This swallow breeds in the mountains of Mexico during summer. Breeding records describe nests in tree cavities; its wintering grounds remain unknown.
Breeding males are bluish purple with a white belly and undertail. Females are similar, but have a dark gray-brown throat and upper breast.
At breeding sites it nests colonially, mainly in tree cavities. The account records one small group of 2–6 birds and historical groups of 15–30 or more; the wintering grounds are unconfirmed.
An extinction-risk assessment has not been added yet.