Description
ADULT MALE: A small kite; generally appears more falcon-like than hawk-like. The head, hind-neck, and secondaries are pale ashy gray and are white-tipped. The mantle is dark, slaty, ashy, gray becoming more black at the bend of the wing; the upper back blending with the paler hind-neck. The tail is almost always squarish to rarely slightly forked; tail and primaries are slaty blackish color. The inner primaries often have a pale rufous area on the outer web and spots of similar color on the inner web. Lores and the area around the eyes are black. Underparts are light gray, but not as pale as the crown and throat. Eyes are deep red. The bill, cere, eyelids, and interior of the mouth are deep black; corner of mouth orange-red. Legs are a variable salmon-orange-red, rarely to yellow; basal phalanges of inner toe are fused to form a single functional unit. Average measurements: wing 286-305 mm; tail 149-172 mm; tarsus 35-41 mm; weight 216-269 g.
ADULT FEMALE: Sexes similar; female being larger with a darker gray head compared to the male. Average measurements: wing 300-315 mm; weight 278-339 g.
JUVENILE: Generally dark brown to blackish above. Head, neck, and ventral body is heavily streaked; secondaries are not lighter than primaries. On the tail feathers, the white areas on the inner webs are extensive and from two to three broad transverse bars. Eyes dark brown; bill bluish-gray; cere, corners of mouth, and legs yellowish-orange to orange.
IMMATURE: The body plumage is similar to the adult with the juvenile wing, tail quills, and a variable number of contour feathers retained. The mixture of adult and juvenile plumage creates a white spotted effect. Eyes may be less red than the adult; bill black; cere and legs may be more yellowish.
HATCHLING: White and downy with black eye-ring and lores. Beak blackish, cere and rictus vivid to pale yellow. Eye dark brown. Legs usually orange-yellow.
EGGS: white.
See also Johnsgard (1990), Parker (1988), National Geographic Society (1987), Terres (1980), Harrison (1975), Brown and Amadon (1968).
Diagnostic Characteristics
No other raptor can be confused with the "adult" kite (Parker 1988). Juvenile birds are likely to be mistaken for young of other species (e.g., Broad-winged hawk (BUTEO PLATYPTERUS), peregrine falcon (FALCO PEREGRINUS)). Wing and tail shapes are key distinguishing features. In flight, the wings are pointed with the leading primary relatively short and from a distance can be confused with a peregrine falcon. The uniformly black tail readily distinguishes this raptor from any other. Very similar in appearance to the Plumbeous Kite (I. PLUMBEA); where ranges overlap, sight identification becomes difficult.
Habitat
BREEDING: Tall forest, open woodland, prairie, semiarid rangeland, shelterbelts, wooded areas bordering lakes and streams in more open regions, scrubby oaks and mesquite, and lowland/floodplain forests. Requires open areas near nesting sites for foraging. More specific breeding habitat components vary by region (Great Plains and Southeastern U.S.). Nests in fork or crotch of tree, high up where possible but sometimes low in scrubby trees (Harrison 1978). May sometimes nest in stands of mature trees in towns. Most nests placed in non-conifer near woodland edge. Often reuses old kite nest.
Historically, in the Great Plains was associated with areas having sizable riparian woodlands along major river systems. Kite numbers increased during the 1950's and 60's as the birds began using shelterbelts (tree plantings designed for windbreaks and to impede soil erosion) as nest sites (Johnsgard 1990, Meyer 1990, Bolen and Flores 1989, Parker and Ogden 1979). The increase of mesquite thickets, associated with cattle raising and farming, has also offered new nesting areas, as have farm woodlots and shade trees in towns. This increase in nesting habitat has created a more uniform regional distribution of nesting kites in the Great Plains (Parker 1988, Parker and Ogden 1979).
In contrast, nest site selection in the Southeast has not changed as a result of habitat alteration to the extent that it has in the Midwest (Parker 1988, Parker and Ogden 1979). Nests in the Southeast are most commonly found in mature, undisturbed stands of lowland and floodplain forests and along major rivers and feed over adjacent fields (Hamel et al. 1982, Hamel 1993, Parker 1988).
NON-BREEDING: Little is known of migration and wintering habits (Johnsgard 1990, Parker 1988, Glinski and Ohmart 1983, Parker and Ogden 1979). Because it prefers to forage over open and edge habitats, agricultural expansion and forest removal in Central and South America may increase foraging habitat and prey populations there, as has happened in North America (Parker 1988, Parker and Ogden 1979).
Ecology
Forages or perches alone and in small to large flocks (Parker 1988). Usually forages within 0.5 kilometers of nest; sometimes up to several kilometers.
Reproduction
Nest preparation begins in early to mid-May, but birds may build new or add to old nests during June and early July (Parker 1988). Single brooded, clutch size one to two (usually two, rarely three). Incubation 29-31 days (also reported as 32 days), by both sexes. Young tended by both parents, climb out of nest to adjacent branches at 15-18 days, can fly at 34 days, rely on adults for several weeks thereafter (Parker 1988, Brown and Amadon 1968). Studies in the Great Plains, Arizona, and Illinois found about 50% of nests fledged young (Palmer 1988). Yearlings may breed or help at nest. Often a gregarious nester. Productivity very high in some suburban settings (e.g., golf courses), which provide protection from predators (Glinski and Gennaro 1988, Gennaro 1988).
Nests are found in groups sometimes referred to as colonies. There are no home range data in literature (Kalla and Alsop 1983), however home range has recently been studied by the University of Missouri. Glinski and Ohmart (1983) state that territory size consisted of a space within 50 to 100 meters from an active nest. Parker (pers. comm.), however, questions this claim stating that he has never seen clear territorial behavior in these kites. Glinski and Ohmart (1983) also noted that nests within their study groups were spaced from 125 to 1,700 meters. Adult kites seldom fail to pair and attempt nesting (Glinski and Ohmart 1983, Parker 1988).