The grey warbler (Gerygone igata) is the main host of the shining cuckoo (Chrysoccocyx lucidus) in New Zealand. I describe 4 observations of egg-laying by shining cuckoos in the nests of grey warblers, and 2 observations of adult cuckoos evicting, or attempting to evict, nestling warblers from non-parasitised nests. Nest were parasitised from 0658 to 1731 h NZDT, and the cuckoos took 5–18 s to lay their egg. In 3 nests in which it could be determined, the cuckoo left the nest with an egg in its bill. Warblers were present at 2 nests during parasitism and responded by attacking the cuckoo. Cuckoos evicted nestlings by pulling them out through the nest entrance and throwing them on the ground. Head- wounds on evicted chicks suggest they were pecked. Nestling eviction by adult shining cuckoos has not been previously reported and it may be a strategy to increase nest availability by inducing hosts to relay.
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.
We counted the black shags (Phalacrocorax carbo) frequenting a night roost at Melling, 4.5 km up-river from the Hutt River mouth, Wellington, New Zealand, and studied the timing of breeding at various colonies in the Wellington region. Numbers at the roost were counted from Oct 1993 to Sep 1998: maximum and minimum mean monthly counts were in Feb and Aug, respectively. The main egg-laying period of 3 coastal colonies (0–2 km) (Mar–May) was c. 3 months earlier than at 2 inland (5 – 33 km) colonies (Jun–Aug. We discuss the possibility that the difference in timing of breeding by shags in colonies at different distances from the coast is related to the different timing of peak prey availability in the 2 habitats (coastal marine, and inland riverine).
From satellite tracking data, we recognised 5 major flight patterns in the annual cycles of 3 Chatham albatrosses (Thalassarche eremita) tracked in 1997 and 1998: foraging flights while the birds were breeding; eastward and westward migrations across the southern Pacific Ocean; northward migration along the South American coast; and localised foraging at low latitudes off the northwest coast of South America. We hypothesised that the 5 modes of flight indicated different biological activity. The associated speeds, point-to-point distances flown day-1, and other indices of activity were inferred from distances and times between satellite location records. Mean minimum point-to-point flight speeds were up to 85 km h-1 and were a function of the time interval for the measurement. Daily rates of change for latitude and longitude and the minimum daily distances travelled were calculated. These are the 1st measurements for this species of the sustained speed of flight point-to-point over varied time periods, and for short and long distances throughout the year. These data and the analytical techniques developed show what information can be obtained from a few individuals, and the confounding variables that result from the satellites’ orbits, and the transmitting characteristics of long-duration PTT experiments. The interrupted reception of transmitters through the intermittent satellite passes biases speed and other measurements and difficulties interpreting these data are discussed. The results provide a guide to the design of satellite transmitter experiments for long distance and duration studies with other oceanic species. They also contribute to an understanding of where this species obtains its food, and of its potential risk of interaction with fisheries.
A massive northward movement and wreck of prions (Pachyptila) along the coast of Antofagasta, Chile is described, and I review the occurrence of prions along the west coast of South America. Prions breed in southern Chile and the sub-Antarctic and move northwards to the coasts of northern Chile and Peru in the Southern Hemisphere winter. Chilean and Peruvian wrecks are primarily P. belcheri, with smaller numbers of P. desolata. P. vittata has only been recorded once. The occurrence of P. salvini is unproven. There are no records of P. turtur; a purported specimen from Chile is actually P. belcheri. The only report of P. crassirostris is that of a bone fragment from an archaeological site on Easter Island, Chile.
Gray studied the last natural mainland population of kakapo in Fiordland in the 1970s. Between 1974 and 1977 all 15 male birds located occupied home ranges high on the sides of valleys in areas of diverse vegetation associated with the tree line or avalanche and alluvial fans. Track-and-bowl systems were frequently positioned on the crests of ridges and knolls on well-drained sunny slopes. Studies of feeding sign and of faecal content using cuticle analysis provided detail of kakapo diet, confirming the bird to be an herbivore. About 80 species of plants were eaten in Fiordland. The kakapo bill is adapted to crushing and extracting nutrients and retaining fibre which is expelled as distinctive ‘chews’. A preliminary study of the nutrients in kakapo food suggested that the birds selected the most nutritious plant parts and species.