[birdky] Red-necked Grebe migration info

From: Tina Nauman <tinanauman@xxxxxxxxx>
To: BIRDKY Freelists <birdky@xxxxxxxxxxxxx>
Date: Mon, 10 Mar 2014 08:12:38 -0400
I found this post from South Carolina very interesting to help explain .

From: Marilyn Westphal <mjwestph@xxxxxxxxxxxx>
To: Harry LeGrand <hlegrandjr@xxxxxxxxx>
Cc: Philip Dickinson <pdickins@xxxxxxxxxxxx>, John Fussell <jfuss@xxxxxxxx>,
carolinabirds <carolinabirds@xxxxxxxx>
Date: Sun, 9 Mar 2014 09:24:50 -0400
Subject: Re: Regarding the recent counts of Red-necked Grebes on inland
lakes
Bird migration being as complex as it is, it is fun to speculate.  Checking
through BNA and ebird and as mentioned by one carolinabirds contributor,
Red-Necked Grebes are generally much more of an east-west migrant, but may
be forced farther south some years of heavy lake freezing. Most generally
winter along the northern US seacoast and migrate west across the Great
Lakes in March and April.  As I mentioned in an earlier email, this year in
February the RN Grebe ebird reports were centered farther south along the
Atlantic coast than reports from previous years in February.  I speculate
that this year they are starting from a more southerly position and moving
over and stopping at more southerly and more populated areas than normal,
thus many more reports than usual.  Weather patterns and frozen water may
have even pushed then farther south into the Carolinas during their
movement. There are even more reports than usual now in some of the Great
Lakes states probably because the RN Grebes can't use the Great Lakes as
much and are forced to land in rivers and bays that are kept open by
flowing river water or by ice-breakers, the kinds of areas they are more
likely to be seen by birders.

Diving ducks, of course as mentioned, are more limited to areas closer to
shore because they feed off the bottom, so they can't move to deep open
waters in the Great Lakes, so they probably did have to move to more inland
or more southerly areas sooner than mergansers or grebes.  Mergansers are
more common in winter along the Great Lakes than RN Grebes in any year and
maybe will also use rivers or open bays more readily than RN Grebes.  I
tend to doubt that grebes or mergansers would move way out to fish in deep
waters of the Great Lakes when most of the lakes are frozen because I
suspect the fish populations hanging out near the surface of the water
way out there in the middle of the lakes aren't that great.  The fish don't
care if the surface is frozen over where they are closer to shore, so they
aren't going to move out there.  The Great Lakes aren't as
biologically rich as the ocean.  But I'm no Great Lakes fish expert, so
maybe I will be corrected about that.  I did grow up along the shores of
Lake Michigan, though, so I'm quite familiar with frozen lakes.  I do
remember one winter when I was a teenager (long time ago) that Lake
Michigan froze completely across, but this may be the first time since then
that it has been so frozen over.

So, the bottom line is that I think that the RN Grebes winter less in the
Great Lakes to start with, this year they moved farther south along the
ocean coast in late winter than usual, and they are migrating west from a
more southerly route than usual and stopping in more inland and more
populated areas than usual.  That's just my speculation, though.  I'm sure
there are many other ideas out there.
Marilyn
[birdky] Red-necked Grebe migration info

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