Friday, 2 September 2011

Madeiran Storm-petrel first for Britain - reasons to celebrate?

by Bob Flood

Which population did this Madeiran originate from? (Photo: Joe Pender)

Other blog sites have announced that the 'Scilly Madeiran' is now on the British list. Taking it that this is true, is it time for Scilly listers to celebrate? Not really, given taxonomic developments that we have summarised in our new Multimedia Identification Guide to Storm-petrels & Bulwer's Petrel. DNA analysis shows that a number of distinct populations breed in the northeast Atlantic. Genetic isolation led to speciation and some authorities already recognise four species in the northeast Atlantic, with BirdLife recognising the population off the Azores as a good species with common name Monteiro's Storm-petrel. Whilst we think that it is too early to accept the four species taxonomy suggested in several publications (since research is still ongoing) we recognise that this taxonomy, or something like it, in the coming years will become accepted.
Is it possible to know which population (and in due course which species) the Scilly Madeiran belongs to? The short answers is, 'no'. Our studies to date show that there are no known reliable field characteristics to separate these cryptic popluations (taxa if you like). Even if field characteristics are worked out, and that is a big if, the level of detail recorded in our notes of the Scilly bird and the sole useful photograph are insufficient for future identification. The Scilly bird was in relatively fresh plumage and so there were no clues to its origin in this regard.
What does this mean for Scilly listers?
For the reasons given above, I took Madeiran off my Scilly list several years ago. It is technically correct to tick this bird now using the taxonomy operated by BOURC, but for those who have ticked Madeiran, you'd best keep a bottle of tipex nearby.

Notes by Tony James