Oops, forgot to write my name and location: Linda Bainbridge,
Greenbank, Whidbey Island

I hang mylar strips from my many windows, but still get window strikes.
Last summer two Olive-sided Flycatchers hit my window. I think the
problem is worse during migration or when the new-born birds have
fledged.

Audubon has a good discussion of the problem at:
http://www.audubon.org/bird/at_home/SafeWindows.html

Here's what they say about decals and mylar strips:

"Practicality - MED: Although decals are easily affixed to windows and
are available in a range of styles (it is not necessary to use a hawk
silhouette), they must be spaced close to each other to be effective -
at most 2 inches apart horizontally, and 4 inches apart vertically.
Objects, such as ribbon draped on the exterior side of a window must
also be spaced strategically to create density. This density causes too
much visual obstruction for many people. Covering just a portion of a
window is better than no coverage at all."
<http://www.audubon.org/bird/at_home/SafeWindows.html>