Some of the birds I have been helped to identify recently, such as the common moorhen and the house sparrow, appear to be in their 'summer' plumage according to my field guide even though it is december. Now granted, December in Phoenix averages about 70 degrees. So is a bird's 'winter' plumage based on temperature rather than the calendar? That is my assumption but my field guide doesn't address this so I thought I'd ask. Thanks for any help.
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Question about IDing birds based on summer/winter plumage (1 Viewer)
- Thread starter AdAstra09
- Start date
Hi! No it's based on the calendar. However, some birds have no difference between winter and summer plumage such as for example Common moorhen and House Sparrow.
Edit: Of course "no difference" was a simplification of the matter. See Steves excellent explanation below.
Edit: Of course "no difference" was a simplification of the matter. See Steves excellent explanation below.
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In general, NA species plumage will follow the calendar. The two species that you mention are somewhat interesting, however, in that they do not undergo two molts (basic and alternate) but rather one into the basic. I'm not 100% sure about the moorhen but think that the summer (breeding season) appearance that is characterized by the red and yellow in the bill and red face plate is almost certainly the result of exposure to sex steroid hormones. That's certainly the case for many of the seasonal changes in 'soft part' coloration.
House sparrows (European starlings too) wear into their 'breeding' plumage in that the outer feathers wear to reveal different colors beneath (i.e., the black breast badge in male house sparrows becomes larger and more pronounced).
House sparrows (European starlings too) wear into their 'breeding' plumage in that the outer feathers wear to reveal different colors beneath (i.e., the black breast badge in male house sparrows becomes larger and more pronounced).
Thanks for the clarification! So, it's not summer/winter but rather breeding plumage? The birds are mating now? The reason I ask is because I was looking up the birds I identified recently in my field guide and the moorhen definately had the extensive red of the 'summer version', and the 'winter' house sparrow male appeared to have a dark grey breast with the black bib blending in rather than the cream colored bibs on the house sparrows I've seen recently with the black bibs standing out. And the field guide I use doesn't show breeding plumage for these two species, just winter/summer, although it does show breeding plumage for other species, which makes it more confusing. I use the Stokes Field Guide to Birds: Western Edition, if that makes a difference.
Winter vs. summer is more or less equivalent to nonbreeding vs. breeding. Though note there are exceptions and considerable variation in when birds breed both within and among populations and species.
grebefeet9
elegant tern of phrase
because ducks pair up on the wintering grounds.
