Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The global population is estimated to number c.2,600,000-2,800,000 individuals (Wetlands International 2015). The European population is estimated at 352,000-524,000 pairs, which equates to 704,000-1,050,000 mature individuals (BirdLife International 2015).
The overall population trend is decreasing, although some populations have unknown trends or are stable (Wetlands International 2015). The European population is estimated to be decreasing by less than 25% in three generations (19.5 years) (BirdLife International 2015).
Behaviour This species is highly migratory, breeding widely across Western Eurasia and wintering within the northern tropics (Scott and Rose 1996). It migrates on a broad front, the autumn migration beginning in late July and peaking in August or early September (in Europe and Egypt), with birds beginning to arrive in East and West Africa in early September, peaking in October (Scott and Rose 1996). Once the species reaches Africa it migrates in relation to seasonal flooding, the central point of its occurrence shifting gradually along the course of rivers as the winter progresses (Alerstam 1990). The spring migration begins in February, with birds beginning to arrive on breeding grounds from mid-March to early-May (Scott and Rose 1996). It is a highly sociable and gregarious species (Cramp and Simmons 1977, Madge and Burn 1988), and whilst breeding can be found in single pairs or small groups, but regularly forms large congregations of several hundred on passage, and flocks of up to several thousand are common in African and Asiatic winter quarters (Cramp and Simmons 1977, Madge and Burn 1988). Adults undergo a post-breeding moult period that leaves them flightless for 3-4 weeks, with males moulting between mid-July and mid-August, and females between mid-August and September (Cramp and Simmons 1977, Kear 2005b). The Volga Delta, in particular, is a major moulting area for this species. Birds of this species are both diurnal and nocturnal feeders, and when migrating often travel by night and rest on open water during the day (Johnsgard 1978). Habitat Breeding In the breeding season this species frequents small, shallow ponds and lakes with abundant floating, emergent and fringing vegetation (Johnsgard 1978, de Hoyo. 1992) (that is not too tall or dense, such as bulrush - Typha spp.) (Cramp and Simmons 1977, Green 1998), in grass dominated environments, like swampy meadows, flooded fields, shallow freshwater marshes (Johnsgard 1978, de Hoyo. 1992, Schricke 2001). Non-breeding During this season the species shows a preference for large freshwater or occasionally brackish lakes, again with abundant floating, emergent and fringing vegetation (Kear 2005b), also shallow flood plains, shallow dams, pans and sewage ponds (in South Africa) (Hockey et al. 2005). The species also frequents coastal saltmarshes and lagoons on passage (de Hoyo. 1992) and may spend the day resting on marine inshore waters when migrating (Madge and Burn 1988). Diet Breeding When breeding this species is omnivorous (Johnsgard 1978). In spring and summer its diet is dominated by animal matter: chiefly molluscs, aquatic insects and their larvae (waterbugs, caddisfly, waterbeetles, midges), crustaceans (ostracods and phyllopods especially), worms, leeches, young and spawn of frogs, and small fish (Johnsgard 1978, Hockey et al. 2005). Seeds, roots, tubers, stems, leaves and buds of plants such as Hornwort Ceratophyllum, Naiad Najas, sedge, grass and other aquatic plants are also important at this time (Cramp and Simmons 1977, Johnsgard 1978, de Hoyo. 1992). Non-breeding During this season the birds are mainly vegetarian, with a diet dominated by the seeds of pondweeds, smartweeds Polygonum, sedges, dock Rumex, wild rice and grass (Kear 2005b), (with the seeds of Echinochloa colona, Nymphea micranthia and Nymphea lotus being the most preferred food items) (Treca 1981). Breeding site Meadows are the favoured nesting areas of this species, with nests rarely located more than 150 m from water (usually within 20 m) (Cramp and Simmons 1977). The nest itself is a depression in the ground, typically situated under rushes or tall grasses (such as manna grass, Glyceria), but not generally under shrubs (Johnsgard 1978, de Hoyo. 1992).
Breeding The most significant threat encountered by this species on its breeding grounds in Europe is habitat deterioration through the drainage and reclamation of wetlands (Kear 2005b), the increasing climatic aridity and subsequent lowering of the water table, and the transformation of wetlands to dammed reservoirs (Scott and Rose 1996). Other threats to this species include the destruction of nests during the early mowing of meadows (Kear 2005b), increased human disturbance (Kear 2005b), lead poisoning, botulism during hot summers (Kear 2005b) and hunting disturbance in Africa and Europe (Vaananen 2001) (> 500,000 are shot annually in Russia, Ukraine, France and Poland) (Kear 2005b). The invasive species American Mink Mustela vison also poses a threat through nest predation (Opermanis et al. 2001), and the species is susceptible to avian influenza (particularly strain H5N1) so is therefore threatened by outbreaks of the virus (Melville and Shortridge 2006). Non-breeding On its wintering grounds in Nigeria and Senegal the species is threatened by habitat destruction through dam construction, vegetation overgrowth and desertification (del Hoyo 1992, Polet 2000, Triplett and Yesou 2000), and in West Africa it is threatened by large-scale river diversion and irrigation schemes (Scott and Rose 1996). The species is also at risk from avian influenza in its African wintering grounds (Gaidet et al. 2007) as well as in its breeding areas (Melville and Shortridge 2006). The proportion of the species which migrates via the West Siberian flyway is susceptible to West Nile Virus, and is therefore threatened by future outbreaks (Ternovoi et al. 2004). Utilisation This species is hunted in Denmark , but there is evidence that this may be sustainable (Bregnballe et al. 2006). The species is also hunted for commercial and recreational purposes in Gilan Province, northern Iran (Balmaki and Barati 2006).
Conservation Actions Underway
CMS Appendix II.
Conservation Actions ProposedThe following information refers to the species's European range only: Key areas of breeding habitat for this species should be identified and protected. Monitoring should be implemented and accurate bag numbers recorded in countries where the species is hunted to ensure sustainability. Predator control may be necessary in some areas.
Text account compilers
Ekstrom, J., Butchart, S., Malpas, L., Symes, A., Ashpole, J
BirdLife International (2019) Species factsheet: Spatula querquedula. Downloaded from http://www.birdlife.org on 19/08/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/08/2019.