Abstract:
The behaviour of Campbell Island Teal Anas aucklandica nesiotis was studied by direct observation and remote monitoring of captive birds at the National Wildlife Centre, Mount Bruce, New Zealand. The subantarctic Campbell Island Teal is considered critically endangered with the wild population estimated to be 30-100 individuals, confined to Dent Island, a 23 hectare rock stack off Campbell Island.
Observations on captive Campbell Island Teal from November 1993 to February 1995 have provided new information on their activity and behaviour that has assisted their captive management and breeding at Mount Bruce. The teal were found to be active throughout the day and showed heightened activity at dusk and throughout fine nights. Birds were predominantly immobile in the day-time. Males showed territorial behaviour throughout the year and formed a dominance hierarchy. The ownership of territory appeared to be closely linked with pair formation and productivity. Accommodating the territorial nature of the teal has implications for cage design for teal aviculture.
The behaviour of the captive Campbell Island Teal was compared with that of other Austral teal. The captive Campbell Island Teal lacked some calls and major displays recorded in closely related Brown Teal A. a. chlorotis, Chestnut Teal A. castanea and Grey Teal A. gracilis. The two flightless forms, the Auckland Island Teal A. a. aucklandica and Campbell Island Teal A. a. nesiotis, were found to have almost identical behavioural and vocal repertoires, and had calls which the flighted teal lacked.
The behavioural study addressed the wider conservation issue of determining why the Campbell Island Teal had not bred in captivity despite birds being held since 1984. One pair bred for the first time in captivity over the 1994/95 summer, bringing the captive population to thirteen. The pair formed within a flock of six teal and raised two successive broods each of two ducklings. The work of this project has helped to realise a principal objective of the Subantarctic Teal Recovery Plan to establish a breeding population of Campbell Island Teal in captivity.
