[CT Birds] Eared Grebes CAREFUL!
Steve Mayo and Rebecca Horowitz
rsdmayo at sbcglobal.net
Sun May 11 12:51:40 EDT 2014
From: greg hanisek <ctgregh at yahoo.com>
To: "ctbirds at lists.ctbirding.org" <ctbirds at lists.ctbirding.org>
Sent: Saturday, March 29, 2014 10:28 PM
Subject: [CT Birds] Eared Grebes CAREFUL!
at this time there is a rash of Eared Grebe reports just as Horned Grebes enter molt and transitional plumage. Right now many Horned Grebes look nothing like any picture in any field guide, and cause all kinds of confusion. In order to successfully document an Eared Grebe it’s important to set aside plumage details and concentrate on structure, which unlike plumage is quite consistent. The keys for Eared Grebe are head shape (peaked rather than flat with the high point above the eye) and bill shape (upturned appearance because of shape of lower mandible). Head pattern on Horned Grebes can be all over the place, and either mimic to some extent Eared Grebe or just look so little like a typical Horned Grebe as to encourage the conclusion that it must be something else.
In the past week I've fielded questions, looked at photos and queried some eBird reports that for the most part were generated by molting Horned Grebes. I do want to point out
that the report today by John Marshall did include structural characters consistent with Eared Grebe, so in no way is that report what prompted this post. I've been meaning to do it and unfortunately didn't get around to it until after John's report. (The Eared Grebe that's been around Greenwich for a while now is well documented).
At any rate, Eared Grebes historically are not documented any more often at this time of year than at various other times, yet when the Horned Grebes appear in transitional plumage about now, undocumented Eared Grebe reports go through the roof. Throughout the winter Horned Grebes are very crisp, neat-looking black-and-white birds, but as they molt they can become quite messy. A "dirty" neck and/or cheek is usually good for Eared, but right now Horneds can have that look to some extent. Molting of the head feathers can even affect the typical squared off look of the head. Horned Grebe heads can now have a
more rounded look, but they still remain flat on the crown without the Eared Grebe's peak. Horned Grebe bills also will be straight without the odd upturn of Eared.
So just be careful out there.
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