Black-winged Kite (Elanus caeruleus)
Elaninae or elanid kites, sometimes white-tailed kites, is any of several small, long-winged, hovering birds of prey. All are specialist rodent hunters and most are members of the genus Elanus. Some authorities list the group as a formal subfamily, Elaninae. As a subfamily there are eight species in five genera with four of these genera being monotypic.
Elanid kites have a near-worldwide distribution, with three endemic species found in the Americas, two in Australia, one each in Africa and southern Asia, while the black-winged kite is found over a vast range from Europe and Africa in the west to Southeast Asia in the east.
Taxonomy and Systematics
In 1851 British zoologist Edward Blyth described Elaninae, the "smooth clawed kites", as a formal subfamily of Accipitridae. However they are also grouped in Accipitrinae, the broader subfamily of hawks and eagles described by French ornithologist Louis Jean Pierre Vieillot in 1816.
Vigors in 1824 had grouped Elanus and "true Milvus" together into Stirps Milvina, the kites. Earlier, the terms "kite" in English or "iktinos" in Greek referred only to the red or black (milvine) kites. He listed three known species: Elanus melanopterus, Elanus furcatus, and Elanus riocourii. But he noted that the latter two had more forked tails and probably didn't have nails that were rounded underneath.
In 1931, Peters used the subfamily Elaninae, listing its members as Elanus, Chelictinia, and Machaeramphus. He placed Elanoïdes in subfamily Perninae, and Gampsonyx with the forest falcons in Polyhieracinae. In the 1950s, several authors found Gampsonyx was related to Elanus rather than the falcons, based on morphological features and molt schedule.
Lerner and Mindell describe the Elaninae as: "Kites noted for having a bony shelf above the eye, Elanus is cosmopolitan, Gampsonyx is restricted to the New World and Chelictinia is found in Africa". This is in contrast to the Perninae, which are: "Kites mainly found in the tropics and specializing on insects and bee or wasp larvae, all lack the bony eye shield found in the Elaninae".
Comparisons of sequences for certain mitochondrial marker genes indicate that some elanid kites split early from the rest of the Accipitridae. Wink and Sauer-Gurth found that Elanus was less related than the osprey and secretary bird (which are often placed in a separate family), but noted that this was not strongly indicated. However, Lerner and Mindell found that the osprey was less related, but Elanus leucurus was basal to the other Accipitridae.
Lerner and Mindell also found that Elanoides forficatus grouped with Perninae, such as the type species Pernis apivorus and the Australian endemics Lophoictinia and Hamirostra.
Chelictinia, Machaerhamphus, and Gampsonyx were not included in these genetic sequencing studies.
Current Elaninae Genus: Elanus Black-shouldered Kite (Latham, 1801) (Elanus axillaris) Black-winged Kite (Desfontaines, 1789) (Elanus caeruleus) White-tailed Kite (Vieillot, 1818) (Elanus leucurus) Letter-winged Kite (Gould, 1842) (Elanus scriptus) Genus: Gampsonyx Pearl Kite (Vigors, 1825) (Gampsonyx swainsonii) Genus: Chelictinia Scissor-tailed Kite (Vieillot, 1822) (Chelictinia riocourii) Previously in Elaninae Genus: Machaerhamphus or Macheiramphus (subfamily Harpiinae) Bat Hawk (Bonaparte, 1850) (Macheiramphus alcinus) Genus: Elanoides (subfamily Perninae) Swallow-tailed Kite (Linnaeus, 1758) (Elanoides forficatus)