James and Niall Machin found a pale Wheatear on Peninnis Head (St Mary's, Scilly, UK) on 3rd October 2007 which they felt was possibly an Isabelline Wheatear.
They released the news as a possible and I, along with about 15-20 others, saw the bird during the evening. I am not familiar with Isabelline Wheatear but this bird did not match my expectation of the species and I went away believing that it was an unusually pale and long-legged Northern Wheatear. There didn't appear to any strong support from other observers in either direction but my impression was that the balance of opinion leaned towards Northern (with most sitting on the fence). So far as I know the bird was not present the following day and was not seen by any observers who were very familiar with Isabelline Wheatear.
Niall has recently shown my photos to a number of experienced birders who have lent support to his original identification as Isabelline Wheatear.
I will be more than happy (if a little embarrassed) if this bird can be shown to be Isabelline and not Northern as I had originally presumed. We would be interested to hear your views. I have posted photos and some notes at http://www.gobirding.eu/Photos/PaleWheatear.php.