European census of captive North American Ruddy Ducks Oxyura j. jamaicensis

Abstract

An international initiative to stop and reverse the population and range expansion of the naturalised North American Ruddy Duck in the Western Palearctic, in order to safeguard populations of the globally threatened White-headed Duck from hybridisation, began in earnest in 1993. As part of this initiative, a census of North American Ruddy Duck in captivity in Europe was conducted in 39 European countries in 1995. A total of 741 birds was reported, distributed amongst 80 private collections and zoos in nine countries, entirely within western Europe. However, it was estimated that the true number of Ruddy Ducks in captivity was in excess of 3,300 birds and thought to be increasing. Observed levels of duckling production suggest that the captive Ruddy Duck population has a high capacity for growth. Belgium, the Netherlands, United Kingdom, France and Germany held the largest captive populations. A general reluctance of aviculturists to respond to the questionnaire was attributed to a) adverse publicity associated with the current threat to the White-headed Duck, b) the growing call in some European countries for the outlawing of pinioning and c) speculation over legislation restricting the keeping of Ruddy Ducks. A major report published by the Council of Europe in 1996 suggested strict and legally-enforceable regulation of the keeping of potentially harmful exotic species. A preferable option for aviculturalists may be the establishment of a self-regulatory system. Given the threat to the White-headed Duck from Ruddy Ducks escaping from captive collections, persons dealing with Ruddy Ducks should consider whether free trade is justifiable.