General Discussion
Another Threat To The Black Swans
Found this on the Daily Torygraph website. Make of it what you will:
Aggressive, Australian and over here – black swans are spreading across the UK and threatening to force out their native cousins, conservationists have warned.
The birds, which originate in Australia and have escaped from private collections in Britain, are now breeding at dozens of sites across the country.
The number of locations at which the birds are found has more than doubled in the past five years, while the number of breeding sites has more than tripled, new research from the British Trust for Ornithology (BTO) has found.
Because they are more aggressive than other species, there are fears they may "out compete" white – or mute – swans for food and habitat in many areas. They could also breed with mutes – a hybrid has been created in captivity called a blute swan. Black swans are also thought to be more aggressive to humans than other species.
The research suggests th black swan numbers have increased at such a rate that they may now be added to the authoritative "British List" of birds found in the UK. Until now, the black swan population has not been considered large enough to be self-sustaining.
Dawn Balmer, the BTO officer who has been leading the research, said: "They are cropping up all over the place now. We have been surprised by the numbers we have found. It will now need to be looked at to see if the black swan is added to the British List."
The project has uncovered 500 reports of black swans, in at least 170 different locations around the UK. Each location is a 10km square, to reduce the chances of the same birds being recorded twice.
Of these locations, 37 are thought to be sites where the birds are breeding. A survey in 2004 found the birds at only 73 sites, of which only 11 were breeding sites.
The largest cluster is in Dawlish, in Devon, where they were introduced in the last century. They have been the town's emblem for more than 40 years.
Opinion on what to do with the invader is mixed. Ms Balmer added: "Some people would be upset if you said black swans might be killed, but others see them as a serious threat to biodiversity. They compete with other species for food and habitat and are quite aggressive."
There are currently no proposals to control the numbers, although other non-native species, such as ruddy ducks, can now be killed to keep their numbers down.
The black swan occurs in western, eastern and southeastern Australia, Tasmania, and southern New Guinea. It was introduced into New Zealand in 1864, and is now widespread there.
Some were kept in the UK in captivity during the nineteenth and twentieth centuries. Owners could clip their wings to prevent them from flying away, but the feathers grow back and many have escaped in this way.
Until now, the black swan has not appeared on the British List of birds, which is compiled by the British Ornithologists' Union, because the population was not considered to be self-sustaining at the last review. However, the union will now reconsider that, in the light of the new information.
Steve Dudey, senior administrator from the British Ornithologists' Union, said: "For a bird to be on the British list it has to have a self sustaining population. In the past, we have not considered the black swan to be in that category but this study will give us a far better handle on that.
"This looks like a major increase and once we can see the evidence we will assess it to see if it now qualifies as a self-sustaining population.
"Black swans are Australian and are known to be aggressive. They will defend a body of water from other species, by driving them away. That is one of the big issues with non-native species establishing themselves. They usually have a negative impact."
It could not have helpled the situation, when Dawlish Town Council sold five to a private collector a couple of years ago, Just ask our illustrious Mayor Wills for verification.
And many others went to auction. Look at some of the poultry dealers on the web sites and see how many now sell black swans?
At least when the other warden looked after the waterfowl for peanuts, He vetted who had the surplus.
