The Chatham Island Pigeon or Parea (Hemiphaga novaeseelandiae chathamensis), is the endangered subspecies, endemic to the Chatham Islands, of the New Zealand Pigeon or Kereru (H. n. novaeseelandiae). During the early period of European and Maori settlement, 1820s to 1870s, Parea were common on Chatham, Pitt and Mangere Islands, but by 1990 the population possibly comprised fewer than 50 birds, mostly in forest habitats of the southern part of Chatham Island. Between 1989 and 1994, the numbers of feral cats and brushtail possums (Trichosurus vulpecula) were reduced in areas occupied by Parea in the Awatotara and Tuku Valleys of south-western Chatham Island The adult Parea population of these valleys increased three-fold from 27 in 1990 to 81 in 1994. The long-term future of the Parea is dependent on the exclusion of cattle, pigs and sheep from forest reserves. Keeping cat and possum numbers at low levels in Parea habitat on Chatham Island, and the establishment of a population on Pitt Island once cats have been removed from one or more of its reserves.
Wetland birds on 11 rivers of the Upper Waitaki Basin, South Island, New Zealand were surveyed annually between 1991 – 1994. Diversity, minimum abundance and density of birds were compared. In total 26 species of wetland birds were recorded. Minimum estimated river bird numbers were: 3566 Black-backed Gulls (Larus dominicanus), 3302 Black-fronted Terns (Sterna albostriata), 3260 Banded Dotterels (Charadrius bicinctus), 793 Black-billed Gulls (Larus bulleri), 789 Wrybills (Anarhynchus frontalis), 788 South Island Pied Oystercatchers (Haematopus ostralegus), 421 Pied Stilts (Himantopus himantopus), 85 Black Stilts (Himantopus novaezelandiae), 51 Caspian Terns (Hydroprogne caspia), and 3680 waterfowl and cormorants. Densities of birds ranged from 0.17 birds ha-1 on the Pukaki River to 0.95 birds ha-1 on the Lower Ohau River. The Cass, Lower Ohau, Godley, Tekapo and Ahuriri Rivers had higher densities of one or more species than the Upper Ohau and/or Pukaki Rivers. Densities of Black-fronted Terns, Black Stilts, Pied Stilts and Caspian Terns were negatively correlated with altitude, and in general birds preferred river sections with low or moderate flows, and low or moderate vegetation cover. Eight of the 11 rivers surveyed had more than 1% of estimated total populations of one or more of three globally vulnerable or endangered species, and in combination rivers of the Upper Waitaki Basin support almost all known Black Stilts, 15% of all Wrybills and 32% of all Black-fronted Terns. We suggest that the Upper Waitaki Basin may now provide half of all remaining suitable braided river bird habitat in New Zealand.
Records of all mollymawk sightings on Bollons Island, Antipodes Islands, are reviewed. Data are provided to confirm the breeding record for Black-browed Mollymawk Diomedea melanophrys melanophrys and add a new breeding record for the NZ White-capped (Shy) Mollymawk Diomedea cauta steadi.
When interpreting counts of forest birds it is seldom possible to distinguish the effects of changing density from those of changing conspicuousness; these often arise from the birds’ singing and calling. To investigate this, birds first seen were recorded separately from those first heard when counting birds in forest of the Orongorongo Valley, Wellington, New Zealand. Apparent changes in the frequency of Paradise Duck (Tadorna variegata) in the river valley, and of the Song Thrush (Turdus philomelos), Whitehead (Mohoua albicilla), Grey Warbler (Gerygone igata) and Chaffinch (Fringilla coelebs) in the forest coincided with changes in the frequency of their singing or calling; they were considered suspect. Changes in the frequency of the Black-backed Gull (Larus dominicanus) on the riverbed, and of N.Z. Pigeon (Hemiphaga novaeseelandiae), Blackbird (Turdus merula), Fantail (Rhipidura fuliginosa), Silvereye (Zosterops lateralis), Bellbird (Anthornis melanura), Tui (Prosthemadera novaeseelandiae), and Australian Magpie (Gymnorhina tibicen) did not show a similar correlation. Special study of the ways in which birds either advertise or conceal themselves is needed. Correction factors may never compensate completely for the effects of the birds’ varying conspicuousness.
Captive Weka (Gallirallus australis) were offered two species of native frogs (Leiopelma hochstetteri and L. archeyi) as prey. The anti-predator behaviour and/or gland secretions of the frogs were sufficient to avoid damage and allow them to escape. The leaf litter habitats where frogs occur in the Coromandel Ranges are least likely to be favoured by Weka. Objects under which frogs were found were heavier than those generally moved by Weka while foraging. Weka seem to constitute less of a risk to frogs than earlier believed.
We studied Cape Pigeons Daption capense at The Snares, one of its northern most breeding sites, from pre-laying to fledging during 1985/86 and 1986/87, and compared our data with those from other localities. At The Snares, mean laying dates were 10 November 1985 and 8 November 1986, mean hatching date was 25 December 1985, mean fledging date was 14 February 1986, breeding success was 58.7% in 1985/86 and 50.0% in 1986/87, and adult male annual survival was 94%. Laying mainly begins later at higher latitude breeding sites and there are differences in pre-laying colony attendance between some populations. Incubation and nestling periods are similar throughout the species’ range suggesting an inherent rather than environmentally-induced explanation for the relatively short nesting season of fulmars compared to other petrels.