Ruddy ducks and white-headed ducks
6 August 2009
Ruddy ducks are native to North America and, like white-headed ducks, are a member of the stifftail family. They were brought to the UK in the 1930s and 1940s for captive wildfowl collections. Escapees first bred in the wild in 1952, and by 2000 the UK population numbered 6,000 birds. They would not have made it here, however, without the help of humans.
The white-headed duck is the only stifftail to occur naturally in Europe, with a patchy distribution running from the western Mediterranean through to Central and East Asia. Most breed in Russia and Kazakhstan, and winter in the eastern Mediterranean, Turkey and Asia. There is a small resident population in Spain.
In contrast to the ruddy duck in North America, numbers have declined severely over the last century, from 100,000 birds to fewer than 10,000. Hunting and habitat loss have been the main causes. The species is globally threatened with extinction.
'The white-headed duck is a symbol of successful conservation in Spain, in the same way that the red kite is in the UK.'
In Spain, a recovery programme to protect and manage breeding sites and a ban on hunting has enabled the Spanish population to recover from just 22 birds in 1977 to 2,500 birds.
The white-headed duck is a symbol of successful conservation in Spain, in the same way that the red kite is in the UK. If it was to disappear then a key argument used in achieving protection of wetland habitats and control of hunting would vanish. This could have serious consequences for these wetlands, their flora and fauna and for future conservation initiatives.
A conservation problem
As numbers of ruddy ducks increased in the UK, greater numbers were recorded in continental Europe. There have been over 900 records of some 1,500 ruddy ducks in 21 European and North African countries. Ruddy ducks were first seen in Spain in 1983, with around 20 birds occurring annually.
Ruddy ducks interbreed with white-headed ducks, producing fertile hybrids. This is happening in Spain, and there is a real danger that if the number of ruddy ducks arriving in Spain were allowed to increase, they would inundate the white-headed duck population. As ruddy ducks are more promiscuous in their mating behaviour, the likely result would be a population comprising increasing numbers of hybrids showing fewer characteristics of the white-headed duck, until the species disappears. This has been seen in New Zealand where the introduction of mallards has resulted in the catastrophic decline of the native grey duck due to hybridisation.
The Spanish authorities make every effort to remove ruddy ducks and hybrids, but this task would become increasingly difficult if numbers increased. Ruddy ducks have also been recorded in Turkey – the wintering grounds of the central Asian population of white-headed ducks. If ruddy ducks became established here and spread eastwards, control would be impossible due to lack of infrastructure and resources.
Action in the UK
International conservation organisations and European governments believe that hybridisation poses a very serious threat to the survival of the white-headed duck. The UK supports the largest population of wild-living ruddy ducks in Europe, and it is therefore vital that action is taken to remove the source of birds reaching the continent. Other European countries with small feral populations of ruddy ducks, such as France, must also play their part in addressing this threat to the white-headed duck.
The Central Science Laboratory (now the Food and Environment Research Agency), under contract to the Department for Environment, Food and Rural Affairs, assessed the feasibility of eradicating ruddy ducks from the UK. The results showed that eradication could only be achieved through a carefully controlled programme of shooting.
'Difficult as it is, our position is based on lengthy and careful consideration of the detailed scientific research carried out into this issue.'
In 2003, the Government decided to proceed with an eradication programme as part of a package of measures to help safeguard the white-headed duck. A five-year eradication project managed by FERA began in 2005, which by March 2008 had reduced the UK’s population of ruddy ducks to 400-500 birds. It is illegal to trade ruddy ducks in the UK without a licence, and further restrictions on keeping will be sought to prevent any future escapes.
The RSPB welcomes the European Commission’s support for efforts to eradicate ruddy ducks from the UK. We commend the high priority for action the UK Government is giving this issue, and are facilitating the eradication project where possible.
Difficult as it is, our position is based on lengthy and careful consideration of the detailed scientific research carried out into this issue. We are faced with a stark choice: either we act to stop ruddy ducks spreading from the UK, or we stand by and watch as the white-headed duck is pushed ever closer to extinction. Taking this action will help secure the future of the white-headed duck, while the ruddy duck will continue to thrive in its native North America.
Habitat loss and degradation, and hunting, continue to pose a major threat to the white-headed duck and it is important to find solutions to these problems. However, failure to tackle the spread of ruddy ducks in Europe could condemn the white-headed duck to global extinction. We have no wish to see the white-headed duck become the first European bird species to become extinct since the founding of the RSPB in 1889.