sparrow hawk vs American kestrel

sparrow hawk and American kestrel both are nouns.

Word	Noun	Adjective	Verb	Adverb
sparrow hawk	Yes	No	No	No
American kestrel	Yes	No	No	No

As nouns, sparrow hawk and American kestrel are synonyms defined as:

Other synonyms of sparrow hawk include Falco sparverius, kestrel.

sparrow hawk (noun)	American kestrel (noun)
small North American falcon	small North American falcon
small hawk of Eurasia and northern Africa