What is "sharp-shinned hawk"

n. The smallest hawk to reside in USA and Canada, which preys on songbirds, Accipiter striatus

The sharp-shinned hawk (Accipiter striatus) is a small hawk described from Hispaniola, with males being the smallest hawks in the United States and Canada, but with the species averaging larger than some Neotropical species, such as tiny hawk. The taxonomy is far from resolved, with some authorities considering the southern taxa to represent three separate species: white-breasted hawk (A. chionogaster), plain-breasted hawk (A. ventralis), and rufous-thighed hawk (A. erythronemius).