The second clade includes the American subspecies,
H. r. erythrogaster, together with the two exclusively Asian
subspecies: H. r. gutturalis of Southeast Asia and H. r. tytleri from
northwest Asia. This division of the Barn Swallow into two major
groups is further supported by a conspicuous plumage trait, the extent
of the dark breast band; this band is broad and complete in all
subspecies within the Europe-Middle East clade, and it is narrow
and sometimes incomplete in the subspecies within the Asia-
America clade.