Tropical kingbirds appear to be monogamous. In most parts of the species' range, they are permanent residents and remain together in pairs year-round.(Sibley 2014)[page needed] The call is a high-pitched twittering trill, tree-e-e-e-e-e-e, with a more complex version sung by the male at dawn.
Their breeding habitat is semi-open areas with trees and shrubs, including gardens and roadsides. Tropical kingbirds like to observe their surroundings from a prominent open perch, usually high in a tree, undertaking long flights to acrobatically catch insects in mid-air (hawking), sometimes hovering to pick food off vegetation (gleaning). The insects preyed upon include beetles, bees, wasps, termites, butterflies, moths, dragonflies and grasshoppers. They also eat some berries and fruit from such diverse species as tamanqueiro (Alchornea glandulosa), common guava (Psidium guajava), the Annonaceae, Cymbopetalum mayanum and gumbo-limbo (Bursera simaruba); foraging for these even in disturbed habitat. As they keep mainly to the upper levels of trees, they find little profit in following mixed-species feeding flocks in the understory.
Aplomado falcons have been known to prey on adult tropical kingbirds, while eggs and young have been attacked by swallow-tailed kites and chestnut-mandibled toucans. These birds aggressively defend their territory against intruders, even much larger birds such as magnificent frigatebirds, toucans, caracaras or hawks. In a study in Parque Nacional de La Macarena of Colombia, parasitism by microfilariae and trypanosomas (presumably T. everetti) was infrequently recorded in tropical kingbirds.
The male and female inspect potential sites together before selecting a site, typically a fork or crotch high in a tree (up to 20 m (66 ft) high) but sometimes just a few metres above water.(Sibley 2014)[page needed] The female builds a bulky, sloppy-looking, shallow nest of vines, rootlets, twigs, weeds, and grasses; it is unlined or lined with hair. Nests average about 13.2 cm (5.2 in) across and 7.6 cm (3.0 in) tall, with interior cup about 7.6 cm (3.0 in) across and 4.1 cm (1.6 in) deep.
The female incubates the typical clutch of two to four eggs for approximately 16 days, and the nestlings fledge in another 18 or 19 days. The eggs are whitish or pale pink with variable amounts of dark blotching.
