Behaviour Birds breed during the wet season months of December to March (Kear 2005, Joiner et al. 2006, Young 2011), and moult at select, secure sites at the beginning of the dry season when they become flightless for a period (Razafindrajao 2000, Young 2006, Razafindrajao et al. 2012). They then move short distances to coastal areas in search of suitable habitat for the dry season (Kear 2005, Young 2006). During the breeding season the species occurs in solitary, dispersed pairs, but during the non-breeding season it is more gregarious and occurs in loose groups of up to 40 individuals (Green et al. 1994, Scott and Rose 1996). Pair-bonds may last through consecutive seasons and investment by males is high and involves the protection of the female and young (Young 2006). Habitat Breeding The species breeds only in seasonally flooded, non-tidal areas dominated by Black Mangrove Avicennia marina, on the landward side of littoral forest (Razafindrajao 2000, Joiner et al. 2006, Young 2006, H.G. Young in litt. 2007, Young 2011). Non-breeding During its post-breeding moult, during which time it is flightless (Young 2006), the species seeks out lakes that are rich in aquatic vegetation, and in the subsequent dry season it is found in coastal wetland areas of shallow water and nutrient-rich mud, including saline and brackish areas (Razafindrajao 2000, Kear 2005, Young 2011). Here it prefers open rather than vegetated wetlands (Young 2006) and is most often found in coastal mangrove forest, bays, estuaries and shallow saline wetlands just inland of mangroves (tannes), though it can also be found less frequently in marshes, dense deciduous forest, areas of open water and herbaceous savannah, especially where Hyparrhenia and Heteropogon grasses are present (Joiner et al. 2006). Diet Little is known about its diet except during moulting when it feeds on terrestrial and aquatic insects including Hymenoptera, Coleoptera, and Diptera, in addition to the seeds of various plant families and the leaves and stems of monocotyledons (Kear 2005). It usually feeds by dabbling in the mud while wading (Young 1995, Morris and Hawkins 1998). Breeding Site Nesting takes place in holes in Avicennia marina mangrove trees that have been created by storm damage or decay (Kear 2005, Joiner et al. 2006). Ducklings fledge at 45-49 days (Young 2006).

Anas bernieri is endemic to western Madagascar. Its range encompasses a narrow coastal strip along the whole of the west coast and the extreme north-east (Langrand 1995, F. Razafindrajao per R. Safford in litt. 1999, ZICOMA 1999, Young 2011). Sites of major importance to the species are concentrated in the central west to north west; the Mahavavy Kinkony Wetland Complex, Bembetoka River esturay and the Baie de la Mahajamba in Boeny region, numerous smaller sites in Menabe and Melaky regions on the central west coast (Young et al. 1993, Morris and Hawkins 1998, Razafindrajao et al. 2001, Carboneras and Kirwan 2020, Zöckler et al. 2021), with another key site in northern Atsimo-Andrefana: the Mangoky-Ihotry wetland complex (R. Rabarisoa in litt. 2022). The majority of the population is considered to fall within this area, with relatively few records from sites to the south and north, although a maximum count of 32 individuals was made at Loza Bay to the north in 2020 (R. Rabarisoa in litt. 2022).

Conservation Actions Underway
CITES Appendix II. It has been recorded from Baly Bay National Park, Tsimanampetsotsa Strict Reserve (ZICOMA 1999), Analabe Private Reserve, Kirindy Mitea National Park and Lac Bedo Ramsar Site (H.G. Young in litt. 2007, Young 2011). A captive-breeding programme started in 1993 (Morris and Hawkins 1998, Young 1998, 1999), and these birds are used to study breeding behaviour (Young 2006). The species is held in collections in Europe and North America and has an international studbook (H.G. Young in litt. 2016). Studies on the ecology of the wild birds (including possible provision of nest boxes; R. Lewis pers comm. 2001) and a conservation programme at Lac Antsamaka (in Manambolomaty Ramsar Site) have also been initiated. Flightless birds moulting wing feathers were caught and ringed annually in May and June at Antsamaky (Razafindrajao et al. 2012), but birds are no longer congregating there (H.G. Young in litt. 2012). Four new protected areas have been established, and will benefit this species, at Mahavavy-Kinkony, the Tsimembo Manambolomaty Complex, Menabe Antimena and the Mangoky-Ihotry complex (Razafindrajao et al. 2017). The proportion of protected habitat has now increased from 3% to 56% since 2011 (Razafindrajao et al. 2017).

Conservation Actions Proposed
Survey the distribution and abundance of the species through standardised national surveys and/or the sharing of data between organisations, and search for new breeding sites on the west coast, e.g. north of Mahajanga (Thorstrom and Rabarisoa 1997, M. Rabenandrasana in litt. 2007). Study its ecological needs and complete further ecological studies at Ankazomborona (Thorstrom and Rabarisoa 1997). Conduct research into the species's reproductive ecology; Ankazomborona may be a particularly suitable study site (Joiner et al. 2006). Trial the provision of nest boxes. Ensure adequate protection of nesting, moulting and dry-season sites (Young 2006). Monitor movements using satellite telemetry (H.G. Young in litt. 2012). Protect the four significant areas of good habitat that remain unprotected (Mahajamba bay, Betsiboka bay, Loza bay and Ambaro bay or Ankazomborona) (Razafindrajao et al. 2017).