A dark patch of feathers on the breast [1], or a pattern of uniformly dark breast that contrasts with paler belly [2].
Reference[]
^Liguori, Jerry; Pete Dunne (2011). Hawks at a Distance: Identification of Migrant Raptors. Princeton, NJ: Princeton University Press. p. 3. ISBN0691135592.Cite uses deprecated parameter |coauthors= (help); |access-date= requires |url= (help)
^Clark, William S.; Brian K. Wheeler (2011). Hawks of North America, 2nd Edition. Boston, MA: Houghton Mifflin Company. p. 12. ISBN0395670675.Cite uses deprecated parameter |coauthors= (help); |access-date= requires |url= (help)
This article is part of Project Glossary, an All Birds project that aims to write comprehensive articles on each term related to animals.