Hi Freddy
The Spanish and the French are attempting to eradicate Ruddies, but the UK is the main source population for such individuals. I know this is a very volatile subject which has been the subject of much legitmate ethical debate. Many people share Edmund's equally valid opinion that the Ruddies shouldn't have to pay the cost of man's folly. It is a choice between two 'evils' as it were, losing WHD as a genetically pure species (perhaps losing it full stop) and the wholesale slaughter of cuddly, bubbly Ruddy Ducks, coupled with the disturbance and bykill of other waterfowl species. However, the science behind the cull is solid and it does annoy me a bit when people claim this isn't the case. This from
http://digitalcommons.unl.edu/cgi/viewc ... rcinvasive 'In 1982, ruddy ducks were first recorded in Spain and this species has now been recorded annually since 1991. At least 139 individuals have been recorded in a minimum of 43 different locations in Spain. Despite an active and well-organised control programme to cull ruddy ducks, 59 hybrids have been recorded on at least 23 sites (Hughes et al. 1999). The mating strategies of the two species are distinct and the male ruddy duck has an apparent mating advantage over the male white-headed duck. Male ruddy ducks are not territorial, but rather defend “revolving territories†around their mates. Unpaired males attempt persistently to mate with females of both their own and other species. Forced copulation by one or more males on lone females is common (Gray 1980). In contrast, male white-headed ducks form hierarchies, with dominant males forming stable pair bonds with one or more females (Torres et al. 1985) and defending territories of emergent vegetation (Amat and Sanchez 1982). In captivity, ruddy duck x white-headed duck hybrids are fertile to at least the third generation. There is a degree of uncertainty about how the genetic dynamic between the two species would develop if larger numbers of ruddy ducks were allowed to reach Spain. However, given the aggressive and promiscuous mating strategy of the ruddy duck, the extent of hybridisation is likely to increase.'cheers
Alex
Freddy Johnson wrote:
Alex,
Yes I do believe in the POTENTIAL for extinction by introgression of the White-headed Duck, not that I am, nor anyone else is, in possession of the infallible data to fully support an inevitable introgressive extinction belief. I happen to agree with another LBC colleague with whom I have been in touch recently that there has to be some degree of management in all areas of Natural History in our own small ' British Isles '. If the White-headed Duck were a British breeding species, I could therefore at least understand a point of view for a British cull (not that I would agree with it).
However, the Spanish are great hunters and shooters and I would prefer the solution to be that any Ruddy Duck found in Spain could be shot but NO culling to be allowed in the UK. I also tend to think it's another case of the 'soft' Brits anxious to please. If the Spanish or French were asked to perform a similar action in their own countries the answer would probably be (in Spanish/French) - "You must be joking!"
Regards,
Freddy
_________________
Dr Alexander C. Lees
Lecturer in tropical ecologyManchester Metropolitan University
Lab Associate
Cornell Lab of Ornithology,
Cornell University
http://www.freewebs.com/alexlees/index.htm@Alexander_Lees
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