One of my favorite days on the river cruise we took was when
we traveled through the Rhine Gorge. There were castles, pretty villages and
lots and lots of vineyards all over the hillsides. They all looked so lush.
It was harvest time for the grapes while we were there, but
they also left grapes on the vines so they could later make
"Ice wine." This is a late-harvest dessert wine that is
highly-prized.
In order to make it, they have to let the grapes go through
a couple of frosts which makes them sweeter. However, that can be problematic
because birds will try to eat all of those grapes.

Their solution? You'll notice in the second photo that some of
the vines are covered with blue netting. That's what their using to keep the
birds at bay. Pretty ingenious, eh? (
click on the second photo to see an enlarged view)