|Cooperation on Ruddy duck eradication in Europe
The White-headed duck is a globally threatened species with a world population of only 10,000. Around 2,500 of these are found in Spain – the population having recovered from near extinction, driven by habitat destruction and overexploitation, in the 1970s. The main risk now to the survival of the White-headed duck is hybridisation with the introduced North American Ruddy duck. Having good conservation status in America, the Ruddy duck has a naturally promiscuous mating strategy, in contrast to the White-headed duck’s monogamy. In freely interbreeding populations – only meeting because humans brought Ruddy ducks from America and allowed them to escape (the ruddy duck has never been reported in Europe as a natural visitor), this means that directional gene flow would eventually extinguish the White-headed duck as a species.
Ruddy ducks were first introduced in the UK around 60 years ago, but have since spread to Spain and to France, and subsequently to Belgium and the Netherlands. In 2005 the British and Spanish governments secured EU LIFE funding for a project to eradicate Ruddy duck from the EU.
By April 2012 numbers in the UK had fallen from a peak of 6000 individuals to just 60, while in France 239 birds were recorded in 2011 and 127 of these were culled. In Belgium only eight Ruddy Ducks were seen in 2011 (including a brood of four ducklings) and a pilot project was due to start in January 2012 aimed at eradicating the species in the wild. In the Netherlands a restructuring of the nature conservation authorities has delayed any action being taken, but numbers remain low and it seems likely that eradication can proceed quite quickly once these issues have been resolved.
The project demonstrates that eradication of even a widespread mobile invasive alien species is possible at EU level, provided national authorities cooperate and action is taken in a concerted manner.
RSPB (BirdLife partner in the UK)
Alistair Taylor, Alistair.Taylor(at)rspb.org.uk