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.
Satellite tracking, with the CLS:Argos system, has provided enormous benefits to wildlife studies, especially for oceanic bird species. The system provides 2 locations, (1 from each side of the satellite orbit), but they are irregular over time and of variable accuracy. Procedures are described here to identify outlier locations and retain the maximum number of valid observations from DIAG files, thus producing a more homogeneous data set from which to map distributions, track movements, and investigate behaviour, while determining the rate and direction of travel.
Bird observations made during visits to Motuhoropapa Island between Nov 2004 and Sep 2006 have been compiled and compared to a bird list published in 1985. Variable oystercatcher (Haematopus unicolor) and paradise shelduck (Tadorna variegata) were recorded on the island for the 1st time, and tui (Prosthemadera novaeseelandiae) and morepork (Ninox novaeseelandiae) were recorded breeding. The island has now been free of introduced rats since 2002; the implications of the absence of rodents for birds on the island are discussed.
Roost sites in Whangarei Harbour and Ruakaka Estuary were used regularly by 12 wader species and 6 other species were present occasionally between 1974 and 2000. Counts at 7 roost sites in Nov, Jun/Jul, and Mar showed that 4 species, eastern bar-tailed godwit (Limosa lapponica), lesser knot (Calidris canutus), pied stilt (Himantopus leucocephalus), and South Island pied oystercatcher (Himantopus ostralegus finschi) contributed 70–99% (median 94%) of the waders. Most of the common waders used several roosts at each tide, but numbers and species richness of resident and vagrant species were greatest along the southern margin of the harbour. Changes in roost structure and proximity to feeding areas, and differences in migration patterns affected counts at individual roosts and the overall totals of wading birds counted in the harbour and its environs.
New Zealand average atmospheric temperatures showed little increase from the 1850s onwards for almost 100 years, but increased rapidly after c. 1940. The increase in temperatures was accompanied, at least in parts of New Zealand, by an increase in precipitation,. We investigated the relationship between the arrival years (1st breeding) of the bird species that self-introduced to New Zealand during the 20th century and the period of turpentine increase. Because these birds come from Australia the warming might be a prerequisite to colonize New Zealand. When considering the 1st breeding years as events in a univariate point process the process is non-stationary and the rate function has its estimated maximum in 1953. This estimate may indicate that the sequence of invasions of New Zealand by additional bird species could be a response to climate changes although the coincidence is on its own not sufficient to prove that climate changes have affected the self-introduction of birds from Australia into New Zealand. Alternative and additional explanations are discussed.
The CLS:Argos location and data collection system is used widely by researchers tracking the movements of animals. The accuracy of the Argos location classes is undefined for most Argos locations for studies involving tracking animals. Published empirical data on the accuracy of animal-mounted transmitters are limited to stationary units. The accuracy of the positions is defined by Argos, except for location classes (LC) = 0, A, B, and Z. The distinction between ‘accuracy’ and ‘precision’ is discussed using field measurements from 24,466 Argos records collected throughout the world, but mostly in the Southern Hemisphere, between 1992 and 2001. Factors affecting the defined ‘accuracy’ and ‘precision’ are identified from this analysis. Neither the transmitter’s age, nor its attachment to a bird degraded its performance. However, the performance of transmitters in terms of the locations they provided was affected when the objects they were attached to moved rapidly, and, with 1 platform transmitter terminal (PTT), by altering of the proportion of location classes within the experiment, but not the ‘precision’ of the classes (LC = 3, 2, 1, and A). The ‘precision’ (rounded, measured as 1 SD of the mean of the distance of the location from the actual position occupied by the transmitter, for ”Location Classes” 3, 2, and 1 was <2.5 km; that for LC = A, 15 km; LC = 0, 25 km, and for LC =B, 56 (latitude) and 94 km (longitude). The ‘accuracy’ (mean distance between the Argos location and the actual position of the transmitter, was 0.1-5.0 km for LC = 3 to B, which covers almost all the locations used by animal telemetry studies. The variation in ‘accuracy’ was, therefore, negligible compared to the variation in ‘precision’.
Males that defend territories with song benefit from sharing song types with their neighbours. Repertoire size, repertoire overlap between neighbouring birds, and song type delivery strategy were described for the South Island saddleback (Philesturnus carunculatus carunculatus). The song elements of 27 male South Island saddlebacks in the Ulva Island population near Stewart Island was categorised into one of 33 discrete phrase types; 10 common and 23 rare types. No stereotyped song types were found in the population. All syllables had harmonics and were simple in structure, consisting of a maximum of 2 or 3 elements. Male South Island saddlebacks had small to moderate phrase type repertoires and exhibited relatively high degrees of phrase type sharing with neighbours, which was even more prevalent when phrase cores and introductory syllables were analysed separately. Birds used a mixed-mode singing strategy, but also repeated partial and full phrases in song bouts. Compared to song studies of its North Island counterpart, the South Island saddleback had a larger phrase repertoire size, but phrase type sharing between neighbours seems to be important in both subspecies.
Roost sites in Whangarei Harbour and Ruakaka Estuary were used regularly by 12 wader species and 6 other species were present occasionally between 1974 and 2000. Counts at 7 roost sites in Nov, Jun/Jul, and Mar showed that 4 species, eastern bar-tailed godwit (Limosa lapponica), lesser knot (Calidris canutus), pied stilt (Himantopus leucocephalus), and South Island pied oystercatcher (Haematopus ostralegus finschi) contributed 70-99% (median 94%) of the waders. Most of the common waders used several roosts at each tide, but numbers and species richness of resident and vagrant species were greatest along the southern margin of the harbour. Changes in roost structure and proximity to feeding areas, and differences in migration patterns affected counts at individual roosts and the overall totals of wading birds counted in the harbour and its environs.