Presumed intermedius Lesser Black-backed Gull

Heuglin's Gull - Larus heuglini

1: © Ruud Altenburg, 11-07-04; 2: © Ruud Altenburg, 29-06-04; 3, 5: © Ruud Altenburg, 10-07-04; 4: © Ruud Altenburg, 09-07-04. Amsterdam, Netherlands.

Individuals like this represent another blank spot in the current knowledge of Lesser Black-backed Gulls s.l. This bird has replaced all rectrices and secondaries at the wintering quarters and has also replaced P1-2 in its left wing and P1-5 in its right wing. Video stills indicated that probably P9 in the right wing is second generation as well. For now, replacement of the primaries before the first complete moult is known in Baltic Gull (see most birds in the fuscus section) and in Heuglin's Gull (the two examples in the heuglini section are this bird and this bird) but not in graellsii or intermedius. The fresh grey tertials and wing coverts of this bird probably are too pale for fuscus. On the other hand, they are on the darkest end of the spectrum for Heuglin's Gull. The irregular replacement of primaries (assuming P9 indeed has been renewed) does occur in Heuglin's Gull. For more pictures and information about this bird, please see Ruud Altenburg's site.

If you have photographs of a ringed 2cy Lesser Black-backed Gull with renewed primaries, please contact the authors.