During World War II, it was discovered that grouping cargo ships in large
"flocks" improved the odds of success because U-boats could only sink one
before they were discovered. Whereas, U-boats could stalk and sink lone
ships with impunity. If the U-boats could sink one ship per group, then the
larger the group, the higher the percentage that survived. Perhaps someone
figured this out by observing migrating bird flocks.
Gene Bullock
Poulsbo WA
----- Original Message -----
From: "WAYNE WEBER" <WAYNE_WEBER at bc.sympatico.ca>
To: "GRANT HENDRICKSON" <granth at halcyon.com>; "TWEETERS"
<tweeters at u.washington.edu>
Sent: Thursday, December 07, 2000 7:57 AM
Subject: DENSE COOT FLOCKS


> 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
> >
>
>