How many of the potential raptor species for the U.K have people seen? (1 Viewer)

[Andy Adcock]

I think there's a basic misunderstanding of raptor flight in that Buteos don't sit on the ground on cloudy days in winter (for instance) for lack of thermals and American warblers don't actively fly the Atlantic they get blown across on air currents moving very fast indeed: air currents more than capable of being exploited by raptors. A more significant factor is whether or not the birds migrate somewhere likely to get them caught up in a fast-moving system and there I have no basis on which to speculate except to note the Irish Bald Eagles which suggest it would be unwise to rule out anything.

My point in post #12

So far as European vultures go, currently we have past records of Egyptian Vulture, Black Vulture, Griffon Vulture and Lammergeier that demonstrate in some cases the certainty of capability and in others a debate over the actual individuals that might repay revisiting. But all of them are clearly capable, as are Booted Eagles.

I think that any bird, soaring as high as Vultures are known to go, could easily end up on the English side of the channel.

In recent years the satellite tagging of Sakers has demonstrated juvenile wanderings that have included many parts of Western Europe so that it is clear that they could not be ruled out as visitors to Britain on inability or disinclination to come this far

The level of proof required for a first is really a higher barrier than the ability to get here.

John

Blighted by the inevitibility, that until proven otherwise, it will be deemed an escape.

 

[Jacana]

Levant Sparrowhawk should also be included on any list of potential new species for the UK. While I don't think there have been too many records in Western Europe (but I also know next to nothing about this species), it seems like it should be easily as likely as some of the other suggestions here so far.

 

[Andy Adcock]

Levant Sparrowhawk should also be included on any list of potential new species for the UK. While I don't think there have been too many records in Western Europe (but I also know next to nothing about this species), it seems like it should be easily as likely as some of the other suggestions here so far.

IOC shows nearest range as a vagrant, to be well, East of the UK, Czech, Austria, Poland and Italy, no idea how complete that is though.

 

[pete wragg]

I suppose given that a couple of lammergeiers have made it across, a black/cinerous vulture might at some point.

It already has. mid Wales somewhere, late 70's. on my list!

 

[Patudo]

I think there's a basic misunderstanding of raptor flight in that Buteos don't sit on the ground on cloudy days in winter (for instance) for lack of thermals and American warblers don't actively fly the Atlantic they get blown across on air currents moving very fast indeed: air currents more than capable of being exploited by raptors. A more significant factor is whether or not the birds migrate somewhere likely to get them caught up in a fast-moving system and there I have no basis on which to speculate except to note the Irish Bald Eagles which suggest it would be unwise to rule out anything.

Buteos may not be totally grounded in unfavourable conditions, but you certainly won't see anywhere near as many in the air as when conditions are good (including bright sunny days in winter) - which proves how dependent on thermals they are to get up high (which is probably a good idea if trying to make it across a large body of water). There's been a fair amount of literature noting how even the relatively short eight mile crossing across the Gibraltar Strait can be challenging for a variety broad-winged raptors ranging from black kites to griffon vultures. The English Channel at its narrowest point is 21 miles across; easy to see why it'd be a significant barrier. Obviously anything is possible, but I'd have thought the chances of any American buteo making it all the way over without ship assistance must be slim indeed - after all, none appear to have done during the great heyday of game preservation, when any vagrant redtail or Swainson's would have been shot on sight. I'm stunned that the two immature bald eagles made it.

In recent years the satellite tagging of Sakers has demonstrated juvenile wanderings that have included many parts of Western Europe so that it is clear that they could not be ruled out as visitors to Britain on inability or disinclination to come this far.

The only study I've been able to find is Nemcek et al 2014 - would be grateful for others. Yes, some of those juveniles travelled a good distance, but it strikes me that the further a wandering juvenile gets, it's more likely to turn back than to go onwards. But no doubt it's more likely for this species to reach the UK than some of the others mentioned.