mouse hawk
/ˈmaʊs hɔːk/noun
A bird of prey that catches mice; especially †(a) the short-eared owl, Asio flammeus ( obsolete ); (b) US the hen harrier, Circus cyaneus; (c) US the rough-legged buzzard, Buteo lagopus ( rare ).
Origin
Old English; earliest use found in Corpus Glossary. From mouse + hawk.