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Black-headed Gulls

snathdag
04/02/2010 02:48

Hallo,

I've recently seen a black-headed gull with a completely brown face, my first of the year. I must admit I was surprised to see it as I regularly keep an eye on a nearby colony and hadn't noticed that any birds had started the transformation (to their nuptial plumage ?). I've subsequently spotted a couple of them at differing stages of change. Can anyone tell me how long the process usually takes?

Cheers

  • 0 04/02/2010 03:04

     

    Hi,

    Black headed gulls normally  start to moult from mid Jan, the head darkens from the nape forward.  How long it takes probably depends on temperature, diet and other factors.

    :)

    S

    For advice about Birding, Identification,field guides,  binoculars, scopes, tripods,  etc - put 'Birding Tips'   into the search box

  • 0 18/02/2010 16:08 in reply to seymouraves
    Hi both,To my mind the majority will be in transition/spring moult around mid March time but there will still be a few birds showing winter plumage after even after this. It is potentially possible to see BHGs in summer plumage at any time of the year, but Jan/Feb time probably accounts fro less <1% of the population. I've also seen 2/3 in full summer plumage - certainly a double take *slap face* moment!The timing of moults coincides with with the time of year the bird was first born. So if the the gull in question was born early in the year it will go through it's first partial moult (into first winter plumage) earlier than the majority of other birds of the same species. so June rather than August for example. Therefore subsequent moults will be out of sync with the vast majority of others.    CheersL 
  • 0 20/02/2010 03:49 in reply to LloydScott

    Thanks for taking the time to reply (and to seymouraves too). You've both answered the question I should have asked, i.e. when do they normally start to begin the spring moult and not how long does it take. It's interesting that some birds are out of sync with the normal moult cycle and it begs another question or two:

    a) does a precocious summer plumage indicate that a BHG (or any bird for that matter) is out of sync in all aspects of its life cycle and therefore, when it's at its reproductive peak, less likely to find a receptive mate?

    b) does a changing climate mean that the courting, mating, breeding etc seasons will tend to be more spread out and to overlap with increasing numbers of birds being out of sync with the norm?

    The second question's probably worth another thread on its own. Don't worry, I'm not expecting a quick answer or any at all!