There is very little information on the behavior of Red-billed Tyrannulet, although its general actions are similar to those of other members of the genus Zimmerius: it forages primarily in the canopy, often cocks the tail above the horizontal and occasionally flicks the wings, and takes its food with gleans and short sallies (Fitzpatrick 2004).
There are no published data on territorial defense, maintenance, or fidelity, or on home range size, for Red-billed Tyrannulet.
Undescribed; Red-billed Tyrannulet presumably is at least socially monogamous.
Social and interspecific behavior
Red-billed Tyrannulet usually is solitary or in pairs, which may associate with mixed species flocks (Fitzpatrick 2004).
No reports of predation on Red-billed Tyrannulet?