The swallow family consists of 74 bird species which typically hunt insects in flight. The two river martins have long been recognised as very distinctive, and are placed in a separate subfamily, Pseudochelidoninae, leaving all other swallows and martins in the Hirundininae. DNA studies suggest that there are three major groupings within the Hirundininae subfamily, broadly correlating with the type of nest built. The groups are the "core martins" including burrowing species like the Sand Martin, the "nest-adopters", with birds like the Tree Swallow which utilise natural cavities, and the "mud nest builders". The Cecropsis species construct a closed mud nest and therefore belong to the latter group. It is believed that the evolutionary sequence is from species that make open cup nests (Hirundo and Ptyonoprogne), through Delichon house martins with closed nests, to Cecropis and Petrochelidon, which have retort-like closed nests with an entrance tunnel.
The species (in taxonomic order) are:
- Greater Striped Swallow Cecropis cucullata
- Lesser Striped Swallow Cecropis abyssinica
- Red-breasted Swallow Cecropis semirufa
- Mosque Swallow Cecropis senegalensis
- Red-rumped Swallow Cecropis daurica
- Striated Swallow Cecropis striolata
- Rufous-bellied Swallow Cecropis badia