SAW-WHET OWL: Aegolius arcadicus.
The only tiny tuftless owl likely to be seen in the central and eastern states. (Length 7", Wingspan 17")
Commoner than generally believed, but nocturnal and seldom seen unless found roosting in dense young evergreens or in thickets. ...
Common call is a long series of short whistles." (Birds of North America, by Chandler S. Robbins, et al. p. 164)
Range covers the entire United States, with the exception of the far southeast.