Behavior

Black-capped Pygmy-Tyrant primarily forages from the midstory to the canopy. These small flycatchers perch quietly, then sally out to glean small insects or arachnids from the undersides of leaves in quick darting movements before once again perching and remaining still (Slud 1964, Sherry 1984, Greenberg and Gradwohl 1980, Greenberg and Gradwohl 1985, Robinson 2001). The foraging sally is very fast, described as a "lightning flit" (Slud 1964) or as a dart (Stiles and Skutch 1989). They sometimes also hover glean (Stiles and Skutch 1989; Greenberg and Gradwohl 1980; Greenberg and Gradwohl 1985).

Due in part to its very small size, and it's tendency to remain still while scanning for prey, this pygmy-tyrant often is often difficult for human observers to detect (Slud 1964); they have been described as resembling "tiny knots of wood rather than birds"(Wetmore 1972). Furthermore, their vocalizations are easy to pass off as the call of a frog or insect, although once its vocalizations are learned, the human observer often then realizes that this bird in fact is quite common (Slud 1964).

Black-capped Pygmy-Tyrant presumably is territorial, but there are no published data on territorial defense, maintenance, or fidelity, or for territory or home range size, for this species.

Black-capped Pygmy-Tyrant presumably is at least socially monogamous.

Dan Lane observed an apparent courtship display between two birds that were "sitting on Cecropia petioles at about 4m up. One would hover, like [a] hummingbird, in front of the other while giving the grunting calls. Eventually, one flew farther away (male?), giving the 'song', to be joined by the other and do [the] display again".

Sandoval and Arendt (2011) observed a pair of Black-capped Pygmy Tyrants in early March moving "furtively within a bush on the forest edge", and suggested that the pair was searching for a nest site.

Most often found in alone or in pairs (Greenberg and Gradwohl 1985), and may occur in family groups (adults with recently fledged juveniles; Stiles and Skutch 1989). Black-capped Pygmy Tyrants does not associate with mixed species flocks (Ridgely and Gwynne 1989).

No reports of predation on Black-capped Pygmy-Tyrant?