Royal spoonbill (Platalea regia) nestlings (n = 158) were colour-banded between 1990 and 2005 at Green Island, Otago and Wairau lagoons, Marlborough. A total of 75% and 84% of Otago and Wairau birds, respectively, were resighted between 1991 and 2012. The pattern of independent resightings (n = 737) indicates that adult royal spoonbills in New Zealand undertake repeated seasonal inter-island migration, moving north to wintering sites (mainly Parengarenga, Rangaunu and Whangarei, up to 1200 km away), then relocating to the south again in summer to breeding sites. Most juveniles move as far north as adults, although a third of juveniles from Wairau were seen in winter in the Nelson region, a distance of < 100 km away. Juveniles and immatures (< 2 year old) remain in northern locations in summer, and return as adults (2 years and older) to their natal area. In summer all adult birds banded in Otago were resighted only in Otago, which indicates a high degree of philopatry. In contrast, a third of nestlings banded at Wairau were resighted as adults in the Otago area, indicating a southward natal dispersal. The annual survival rate is estimated to be 0.89 and 0.92 for Otago and Wairau birds, respectively. The oldest bird seen alive was 18 years and 3 months.
Interactions among invasive bird species have received relatively little attention despite the potential important consequences for community dynamics and invasion spread. Where species occupy similar environments the outcome may be particularly unpredictable. In this study we examined the foraging behaviours of 2 sympatric invasive birds in Mo’orea, the common myna (Acridotheres tristis) and the red-vented bulbul (Pycnonotus cafer), to determine if they exhibit behavioural or habitat partitioning. We investigated the ratio of foraging to vigilance behaviour of both species at novel food stations, as well as the effects of foraging group size and species composition on their behaviour. While the myna and bulbul exhibit similar behaviour, sites where they occur were partitioned within habitats. Novel food stations however, encouraged foraging at the cost of vigilance behaviours. Behaviours were not influenced by conspecific group size, and intraspecific interactions were more frequent, and of a greater intensity than interspecific interactions. These results suggest that the 2 species minimise competitive interactions by occupying different sites within the same habitat, and prioritise food acquisition in a new environment. Sympatric introduced species may avoid competitive exclusion if habitat usage limits the frequency of interactions.
Information was collected on the calling and display behaviour of 3 peacocks in the absence of peahens at Mansion House Historic Reserve, Kawau Island. The peacocks used an exploded lek display structure from late August to late December. Peacocks predominantly used the eow and occasionally the ka notes during tail displays but were silent during many displays. The overall composition of call notes given during the breeding period differed from than those used in a large dense peafowl breeding population in Japan.