The falcon face marks, called mustache marks, act much like the a football player's cheek black, cutting glare. The American Kestrel nests in cavities in trees. They can use nesting box as well. Males and females have mustache and sideburn marks. Males have blue gray wings, a reddish back and a reddish tail with a single sub-terminal tail band.
Females have reddish wings but are darker from the wrist to the tip of the wing and reddish backs.
The female has a reddish tail with multiple narrow bands. Kestrels hunt by hovering over a spot or from a perch in a tree, on a phone or power wire or post. The female does not have the blue gray wings of the male kestrel. The female has many dark bands on the tail while the male has one wide black band on the tail. Photos taken at Hawk Hill during Golden Gate Raptor Observatory banding demonstrations.