Milvus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of medium-sized birds of prey

Bird of prey

Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....

. It is an Old World

Old World

The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....

 group consisting of three kites

Kite (bird)

Kites are raptors with long wings and weak legs which spend a great deal of time soaring. Most feed mainly on carrion but some take various amounts of live prey.They are birds of prey which, along with hawks and eagles, are from the family Accipitridae....

 which form part of the subfamily Milvinae. Its systematics

Systematics

Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...

 are under revision; it contains 3 or 4 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

.

• Red Kite
  Red Kite
  The Red Kite is a medium-large bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as eagles, buzzards, and harriers. The species is currently endemic to the Western Palearctic region in Europe and northwest Africa, though formerly also occurred just...
  
  , Milvus milvus
  • Cape Verde Kite, Milvus (milvus) fasciicauda – extinct (2000)
• Black Kite
  Black Kite
  The Black Kite is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors. Unlike others of the group, they are opportunistic hunters and are more likely to scavenge. They spend a lot of time soaring and gliding in thermals in search of food. Their...
  
  , Milvus migrans
  • Black-eared Kite, Milvus (migrans) lineatus
  • Yellow-billed Kite
    Yellow-billed Kite
    The Yellow-billed Kite is the Afrotropic counterpart of the Black Kite , of which it is most often considered a subspecies. However, recent DNA studies suggest that the Yellow-billed Kite differs significantly from Black Kites in the Eurasian clade, and should be considered as a separate,...
    
    , Milvus (migrans) aegyptius

Allozyme

Allozyme

Variant forms of an enzyme that are coded by different alleles at the same locus are called allozymes. These are opposed to isozymes, which are enzymes that perform the same function, but which are coded by genes located at different loci....

 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

Correlation

In statistics, dependence refers to any statistical relationship between two random variables or two sets of data. Correlation refers to any of a broad class of statistical relationships involving dependence....

 between molecular characters and biogeography

Biogeography

Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...

 and morphology

Morphology (biology)

In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....

 in the Red Kite

Red Kite

The Red Kite is a medium-large bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as eagles, buzzards, and harriers. The species is currently endemic to the Western Palearctic region in Europe and northwest Africa, though formerly also occurred just...

 due to very incomplete lineage sorting.

The Yellow-billed Kite is apparently a good species, as indicated by mtDNA phylogeny showing two supported clades (Johnson et al. 2005), 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 (Johnson et al. 2005), it is still best regarded as a distinct species. Whatever its status, this population is extinct.

A prehistoric kite from the Early Pleistocene

Early Pleistocene

Calabrian is a subdivision of the Pleistocene Epoch of the Geologic time scale. ~1.8 Ma.—781,000 years ago ± 5,000 years, a period of ~.The end of the stage is defined by the last magnetic pole reversal and plunge in to an ice age and global drying possibly colder and drier than the late Miocene ...

 (1.8 million – 780,000 years ago) deposits at Ubeidiya (Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

) was described as Milvus pygmaeus.