The Kestrel is the smallest of North American falcons. It is about the size of a mourning dove. Evidently, this one is a female I saw as I walked the Mill Race Path.
According to 'All About Birds'
"It's one of the most colorful of all raptors: the male’s slate-blue head and wings contrast elegantly with his rusty-red back and tail; the female has the same warm reddish on her wings, back, and tail. It packs a predator’s fierce intensity into its small body."
"American Kestrels occupy habitats ranging from deserts and grasslands to alpine meadows. You’re most likely to see them perching on telephone wires along roadsides, in open country with short vegetation and few trees."