these invading species Behaviour The brown teal is largely nocturnal in habit by dabbling duck standards. This is an evolutionary response to natural diurnal predators such as the New Zealand falcon, Eyles' harrier, or skuas further south in their range. Brown teal have no defense against introduced cats, dogs, stoats & ferrets, which can kill adults & ducklings, or against rats which eat eggs. Diet It feeds by dabbling and upending, like its relatives. Its diet consists mainly of aquatic invertebrates like insects and their larvae, or crustaceans. It appears quite fond of mollusks. Small species such as pipi (Paphies australis) and large wedge shell (Macomona liliana) are eaten whole and crushed in the gizzard. For feeding on larger cockles such as Austrovenus stutchburyi (New Zealand cockle), at least some New Zealand teals have developed a peculiar technique, as of now undocumented in other birds, to force their rather soft bills between the cockle shells and tear out the flesh with a jackhammer-like pumping motion. At night brown teal will forage on land some distance from the streams used as a refuge during the day (Worthy 2002). Breeding Nest of dry grass near water or under shelter of large Carex, heavily lined with down. A clutch of four to eight creamy-brown eggs is laid. Incubation is done by only the female and takes 27–30 days. The male stays in his territory as a guard, aggressive to all other waterfowl. Distribution & conservation This species is endangered and occurs predominantly on offshore islands but also in predator-proof sanctuaries on the mainland such as Tawharanui Regional Park. Formerly, it was widespread on the New Zealand mainland, but it disappeared there due to introduced predators like cats, dogs and rats, which easily preyed on this unwary, weakly flying bird. According to the IUCN categorization as VU D1, fewer than 1000 adult birds remain. The species has recently been upgraded to endangered by Birdlife International (Birdlife 2007), and the change will be reflected in the next update of the IUCN red list. References BirdLife International (2007) Species factsheet: Anas chlorotis. Downloaded from https://www.webcitation.org/5QE8rvIqH?url=http://www.birdlife.org/ on 5/9/2007 Moore, Suzanne J. & Battley, Phil F. (2003): Cockle-opening by a dabbling duck, the Brown Teal. Waterbirds 26(3): 331–334. DOI:10.1675/1524-4695(2003)026[0331:CBADDT]2.0.CO;2 PDF fulltext Worthy, T.H. & Holdaway, R.N. (2002) The Lost World of the Moa, Indiana University Press:Bloomington, http://www.stuff.co.nz/science/9396503/South-Island-duck-extinct Further reading External links Brown Teal Site brown teal Endemic birds