I replied, in the role of Armchair Ethologist, to Candace:
"A hawk which is eating is a hawk which is not hunting.
For that matter, a hawk which is in plain view is not a
hawk which is making a high-speed surprise attack.
That hawk did not represent any threat to the survivors.
Perhaps in summer, when there are slow, naive, closely-
related fledglings to protect, it would make sense to
make a fuss and warn the young birds that a hawk is
dangerous, or to try to oust it if it were still hungry. But
in winter, with young dispersed (or already eaten),
and a hawk occupied for now and not to be hungry
for some time to come, and cold weather to endure,
it makes sense that eating is the higher priority."
"A hawk which is eating is a hawk which is not hunting.
For that matter, a hawk which is in plain view is not a
hawk which is making a high-speed surprise attack.
That hawk did not represent any threat to the survivors.
Perhaps in summer, when there are slow, naive, closely-
related fledglings to protect, it would make sense to
make a fuss and warn the young birds that a hawk is
dangerous, or to try to oust it if it were still hungry. But
in winter, with young dispersed (or already eaten),
and a hawk occupied for now and not to be hungry
for some time to come, and cold weather to endure,
it makes sense that eating is the higher priority."
However, she added in reply:
"The
feeder birds did not seem disturbed at all by the hawk,
not when it first swooped down prior to the catch nor after it
took the junco. Wouldn't the Sharpie pose at least an initial
threat to all? My first impression was that In the middle of a
snowstorm, the energetic benefits of obtaining food might
outweighs the benefits of fleeing. Do you think that's the issue?"
not when it first swooped down prior to the catch nor after it
took the junco. Wouldn't the Sharpie pose at least an initial
threat to all? My first impression was that In the middle of a
snowstorm, the energetic benefits of obtaining food might
outweighs the benefits of fleeing. Do you think that's the issue?"
To which I wrote:
"If the prey species never reacted even when the hawk attacked,
then I don't have a good explanation, other than that they were
very unobservant, naive, hungry, or some combination. There
ought to be some self-preservation kicking in to avoid being the
one who gets eaten."
--Dave Nutter
On Jan 16, 2011, at 10:03 AM, "W. Larry Hymes" <w...@cornell.edu> wrote:
Recently Candace Cornell asked the question why other birds would stay
around and feed relatively uperturbed, when nearby a sharp-shinned is
feeding on a bird it recently captured. I think that's a very
interesting question, but so no response posted on cayugabirds. Do
other birds sense there is less danger from a predator, when they
observe it being preoccupied with its prey? Any thoughts from you bird
behaviorists?
Larry
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================================
W. Larry Hymes
120 Vine Street, Ithaca, NY 14850
(H) 607-277-0759, w...@cornell.edu
================================
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