Justification of Red List Category
This species is listed as Endangered because it has a very small population, in one subpopulation, that is undergoing a rapid and continuing decline owing to habitat loss and hunting.
The total population is estimated at 1,500-2,500 individuals (H. G. Young in litt. 2002), roughly equivalent to 1,000-1,700 mature individuals.
This species's population is suspected to be decreasing rapidly, in line with extensive habitat loss and disturbance throughout its breeding range, exacerbated by hunting at both breeding and moulting sites.
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, Safford and Hawkins 2013). It is known to breed at many sites in Menabe and Melaky on the central west coast, and at Ankazomborona on the far north-west coast (Razafindrajao et al. 2001): 100-500 were estimated to be present between Antsalova and Morondava in July-August 1993 (Young et al. 1993, Morris and Hawkins 1998) and a flock of 67 was seen near Tambohorano in 1998 (Anon. 1998c); and a new breeding population of 200-300 individuals was discovered at Ankazomborona, north of Mahajanga and some 720 km north of the Masoarivo breeding site. The population in Baie de la Mahajamba was estimated to be 150-200 birds in November-December 2003 (Joiner et al. 2006). The total population is estimated at 1,500-2,500 individuals (H. G. Young in litt. 2016).
Behaviour Birds breed during the wet season months of December to March (Joiner et al. 2006, Kear 2005b, Safford and Hawkins 2013), 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 2005b, 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, Safford and Hawkins 2013). 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 2005b, Safford and Hawkins 2013). 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 2005b). 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 2005b, Joiner et al. 2006). Ducklings fledge at 45-49 days (Young 2006).
The species is now extremely threatened throughout its breeding range, by extensive habitat loss and disturbance. The distribution of known sites suggests that the single subpopulation is being fragmented as areas of habitat become unsuitable (Young 2006, H. G. Young in litt. 2007). The species has limited dispersal capabilities and isolation may result in the loss of genetic diversity (Young 2006). Furthermore it is threatened by virtue of being highly specific to a series of habitats - which are themselves threatened - throughout its annual cycle (Razafindrajao 2000). Conversion of shallow, muddy water-bodies to rice cultivation (Young et al. 1993) has been so widespread on the west coast that in the non-breeding season the species now appears to be confined to the few suitable wetlands that are too saline for rice-growing, i.e. some inland lakes and coastal areas such as estuaries and mudflats (Green et al. 1994, Safford and Hawkins 2013). In 2004, during a dry-season survey in Menabe, this species was only found in saline wetlands (Young et al. 2014). Pressures on coastal wetlands are exacerbated by the movement of people from the High Plateau to coastal regions, which is driven by the over-exhaustion of land (Joiner et al. 2006). Mangroves are under increasing pressure from prawn-pond construction and timber extraction, which also leads to massively increased hunting (Morris and Hawkins 1998). Subsistence hunting during the nesting season and the trapping of moulting birds are major threats (Young 2006). It is considered a delicacy by hunters and was found in markets in Sofia in 2011 (H. G. Young in litt. 2012). In contrast, the breeding site at Ankazomborona is not threatened by aquaculture and there is little pressure from subsistence hunters, though there is some pressure from sport hunters (Razafindrajao et al. 2001). Breeding birds may suffer disturbance from human activity, such as the collection of crabs (Joiner et al. 2006). The species is potentially in competition for the use of suitable nest-holes with the Comb Duck Sarkidiornis melanotos, parrots Coracopsis species and nocturnal lemurs Lepilemur spp. and Cheirogaleus spp., though lemurs are absent in mangroves (Joiner et al. 2006, Young 2006).
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, Safford and Hawkins 2013). 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).
40-45 cm. Small dabbling duck. Rather pale, warm greyish-brown all over, scalloped darker most conspicuously on flanks and breast, wing with black speculum. Head rather uniform, pale, pinkish-grey bill, slightly upturned. Similar spp. Told from all other ducks by lack of conspicuous head-pattern, bill colour, rather long neck, wide white borders to distinctive black speculum, and habit of feeding by wading in shallow muddy water. Hints Usually in pairs or small groups, feeding in mangroves, on lake edges or estuarine mudflats.
Text account compilers
Benstead, P., Ekstrom, J., Evans, M., Khwaja, N., Pilgrim, J., Shutes, S., Starkey, M., Symes, A., Taylor, J., Westrip, J.
Razafindrajao, F., Rabenandrasana, M., Lewis, R., Young, G., Safford, R.
BirdLife International (2021) Species factsheet: Anas bernieri. Downloaded from http://www.birdlife.org on 26/02/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/02/2021.