Slate-throated Redstart is an active forager, noted for its prominent flush-pursuit foraging displays; it hops and flits through foliage or over trunks and along branches, often with an erect, spread tail that reveals the contrasting white patches in the outer rectrices. The animated foraging display helps to flush insects that are then captured in intricate aerial pursuits or, less often, gleaned from bark or foliage (see Diet and Foraging). It frequents treefall gaps and forest edges and often is tolerant of human disturbance.
Slate-throated Redstart is generally permanently territorial and remains paired throughout the year (Stiles and Skutch 1989), although unpaired territorial males and non-territorial male floaters occur in at least some populations (see Demography and Populations). During winter at high latitudes (e.g., northern Mexico) or during bad weather at high-elevation tropical locations, individuals may temporarily abandon their territories and move to lower elevations (Shopland 1985, Curson et al. 1994, Howell and Webb 1995).
Slate-throated Redstart generally is socially monogamous, with biparental care of nestlings and fledglings (see Breeding). During five years of study of a color-banded population in Monteverde, Costa Rica, only one case of probable polygyny was observed (R. L. Mumme, unpublished data). Extra-pair paternity, which occurs frequently in Parulidae that breed in North America, has not been investigated in Slate-throated Redstart.
Social and interspecific behavior
Usually in pairs throughout year, and Slate-throated Redstart often accompanies mixed-species foraging flocks (see Diet and Foraging). In areas where it is syntopic with other species of Myioborus, Slate-throated Redstarts can show weak interspecific aggression (Shopland 1985, Fjeldså and Krabbe 1990, Curson et al. 1994).
No information on predation on adults is available. Birds from south central Costa Rica (subspecies aurantiacus) are host to a recently described species of chewing feather lice, Myrsidea myiobori (Founek et al. 2011). See Breeding for information on nest predation.