The hihi (Notiomystis cincta) is a small threatened passerine endemic to New Zealand, for which few methods are known for ageing and sexing wild unbanded individuals. We monitored hihi on Tiritiri Matangi Island over 3 years, studying moult and other sexing and ageing techniques. Juvenile hihi before their first partial moult can be sexed by the white bases of primary coverts on males, which appear brown in females. After juveniles undergo their first partial moult, they appear similar to adults; however juvenile males retain old feathers in their primary coverts, alulae, or sometimes greater coverts or inner primaries, while adults undergo a complete moult. These patterns can be difficult to see in juvenile females, but wear of juvenile tails is much greater than in adults at any given time of year, making ageing of females reliable. Moult in the outer primaries and secondaries in autumn also indicate adult birds. This information should help inform future translocations and attempts to monitor viability of wild populations. Finally, we also comment on alternative definitions for ageing criteria from Melville (2011), based not on suspected birth-dates, but on appearance of plumage in hand.
The foraging ecology of Pitt Island shag (Stictocarbo featherstoni) was studied using GPS archival and Time Depth Recorder devices deployed on incubating birds. Pitt Island shags foraged exclusively during daylight, with a tendency for males to forage mainly during mid-morning and late afternoon, and females in the early morning and around mid-day. Mean foraging distance from colonies was 5.2 km (range 0.4-18.2 km), with males (mean 9.7 km) foraging significantly further than females (3.7 km). Both sexes showed high foraging site fidelity. The depth of most (83%) dives > 5 m deep were similar to the depth of the preceding dive (within 30%), indicating that birds are almost exclusively benthic feeding with the small fluctuations in dive depth likely reflecting changes in seafloor topography. Mean dive depth was 6.6 m, with maximum depth 24.4 m, although 90% of all dives were shallower than 13 m deep. Mean dive duration was 22 s, with a maximum of 69 s, although over 90% of dives were shorter than 40 s. There was a positive relationship between dive duration and dive depth, where deeper dives had longer duration. Mean rest period was 19 s with a weak positive relationship between rest period and duration of the preceding dive. Mean percentage time underwater during each foraging trip was 50.1%, indicating relatively high foraging efficiency. Favoured foraging locations in shallow inshore waters is likely to be a response by birds selectively foraging in sheltered waters protected from oceanic swells. This may be a factor influencing population declines as it intensifies risk to birds as potential threats may be more concentrated in these areas.
Hutton’s shearwater (Puffinus huttoni) currently breeds only in 2 colonies in the Seaward Kaikoura mountains, South Island, New Zealand. Conservation measures now include re-locating young to establish a new low altitude colony. To assess the genetic similarity of birds breeding in the 2 colonies as a basis for decisions on sourcing recruits to the present and potentially other new colonies, we genotyped 9 microsatellite loci, with 3-13 alleles, in 30 birds from the Kowhai River catchment colony and 29 from Shearwater Stream. There was no significant population genetic differentiation between the 2 sampling locations. Our results suggest that there would be little genetic risk to mixing birds from both relict colonies in newly established colonies. Future analyses of the former distributions of Hutton’s shearwater, the fluttering shearwater (P. gavia), and the extinct Scarlett’s shearwater (P. spelaeus) will require an analysis of the levels of genetic similarity between birds from the relict colonies and those of former, widely separated colonies.
Alofi, Futuna and Uvea (also called Wallis), 3 islands situated north of Fiji and Tonga archipelagos, are rarely visited by ornithologists. We present new data on the avifauna obtained during surveys in 2014 and we compare them with previous surveys made in the 1920s, 1980s and 1990s. We recorded the extirpation of 1 species (friendly ground-dove, Alopecoenas stairi) probably related to predation, and the decline of another (lesser shrikebill, Clytorhynchus vitiensis) linked to deforestation. Although the recent arrival of the black rat (Rattus rattus) in Futuna is a potential threat for the blue-crowned lorikeet (Vini australis), no decline is apparent at the present time. In general, most landbirds seemed common despite loss of native habitats and hunting pressure; similarly, the seabird populations and number of species appeared stable, a situation probably linked with the general decrease of harvesting. Finally, 2 breeding species (spotless crake, Zapornia tabuensis, and tropical shearwater, Puffinus bailloni) and 3 vagrants (white-faced heron, Egretta novaehollandiae, masked lapwing, Vanellus miles, and pectoral sandpiper, Calidris melanotos) are added to the list.
The remnant wild populations of the critically endangered orange-fronted kākāriki (Cyanoramphus malherbi) are restricted to 3 North Canterbury valleys where they co-occur with the yellow-crowned kākāriki (C. auriceps). Mixed pairs of Cyanoramphus kākāriki species have been documented throughout the genus, but the extent to which orange-fronted and yellow-crowned kākāriki mate assortatively, particularly when one species outnumbers the other, remains unclear. Here, we investigate the level of assortative mating between orange-fronted and yellow-crowned kākāriki. Based on 355 confirmed nests during 1999-2011, 99% (n = 351) were pure pairings and 1% (n = 4) were mixed pairings. With one exception, the ratio of orange-fronted to yellow-crowned kākāriki encountered during annual surveys ranged between zero and 0.78. These results indicate that the 2 congeners exhibit assortative mating, even when the orange-fronted kākāriki is outnumbered by yellow-crowned kākāriki. The low levels of mixed pairing we observed suggests that the reintroduction of orange-fronted kākāriki should not be precluded to sites where yellow-crowned kākāriki already occur.
Monitoring of wetland birds was undertaken at Lake Ellesmere/Te Waihora during the post-breeding period in February 2006, 2007 & 2008. Census totals were 38,726, 39,917 and 39,175 individual birds over the 3 years, respectively, and 46 wetland bird species were recorded. Nine species had a maximum count exceeding 1000 individuals, including 11,245 grey teal (Anas gracilis), 10,651 black swan (Cygnus atratus), 5776 pied stilt (Himantopus himantopus), 4899 Canada goose (Branta canadensis), 3405 Australasian shoveler (Anas rhynchotis), 1873 banded dotterel (Charadrius bicinctus), 1640 paradise shelduck (Tadorna variegata), 1592 black-billed gull (Larus bulleri) and 1389 mallard/grey duck (A. platyrhynchus/A. superciliosa). Fourteen species were recorded in numbers that met or exceeded the 1% Ramsar international significance criterion: Australasian crested grebe (Podiceps cristatus), black cormorant (Phalacrocorax carbo), white heron (Ardea modesta), black swan, paradise shelduck, grey teal, Australasian shoveler, pied stilt, black stilt (Himantopus novaezelandiae), banded dotterel, wrybill (Anarhynchus frontalis), black-billed gull, black-fronted tern (Childonias albostriatus), and Caspian tern (Hydroprogne caspia). Lake Ellesmere also supported populations of migratory bird species that are uncommon in New Zealand including curlew sandpiper (Calidris ferruginea), sharp-tailed sandpiper (C. acuminata), red-necked stint (C. rufficolis), Pacific golden plover (Pluvailis fulva) and white-winged black tern (Childonias leucopterus). When compared to other coastal wetlands in terms of bird numbers, Lake Ellesmere ranked as the most important site in the Canterbury Region.
We used data from 3 sources to examine the population size and trend of Salvin’s albatrosses (Thalassarche salvini) breeding on Proclamation Island, Bounty Islands, New Zealand. Island-wide counts of breeding birds during incubation resulted in totals that declined 14%, from 3065 in 1997 to 2634 in 2004. A count of breeding albatrosses over part of the island in 2011 indicated a further decline of 13% between 2004 and 2011, and an overall decline of 30% between 1997 and 2011. Additional counts on part of Depot Island indicated a decline of 10% in the numbers of breeding pairs between 2004 and 2011. Daily observations of 70 nests showed that hatching spanned the period from 5 to 21 November 1997, with a median of 15 November, apart from 5 eggs that had not yet hatched by the end of the study period. Based on the banding and recapture of chicks banded in March 1985 annual survival was estimated at 0.926. The scale of the decline estimated in this population has resulted in the conservation status of Salvin’s albatross being upgraded from nationally vulnerable to nationally critical.
Discriminant function analysis (DFA) was used to determine gender and geographic variation in the morphometrics of white-chinned petrels (Procellaria aequinoctialis) measured from fisheries bycatch in New Zealand. Samples were divided into 5 clusters based on capture location. A DFA model was created using adult breeding birds presumed to be from the 2 main locations at the Auckland Islands and Antipodes Islands. Geographic variation in head and bill, skull width, culmen, culmen depth at base, culmen width at base, right and left mid-toe and claw, tail, and right and left wing was found between birds presumed to be from the ‘Auckland’ and ‘Antipodes’ clusters, with ‘Antipodes’ birds being generally larger than ‘Auckland’ birds. Gender variation in head and bill, skull width, culmen, culmen depth at base, culmen width at base, minimum bill depth, right and left mid-toe and claw, right wing, right and left tarsus existed for ‘Auckland’ birds. Gender variation in head and bill, skull width, culmen, culmen depth at base, culmen width at base, minimum bill depth, right and left mid-toe and claw, and tail existed for ‘Antipodes’ birds. Birds in the other 3 clusters were classified as originating from the Auckland Islands or Antipodes Islands. The clustering suggested that birds from the Auckland Islands tended to forage mostly north and west, whereas birds from the Antipodes Islands foraged mostly towards the north. There were large overlaps at Puysegur Point and particularly the Chatham Rise of birds from both breeding locations. This study shows the usefulness of bycatch necropsies, and emphasises the need for further studies in geographic variation and sexual dimorphism at all New Zealand breeding locations.
The Chatham Island duck (Anseriformes: Anatidae: Anas chathamica) had a pronounced and rugose enlargement to the tip of the processus extensorius at the proximal end of its carpometacarpus. This “carpal knob” was the equal in size of those found in some much larger waterfowl (e.g., steamer ducks, Tachyeres sp.), and was disproportionately larger than those of all other New Zealand waterfowl. The knobs on 20 carpometacarpi examined all showed evidence of continuous bone deposition at their tips and their use as weapons is implied. Comparisons with other duck species having similarly prominent and rugose carpal knobs suggests the Chatham Island duck maintained long-term pair bonds and occupied combined feeding and breeding territories year-round which both sexes defended belligerently.
Banded rails (Gallirallus philippensis) were surveyed in saltmarshes and mangrove fringed habitats at Onerahi, Whangarei, New Zealand. A total of 13 sites were surveyed 3 times per year around sunset during late spring in 2004, 2007 and 2013. On average 4.41 calls were heard per hour. Banded rails were detected at 12 sites with between 0.01 and over 2 ha of saltmarsh and extensive mangroves, but not a saltmarsh site lacking mangroves. Occupancy models favoured those with no change in occupancy state, seasonal detection, and there was with some support for random colonisation of sites. Records from Awaroa Creek indicate that rails can be detected from late afternoon calls throughout the year. Surveys should include the half hour before until at least 10 minutes after sunset.
Discriminant function analysis (DFA) is widely used to determine sex in the field from morphological measurements of bird species with monomorphic plumage. Sexual dimorphism was examined in black petrels (Procellaria parkinsoni) using 7 external measurements of adult birds breeding on Great Barrier Island, New Zealand. Males were significantly larger than females in absolute values of all measurements except for tarsus. Two stepwise DFA models were developed. The first used all 7 parameters, while the second model used only 6 parameters in order to increase sample size. Model one and two showed an 88 and 82% classification success, respectively, most likely due to the high overlap in measurements between males and females. These canonical functions were not accurate enough for field surveys, but may be improved using a larger and more representative sample size.
Flesh-footed shearwaters (Puffinus carneipes) are considered to be one of New Zealand’s seabird species that is most heavily impacted by both commercial and recreational fisheries, yet they have an IUCN ranking of “Least Concern”. To resolve this contradiction we conducted surveys on 3 large breeding colonies and compared our results to historical data. We found that the burrow density on the most northerly island (Lady Alice Island/Mauimua) has increased since the last set of surveys; however the density of flesh-footed shearwaters nests has remained stable. At the largest colony we surveyed (Ohinau Island), the density of burrows has remained stable, while the density of nests has declined. At New Zealand’s most southerly colony (Titi Island), both burrow and nest densities have remained stable. Our results suggest that the status of flesh-footed shearwaters populations in New Zealand is variable with 2 populations that are stable and 1 that is declining. Nevertheless, due to the short time period between our surveys and the historical data, repeated surveys in the future are needed to determine if further declines in the largest colony warrant a reassessment of the status of this species.
Of 4 importations of Canada goose Branta canadensis into New Zealand, 2 (in 1905, 1920) resulted in breeding. Commencing in 1907, multiple and repeated releases of the 1905 geese and their progeny had, by 1922, established flocks of several hundred distributed along the eastern Canterbury and Otago foothills of the Southern Alps. Thereafter, the geese spread widely but remained resident and breeding only in the South Island. Establishment of Canada geese in North Island commenced in 1969 with the first of 4 transfers by the Wildlife Service, collectively totalling 280 birds from Canterbury’s Lakes Ellesmere and Forsyth, to coastal Wairoa lakes and nearby locations. The Wildlife Service assisted numerous other transfer and release initiatives, of at least 800 birds, in North Island in the 1970s and 1980s, principally by Wellington and Auckland Acclimatisation Societies, Ducks Unlimited, and private waterfowl enthusiasts. At the same time it supported transfers of 450 geese to the South Island’s West Coast. From these multiple releases Canada geese have become widespread in rural New Zealand.
Kiwi (Apteryx spp.) are the most vocal of the ratites. Of the 5 Apteryx species only 2 have previously been subject to detailed vocal analysis: the North Island brown kiwi (A. mantelli) and the little spotted kiwi (A. owenii). This paper describes the vocalisations of the great spotted kiwi (A. haastii), the largest of the Apteryx species. Acoustic recorders were installed near the breeding den sites of 7 great spotted kiwi pairs residing in Hawdon Valley, Canterbury between November 2012 and March 2013. A total of 133 whistle vocalisations from 10 individuals were subject to detailed temporal and spectral analysis. Male and female syllables were found to be sexually dimorphic; syllables in male calls tended to be longer and more highly pitched than their female counterparts. Despite this dimorphism, patterns of intra-call variation were consistent between the sexes. It appears that intra-call variation is a trait which varies markedly within the Apteryx genus.