This paper describes the birds of Disappointment Island, a small pristine island in the subantarctic Auckland Islands archipelago, from an accumulation of observations made by ornithologists during 16 visits to the island during 1907–2019. The island supports large populations of both the Auckland Island rail (Lewinia muelleri) and the Auckland Island teal (Anas aucklandica), most of the global population of the New Zealand endemic white-capped mollymawk (Thalassarche cauta steadi) – an annual average of 63,856 breeding pairs during 2009–17, an estimated 155,500 pairs of the circumpolar white-chinned petrel (Procellaria aequinoctialis), and unquantified numbers of smaller petrels. The topography and vegetation communities of the island are described, the history of visits by ornithologists to the island is outlined, and a list of bird species and their breeding status is recorded.
Thinornis rossii is a charadriiform taxon represented by a single specimen reportedly collected on the Auckland Islands, south of New Zealand, in 1840, and obviously closely related to the shore plover (T. novaeseelandiae), of mainland New Zealand and the Chatham Islands. Since the early 20th century, the name T. rossii has commonly been treated as a synonym of T. novaeseelandiae owing to doubts over its provenance based on an untraced quotation from the naturalist (Robert McCormick) who was presumed to have collected it. However, there seems to be no other evidence that the specimen might originate from somewhere close to modern-day Auckland, in the northern part of New Zealand’s North Island, rather than the Auckland Islands, despite the fact that the relevant collecting expedition visited both areas. Moreover, the untraced quotation questioning the Auckland Islands origin seems very possibly to be an artefact of a misremembered reading of McCormick’s unpublished diary or his memoirs, and the circumstantial published and unpublished evidence points with reasonable strength to the bird having been collected where originally stated. Morphological characters (darker, browner upperparts, brownish-grey flanks, longer central toe) suggest that T. rossii might be a valid (but extinct) taxon most appropriately ranked at subspecific level, but the possibility remains that it represents a melanistic specimen. Ideally, the type should be subject to a counterpart molecular investigation.
We analysed standardised estimates of local occupancy probability of 13 species of native wading birds, terns and gulls (order Charadriiformes) derived from the New Zealand Ornithological Society’s national Atlas of Bird Distribution collated in 1969–1979 and 1999–2004. We show systematic patterns in changes with taxonomic level of endemism, breeding habitat (coastal or inland), and location (distance from the coast, road density, and degree of land development for agriculture and forestry). The main changes were decreases in endemic inland breeding species within their inland South Island breeding ranges, and increases in most coastal-breeding species and some inland-breeding species around much of the coast, especially near urban centres in the North Island. Our results are consistent with both intensive land use and predation contributing to widespread declines of inland-breeding species across inland South Island. Potential causes of occupancy changes around the coast are less clear, and we offer some suggestions.
In New Zealand’s subantarctic Auckland Islands, the island-wide population size of white-chinned petrels (Procellaria aequinoctialis) is unknown. On ten islands in the group, surveys for burrow distribution were followed by whole-island burrow counts or stratified random sampling of white-chinned petrel habitat. White-chinned petrel burrow density, burrow occupancy, and slope-corrected surface areas were used to calculate the breeding population size. Burrows were patchily distributed and most abundant in dense megaherb communities. White-chinned petrel burrow density at Adams Island was 701 burrows/ha (95% CI: 480–803 burrows/ha). Burrow occupancy was 0.59 ± 0.02 (mean ± se) at the start of incubation. An estimated 28,300 (10,400–44,800) white-chinned petrel pairs breed on Adams Island. Including the small colonies on Ewing, Monumental, and Enderby Islands (together c. 100 pairs) and the estimated 155,500 breeding pairs on Disappointment Island, the Auckland Island group has an estimated 184,000 (95% CI: 136,000–237,000) pairs of breeding white-chinned petrels.
Enderby Island is a much-visited small island in the New Zealand subantarctic, and is an important area for birdlife. However, despite this, the bird community of Enderby Island has never been systematically described. We summarise bird records on Enderby Island from 1840 to 2018. Using these data we describe the bird community with an emphasis on resident species, and compare the frequency of sightings before and after eradication of invasive mammals in 1993. We also investigate trends in bird sightings from 1992 to 2018. There was a significant increase in the sightings of some species, including tui (Prosthemadera novaeseelandiae) and silvereye (Zosterops lateralis), and a significant decrease in others, including white-fronted tern (Sterna striata). Some species, such as New Zealand falcon (Falco novaeseelandiae) and Auckland Island snipe (Coenocorypha aucklandica aucklandica), have recovered successfully following dramatic historical declines. We hypothesise that these trends in sightings are driven by changes in human exploitation, the introduction and subsequent eradication of browsing mammals and mice, changes in the abundance and structure of the invertebrate community, and changes in vegetation cover. However, we believe that trends in sighting rates of southern royal albatross (Diomedea epomophora) may be an artefact of changes in visitor behaviour following the construction of a boardwalk, rather than changes in the species’ abundance.
We undertook a survey of coastal wetlands in Canterbury (NZ) during a widespread river flooding event in Spring 2013 to quantify numbers and distribution of wrybill (Anarhynchus frontalis). We found 740 birds, of which 685 (92.6%) were at Lake Ellesmere/Te Waihora. We calculate that 15.8% of the estimated effective wrybill breeding population were displaced from breeding rivers by floods at this time. Our findings support the evaluation by Dowding & Moore (2006) that the network of wetlands along the Canterbury coast appears to be of critical importance to wrybill as breeding season flood refugia.
Ten white-headed petrels (Pterodroma lessonii) from Adams Island, Auckland Islands, were tracked during 2011–14 using miniature geolocators, in the first study to examine the at-sea movements and key foraging areas of this pelagic seabird. Data revealed extensive migrations west to South Africa and east into the central South Pacific Ocean. The birds returned to colonies Aug–Oct. Median departure on pre-laying exodus was 24 Sep. Birds were away for up to 77 days during pre-laying and moved west towards the Indian Ocean. Laying occurred 24 Nov–10 Dec. The first major incubation shifts by males and females were c. 19 days in duration. The maximum foraging range during incubation was 5,230 km from the colony, the most distant recorded by any seabird during this breeding stage. After eggs hatched in January, some birds foraged off Antarctica in sea temperatures down to –1°C. Birds spent the inter-breeding period in disjunct areas (off South Africa, south of Australia, Tasman Sea, and South Pacific Ocean). This study revealed an unusual courtship behaviour not recorded previously in other seabird species. Females returned from distant oceans to spend just a few days ashore in the pre-laying period before leaving the breeding site until the following spring. The males also skipped breeding at the same time as their mates, but returned earlier in the season. The new knowledge gained about the breeding activity of this species will assist with future population assessments.
Four New Zealand pipit nesting attempts were monitored in an urban wasteland field in Onerahi, Whangarei.A female laid two clutches in dense kikuyu (Pennisetum clandestinum) in October and December 2015 and fledged young from both clutches. Pipits were then absent from the site from February until late August 2016. The male reappeared and used the exact same home range, with a new female. This female laid two nests in the more open low gorse (Ulex europaeus) and aristea (Aristea ecklonii) cover in September and October 2016 but both nests were depredated at 3–5 and seven days after hatching, respectively. All three chicks, the female, and possibly the male were killed during the latter predation event. There were differences in adult behaviour throughout the breeding cycle. The female constructed the nest and undertook all the incubation. During the incubation period the male was only present at the nest site in the early morning and did not roost at the site each evening. The pair was present throughout the day after the chicks hatched. Pipits used more frequent calling rates when there was a perceived threat, and when that threat was near a nest.
Black-fronted terns (Chlidonias albostriatus) are globally endangered and are one of six endemic bird species that rely on New Zealand’s braided river ecosystems for breeding. Like other marsh tern species, black-fronted terns are predicted to have low breeding-site fidelity due to the instability of their breeding habitat, small colony sizes and high predation rates. We used breeding colony location data collected from nine South Island rivers for 3–12 years (2004–2015) to investigate the breeding-site fidelity in black-fronted terns. The distribution of breeding colony locations from seven of the nine rivers analysed were not significantly different to a simulated random distribution. The tendency of black-fronted terns to form breeding colonies near past breeding site compared to new sites was only significant for two of the nine rivers analysed. Overall, there was low breeding-site fidelity in black-fronted tern colonies from year to year across the rivers analysed.