Madeira (atlantis)

Size: smaller; most individuals are similar to graellsii.

Structure: on balance slighter; most are lightweight showing smaller heads and thinner necks in particular. The bills and chests are on balance stouter than those of graellsii but the difference is smaller than in any other area studied. On six perched birds the tail reached to P7 on three, just outside P7 on one, P8 on another with just one short of P7 at half way between P6 and P7. On graellsii the tail generally extends to around P6.

Primaries: tendency for a smaller mirror on P10 with as many as 32% showing a small mirror on P10. Slightly less (16%) show a mirror on P9.

Calls: generally appearing quite different; the majority of both long and mew calls (75-80%) are close to argenteus. The birds were in general taciturn

Moult in first-summers: in late March 78% had still to shed a primary. 13% had moulted P1/P2 and 9% P1 only. The heads showed a tendency to be whiter with 35% very pale by this time. The breasts and bellies also showed a greater tendency (45-55%) to be sparsely, rather than heavily, marked. Advanced birds are showing the first hint of grey on the scapulars.

First-years: predominantly grey-brown with a ruddy tinge (75%) with only 20% looking almost entirely grey-brown like the juveniles in autumn. Old tertials showed the graellsii pattern of a narrow white fringe around the feather; new tertials show much more white, particularly around the tip.

Second-years: very variable, some show clear blue-grey back and scapulars while others are showing a mottled grey-brown appearance here. On advanced individuals the bill is 4/5 yellow while on others the bill is mostly black still.

Comment: close to those of the eastern Canaries in size, structure and calls but even lighter on structure on balance. Closer to those of the central and western Canaries on wingtip pattern with relatively little white on the outer two primaries.

Vaurie (1965) also thought that Madeiran adults had no mirror on P9. Two adults photographed at Madeira (Grant, 1986, no.258) show a typical wingtip structure for those at Faro (and elsewhere on the Atlantic) with P9 only very slightly shorter than P10 and P8 closer to P9 than to P7. Further photographs by Regan & Fisher (2001) in Madeira confirm that a large white mark on P10 and no mirror on P9 are not uncommon. The moult pattern of P1-P8 new and P9/P10 growing, in September suggests a similar timing to that in the Canaries. The heads are sometimes quite dusky in moult as in north Morocco. Teyssèdre (1983), thought that the calls of the Madeiran birds were less shrill than those of the Canaries (see central Canaries), perhaps making them very similar to those in south Portugal. An adult and first-year Yellow-legged Gull are shown at (Parque 1999). The adult is depicted with heavy protruding chest, strong stubby bill with a large bright red gonys, extensive black triangle on the wingtip and a large mirror on P10 and none on P9; the first-year with a scaley grey-brown mantle, an all-black bill and short legs.