White-headed duck  (Oxyura leucocephala)

Classified as Endangered (EN) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

The white-headed duck is one of Europe’s rarest birds (4). The name of the genus ‘Oxyura’, means pointed tail, while leucocephala means white-headed. It is actually the males that have a white head, with a black cap. They also have a distinctive blue bill which is swollen at the base (2). Females have a pale face with a cheek-stripe, a dark cap, and a blackish, less swollen bill. Both males and females are chestnut-brown, with short, black webbed feet. These ducks are usually quiet but, when displaying, low rattling noises are produced (2).

The white-headed duck has a wide range and occurs in Spain, Algeria, Tunisia, Russia, Kazakhstan, Turkey, Iran, Afghanistan, Uzbekistan, Pakistan and Mongolia. Its status in China is unclear. It is found on passage in winter months in the eastern Mediterranean, the Middle East, central Asia and the Indian subcontinent (2).

Inhabits wetlands that are composed of freshwater or alkaline eutrophic lakes, with plenty of vegetation (2). The body form of the white-headed duck makes it more dependent on water than other duck species, as it is awkward on land (5).

During the winter the white-headed duck forms large flocks which feed together on insect larvae and submerged plant material and seeds. They dive continuously, staying underwater for around forty seconds at a time. In late winter they moult and are rendered flightless. Once re-feathered they begin the migration to their breeding grounds in late February (6). At the breeding grounds they break up into small groups to find suitable nesting sites (7). The white-headed duck is polygamous and nests in reed beds, sometimes on top of abandoned coot (Fulica atra) nests. Between four and nine eggs are laid and incubated for 22 to 24 days. Eight to nine weeks after hatching, the young fledge (5). Unusually for ducks, the adults moult twice each year, once in winter and again after breeding. Once this is complete, both young and adults migrate back to the wintering grounds (7).

This endangered duck faces several threats. The world population lies between 7,910 to 13,110 birds (2). At present, the main threat to the Spanish population is its interbreeding with non-native North American ruddy ducks Oxyura jamaicensis, which were brought to the UK in 1930s for captive wildfowl collections (8). Some young ruddy ducks escaped from captivity in 1952 and began to breed in the wild. The hybrids produced are fertile, and therefore pose an increasing threat to the white-headed duck. The expansion of the ruddy duck could also threaten populations of white-headed duck across Asia (9). Evidence strongly suggests that UK birds are responsible for the ruddy duck's spread across Europe (10).

Further threats include the loss of habitat of the white-headed duck. During the 20th Century approximately 50 percent of breeding habitat was drained for development and agriculture. Remaining sites are vulnerable to pollution. In addition, this duck faces threats of hunting, drowning in fishing-nets, and ingestion of lead shot (2).

Ruddy duck populations are currently controlled in Spain, Portugal and France. In the UK, where the spread of the ruddy duck is believed to have originated, the Government conducted a control trial that proved it is possible to eradicate the ruddy duck (11). Re-introduction schemes have also been conducted in Spain, France and Italy to boost this species’ numbers. There is hope for the recovery of the white-headed duck, not least because of Spain’s conservation achievement. In the 1970s there were only 22 individuals, prompting dedicated conservation projects in Spain. These were hugely successful and there are now around 2,500 ducks in Spain (12). It is hoped that other countries can follow Spain’s success to protect the white-headed duck. In 1996 a European Action Plan was published to unite Europe’s bird conservation groups and save the white-headed duck from extinction (5).

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the white-headed duck and its conservation see:

• Birdlife International:
  www.birdlife.org/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=359&m=0
• BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.
• Wildfowl and Wetlands Trust:
  www.wwt.org.uk