Subject: Re: fishy grebe question
Date: Nov 11 21:54:16 1998
From: Michael Price - mprice at mindlink.bc.ca


Hi Tweets,

Bonnie Stout writes:

(snip)
>Last year at this time I observed flocks of HORNED and WESTERN GREBES in
>Semiahmoo Bay (White Rock, BC). (separate flocks Horned Grebe flocks and
>Western Grebe flocks) These flocks were swimming together in a fairly
>tight group (more so than typical resting flocks) and DIVING TOGETHER. All
>or nearly all the birds in the flock would dive nearly simultaneously, over
>and over and over. The flocks also covered a lot of water, moving back and
>forth across and underneath the water as if in pursuit of something. Last
>weekend I saw this behavior again (really quite interesting to watch the
>birds synchronize their behavior).

They're practising their synchronized-swimming routines, Bonnie; the Sydney
Olympics aren't that far off. Seriously, maybe they're not in pursuit of
fish but each other: I've often wondered when seeing what you describe
whether there may be some kind of underwater courtship/flock bonding/display
(vocalisations?) routines happening below the surface. Has anyone ever
dropped hydrophones in the area and listened when they're doing this? And/or
followed them underwater in wetsuit and scuba-dive, or sent a
remotely-piloted videocam, to observe what they're doing, whether preying or
playing--and at what depth(s)--between the simultaneous dive and the
raggedly unison resurfacing?

Michael Price
Vancouver BC Canada
mprice at mindlink.net

"She's psychic....we've decided to find it charming."
--Frasier