I did check the Bent's Life Histories series, and eared grebes have a very
short-span "winter plumage." This should be called "fall" plumage as it
only lasts for 3-4 months. According to Bent, there is wide variation
amongst eared grebes in both the onset and degree of plumage change, but
the moulting changes can begin as early as December. That is what I saw!
It would be interesting to understand the evolutionary pressures within
this species to account for this plumage strategy.
Thank you, Maureen E. Ellis...me2 at u.washington.edu and DesMoines WA
********************************************************************
On Sun, 22 Dec 1996 jcbowling at mindlink.bc.ca wrote:

> Maureen asked -
>
> > A tardy-plumed eared grebe has been a winter
> > visitor for the past several years; perhaps it is the same bird returning
> > annually. I'm going to do a literature search for any information about
> > eared grebes' plumage cycles. If I find anything, will report here.
> > Anyone out there who can provide commentary about grebe seasonal plumages?
>
> I was at White Rock, BC Nov. 16, 1996 and took a walk out on the pier. I
> was surprised to find an adult Eared Grebe apparently just starting to moult.
> I thought they would be much deeper into basic plumage by then. Neither
> Horned nor Eared Grebes have been written up yet in the "Birds of N.A." series.
> When they are, I will check for info re. moulting sequences and post here.
>
> - Jack
>
>
>
> Jack Bowling
> Prince George, BC
> jcbowling at mindlink.bc.ca
>