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RE: Rooks cooperate to get treats



Tree creepers. Steller's Jays. The jays climb trees close to the trunk by
hopping - Name anything some other animal can do and there is probably a bird
that does it. 

- Sylvia Hope

-----Original Message-----
From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
evelyn sobielski
Sent: Thursday, April 03, 2008 9:23 AM
To: dinosaur@usc.edu
Subject: RE: Rooks cooperate to get treats


--- don ohmes <d_ohmes@yahoo.com> schrieb:

> 
> Personal observation (in N Florida, mid-December):
> two
> owls in  dimmest pre-dawn light, working their way
> up
> a gum tree in a swamp, leaping from
> branch-to-branch.
> As they reach the top branches, a lone crow flees
> from
> his perch and disappears into the southwestern sky.
> 
> In full daylight, a phalanx of 9 crows from the
> southwestern quadrant, flying bee-line to that tree.
> 
> One owl flies away as the crows light on the tree,
> and
> the crows follow it, and mob it. The other owl sits
> tight, and is un-molested.
> 
> My conclusion -- crows communicate well.

That is as good as certain. But are they up to the
task presented here?

I guess that with flocking corvids it's more like a
high-rise situation - you know all your neighbors by
sight and you greet them in the hallway, but you are
not especially close to them or would automatically go
to them for help in unusual or difficult tasks. 

Scrub-jays OTOH hang around in smaller and looser
groups, and we know that there are helpers in nesting,
even birds that are not direct offsprings but more
distantly related seem to help hesting pairs; they'll
learn skills they can later use, but this can only
explain why this behavior is maintained, not why it
evolved - it will benefit any bird with a similar
social structure, but is it not the rule.

(I presume here that all corvids have a concept of
"self" vs "conspecific"; it has been shown in some but
there is nothing to suggest it's not present in all)

I wonder how New Caledonian Crows would do in this
test - they're less social, but too little is known
about their habits to say whether they only can be
expected to cooperate with their mates and offspring
or also with "buddies". But the group that studies
their intelligence would probably know.


Regards,

Eike

PS - the Rook is partially migratory and in eastern
Europe for example local birds will freely mingle with
those that arrived from Siberia for winter. So
depending on strong social bonds other than to the
mate is actually a liability in this species. Their
groups are an order of magnitude larger than those of
chimps are, and they cannot phone or write mail to
keep contact. So a difference in cooperative behavior
is no surprise - in a chimp group everybody knows
everybody else *personally*. Rook groups are quite
anonymous by comparison.

So what would they do if put to a task where they have
to recruit a handful of conspecifics at least for them
*all* to gain a benefit? Your observation with the
owls gives a hint.


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