Quote:
Originally Posted by za64  i saw a flock of approx 60 black headed gulls in winter plumage today, but one had a compleatly black head as if in its summer plumage.
are there any gulls that keep their black head in the winter?
alan |
Not usually as far as I'm aware- certainly all the species I'm familiar with that have a dark hood in breeding plumage lose most of it during non-breeding season, though Franklin's Gull has a half-hood effect in winter.
Gulls generally moult their head/body feathers twice a year compared to once for main flight/tail feathers. The moult pattern is controlled by hormones which may be influenced by factors such as daylength.
It's not unusual to see the odd Black-headed Gull in breeding plumage by late Jan, so yours may be a bit precocious; perhaps the hormones are a bit out of synch?