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Brown Teal Anas chlorotis

This species has a very small range. Until recently its overall range, area of occupancy, area and quality of habitat, number of locations and sub-populations, and number of individuals were undergoing very rapid declines; however, intensive management has halted the decline and populations are now increasing, with several new populations being established. It no longer has a very small range, the species's extent of occurrence (EOO) and area of occupancy (AOO) are no longer continuing to decline, it is present at approximately seven locations and the population has been increasing since 2003, following the establishment of new populations. The number of mature individuals is thought to be >1,000. The species therefore qualifies as Near Threatened as it almost qualifies for a threatened listing under criterion D1+2.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Taxonomic note
Anas aucklandica (Sibley and Monroe 1990, 1993) has been split into A. aucklandica, A. chlorotis and A. nesiotis following Daugherty et al. (1999).

48 cm. Small, dark brown duck. Brown eclipse male, female, juvenile. Mottled, dark brown breast. White eye-ring. Breeding male, glossy green head. Very narrow white collar. White flank patch. Similar spp. Grey Teal A. gracilis, Chestnut Teal A. castanea have a white triangle in front of speculum when in flight and no white eye-ring. Voice Soft, high-pitched wheezy whistles, popping (male), low quacks and growls (female).

Distribution and population
This species is endemic to New Zealand, where it was once widespread in the North, South, Stewart and Chatham Islands, but its range is now much reduced. The current strongholds are on Great Barrier Island, where there were 1,300-1,500 birds in the early 1990s, declining to little over 500 in the early 2000s and increasing to approximately 800 birds in 2013 (Hayes 2013), and at Mimiwhangata and Teal Bay on the east coast of Northland where the population declined by 65% in the period between 1988 and 1999 to c. 100 individuals in 2001 before increasing to nearly c. 350 by 2007 (Williams and Dumbell 1996, M. Williams in litt. 1999, Parrish and Williams 2001, Roxburgh 2005, S. Moore and P. Battley in litt. 2012). The latest estimate for the Northland population is approximately 500 individuals (Hayes 2013). The re-introduced population in the northern Coromandel numbered c. 500 individuals in early 2008, and the latest census in 2011 estimated the population at 1,000 individuals (Hayes 2013). Its estimated area of occupancy is only c. 300-500 km2 (Callaghan et al. in prep)

After a study on Great Barrier Island indicated that the population was halving every 4.1 years and could rapidly decline to extinction intensive management was initiated which has seen populations rising again (Ferreira and Taylor 2003, Roxburgh 2005, Hayes 2006, Sim and Roxburgh 2007). Small islands where birds have previously been introduced and persisted for one to two decades may be too small for long-term survival, and some of these populations appear to be approaching extinction; however, the overall population trend is now positive (M. Williams in litt. 1999, Roxburgh 2005, Sim and Roxburgh 2007)

New populations have been established at Tawharanui, Cape Kidnappers and Tuhua Island (A. Booth et al. in litt. 2012). The re-introduced population at Cape Kidnappers is now estimated to number c. 135 birds (Booth 2011). By 2010, an estimated 1,700 birds were present at the three main sites (Great Barrier Island, Northland and Coromandel) and including the newly established populations, this figure was suggested to be in excess of 2,000 in 2010 (A. Booth et al. in litt. 2012). By 2013 the total number of birds was estimated at approximately 2,500 (Hayes 2013).

Population justification
Over 1,100 birds were estimated in 2005 at Great Barrier Island and Northland alone (with c. 600 at each) (A. Booth et al. in litt. 2012, N. Hayes in litt. 2012), and the population on Coromandel has been estimated at c. 700 birds (N. Hayes in litt. 2012), suggesting that the population numbered c. 1,900 individuals or c. 1,300 mature individuals, based on the assumption that they account for around 2/3 of the total population. By 2010, an estimated 1,700 birds were present at the three main sites (Great Barrier Island, Northland and Coromandel) and including the newly established populations, this figure was suggested to be in excess of 2,000 in 2010 (A. Booth et alin litt. 2012). By 2013 the total number of birds was estimated at approximately 2,500 (Hayes 2013), equating to 1,700 mature individuals.

Trend justification
The population had been falling rapidly owing to predation by introduced mammals; however, since 2003 it has been increasing as a result of intensive management. The rate of increase has not been estimated.

It formerly occurred in a wide range of habitats, including freshwater and coastal wetlands, and inland forests up to 800 m (Worthy 2002). It is now restricted to coastal streams, wetlands and dams in predominantly agricultural environments (M. Williams in litt. 1999). It nests in bowls of grass, always under dense, low vegetation, and usually lays six eggs. Peak breeding takes place between May and September, but can occur throughout the year (Sim and Roxburgh 2007). Only the female incubates the eggs (Sim and Roxburgh 2007). It feeds on terrestrial, freshwater and marine invertebrates and terrestrial and freshwater vegetation (Williams and Dumbell 1996, Moore et al. 2006). Often nocturnal (del Hoyo et al. 1992).

Between the 1890s and 1930s, wetland drainage and severe hunting pressure (which continued in several areas despite legal protection in 1921) caused widespread local extinctions (Heather and Robertson 1997, Callaghan et al. in prep). Predation by introduced mammalian predators, primarily cats, dogs, mustelids Mustela spp. and possums Trichosurus vulpecula, as well as the native Purple Gallinule Porphyrio porphyrio (locally known as Pukeko), were the primary cause of the modern decline (Heather and Robertson 1997, Ferreira and Taylor 2003, Hayes 2006, Conner et al. 2007, Sim and Roxburgh 2007). Habitat modification, drought-induced habitat change, traffic-caused road deaths and especially predation continue to endanger remnant mainland populations (M. Williams in litt. 1999, Parrish and Williams 2001, Hayes 2006, O'Connor et al. 2007, Sim and Roxburgh 2007). The threat of habitat loss to agriculture has diminished to some extent in recent years (N. Hayes in litt. 2012).

Conservation and Research Actions Underway
CITES Appendix I. In 2007, a species recovery plan was produced with the goal of securing in the wild a combined protected population of 2,000 birds at 5-10 managed sites by 2010. Following a major audit of the recovery programme in 2000 the population has begun to increase. 

A captive breeding programme was initiated in 1973, founded by 22 birds (Bowker-Wright et al. 2012). Over 200 birds are held in captivity. Although initial mainland releases totalling over 1,000 birds (Williams and Dumbell 1996) failed, releases are now conducted in combination with intensive predator control and breeding populations appear to have become established in several locations (Heather and Robertson 1997, Hayes 2006, O'Connor et al. 2007, Sim and Roxburgh 2007), and that the species's total population is entering a recovery phase (Hayes 2010, A. Booth et al. in litt. 2012). At least 139 individuals have now been released in a predator-controlled area of Fiordland on the South Island with the hope of establishing a population (Anon. 2011). Predator control, including that of Purple Gallinule (Pukeko), on Great Barrier Island has also led to stability in this population (Hayes 2010). To date, new populations derived from captive birds have been established at: Mana Island, Kapiti Island, Tiritiri Matangi Island, Karori Wildlife Sanctuary and Moehau (where a small remnant wild population was supplemented by captive birds) (Bowker-Wright et al. 2012). 

Hazing fences on roads have been erected to force ducks to either fly or use culverts when passing between favoured feeding sites, these have met with success and are planned for more areas (Hayes 2006, Sim and Roxburgh 2007). Habitat is being restored in Northland and Coromandel with the co-operation of local landowners, and some wetlands are grazed to create improved conditions for teal (Sim and Roxburgh 2007). Predator control programmes and release of captive-reared birds has taken place at Northland (Hayes 2013). Research is on-going, focusing on management techniques and habitat requirements (Williams and Dumbell 1996). Conservation and Research Actions Proposed
Continue to implement the species recovery plan. Continue to maintain a viable breeding population at a minimum of two locations on the North Island mainland. Continue measures to increase the population on Great Barrier Island. Continue predator control measures at key sites. Erect more hazing fences in areas where road mortality is greatest. Continue the captive breeding programme as a source of birds for translocations. Continue to encourage public support and involvement (Williams and Dumbell 1996). Conduct research into seasonal starvation events (A. Booth et al. in litt. 2012). Carry out studies into habitat use by the species. Conduct research into causes of declines. A recent study indicated that the range of genetic diversity present in the wild populations was not reflected in the captive population (Bowker-Wright et al. 2012, Williams and Bowker-Wright 2013). Supplementing the captive population or renewing the breeding stock to ensure the full genetic diversity found in the wild population is represented in captive birds should be considered as well as introducing genetic diversity into all new populations (Bowker-Wright et al. 2012). A genetic analysis indicates that the species once inhabited forested habitats and their current habitat of estuarine and riparian areas may represent only a small part of the species's potential habitat (Holdaway et al. 2013). The researchers suggest that work is needed to evaluate whether the species is capable of surviving in forested habitats.

Anon. 2011. Pateke (Brown Teal) release in the Arthur River-Milford Track. Available at: (Accessed: 06/03/2012).

Bowker-Wright, G.M., Bell, B.D., Ritchie, P.A. and Williams, M. 2012. Captive breeding and release diminishes genetic diversity in Brown teal Anas chlorotis, an endangered New Zealand duck. Wildfowl 62: 176-189.

Daugherty, C. H.; Williams, M.; Hay, J. M. 1999. Genetic differentiation, taxonomy and conservation of Australasian teals Anas spp. Bird Conservation International 9: 29-42.

Ferreira, S. M.; Taylor, S. 2003. Population decline of brown teal (Anas chlorotis) on Great Barrier Island. Notornis 50: 141-147.

Hayes, N. 2006. Brown Teal released at Port Charles, New Zealand. TWSG News: 16-18.

Hayes, N. 2010. Pateke in recovery mode. Southern Bird: 10-11.

Hayes, N. 2013. New Zealand Brown Teal News. TWSG News - Bulletin of the Wetlands International - IUCN SSC Threatened Waterfowl Specialist Group 16, December 2013: 6.

Heather, B. D.; Robertson, H. A. 1997. The field guide to the birds of New Zealand. Oxford University Press, Oxford, UK.

Holdaway, R.N., Williams, M. and Hawke, D.J. 2013. A comparison of the pre-human and present isotopic niches of brown teal (Anas chlorotis): implications for conservation. Notornis 60: 233-244.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: (Accessed: 19 November 2015).

Moore, S. J.; Battley, P. F.; Henderson, I. M.; Webb, C. J. 2006. The diet of Brown Teal (Anas chlorotis). New Zealand Journal of Ecology 30: 397-403.

Moore, S.J.; Battley, P.F. 2006. Differences in the digestive organ morphology of captive and wild Brown Teal Anas chlorotis and implications for releases. Bird Conservation International 16(3): 253-264.

O'Connor, S. M.; Maloney, R. F.; Pierce, R. J. 2007. Pateke (Anas chlorotis) recovery plan, 2005-2010. Department of Conservation, Wellington.

Parrish, R.; Williams, M. 2001. Decline of Brown Teal (Anas chlorotis) in Northland, New Zealand. Notornis 48: 131-136.

Roxburgh, J. 2005. Brown Teal (Pateke). Wingspan 15: 15.

Sim, J.; Roxburgh, J. 2007. Brown Teal bouncing back. Southern Bird: 8-9.

Williams, M. and Bowker-Wright, G. 2013. Brown Teal captive breeding comes under genetic scrutiny. TWSG News - Bulletin of the Wetlands International - IUCN SSC Threatened Waterfowl Specialist Group 16, December 2013: 28-29.

Williams, M.; Dumbell, G. 1996. Brown Teal (Pateke) Anas chlorotis recovery plan. Department of Conservation, Wellington.

Worthy, T.H. 2002. Fossil distribution of Brown Teal in New Zealand. DoC Science Internal Series. Department of Conservation, Wellington.

Further web sources of information
Explore HBW Alive for further information on this species

New Zealand Govt - Dept of Conservation - Recovery Plan

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Martin, R, Pilgrim, J., Taylor, J. & Ashpole, J

Battley, P., Booth, A., Hayes, N., Holzapfel, A., Miller, N., Moore, S., Roxburgh, J. & Williams, M.

IUCN Red List evaluators
Symes, A.

Recommended citation
BirdLife International (2015) Species factsheet: Anas chlorotis. Downloaded from on 30/11/2015. Recommended citation for factsheets for more than one species: BirdLife International (2015) IUCN Red List for birds. Downloaded from on 30/11/2015.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Brown teal (Anas chlorotis) 0

Key facts
Current IUCN Red List category Near Threatened
Family Anatidae (Ducks, Geese, Swans)
Species name author Gray, 1845
Population size 1700 mature individuals
Population trend Increasing
Distribution size (breeding/resident) 940 km2
Country endemic? Yes
Links to further information
- Additional Information on this species