Thanks, SØREN, for an excellent photo
of 3 vivid Knots in different flight
'mo(ve)ments'!

I commented S. Skov's photo of 21st
May 2006 of flying Knots, regarding a
distinct dark patches appearing on
the hand coverts of some of the birds,
but not all of them.

The right Knot on Your photo demonstrates
that the SAME individual can display a
dark patch on one wing, and None on the
other one.
So, apparently it's solely a matter of
light/angle if a KNOT displays a black
wing patch in spring - or NOT...

Thanks ............. Yours C.