The introductions of mallard (Anas platyrhynchos) to New Zealand, and their breeding and release as a game bird by Acclimatisation Societies are summarised. We identify 19 importations, 14 of which (a total of 115 birds all from Great Britain) were sufficient to establish small feral populations in southern and central New Zealand by about 1910. Five subsequent importations were made by Aucklander C.A. Whitney, 3 from Great Britain in 1910 (6 birds), 1914 (number unconfirmed) and 1927 (393 birds), followed by 99 birds (1937) and 45 eggs (1941) both from the USA. It was Whitney’s distribution of eggs following his initial USA importation that prompted widespread breeding and release programmes which, in some regions, extended into the 1960’s and 70’s. We identify a minimum of 30,000 mallards having been released by Acclimatisation Societies, but numerous releases by private individuals remain unrecorded. Almost all regional Acclimatisation Societies at some time released mallards into the wild.
One-legged standing (or unipedal posture) in birds was investigated with a particular focus on the role of ambient air temperature on this behaviour in a variety of wading birds and waterfowl. Waterfowl (Anas platyrhynchos and Cygnus atratus) were less likely to be observed standing on 1 leg than long-legged species of wading birds (Ardea novaehollandiae, Limosa lapponica, Platalea regia, Himantopus himantopus), perhaps because of differences in the length of their legs. Feeding behaviour and activities associated with disturbance influenced the frequency of unipedal posture. For captive flamingos (Phoenicopterus roseus) and pied stilts (Himantopus himantopus) the proportion of birds observed standing on 1 leg increased as the temperature increased from 8 to 19C. This observation contradicts the theory that unipedal posture is a behavioural adaptation to minimise heat loss on cold days. An alternative theory based on unihemispheric slow wave sleep (USWS) patterns is proposed as an explanation for unipedal posture and is recommended as a focus for future research. Our results also confirm the importance of considering differences between species in leg anatomy and activity levels to measure the effects of temperature.
There have been few studies on the temporal patterns of social behaviours and how they relate to timing of life history stages in nocturnal colonial bird species. This study focuses on the threatened Westland petrel (Procellaria westlandica; Procellariidae), to investigate temporal patterns in colonial interactions, including vocalisations and social behaviours, in the context of petrel sociality. We conducted extensive behavioural observations on the colony at different time-scales (throughout single nights, between seasons, and across years) to characterise the temporal dynamics of at-colony behaviours. These analyses show consistent temporal variation in several behavioural attributes (e.g., social interactions, vocalisations, eyes closed, body movements), with little or no temporal variation in others (e.g., self maintenance or stationary behaviours). These data provide the basis for specific predictions to test the role of social interactions between temporally varying vocalisations and social behaviours in nocturnal colonial birds.
In a 5 year radiotracking study of 55 falcons on the Wairau Plain, Marlborough, the causes of death in 21 birds were identified. Of these, 10 (47%) falcons were electrocuted (7 juvenile females, 1 adult female, 1 juvenile male, and 1 adult male). Seven of the 10 poles were fitted with transformers. This level of mortality is thought to be too high to sustain a population of falcons. Suggestions are made how to mitigate the problem.
A pair of barn owls (Tyto alba) was found breeding in Kaitaia farmland in Apr 2008, and observations on their nesting biology and behaviour were made over a period of 24 months. Another injured young barn owl, possibly from an earlier breeding attempt, was found with the pair at the time of their discovery, and brought into captivity. The nest tree was climbed and 2 dead owlets recovered, but the pair re-nested and 3 young successfully fledged. Pellets and prey remains were collected and their diet is described through pellet analysis. This is the 1st record of wild barn owls breeding in New Zealand.
Radio transmitters were successfully attached to 7 male bellbirds (Anthornis melanura) in Kennedy’s Bush and Cass Peak Reserve, Port Hills, Christchurch, during the breeding season. A hand-held radio receiver was used to re-locate them. In addition, we used a grid of 4 remote continuously-operating proximity sensors (radio receivers connected to data loggers) to measure the home-range size of 1 bellbird (#7). Five of the bellbirds were detected regularly within 60 m of the site where they were captured. The other 2 were always detected at least 100 m away. Two of the 5 regularly detected near their capture location were occasionally detected 400–500 m away, in gullies with flowering flax (Phormium tenax) and kowhai (Sophora microphylla). The full home range (100% MCP) of bellbird #7 was at least 3.7 ha, and its core home range (90% MCP) was at least 0.2 ha. Its night-time roost was near the centre of its home range. First departure from the roost was before sunrise and last arrival about sunset. If used more extensively, radio telemetry would be useful for measuring home ranges and detecting long-range movements of bellbirds.
A new subspecies of Coenocorypha snipe from Campbell I is described and named. This bird was discovered on rat-free 19 ha Jacquemart I in 1997, and had probably been confined there as a breeding species for about 170 years. Norway rats (Rattus norvegicus) were eradicated from 11,268 ha Campbell I in 2001, and snipe soon began to recolonise the main island from Jacquemart I 1 km offshore. Twelve adults and 5 chicks were caught on Campbell I in Jan 2006, and 1 nest was found. Genetic analysis of blood samples, and measurements and plumage descriptions from these birds revealed that they were best regarded as a subspecies of Coenocorypha aucklandica, a species here recognised as confined to the subantarctic Auckland, Antipodes and Campbell Is, and specifically distinct from the 2 other extant Coenocorypha snipes (Snares I snipe C. huegeli and Chatham I snipe C. pusilla).