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Population status of great spotted kiwi ( Apteryx haastii ) near Saxon Hut, Heaphy Track, New Zealand

Notornis, 52 (1), 27-33

H.A. Robertson; J.A. McLennan; R.M. Colbourne; T.J. McCann (2005)

Article Type: paper

Recaptures of banded birds, and call counts, indicate a population of great spotted kiwi (Apteryx haastii) near Saxon Hut, Heaphy Track, in Kahurangi National Park has remained stable between 1987 and 2004. The number and the locations of occupied territories have changed little. Although few juveniles were encountered during searches with dogs, at least 10 of 22 territorial adults present in 1987 were replaced by a total of 12 birds over 17 years implying that recruitment kept pace with the annual adult mortality of about 4%. We suggest that the incidence of the main predators of kiwi (stoats, ferrets, cats and dogs) was low in this very wet area (rainfall >5500 mm/ year). Our findings support the current ‘Vulnerable’ conservation threat ranking for the species.



An experimental evaluation of food hoarding by North Island robins ( Petroica australis longipes )

Notornis, 52 (3), 138-142

L. Alexander; C. Duthie; J. Fyfe; Z. Haws; S. Hunt; I. Montoya; C. Ochoa; A. Siva; L. Stringer; J.V. Horik; K.C. Burns (2005)

Article Type: paper

We experimentally evaluated the food hoarding behaviour of North Island robins (Petroica australis longipes) at Karori Wildlife Sanctuary, Wellington. Mealworms were offered to free-ranging pairs of male and female robins to evaluate whether their food hoarding behaviour was similar to previous observations of South Island robins. We also tested theoretical predictions derived in the Northern Hemisphere, which argue that competitively subordinate birds should hoard more food than dominant birds. Results showed that the food hoarding behaviour of North Island robins was similar to South Island robins, except that North Island robins repeatedly used the same cache sites, which is rare in South Island robins. Data did not support the prediction that competitively subordinate birds hoard more food than dominant birds. Males acquired most of the mealworms offered to birds during trials, and won nearly all aggressive interactions observed between sexes. Therefore, males appeared to be competitively dominant to females in winter. However, males stored over five times as many mealworms as females, which is opposite to theoretical predictions. We interpret the reluctance of females to cache food as a strategy to avoid food loss to competitively dominant males.





The distribution and numbers of Australasian crested grebe (kamana) in New Zealand, January 2004

Notornis, 52 (1), 34-42

L.A. Jensen; R.J. Snoyink (2005)

Article Type: Paper

The Australasian crested grebe (kamana: Podiceps cristatus australis) is nationally endangered within New Zealand. A census, conducted on 24 January 2004 by 81 observers, recorded 300 adults and estimated a further 15 as present on 41 of the 93 lakes counted. Assuming approximately 30 grebes to be present on lakes not counted, the national population of adult crested grebes is estimated to be 340-350. This is 40% higher than the population recorded in 1980. In addition, 75 juveniles were counted on 18 lakes. As in the 1980 survey, approximately 55% of the adult crested grebes were recorded on Canterbury lakes. A significant regional change has occurred with birds now present on lakes in Otago, absent from Nelson lakes, and in reduced numbers in Marlborough, North Canterbury, Westland and Fiordland. In addition, a significant decline has occurred at Lake Alexandrina, one of the strongholds identified in the 1980s. Forty percent of the present adult population was recorded on two lakes, Lake Heron and Lake Hayes. We identify priority sites where management to reverse declines could be implemented and we recommend a suite of management actions.

Changes in egg size of exotic passerines introduced to New Zealand

Notornis, 52 (4), 243-246

P. Cassey; T.M. Blackburn; K.L. Evans (2005)

Article Type: paper

Bird species introduced to New Zealand from high northern latitudes are expected to change their breeding behaviour to conform to well-known geographic gradients in avian reproductive parameters. Here, we demonstrate reductions in average egg size and clutch volume for eight species of exotic passerine originating in the UK, and show that the magnitudes of these reductions appear to trade-off against reductions in annual variation in clutch size. Possible reasons for the trade-off are discussed.


Activity rhythms at a gentoo penguin ( Pygoscelis papua ) colony at Cierva Point, Antarctic Peninsula

Notornis, 52 (3), 133-137

R.D. Quintana; P.D. Pratolongo; J.L. Agraz; O. Benitez; A.R. Mengual (2005)

Article Type: paper

We studied activity rhythms at a gentoo penguin (Pygoscelis papua) colony at Cierva Point, Antarctic Peninsula, during the 1992-93 summer. We counted the number of penguins crossing a specific point on their route to and from the colony. Penguins showed a strong daily rhythm of activity, with a two-peak pattern for those leaving the colony and a one-peak pattern for those returning. The peak of penguins departing to sea was at dawn, with a secondary peak in the afternoon which was coincident with the peak of returns. Although this behaviour could be explained by nest relief schedules, the pattern remained once crèches had formed. The main peak of departures strongly correlated with sunrise, which might support the existence of a light signal synchronizing activity. Even though an external factor could be triggering movements, an endogenous circadian clock might drive both patterns.





Forest birds recolonising Wellington

Notornis, 52 (1), 21-26

C. Miskelly; R. Empson; K. Wright (2005)

Article Type: Paper

Kaka (Nestor meridionalis), red-crowned parakeet (Cyanoramphus novaezelandiae), whitehead (Mohoua albicilla), tomtit (Petroica macrocephala), and bellbird (Anthornis melanura) have all recently been reintroduced to sites in or near Wellington city. Prior to or concurrent with these translocations, unmarked individuals of all five species were detected in forested reserves on Wellington peninsula. Based on the number of birds seen, and frequency of sightings, we suggest that red-crowned parakeets, whiteheads and bellbirds have established resident populations in some reserves independent of translocations. We attribute these successful re-establishments to the effective control of possums (Trichosurus vulpecula) and rats (Rattus sp.) undertaken by Greater Wellington Regional Council and the Department of Conservation.

Evaluating distribution modelling using kernel functions for northern royal albatrosses ( Diomedea sanfordi ) at sea off South America

Notornis, 52 (4), 223-235

D.G. Nicholls; C.J.R. Robertson; B. Naef-Daenzer (2005)

Article Type: paper

Satellite telemetry can provide unique information on the biology and behaviour of mobile animals such as albatrosses. Determining areas of concentrated activity, essential resources and time-related changes in range use is of great importance for theoretical biology, practical conservation, and fisheries management. Utilisation Distributions (UDs), from a probabilistic model of the relative time spent by an animal in an area, were prepared using a kernel function in a Geographical Information System. Properties of the model were investigated, using satellite-tracking data from six northern royal albatrosses (Diomedea sanfordi) during eight over-wintering visits to seas off South America. We analysed UD areas and shape for different settings of the kernel smoothing parameter, a variety of location subsets associated with different sample sizes, sampling time periods and telemetry regimes. Small samples and intermittent transmission regimes reduced the UD range area. Individual bird data sets were combined to give comparable UDs. The UD model may help comparison of range areas and the identification of resource use, but they cannot identify an activity without additional information. For pelagic seabirds, UD preparation and interpretation require judgement and care.




Distribution, abundance, habitat use and behaviour of three Procellaria petrels off South America

Notornis, 52 (2), 88-105

L.B. Spear; D.G. Ainley; S.W. Webb (2005)

Article Type:

We studied the distribution along the Pacific coast of South and Central America of three large petrels species that nest on New Zealand and subantarctic islands: white-chinned petrel (Procellaria aequinoctialis), Parkinson’s petrel (P. parkinsoni) and Westland petrel (P. westlandica). During 15 cruises from 1980 to 1995, we conducted 1,020 hrs of surveys over 14,277 km2 of ocean from the shoreline to 1500 km off the coast from Chile north to Panama, and recorded 2114, 179, and 20 individuals, respectively, of the three species. White-chinned petrels occurred throughout the study area, but were most abundant off Chile, Parkinson’s petrels were most abundant along the coasts of Ecuador and Peru, and Westland petrels off southern Chile. All three species preferred waters over the continental slope, although Parkinson’s petrel was abundant also over the continental shelf during the austral winter. Densities of each species were positively related to oceanographic properties that are associated with up-welling features. Abundance estimates, analyzed using generalized additive models, peaked during the non-breeding season of each species. Estimates were 722,000 White-chinned petrels during austral autumn (95% confidence interval “CI” = 349,000 – 907,000); 38,000 Parkinson’s petrels during austral autumn (95% CI = 28,000 – 50,000); and 3,500 Westland petrels during the austral spring (95% CI = 2,000 – 6,400). Scavenging appeared to be the primary feeding method of Procellaria, a habit that would make them susceptible to mortality as a result of their regular association with commercial fishing operations, particularly the recently developed long-line fishery on the continental slope of Chile.