If they have been flying (daylight hours) into twilight, they have dark
adapted as the lighting change has been gradual... they are using a sense of
direction that does not need light so while in the air they can safely
travel and not be lost..... the higher up you are the more of the last rays
of sun you get so it is lighter for them than it appears to us.....

Those are the thoughts I have on the subject... Now someone tell me how they
land????

DK

P.S. We had the most beautiful white heron land in our oak tree above the
pond yesterday. I rushed madly about trying to find a working camera.
Couldn't find one so the three of us just gapped at this huge beautiful bird
hanging over the pond (with me hoping he wasn't going to have lunch at my
expense...). He apparently didn't like the audience he must have sensed and
flew off after about 5 minutes.

"Roger Grady" wrote in message
...
wrote:

that is true. many birds do migrate at night!! I wonder why they
migrate at night
but wont fly when released. Odd.

My un-educated guess: By flying at night they may be less susceptible
to predators. I assume they depart at dusk and fly until dawn. If
disturbed at night on the ground, there are probably obstacles around
that would be hard to see and thus they're reluctant to fly.

Roger Grady
To reply by email, remove "qlfit." from address