Dennis wrote:

>My guess is that the pygmy you described was entirely safe from the great
>horned. Small birds are much more agile than large ones, and, in this
>case, if the pygmy could actually see the horned (I assume it was in
>daylight), it had no reason to fear it.

I should have mentioned the time was late dusk; barely photo-taking light
with tripod at the beginning, pretty dark when I left. But all three owls
were clearly silhouetted, at least from my perspective.

>An owl attracted at night would, obviously, be
>under greater risk, as several posts have made clear.

But why is that necessarily true? Assuming both the Pygmy and Great Horned
have equally good night vision, why would darkness favor the predator rather
than the prey? Or do the larger owls perhaps have better night vision than
the small species?

I had the opportunity to night prowl for birds one time using a passive
night vision monocular (uses available light with no IR source); really
erie, but I'd like to try more of it. On that occasion I did not find any
owls, but it is amazing how well I could see. With the device I was using,
all images were shades of yellow-green, and resolution was surprisingly
good, but 'magnification' was 1x. A small light source improved my vision
enormously; a small flashlight would light up trees 400 yds away like a
spotlight, and the improved lighting also vastly improved the resolution,
which can be grainy in darker areas. Binocs could be held behind the night
vision, but this was pretty klutzy and awkward, so mostly I had to contend
with no magnification.

I can't help but wonder how owl vision compares with night vision equipment.
If they are at all comparable, owls truly have a huge advantage over other
creatures at night. And we, stumbling along with our flashlights, must look
like gas station spotlights, advertising our presence to the owls.

Dave Nunnallee
dnun461 at ecy.wa.gov
Bellevue, WA