Mantle: at least as dark; only slightly paler than graellsii at rest. In flight, the more marked contrast between inner wing and primaries is, however, obvious. The usual colour is a dark grey with a slight purplish tinge but some have a faint blue tinge, most obvious on the scapulars in bright sunshine. The shade appears to be similar to that of an individual photographed in Madeira (Garner, Quinn & Glover, 1997, no.137).

Size: similar so relatively larger than those in south Morocco and in northern and western Iberia.

Structure: similar except legs appear slightly longer and chest often protrudes very obviously.

Primaries: more black and less white; P5 is very well marked with 85% of birds having a broad black band. Only 10% of birds have a mirror on P9.

Calls: slightly deeper; a significant number of long calls (20%) are very close to graellsii.

First-years: notably scaley mantle in 90% of birds.

Moult in first-summers: in late March, 20% of first-summers had shed one primary (P1) with the remainder still to shed any feather.

Information needed: moult.