Aythya nyroca (Güldenstädt 1770)

The ferruginous duck breeds during May and June. The female builds a nest from reeds, grass and leaves and lines it with down from her breast. Well concealed in thick vegetation, she lays between seven and ten eggs which she incubates for 25 to 28 days. Ferruginous ducks share a seasonal pair bond, but the male habitually deserts the female during incubation (9). The chicks are tended by the female alone until they fledge at 55 to 60 days. They reach sexual maturity at one year (10). Ferruginous ducks are found singly or in small groups. They are active at night, foraging for seeds, aquatic plants, aquatic invertebrates, small fish, and amphibians. They feed by diving, dipping the head under water, up-ending, and dabbling (9).

A European Action Plan was published in 2000 and an International Single Species Action Plan is being developed under the African-Eurasian Migratory Waterbird Agreement. Bulgaria plans to restore the habitat of two key breeding sites on the Danube, and has received funding for this purpose (8).

Males of this diving duck species are a deep russet brown with a white triangular patch under the tail and a white belly. The edges of the wings are white, with this colouring visible only in flight. Females and juveniles are similarly patterned, but tend to be a duller brown, with no hint of red. The beak is short, giving the peaked head a particularly triangular appearance. The white eyes stand out from the dark feathers on the head (7).

This species both breeds and winters on shallow lakes, marshes and pools with ample vegetation (7).

Four main populations of the ferruginous duck are recognised, which breed in southwestern Asia, central Europe, eastern Europe, and north Africa. The wintering range overlaps with the breeding range, extending into the Middle East, north-east and west Africa and Southeast Asia (8).

The ferruginous duck is classified as Near Threatened (NT) on the IUCN Red List (1). It is also listed on Appendices I and II of the Convention on Migratory Species (CMS or Bonn Convention) (3), Appendix III of the Berne Convention on the Conservation of European Wildlife and Natural Habitats (4), Annex I of the EC Birds Directive (5), and Annex 2 of the African-Eurasian Migratory Waterbird Agreement (6).

Although protected by law, the ferruginous duck is still excessively hunted due to misidentification or ignorance of the law. It is also at risk from habitat loss as wetland habitats are drained for agriculture (8).