During 1971-75 and 1991-95, surveys of Caspian tern (Sterna caspia) colonies throughout New Zealand were carried out. The breeding population in 1971-75 was 1266 pairs, in 16 colonies, predominately in the northern North Is. In 1991-95, there were 1190 breeding pairs found in 17 mainly northern colonies, suggesting the population had been relatively stable over the 20-year period. As census methodology may under-record the breeding of isolated pairs, we included an estimate of the number of isolated pairs to give a total national population of 1300-1400 breeding pairs. This is less than 3% of the global population. Colony size and location showed some change between survey periods; 6 colonies disappeared and 8 new colonies were formed. Addition surveys in 2011-2015 are recommended to compare recent population trends.
Male and female South Is saddlebacks (Philesturnus carunculatus carunculatus) have monomorphic plumage characteristics and are not easily distinguishable. In this study, we developed discriminant functions to classify males and females using birds of known sex from Ulva I. Three discriminant functions using tarsus length, body mass, and a combination of tarsus length and body mass could classify birds with 90% accuracy.
Three endemic forest bird species, masked shining parrot Prosopeia personata, giant forest honeyeater Gymnomyza viridis, and golden dove Chrysoenas luteovirens were surveyed using distance sampling from forest tracks at 4 sites on Viti Levu, Fiji. Repeat surveys were made at 1 site to better understand the factors affecting detectability. Seasonal changes in detectability reflected the number of calling birds and were almost certainly linked to breeding. The highest mean densities (41 masked shining parrot km-2 (birds), 33 giant forest honeyeater km-2 (calling birds) and 14 golden dove km-2 (calling males) were found in low- to mid-altitude old-growth forest. Densities in degraded re-growth forest and mahogany plantations were about 30% and 50% lower, respectively. Densities in upland forest were very low for masked shining parrot (2.5 km-2), but moderate for giant forest honeyeater (21 km-2)and golden dove (8 km-2). Provisional population estimates of 50,000 pairs of masked shining parrot, 70,000 pairs of GFH and 60,000 pairs of golden dove were made though attention is drawn to the limitations and uncertainties of these estimates. In common with many Pacific Islands, the endemic avifauna of Fiji is threatened by forest loss and degradation and a lack of protected areas. This study could assist in the design of effective protective areas as well as being a baseline for future surveys.
Platform terminal transmitters (PTTs) using the CLS:Argos System were attached to adult sooty shearwaters (Puffinus griseus) at Taiaroa Head, South I, New Zealand. Three PTTs were attached to adults during the pre-breeding period, and 2 were attached to adults during the incubation period. During the pre-laying excursion, 1 male flew a minimum distance of 7700 km over 34 days while another male flew 4200 km during 28 days. The minimum distance flown by a female was 3700 km during 16 days. Pre-breeding birds mainly frequented waters <1000 m deep. During the mid-breeding period a male sooty shearwater flew a minimum of 18000 km in 36 days, while the female flew 4100 km in 13 days. There were comparatively fewer flight locations close to the Otago and the Canterbury coasts for mid-breeding deployments compared to pre-breeding deployments, and most were in waters >1000 m deep.
The 2 species of royal albatrosses, the southern (Diomedea epomophora) and northern (D. sanfordi), breed only in New Zealand, but adults and juveniles are common off the western coast of South America. They can be separated on their plumage at sea. This paper examines the variation in plumages of the royal albatrosses seen in southern Chilean shelf waters at 46°30´S, based on a series of photographs taken in Sep 2004. D. sanfordi were identified by the uniformly black dorsal surface to their wings, and by the absence of a white leading edge to the wing in flight. In contrast, most individuals of D. epomophora had a white leading edge to the humeral and radial section of the wing and generally white flecking on the upper surface of the wing. However, some individuals identified as D. epomophora had no white on the leading edge nor any white on the dorsal surface of the wing. The black carpal patch near the leading edge of the ventral wing surface was variable in occurrence and was not considered diagnostic. D. epomophora out-numbered D. sanfordi by c.9 to 1 in southern Chilean coastal seas in Sep 2004. Most D. sanfordi may have left the area by Sep, moving either to the Patagonian shelf, or to Australasian seas.
The survival of adult and fledgling Antarctic terns (Sterna vittata bethunei) at the subantarctic Snares Islands was studied from 1976 to 2007. Annual adult survival was 0.91 and that of birds banded as fledglings was 0.42 in the first year and 0.94 in subsequent years. On average, a breeding adult would have a reproductive life-span of 10.2 years while a fledgling that survived the first year would have a life expectancy of 17.4 years. The disparity between the survival of birds banded as breeding adults and fledglings is probably be due to relatively small samples sizes. The estimated survival rates of Antarctic terns are similar to those reported for New Zealand fairy terns (S. nereis davisae). No terrestrial predators occur at the Snares Islands, and extensive predator-control is undertaken in the areas where New Zealand fairy terns nest, and so these survival rates may be typical of other breeding terns in the absence of terrestrial predators.