Hello Peter,
Ravens commonly do the same thing with golf balls, presumably for the
same reason. The likely answer is they think they are edible, in
particular an egg. Although stones being natural, one would think that
the mistake would have evolved out of them. But according to this, it
hasn't. I guess the advantage that the occasional round white thing will
be an egg outweighs the disadvantage of the frequent wasted energy on
stones and golf balls.
Philip
-----Original Message-----
From:
On Behalf Of Peter
Ridgeway
Sent: Thursday, 7 April 2011 10:27 AM
To:
Subject: Raven stone 'fossiking'
An interesting observation from colleague Phil Mulhearn:
'In front of my apartment is a large flat roof covered with pebbles. One
morning recently I observed a raven fossicking among the pebbles -
surprising as there is nothing to eat there. I observed that he had a
large pebble in his bill, about 15mm diameter (too big to swallow).
Around the pebbled roof there is a low wall and it is very difficult to
access. Yet every now and again a new pebble appears on top of it. Could
the ravens be putting them there and if so why?'
Has anyone seen similar behaviour before?
Peter Ridgeway | Volunteer Coordinator| Birds Australia Discovery Centre
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