Subject: SV: mobbing
Date: Nov 19 11:59:31 1999
From: Tor Bollingmo - tor.bollingmo at adm.ntnu.no


Well observed by all contributors. I have, in Norway, seen the Goshawk Accipiter gentilis, snatch mobbing Hooded Crows Corvus corone. In one occasion the crow was too heavy for the hawk, and they both splashed into the freezing cold fjord. The hawk then started swimming, using its wings, and when it finally and completely exhausted reached the shore, it still held the soaked, drowned crow in its claws! Similar observations have been reported by others as well.

However, the explanation that birds mob their predators to feed them would provide behavioural theory to be rather considerably rewritten. The explanation probably goes something like this: Mobbing behaviour may be some sort of social ornament. Analogue to the antlers of a reindeer. The boldest mobbers are in fact adult males on top of the social hierarchy. This has been documented in scientific experiments. In one study a dummy Great Horned Owl was placed on a pole at a rubbish dump. The mobbing crows that came closest to the dummy were then shot, aged, sexed and so on (flame the scientist, not me) and documented to be the dominant males. Very easy to generalize and find comparable examples from the human world.

Have a nice birding weekend.
Tor B.
Trondheim, Norway.
----- Original Message -----
From: Nene W <northwestmom at yahoo.com>
To: <tweeters at u.washington.edu>
Sent: Friday, November 19, 1999 5:21 PM
Subject: Re: mobbing


> Couldn't help thinking after reading D. Rockwell's
> account: how convenient to have your lunch following
> you around...
>
> (Just joking...the skill and grace to do what these
> birds of prey are doing to snatch their harrassers
> right out of the air is wonderful)
>
> Danene Warnock
> Bellevue, WA
>
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