Invasive Species Birds

Ruddy duck - Oxyura jamaicensis

Ruddy ducks are small, stout freshwater diving ducks with broad wings and narrow, stiff tails. The male bird is quite distinctive with a chestnut body, black crown, white cheeks and a sky-blue bill. The female and juveniles are a dull,mottled brown with dusky, off-white cheeks and a grey bill. The female has  a diffuse, dark, horizontal stripe across the cheek. Both juvMale ruddy duck Mike Langman - RSPB imageseniles and females have a dark cap. They swim buoyantly often with the tail cocked upright and can gradually submerge without diving. They hardly ever leave the water and more often dive to escape danger rather than taking to flight. (Images: Top Male; Below Female; © RSPB-IMAGES AND ITS IMAGE CONTRIBUTORS.  ALL RIGHTS RESERVED. This image is protected by international copyright laws. Images available at
Problems caused
Ruddy ducks were brought to the UK in the 1930’s from North America, to enhance ornamental wildfowl collections. Subsequent escapes in the 1950’s and establishment in the wild, has resulted in a European conservation problem due to them hybridising with the endangered and naturally occurring white-headed duck populations in southern Spain.   Evidence indicates the UK as being the primary source of ruddy ducks in Europe.
The white-headed duck is the only naturally occurring “stiff tail” duck in Europe, whose population has declined from 100,000 to fewer than 10,000 birds, mainly through hunting and habitat loss. In Spain, numbers fell to just 22 birds in 1977 but a recovery program managing and protecting sites and a ban on hunting has seen the population increase to 2,500 birds.
From the first escaped birds in 1952, the UK population was centred in the West Midlands and has dramatically increased in the subsequent 50 years to approximately 900 breeding pairs.   They have now spread to almost all parts of England, into Scotland, north Wales and Northern Ireland. They have now spread to at least 21 European and North African countries and were first recorded in Spain in 1983.
In England, wintering birds form flocks on large water –bodies, particularly reservoirs and lakes, often numbering several hundred birds and national totals were thought to have exceeded 6,000 individuals by January 2000.
Control measures
To protect the white-headed duck in Spain and other parts of Europe, a jointly financed initiative by EU LIFE and Defra resulted in an eradication program formulated in 2003, with birds being controlled by marksmen from the Central Science Laboratory, as from September 2005. Failure to tackle the spread of ruddy ducks in Europe could lead to the extinction of the white-headed duck – possibly the first species of bird to suffer this fate in Europe since the founding of RSPB in 1889.
Actions by the public
Report any sightings of adults, juveniles or broods to the Essex Biodiversity Project.