Brown teal  (Anas chlorotis)

The brown teal is classified as Endangered (EN B1ab(i,ii,iii,iv,v) + 2ab(i,ii,iii,iv,v)) on the IUCN Red List 2004 (1) and is listed on Appendix II of the Convention on the Conservation of Migratory Species (4). It is also listed as Nationally Endangered by the New Zealand Government’s Department of Conservation and is fully protected by the New Zealand Wildlife Act 1953 (3).

In breeding plumage, the male ducks have a chestnut-coloured breast, a green head and a white stripe down both sides of the body. Some also have a white neckband. However, in non-breeding plumage, males look identical to females and juveniles, with non-descript mottled brown feathers, although males are slightly larger (3). Males utter soft, high-pitched whistles and pops, whereas females emit low quacks and growls (2).

Once found throughout the lowland, freshwater wetlands of New Zealand and several offshore islands, the brown teal is now limited to Great Barrier Island, and the east coast of Northland, south of the Bay of Islands. Numbers currently stand at around 1,000 (3). Reintroductions of captive-reared juveniles to Coromandel over four years has resulted in the establishment of a resident breeding population (5). Small populations are also found on Little Barrier Island, Rakitu Island, Kawau Island, Moturoa Island, Tiritiri Matangi Island and Kapiti Island, mainly due to reintroductions (3).

The brown teal previously inhabited a diverse selection of freshwater wetlands and swamp-forest, particularly in the lowlands, but it is now found only in coastal streams, wetlands and dams near to farmland. It nests in grass bowls under thick vegetation (2). Fossil evidence even suggests that the brown teal was once found in forested areas, far from wetlands (3).

Brown teal are a nocturnal dabbling duck that hides in grass and overhanging vegetation during the day, and forages in fields for worms and insects, or in estuaries for small shellfish at night. It will also sieve through muddy pools and even search through cow dung for invertebrates (3).

In the non-breeding season, the brown teal is social, forming small groups at roost sites. However, during the breeding season, from July to November, pair bonds are formed or re-established and both partners behave very aggressively to defend their territory, occasionally killing invading teals. A nest is built in thick vegetation close to water, in which the female lays five or six eggs, incubating them for 27 – 30 days. The ducklings fledge at 55 days, but will remain with their family until the following breeding season. Adults moult shortly after the ducklings have hatched, migrating to a flock site when the moult is complete (3).

Although the Maori killed brown teal in very large numbers, when European settlers arrived in New Zealand in 1840, it was still the most abundant waterfowl species in the country. Europeans also hunted the brown teal excessively, but it was the introduction of stoats, weasels, ferrets, hedgehogs, cats and dogs that caused the first major decline of this species. In 1921 the brown teal was declared a protected species, but shooting continued, and was compounded by extensive drainage of wetlands and deforestation, leaving less than 10% of wetlands and 30% of native forests (3). The brown teal population stands today at just under 1,000 individuals (5).

The New Zealand Department of Conservation has produced a brown teal recovery plan which is now in action. Five full time staff and a large team of volunteers monitor the ducks and control predators (3) (5). They also oversee a captive breeding programme and the resulting reintroductions. This programme has been extremely successful in producing captive-reared birds – for every bird taken from the wild, 21.5 have been bred and released, bringing the total number of reintroduced brown teal to 2000 since 1964 (3). Improvements in release techniques using supplementary feeders post-release, and predator control at the release site has increased initial post-release survival rates to more than 60% (5). The captive breeding network in New Zealand consists of 20 holders, made up of wildlife parks, zoos and private individuals, on a completely voluntary basis with no financial support. These collectively produce approximately 100 brown teal for release into the wild each year. This programme is now in the third year of releasing the birds into a major release site in Port Charles, Coromandel, which has proved very successful with 60 – 70 percent survival rate of released birds, which are now breeding and producing young in the wild themselves (5).

View information on this species at the UNEP World Conservation Monitoring Centre.

For further information on this species see:

The Brown Teal website:
http://www.brownteal.com

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org