glaucoides - kumlieni

(last update: January 26, 2012)
Coordinators:
Dave Brown (Canada)
Bruce Mactavish (Canada)
Chris Gibbins (Scotland)
Peter Adriaens (Belgium)
Mars Muusse (Netherlands)

PDF's
Ringed birds
Iris classification
Primary classification

1cy Aug - Dec

2cy January
2cy February
2cy Mar - Apr
2cy summer
2cy Sept - Dec

3cy January
3cy February
3cy Mar - Apr
3cy summer
3cy Sept - Dec

sub-ad Jan - Apr
sub-ad summer
sub-ad Sept - Dec

adult January
adult February
adult Mar - Apr
adult summer
adult Sept - Dec

Presumed adult Thayer's Gull (thayeri) at the paler end of the spectrum for this taxon. Pictures: Steve Rottenborn.

Kumlien's Gull in the dark end of the spectrum come very close to Thayer's Gull, especially birds in the paler end of the thayeri spectrum. Below, three images of two birds which are presumed Thayer's, yet the melanism in the wing-tip is dark grey, not blackish.

below: Thayer's Gull (thayeri), January 18 2008, San Jose, California. Picture: Steve Rottenborn.

This would be a "Stage 4" bird, with darker grey or more extensive grey marks on the outer five primaries with complete subterminal bands on zero to three primaries. This stage 4 was scored in 55% of the adult Kumlien's at Newfoundland in the research by Howell & Mactavish. For explanation, see chart.

below 2x: Thayer's Gull (thayeri), January 26 2008, San Jose, California. Picture: Steve Rottenborn.

P9 has a broken subterminal band. This would be a "Stage 4" bird, with darker grey or more extensive grey marks on the outer five primaries with complete subterminal bands on zero to three primaries. This stage 4 was scored in 55% of the adult Kumlien's at Newfoundland in the research by Howell & Mactavish. For explanation, see chart.