Notornis, 52 (2), 114-116
Article Type: short note
Notornis, 52 (2), 114-116
Article Type: short note
Notornis, 52 (3), 173-178
Article Type: Abstract
Notornis, 52 (1), 27-33
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.
Notornis, 52 (4), 238-242
Article Type: short note
Notornis, 52 (3), 138-142
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.
Notornis, 52 (3), 173-178
Article Type: Abstract
Notornis, 52 (2), 106-108
Article Type: short note
Notornis, 52 (3), 173-178
Article Type: Abstract
Notornis, 52 (1), 34-42
Article Type: Paper
Notornis, 52 (4), 243-246
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.
Notornis, 52 (3), 133-137
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.
Notornis, 52 (3), 173-178
Article Type: Abstract
Notornis, 52 (2), 108-111
Article Type: short note
Notornis, 52 (3), 173-178
Article Type: Abstract
Notornis, 52 (1), 21-26
Article Type: Paper
Notornis, 52 (4), 223-235
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.
Notornis, 52 (2), 122-123
Article Type: book review
Notornis, 52 (3), 173-178
Article Type: Abstract
Notornis, 52 (2), 88-105
Article Type:
Notornis, 52 (3), 171-172
Article Type: short note