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Re: on necks and crows

--Orig. Message:--From: "Mickey P. Rowe" <mrowe@indiana.edu>
Date: Fri, 7 May 1999 12:32:51 -0500 (EST)
In-Reply-To: (message from Frank Galef on Thu, 06 May 1999 22:48:50 -0700)

>Are you referring to the work of Bernd Heinrich?  If so, then my
understanding (gleaned largely from John Alcock's description in the
6th edition of _Animal Behavior_) would be closer to disorderly mobs
than fammily gatherings at least for Ravens.  Specifically, it appears
that when a Raven finds a carcass before any other Ravens, it will
keep quiet about it.  If there are more than two Ravens feeding at the
carcass, they will generally squawk to high heaven.  As I understand
the situation, this occurs because Ravens are territorial, and if only
one or two birds have found a carcass it is likely to either be in
their territory or they're interloping and don't want to attract the
attention of the territory's owner.  In either case it "belongs" to
the bird that first found it.

Primates have been known to keep quiet about food if they think they can
keep it a secret (I think I'm thinking particularly of a Gombe chimp -
sorry, no ref for this one).

I suspect the difference between discovering carrion or even a banana, and a
cooperational hunt may be significant.  In the first case, the issue is the
share one gets oneself.  In the second, before the sharing must come the
all-important securing of the meal in the first place.  Canids for example
are well known to compete/exercise ranking rights in the one case, and
cooperate in the other.  I expect people are agreed that chimps can
demonstrate at least the coop. hunting side.