Probable Madeiran Storm-petrel off Agadir (Morocco) (1 Viewer)

[Piqa]

Hi,

What do you think about this probable Madeiran Storm-petrel (Oceanodroma castro) photographed off Agadir on November 6th. thanks
http://moroccanbirds.blogspot.com/2011/11/madeiran-storm-petrel-off-agadir.html

 

[Valéry Schollaert]

I've no experience of the newly described Monteiro's Storm-Petrel (Oceanodroma monteiroi) to answer...

 

[chris butterworth]

It's either Madeiran or Monteiro's. As far as I know there is no way ( at present ) to ID them at sea, as they are 'split' on vocalisations, genetics and time of breeding only.

Chris

 

[smiths]

I find it very hard to exclude Storm Petrel from these pictures...
The wings look too short for Madeiran Petrel, and the pale bar on the upperwing looks very thin, matching the pale tips to the greater coverts of a first-year Storm Petrel.
The underwing pattern is difficult to judge here, but the white underwing bar can be difficult to see in the field, and may even be lacking in a few birds.

 

[KM1]

As others have commented, Madeiran and Monteiro's (as well as Cape Verde and the proposed fourth cryptic species in the so-called 'band-rumped complex', Grant's Storm Petrel) are all extremely difficult to identify to taxon level at sea....but we don't have to worry about any of them in this case. The broad-based, short-armed/long-handed wing shape (somewhat reminiscent of a large hirundine) permit confident identification of the Moroccan petrel as a Wilson's. It is difficult to determine from these images whether or not there is any toe projection beyond the tail (it could easily disappear with this level of softness) but it has been established that, at times, Wilson's travel with the feet fully retracted and this can lead to them being mistaken for one of the band-rumped complex.

The comparatively weak looking carpal bar is likely to be an effect of the strong cast shadow across the far upperwing in the middle shot, but in any case the carpal bar is not always so conspicuous in Wilson's at sea.

I attach an scan of an illustration taken from Petrels Night and Day, by Magnus Robb and Killian Mullarney, published by The Sound Approach, a 'must have' for anyone with a keen interest in this fascinating group! For more information see http://www.soundapproach.co.uk/books/petrels.php

I'd also recommend the excellent new guide to Storm-petrels and Bulwer's Petrel in the North Atlantic Seabirds series, by Bob Flood and Ashley Fisher.

Regards,

Killian Mullarney

 

[smiths]

Thanks Killian.
Wilson's is indeed a better option still.

 

[François Doyen]

I agree it looks like a wilson's

FD