Brown Teal

Taxobox
name = Brown Teal


image_width = 250px
image_caption = Brown Teal
status = EN
trend = stable
status_system = iucn3.1
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Anseriformes
familia = Anatidae
genus = "Anas"
species = "A. chlorotis"
binomial = "Anas chlorotis"
binomial_authority = Gray, 1845
synonyms = "Anas aucklandica chlorotis"

The Brown Teal ("Anas chlorotis") or New Zealand Teal, is a species of dabbling duck of the genus "Anas". The Māori name for it is "Pāteke". It was considered to be conspecific with the flightless Auckland Island and Campbell Island Teals in "Anas aucklandica"; the name "Brown Teal" was applied to that entire taxon. The Brown Teal has since been split, recognizing that the insular "A. aucklandica" and "A. nesiotis" are good species. In international use, the name Brown Teal is still more common than New Zealand Teal for this bird.

The Brown Teal is rather nocturnal in habit by dabbling duck standards. This seems to be an evolutionary response to the fact that most predators on New Zealand, before humans arrived and brought with them carnivorous mammals, were diurnal birds such as Haast's Eagle or skuas.

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 cockel 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).

This species is endangered and occurs only on offshore islands. 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, less 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

*|year=2006|id=1221|title=Anas aucklandica|downloaded=11 May 2006 Database entry includes a brief justification of why this species is vulnerable and the criteria used
* BirdLife International (2007) [http://www.birdlife.org/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=30002&m=0 Species factsheet: "Anas chlorotis"] . Downloaded from http://www.birdlife.org on 5/9/2007
* (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 [http://www.nzshorebirds.com/downloads/moorebattley2003b.pdf PDF fulltext]
* Worthy, T.H. & Holdaway, R.N. (2002) "The Lost World of the Moa", Indiana University Press:Bloomington, ISBN 0-253-34034-9

External links

*cite web | url = http://www.doc.govt.nz/upload/documents/science-and-technical/tsrp59.pdf | title = Pateke ("Anas chlorotis") recovery plan, 2005–10 (Threatened Species Recovery Plan 59) | author = S.M. O’Connor; R.F. Maloney; R.J. Pierce | year = 2007 | publisher = Department of Conservation, Wellington, New Zealand | accessdate = 2007-09-03
* [http://www.brownteal.com/site/ Brown Teal Site]