Justification of Red List Category
This species is listed as Near Threatened owing to its moderately small population size and ongoing declines resulting from a variety of threats. Further quantitative estimates of the rate of decline may qualify the species for Vulnerable.
The population estimate for East Africa has been at 2,000-3,500 individuals (Berruti et al. 2005, 2007), but the severe decline has led to a population possibly as low as <300 individuals. Therefore the population is place in the range of 2,500-9,999 individuals, roughly equivalent to 1,667-6,666 mature individuals, rounded to 1,650-6,700 mature individuals.
The northern population of this species has suffered severe declines, perhaps by 50% in the late 1990s to early 2000s (Berruti et al. 2007), with the species now nearing extirpation in some countries (e.g. Kenya [D. Turner in litt. to P. Ndang'ang'a 2016]). The larger southern population appears stable after a period of range expansion and possible population increase (Berruti et al. 2005) but is considered smaller than previously thought and declines may have begun (Berruti et al. 2007). This information suggests that the overall population is in decline at a slow to moderate rate.
Oxyura maccoa has a large range, divided into a northern population occurring in Eritrea, Ethiopia, Kenya and Tanzania, and a southern population found in Angola, Botswana, Namibia, South Africa and Zimbabwe (Berruti et al. 2005, 2007). South Africa supports the largest national population with 4,500-5,500 individuals (Berruti et al. 2005, 2007). The total population for southern Africa is approximately 7,000-8,250 individuals. The population estimate for East Africa has been at 2,000-3,500 individuals (Berruti et al. 2005, 2007), with the Ethiopian population maybe as high as 500-2,000. However, the population in Kenya is in decline with only 14 individuals observed during a survey from December 2014 to July 2015 (G. Kung'u in litt. to P. Ndang'ang'a 2016), and may now be <50 individuals (D. Turner in litt. to P. Ndang'ang'a 2016); and maybe only a maximum of 100 individuals in Tanzania (D. Turner in litt to P. Ndang'ang'a 2016). Thus the East African population may in fact be far smaller, <300 individuals (D. Turner in litt. to P. Ndang'ang'a 2016).
Behaviour This species is mainly sedentary (Kear 2005) but undertakes some small-scale post-breeding dispersive movements in search of suitable habitat during the dry season (Kear 2005). It is not thought to cover distances greater than 500km (Berruti et al. 2005). Breeding has been recorded in South Africa from July to April, with a peak during the wet season months of September to November (Johnsgard 1978). Further north breeding has been recorded in all months, and appears to be dependent upon rainfall (Berruti et al. 2005, 2007). Breeding occurs in single pairs or loose groups (del Hoyo et al. 1992), with a density of up to 30 birds per 100 hectares (Johnsgard and Carbonell 1996) and with males defending territories as large as 900 square metres (Johnsgard 1978, Johnsgard and Carbonell 1996). During the non-breeding season the species is more congregatory (Berruti et al. 2005, 2007), forming flocks of up to 1000 individuals (Kear 2005). Habitat Breeding During the breeding season it inhabits small temporary and permanent inland freshwater lakes (Berruti et al. 2005, 2007), preferring those that are shallow and nutrient-rich (Johnsgard 1978, Johnsgard and Carbonell 1996) with extensive emergent vegetation such as reeds (Phragmites spp.) and cattails (Typha spp.) (Johnsgard and Carbonell 1996) on which it relies for nesting. It prefers areas with a bottom of mud or silt and minimal amounts of floating vegetation, since this provides the best foraging conditions (Johnsgard and Carbonell 1996). It also breeds on man-made habitats, such as small farm wetlands in Namibia, and sewage-farm basins (Johnsgard 1978, Johnsgard and Carbonell 1996). Non-breeding Outside the breeding season it will wander over larger, deeper lakes and brackish lagoons (del Hoyo et al. 1992, Berruti et al. 2005, 2007). It is thought to find refuge on the larger lakes while moulting (Berruti et al. 2005, 2007). Diet This species feeds primarily on benthic invertebrates including fly larvae (Diptera), Tubifex worms, Daphnia eggs and small fresh-water molluscs (Johnsgard 1978, Johnsgard and Carbonell 1996). It will also feed on algae, the seeds of Persicaria and Polygonum (Johnsgard 1978, Berruti et al. 2005, 2007), and the seeds and roots of other aquatic plants (Johnsgard and Carbonell 1996). It forages by diving and straining the benthic substrate with its bill (Johnsgard 1978, del Hoyo et al. 1992). Breeding Site The species tends to nest over deeper water among emergent vegetation (Berruti et al. 2005, 2007). The nest is usually constructed from reeds and cattails that have been bent down to form a basin (Johnsgard and Carbonell 1996), although old nests of Red-knobbed Coots Fulica cristata may sometimes be used.
Currently the links between population trends and threats facing this species are poorly understood. Pollution is a primary concern, since the species feeds mainly on benthic invertebrates, and is therefore more vulnerable to bio-accumulation of pollutants than other duck species (Berruti et al. 2005, 2007). Habitat loss as a result of the drainage and conversion of wetland areas for agriculture is also a significant threat (Berruti et al. 2005, 2007), as are rapid changes in water level that result from landscape changes such as deforestation and can severely disrupt the breeding activity of the species (Berruti et al. 2005, 2007). There is a high level of accidental mortality from entanglement in gill nets (Berruti et al. 2005, 2007). Hunting and poaching, competition with alien benthic fish and habitat alteration by introduced plants all pose less serious threats (Berruti et al. 2005, 2007).
Conservation Actions Underway
In Kenya and Tanzania approximately 80% of the population is thought to occur in protected areas whereas in southern Africa this figure is much lower, with approximately 20% in South Africa and just 10% in Namibia (Berruti et al. 2005, 2007).
46-51 cm. Male has a black head extending to the hindneck and throat. Bright blue bill. Chestnut body and short, stiff black tail often held erect. The female is largely brown with a pale throat and cheek stripe below the eye and faintly barred flanks. Similar spp. No similar species within the range.
Text account compilers
Bird, J., Butchart, S., Ekstrom, J., Martin, R, Ndang'ang'a, P., Taylor, J., Symes, A. & Westrip, J.
Berruti, A., Butchart, S., Dereliev, S., Hines, C., Simmons, R., Tyler, S., Ndang'ang'a, P., Turner, D. & Kung'u, G.
BirdLife International (2017) Species factsheet: Oxyura maccoa. Downloaded from http://www.birdlife.org on 18/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/10/2017.