Dimwitted Wood Pigeons

slowburner

Some friends have a problem with wood pigeons. They have been in their house for thirty odd years and just lately, the pigeons have started flying in to their (closed) French windows. This never happened before but it has now become a regular occurrence. The biggest problem apart from frightening the bejaysus out of these folk is that the impacts set off the house alarm. Needless to say, the neighbours aren't over the moon about it.
They have asked me to think of a solution but I've drawn a blank.
I suppose there are two questions: why have the pigeons started to do this and how can they be prevented from doing it - short of putting up wire mesh?
Any suggestions?

looksee

stick/hang a hawk sillhouette in the window. http://www.snap2objects.com/2008/07/23/46-free-vector-flying-birds-silhouettes/

slowburner

Thanks for that looksee but the link is incompatible with a Mac
Wouldn't there have to be light behind the glass to make a silhouette effective though?

fiacha

My folks had the same issue with Doves. I hung a CD shiny side out on a plant in front of the window. The light reflecting from the surface of the CD stopped the issue straight away.

Also keeps them off the fruit trees
Hope it helps.
F.

slowburner

Makes sense. I will try that, thanks