Ramphocelus flammigerus is an understory and canopy forager (Parker et al. 1996) and characteristically perches on and pecks pieces from large fruits such as bananas (Restall et al. 2007). It also perches on twigs or branches to take smaller fruits or berries, which are swallowed whole. Short sallies to air for insect-catching although rarely takes berries by sallying. Also peers and picks insects off foliage, grass or ferns and occasionally involves hanging from twigs or leaves in an acrobatic search for insects (Hilty 2011). Foraging takes place mostly below 9 m, usually at a height of 7.5 m off the ground and sometimes higher, up to 25 m (Isler and Isler 1987).
In Panama, male Ramphocelus flammigerus defend breeding territories (Moynihan 1966). No information found on mate guarding.
R. flammigerus appears to be monogamous, although more than one male may display simultaneously in front of a female. Male displays before the female by expanding the rump feathers so that the bright color shows below the line of the wings, later turning the back to her and quivering his wings slightly (Wetmore et al. 1984).
Males still in immature plumage also breed (Wetmore et al. 1984), which indicates the bright coloration of the rump might not be a determining factor for sexual selection among R. flammigerus.
Social and interspecific behavior
The two subspecies of Ramphocelus flammigerus show different social behaviors: R. f. flammigerus is most often seen singly or in pairs while R.f. icteronotus often form noisy small flocks of up to 12 individuals with adult males in minority, constantly uttering loud rat-like calls. Sometimes young or adults are seen alone (Hilty 2011).
Female incubates alone for 11-14 days but chicks are taken care of by both adults (Hilty 2011).
R. flammigerus rarely joins mixed-species flocks but joins feeding aggregations at fruiting trees (Restall et al. 2007). It often occurs with Blue-gray and Palm Tanagers (Ridgely and Greenfield 2001).