The Plumbeous Kite can be found in the tropical zone of the New World, usually below 1,000 or 1.500 meter, from east central Mexico south to northern Argentina and Paraguay. In the northern- and southern-most parts of its range, it is migratory - most of the population of Mexico and Central America wintering in South America. In Argentina it is at least partly migratory, arriving in its breeding territory abundantly about the middle of September, and leaving, perhaps for the Amazon area, in autumn. It is present throughout the year in Surinam, breeding in March—April, the opposite of the more southern area where it breeds in October-November.

This kite has a wide habitat range. In various parts of its range it can be found in the mangrove zone, on pine ridges, over the near-tropical forest and adjacent roads and clearings, and in heavily forested low hills. In parts of the range, for example Costa Rica, it is local or absent except as a migrant.

Mating commences almost immediately on arrival at the breeding grounds, often with no preliminary courtship display. Nest trees are dry season deciduous. Because nest building and incubation takes (in venezuela) place late in the dry season, the trees are usually leafless making the nests conspicuous. Nests become less conspicuous during the nestling period when nest trees leafed out at the onset of the rainy season. Nests averages 25.5 m above ground while nest trees averages 30.0 m tall. Nests are in forks created by two or more limbs, usually against the bole or on major limbs, but sometimes in slender limbs toward the outer part of the crown (n = 4). Nests arre high and exposed to sun and wind. Some nests are built on large clumps of bromeliads. Nests are built of dry sticks, lined with sprigs of green leaves, both sexes participate in construction. throughout incubation and nestling periods adults periodically add green sprigs to nests. Kites nested in the same nests or in other nearby trees from year to year. Supposedly only single-egg clutches and broods of one are laid.
During the incubation period, one adult or the other is on the nest nearly constantly. When no kite is on the nest, adults remain vigilant, with one usually perched in or near the nest tree or soaring nearby. Both sexes incubate, switching roles periodically throughout the day. On average, one adult provided 61% of incubation and the other 39%. Pair members caught their own prey throughout the incubation phase.
Both parents feed the young, one, presumably the female, spending much of the time 'standing guard' in the top of the nesting tree; this individual also broods the young at night. Other birds, including toucans and vultures, are chased away when they approach the nest. In weather when the parents can soar and easily catch insects, the young may be fed as often as ten times an hour, which, for a bird of prey, is very high.

The diet of the Plumbeous Kite consists chiefly of large flying insects, but smaller insects, such as flying termites, are also taken. Most insects are caught in the feet. This is supplemented by snails and occasionally, or in some situations, it takes both warm- and cold-blooded small vertebrates.

This species has a large range, with an estimated global Extent of Occurrence of 13,000,000 km2. It has a large global population estimated to be 1,000,000-10,000,000 individuals (Ferguson-Lees et al. 2001). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern.

Migratory in North and South of range in respective autumns. North birds move South through Panama in August and Septembr, returning to breed in March. Central American population certainly migratory, while even those in North Venezuela and Colombia may migrate South during dry season, when insects less abundant. Limits of permanently resident populations not known. Flocks appear sporadically over Central Amazon, may be nomadic migrants.