The UK's Ruddy Duck Problem
Created | Updated Sep 7, 2011
When the male ruddy duck struts his stuff, he raises two tufts of feathers on his head, cocks his tail up, inflates the air-sack in his neck and drums on it with his bill. The result is an impressive hollow noise and lots of bubbles. Well, it impresses the female white-headed duck, and that's the start of the problem. It probably doesn't help that he's more striking in appearance than her usual partner, being a rich chestnut with white cheeks, dark cap and blue bill. The male white-headed duck is a subtle (but duller) blend of browns with a dark neck, smaller dark cap and a blue grey bill.
The next part of the problem is that these two ducks are closely enough related to breed successfully, resulting in lots of little hybrid ducklings swimming about the ponds of Europe. The reason this is a problem is that the white-headed duck is European, while the ruddy duck is an escaped American import to the UK that has spread to Europe. Without intervention, the ruddy duck's adventuring spirit may be the end of the white-headed duck as it is now known.
So, Ruddy Ducks: do we kill 'em or do we keep 'em?
The Ruddy vs the White-Headed - Round One
Both these ducks belong to the family of stifftailed ducks. Stifftailed ducks are small (approximately 45cm in length), stubby-necked diving ducks. They are adapted to diving by their small wings, their long stiff tail feathers that act as a rudder and their legs which are placed far back on their bodies. The ruddy duck's legs are so far back that it cannot walk on land.
The ruddy duck - (Oxyura1 jamaicensis) - is native to North America, where it is widespread and numbers in the hundreds of thousands. It was imported to the UK as an ornamental species by, among others, the Slimbridge Wildfowl Trust. It escaped and naturalised, bred in the wild and has reached numbers estimated around 4,000. According to the birdbook of the Royal Society for the Protection of Birds (RSPB), the UK population is descended from around 70 young escapees from Slimbridge, between 1956 and 1963. It is present in many Western European countries, ranging from Iceland to Spain, and in Morocco in Northern Africa. Although it is feasible for the occasional duck to reach Europe naturally, it is believed that these populations either spread from the UK or originated from directly imported birds. Its success in colonising foreign habitats shows it to be a competitive and adaptable species.
The white-headed duck - (Oxyura leucocephala) - is not found in the UK. It is Europe's rarest duck and Europe's only native stifftailed duck. A conservative estimate in 1996 put the winter population at 19,000, later estimates range from 5,000 to 10,000. It is found in relatively small pockets in Spain, Greece, Turkey and other Western Palearctic countries. (The Western Palearctic covers Europe, the Middle East, and North Africa. The other countries are Algeria, Tunisia, Israel, Romania, Azerbaijan, Bulgaria, Kazakhstan, Ukraine, and the Russian Federation.) It lacks a flight response when threatened and it prefers to hide. It moults twice a year and cannot fly when moulting. Unsurprisingly, it has the reputation of being one of the easiest ducks to hunt. In Spain, where it is found mainly in Andalucia, pressure on its habitat and hunting led to a decline in numbers to probably less than 50 in the 1970s.
A strong conservation campaign has increased those numbers to an estimated 2,000. The Andalucian population is still threatened by loss of habitat, but its main threat is now recognised to be hybridisation by sun-seeking UK ruddy ducks. A few spread from elsewhere in Europe, but the real source of infiltration is regarded as being the UK. Outside Spain, the white-headed's numbers seem to be stable, but it depends on a type of habitat (seasonal shallow marsh and wetland), which is easily converted to agricultural land by drainage and which is largely unprotected. It has already become extinct in several countries (Italy, Corsica, Morocco, Hungary, Albania, Serbia (former Yugoslavia), Egypt and Armenia) and has lost breeding populations in other areas.
The hybrid ducks are fully fertile and breed with more white-headeds, thereby increasing the speed of hybridisation.
The Ruddy vs the White-Headed - Round Two
At the end of Round One, it doesn't look like much of a contest. All the odds seem to be on the ruddy duck, but that's before looking at who they have in their corners.
In the White-Headed corner we have:
The international community - The white-headed is listed as a species to be protected by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), the Bonn Convention (for the Conservation of Migratory Species of Wild Animals) and the Bern Convention (on the conservation of European wildlife and natural habitats). The eradication of the ruddy duck in the Western Palearctic has been called for under the Bern Convention.
The United Nations - Article 8(h) of the UN's Convention on Biological Diversity, which requires contracting parties to control or eradicate (as far as is possible), alien species which threaten other species, has been applied to the ruddy duck.
The European Economic Community - It is listed in the EU Wild Birds Directive which is aimed at conserving the Community's wild bird species. The European Commission also supports 'The International Action Plan for the White-headed Duck in Europe' drawn up by BirdLife International and Wetlands International which covers the control of the ruddy duck, hunting and conservation of habitats.
The British Government - The UK government is a signatory to the conventions and directives listed above, is committed to the European White-Headed Duck Action Plan, and has decided to take action to control ruddy duck numbers. A three-year control trial was set up and 1,000 ruddy ducks had been culled by June 2000. The remainder of the trial was to continue this, test other control methods and look into the feasibility of eradicating ruddy ducks from the UK.
The White-Headed Duck Task Force - was set up by the UK Government to find the best way to implement the Government's decision and it has recommended exterminating the ruddy duck in Britain within ten years. The Task Force includes representatives from the Department of the Environment Transport and the Regions, English Nature, Countryside Council for Wales, Scottish Natural Heritage, the Royal Society for the Protection of Birds (RSPB), British Trust for Ornithology, Wildfowl and Wetlands Trust, Avoiornis UK, the Wildlife Trusts and BirdLife International.
The RSPB - They state that they want to see both species thrive throughout their natural ranges. The ruddy duck's natural range is North America and the RSPB backs the Task Force's recommendations.
Spain, Portugal, Morocco and France - These countries have introduced a programme of eradication of ruddy ducks. Other countries have stated their support of control measures; some are waiting to see the UK take effective action first.
In the Ruddy Duck corner we have:
Glasgow City Council - In a debate in June 2001, a representative from the Council challenged the science behind the decision to eradicate ruddy ducks, saying that the behaviour of hybrid offspring hadn't been adequately researched and that there was no proof of any wildfowl species having ever been 'genetically swamped'. He also questioned the ethical position and the public relations aspects of a policy aimed at eradicating a species.
Various animal welfare groups - Organisations such as OneKind and Animal Aid are opposed to the killing, pure and simple, but also to the policy of culling one species to preserve another or to preserve 'genetic purity'.
Some conservationists - Many believe it is already too late to save the white-headed duck. Others make the argument that the funds being used to control the ruddy duck would be better spent conserving white-headed duck habitats or looking at the whole issue of controlling non-native species. In its ideal habitat, the white-headed male might be able to compete. The concept and definition of non-native species is not clear cut, and the arrival of a new species is not always unwelcome. (The beech tree was not found in the UK before 600 BC and the horse chestnut was introduced in the 17th Century; it is difficult to imagine the country without either.)
The Ruddy vs the White-Headed - Round Three
At the end of Round Two, the ruddy duck begins to look like the underdog despite his fine feathers and posturing. But evolution is a powerful force. Can the combined strength of the UN, the EEC and a host of national governments really put the ruddy duck's genetic genie back in its bottle? And should they? It could be that the new hybrid stifftailed duck has a much better chance of long-term survival than the easily hunted, less adaptable white-headed duck. The two species are close; this could be regarded as a 'natural' development. The culling of a species, albeit a naturalised one, is an uncomfortable idea to many conservation-minded people. How far should action in the name of biodiversity go to save a species from its close relative, particularly a species that could be argued to be in need of some evolutionary progress to ensure its survival from the other threats to its existence?
On the other hand, the two birds are distinct species. Analysis of their genetic and anatomical structure shows that they have been separated from each other for between two and five million years. That is a lot of history to lose. The white-headed duck has become a symbol for conservation, successful and expensive conservation at that, in Spain. Spain, particularly the Andalucian region, is an important country for the survival of many migratory birds and action to conserve and protect species there is internationally significant. To lose the battle to save 'their' stifftailed duck would be detrimental to the cause of conservation there. To lose the battle to uncontrolled escaped alien ducks from the UK would aggravate the loss.
To take no action could be seen to compromise the principle of protecting native species from introduced species. Such as the red squirrel, whose demise in the UK is largely attributed to the introduced grey2. Or the flightless birds and other species in Australia and New Zealand which lack any evolved protection against introduced predators like cats and foxes. But unlike these examples, the ruddy duck is not exterminating another species but creating a new hybrid in which the genes from both existing species survive. Given the ways in which the planet changes which are beyond human control, change needs to be allowed for in conservation as in everything else.
So whose side is 'Right' on? Either way, the bell has yet to ring for the end of Round Three.
