shows that post-glacial shortening of the wings in this species had already started at that time.

Densities of the North Island Weka (Gallirallus australis greyi) have declined over much of the East Cape region since 1985. The area around Motu township had densities exceeding 0.72 ha-1 in 1985-86, but they disappeared by 1990 and have increased only marginally since. The decline coincided with floods and the spread of ferrets (Mustela furo) into the valley. The only region where Weka density increased is in the hills between Motu and Opotiki Counts in the Toatoa and Whitikau Valleys in 1995 found a maximum density of 0.60 adult Weka ha-1 in mixed farmland and fern, and between 0.08 – 0.18 ha-1 in mature forest. There are less than 1,000 adults in the centre of this region, and in some areas the population is male-dominated.