Grant and Tweeters,

I have always assumed that the reason coots typically aggregate in
dense flocks in the winter is for protection from predators--
especially Bald Eagles. On Okanagan Lake in south-central B.C., where
many thousands of coots winter each year, Bald Eagle attacks on coots
are frequent (and frequently successful). Coots, unlike ducks, are
slow to take off and are not agile in the air, preferring to escape
aerial predators by diving. Gathering in dense flocks seems to give
them some protection from eagles, in the same way that formation of
dense flocks helps to protect Dunlin from Peregrine Falcons and other
raptors.

Wayne C. Weber
Kamloops, BC
wayne_weber at bc.sympatico.ca


-----Original Message-----
From: Grant Hendrickson <granth at halcyon.com>
To: Tweeters <tweeters at u.washington.edu>
Date: Sunday, December 03, 2000 1:53 PM
Subject: Coot Behavior


>Recently Gene Hunn wrote
>
>"I've been checking the waterfowl action on the north end of Lake
Washington in Kenmore and Lake Forest Park of late. There's 2000 to
3000 water birds here regularly, 95% of which are coots."
>
>At the north end of Lake Sammammish there are hundreds of coots
rafted up. This occurs each fall. Can anyone help me understand why
they form these large groups at this time of year?
>
>Grant Hendrickson
>Redmond, WA
>granth at halcyon.com
>