Its systematics are under revision; it contains 3 or 4 species.
- Red Kite, Milvus milvus
- Cape Verde Kite, Milvus (milvus) fasciicauda – extinct (2000)
- Black Kite, Milvus migrans
- Black-eared Kite, Milvus (migrans) lineatus
- Yellow-billed Kite, Milvus (migrans) aegyptius
Allozyme data indicates that the genetic diversity in both Black and Red Kites is rather low (Schreiber et al. 2000). Successful hybridization between Milvus kites is fairly commonplace, making mtDNA analyses unreliable to resolve the genus’ phylogeny.
Furthermore, there is no good correlation between molecular characters and biogeography and morphology in the Red Kite due to very incomplete lineage sorting.
The Yellow-billed Kite is apparently a good species, as indicated by mtDNA phylogeny, biogeography, and morphology.
The Black-eared Kite is somewhat distinct morphologically, but is better considered a well-marked parapatric subspecies.
The status of the Cape Verde Kite is in doubt; while not a completely monophyletic lineage according to mtDNA data, it is still best regarded as a distinct species. Whatever its status, this population is extinct.
A prehistoric kite from the Early Pleistocene (1.8 million – 780,000 years ago) deposits at Ubeidiya (Israel) was described as Milvus pygmaeus.