Forty breeding colonies of three petrel species were found on 35 of 71 islands surveyed in southern Fiordland, Fiordland National Park, New Zealand, in November and December 2017. Almost all islands in Chalky Inlet, Preservation Inlet, Cunaris Sound, Long Sound, and Isthmus Sound were surveyed. Sooty shearwater (Ardenna grisea) was the most widespread and abundant species, with an estimated 23,425 burrows on 25 islands. Broad-billed prions (Pachyptila vittata) were breeding on nine islands (9,940 burrows estimated), and mottled petrels (Pterodroma inexpectata) on five islands (1,240 burrows estimated). This is a 3-fold increase in the number of petrel colonies in Chalky and Preservation Inlets and associated waterways identified in published accounts, and the first estimate of the number of burrows on each island. Long-term survival of most of these colonies is dependent on ongoing control of stoats (Mustela erminea) on islands in these southern fjords. The persistence of remnant petrel colonies on small islands is probably due to stoats being infrequent invaders that are unable to persist when migratory petrels depart at the end of the breeding season.
Face, wing, bill, and leg characteristics of grey ducks (Anas. s. superciliosa), of captive-raised F1 and backcrossed grey duck x mallard (A. platyrhynchos) hybrids, and of wild “grey-like” and “mallard-like” ducks in New Zealand were evaluated to assist recognition of grey duck x mallard hybrids in the field. Face pattern was the single character best able to discriminate grey ducks from all others, most grey-like hybrids from all mallard-like hybrids, but not most F1 and backcrossed mallard hybrids from mallards. Upper wing pattern, and bill and leg colours assisted discrimination alongside face pattern but not so on their own. The extensive phenotypic variability now apparent within the combined grey duck – mallard population in New Zealand restricts consistent discrimination to 3 “taxa”: grey ducks, grey-like ducks (“grallard/greylard”), and mallard-like ducks (“New Zealand mallard”).
Variability of face and wing pattern and of leg and bill colour, and differences in bill and wing lengths, were assessed in Anas superciliosa (Anatidae) specimens from Pacific Islands, Australia, and New Zealand regional populations. The same 3 broad face patterns and 4 wing patterns were found in all populations. Frequency distributions of face patterns, but not wing patterns, differed significantly between populations. The most common face pattern in Australia was very rare in New Zealand and uncommon in Pacific Islands. A secondary face pattern in Pacific Islands and New Zealand was absent in Australia. Australian and New Zealand ducks did not share bill colour and pattern and no legs of New Zealand birds displayed yellow/orange hues common to 35% of Australian specimens. Bill and wing lengths of Pacific Islands specimens were significantly shorter than all others while wing lengths of male specimens from northern Australia were significantly shorter than those from southern Australia and New Zealand. These differences offer emphatic support for historic subspecific differentiation of Pacific Island specimens. Historic, but now discarded, taxonomic distinction between Australian and New Zealand populations based on phenotype could be reconsidered.
Data on the effects of aerial 1080 operations on non-target bird species in New Zealand are scarce and largely limited to short-term colour-banding or radio-tracking studies, or standardised call counts. During a 22-year study in Tongariro Forest, all 142 radio-tagged North Island brown kiwi (Apteryx mantelli) survived 4 landscape-scale (20,000 ha) aerial broadcast 1080 operations targeting brush-tailed possum (Trichosurus vulpecula) and rats (Rattus spp.). Furthermore, both kiwi chick survival to 6 months old and New Zealand fantail (Rhipidura fuliginosa) nesting success were significantly higher in the first 2 breeding seasons following the use of 1080 poison than in subsequent years of the 5-year cycle. We observed several episodes of ferret (Mustela furo) killing multiple adult kiwi, particularly in the last half of the 1080 cycle. Population modelling showed that a 5-year 1080 operation cycle resulted in population gains for 2 years, followed by declines in the remaining 3 years that largely negated these benefits. Our data thus support the shift to a 3-year 1080 operation cycle which will more likely result in this kiwi population growing at close to the 2% per year target set by the 2018–2028 Kiwi Recovery Plan.
Australasian little grebe (Tachybaptus novaehollandiae) was detected at the Whangarei sewerage wetlands at Kioreroa Road, in September–October 1996, and since 2012 has attempted to breed. Between October 2015 and April 2017, a pair of grebes produced 4 fledglings from 5 nesting attempts. Adults fed chicks for 26–29 days by diving in open areas with swamp lily (Ottelia avalifolia). Fledglings began independent foraging between 19 and 26 days old. Fledglings were not seen at the site after reaching c. 55-days old. The young from late clutches left the natal site in March–April, 3 weeks after their parents were last detected there. The site was not used by any grebes in June and July.
Variable oystercatcher chicks (Haematopus unicolor) were banded at the Kaikōura Peninsula between summer 1999–2000 and summer 2016–2017. Prior to colour banding, there were no reports of Kaikōura Peninsula oystercatchers being sighted at other locations. Since summer 2006–2007 colour banding sequences have been available and these unique identifiers enabled movements of individual juvenile and immature birds to be determined. Forty-two colour banded chicks fledged, and 25 of these have been sighted at 11 locations between Collingwood 215 km to the northwest, and the Avon-Heathcote Estuary near Christchurch, 145 km south. Twelve of the 25 birds sighted away have not been seen back at the Kaikōura Peninsula, the other 13 returned of which 4 travelled away for a second time and did not return. Seventeen birds were not seen away from the Kaikōura Peninsula but 7 with no sightings for periods over 7 months may been away and returned. Siblings often went to different locations. Of 9 pairs of same nest siblings, 1 pair stayed at the Kaikōura Peninsula, 1 pair went initially to Nelson and 1 pair to the Avon-Heathcote Estuary, and birds of the other 6 pairs went to different locations including staying at Kaikōura. Birds seen at Nelson were also seen at the Avon-Heathcote Estuary.
We describe the creation of a standardised set of data from the two national atlases of bird distribution compiled by the Ornithological Society of New Zealand. The data provide estimates of local occupancy probability for each of 64 taxa of native land birds, in each of 2,155 grid squares covering the North, South, and Stewart islands, in two measurement periods (September 1969 – December 1979, and December 1999 – November 2004). Because these local occupancy estimates were derived on an identical basis for each bird taxon and each time period, they enable unbiased comparisons between time periods and among species. Links to permanent data repositories of the original and standardised data are provided.