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Molting

Last post 11-01-2009, 7:56 PM by Matt. 16 replies.
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  •  10-27-2009, 3:51 PM 122309

    Molting

    Thought you would enjoy this response I got from a birding friend.  I published a female rufous and complained that the exact feathers I needed to determine juvenile from adult were missing and in the wrong time of year. 

    Moulting, and timing of just about everything is controlled by the pineal gland.  The pineal gland is influenced by the amount of light entering the retina.  This light, daylight, stimulates the pineal gland which in turn activates the anterior pituitary gland that then sends out various hormones controlling much of what a bird does, the timing, the circadian rhythms and seasonal timing of everything.  Temperature can be a slight modifying factor that influences when stuff happens.  Hence, we had a seasonally warm summer, with temps remaining warm through September.  This most likely this disrupted the moult slightly... my guess on this.  We sometimes hear of individuals which do not migrate, or reverse migrate, that is they go north when they are suppose to be going south (usually from banding records and sightings).   Guess what, malfunctioning pineal glands, pituitary glands or a combo.  I was once on the west coast of Florida in the summer.  And while birding for a week concentrating on coastal species, I came upon about 6 species that should have been in the Arctic breeding and here they where in Florida.  I was a biologist for The Audubon Society at that time and notified the assistant director of Audubon Sanctuaries who managed a sanctuary just north of St. Petersburg.  Dusty said he sees it every summer with Arctic breeding species who stay behind... yup screwed hormonally, from the anterior pituitary.  So, the short of this, get your normal dose of sunlight or you may start walking in circles, yes, we too have a pineal gland, but it is not as active as those still quadupeds or with wings. 
    Ok, now I have a  question for you.  If I see a woodpecker that looks in every respect to be gila woodpecker, but it has no tail, have I just stumbled upon a new species, one that I can rightfully name Melanerpes tederii??? > TED

     


    Latest Birds: Black-throated Green Warbler, Pine Warbler, Eastern Kingbird, Rufous-backed Robin, Crissal Thrasher
  •  10-27-2009, 5:55 PM 122333 in reply to 122309

    Re: Molting

    Very cool!  Thanks for sharing that.
  •  10-27-2009, 6:25 PM 122344 in reply to 122333

    Re: Molting

    Amazing!!!  Hope I'm not offending anyone by saying this but when I read something that amazing it really enforces my belief that God is behind everything on this planet.  Nothing this perfect could be accidental............Yes 

    Okay, I'm off the pulpit.......


    Life List: 139
    Latest: Cedar Waxwing!!!!!!!
  •  10-28-2009, 10:54 AM 122465 in reply to 122344

    Re: Molting

    Attachment: Molt.jpg

    This is a different comment, but still on the subject of molting.  This is on the manner of molting... on a Hummingbird.

    Fraser


  •  10-28-2009, 11:11 AM 122469 in reply to 122465

    Re: Molting

    Attachment: Molt2.jpg

    Another example...

    F


  •  10-31-2009, 12:19 AM 122930 in reply to 122469

    Re: Molting

    Attachment: ANHU 720 540 HYM.jpg
    A hatch year male Anna's going through its first molt.


    Latest Birds: Black-throated Green Warbler, Pine Warbler, Eastern Kingbird, Rufous-backed Robin, Crissal Thrasher
  •  10-31-2009, 1:52 AM 122931 in reply to 122930

    Re: Molting

    i have a question about molting... doesn't that involve the feather just falling out, like a cat shedding its winter coat? some of your photos seems more like combat scars. .. just wondering, cuz  i have watch some severe combat  with hummingbirds...

    http://whatbird.com/forums/photos/early_summers_birds/
    IM: oldguyrich
  •  10-31-2009, 8:31 AM 122942 in reply to 122931

    Re: Molting

    The key to the above pictures is time of year.  I shoot Anna's year around and only see the feathers missing during molting season.  That's not to say that injuries don't happen though.  One of my books has a picture of two hummers impaled in each other's beak due to a head on collision but I don't think that their beak strength is enough to grab and pull feathers out.  One totally useless piece of data, did you know that hummers can't walk?

    Latest Birds: Black-throated Green Warbler, Pine Warbler, Eastern Kingbird, Rufous-backed Robin, Crissal Thrasher
  •  10-31-2009, 11:18 AM 122959 in reply to 122931

    Re: Molting

    that is the question i had---. does a bird molt feathers in one piece, or do they break down like a dead branch on a tree?

    http://whatbird.com/forums/photos/early_summers_birds/
    IM: oldguyrich
  •  10-31-2009, 11:49 AM 122971 in reply to 122959

    Re: Molting

    The feather, like a loose tooth, falls off.  Many of those feathers are well worn though.  When the grackles molt I get over 100 large feathers in the backyard grass between mowings.  At sundown, I have an excess of 150 grackles that perch in a couple of citrus trees.  I get feathers everywhere.  

    Latest Birds: Black-throated Green Warbler, Pine Warbler, Eastern Kingbird, Rufous-backed Robin, Crissal Thrasher
  •  10-31-2009, 1:13 PM 122990 in reply to 122971

    Re: Molting

    Yes, Matt is correct.  I have an Amazon parrot, and I find feathers on bottom of his cage - when he loses flight feathers, they are so beautiful I usually keep them.  One thing I have noticed, which is another miracle of "nature" is that when one flight feather is lost, the exact same feather on the other side (wing) is lost shortly after that (within a day or two), so that the birds are balanced when flying during molting.


    Life List: 139
    Latest: Cedar Waxwing!!!!!!!
  •  10-31-2009, 2:13 PM 123002 in reply to 122990

    Re: Molting

    Interesting observation on the balance of the molt.  The hummer that Fraser posted shows both P9s coming in. 

    Latest Birds: Black-throated Green Warbler, Pine Warbler, Eastern Kingbird, Rufous-backed Robin, Crissal Thrasher
  •  11-01-2009, 3:22 PM 123238 in reply to 123002

    Re: Molting

    yes, flight feather molt is almost always perfectly symmetrical.
  •  11-01-2009, 4:23 PM 123272 in reply to 123238

    Re: Molting

    so ithat i am clear on this- the feather on photog's first shot here  is more likely a broken, instead of a molting feather... am i getting this correct?

    http://whatbird.com/forums/photos/early_summers_birds/
    IM: oldguyrich
  •  11-01-2009, 4:45 PM 123280 in reply to 123272

    Re: Molting

    Birdseye... I think that the first photo is in the manner that the molt occurs.  That primary appears to be about to fall out... or is being pushed out.  I don't think that it is damaged... At least that is my read.

     Fraser

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