O. abeillei forages with mixed species flocks in pairs and small groups of usually 4-5 high in the canopy (Isler and Isler 1987, Ridgely and Tudor 1998, Hilty 2011). Davis (1946) found that they are regular members of these mixed species flocks. The Brown Tanager forages by hopping or clambering along larger shady branches inspecting epiphytes, dead leaves, moss, lichen, and even spider webs (Isler and Isler 1987, Ridgely and Tudor 2009, Hilty 2011). The Brown Tanager catches insects by sudden sallies or lunges (Isler and Isler 1987, Sick 1993). When at rest it perches upright (Isler and Isler 1987, Ridgely and Tudor 2009).
The Brown Tanager has a pre-copulatory display that consists of wing-fluttering, tail-lifting, and crouching on a horizontal branch (Willis 1976). The male and female face each other about 10 cm apart, motionless and upright, with wings drooping and tail spread and depressed (Isler and Isler 1987, Hilty 2011).
Social and interspecific behavior
The Brown Tanager occurs in mixed species flocks with the Buff-fronted Foliage Gleaner (Philydor rufum) at 1100-1500 m elevation in the montane forests of southeastern Brazil. The Brown Tanager is a possible mimic of P. rufum (Willis 1976). The case of mimicry was evaluated by Beauchamp and Goodale (2011) using multiple rater blind analysis and was concluded to be “probable.” The Brown Tanager is probably the mimic based on tanagers rarely being protectively colored and the divergence from others of its family. It is most likely not competitive mimicry because of the different bill shapes that suggest different diets (Willis 1976). Sazima (2010) stated that joining mixed flocks with P. rufum provides benefits when predators attack the flock. Sazima (2010) observed the Brown Tanager in a mixed species flock with about four different species including P. rufum and Pachyranphus castaneus, the Chestnut-crowned Becard, which both resemble the Brown Tanager, the former more so than the latter. The flock scattered noisily when attacked, with the exception of the Brown Tanager, which hid under a leaf. Due to this different evasive tactic, Sazima (2010) suggested that the Brown Tanager benefits from its resemblance of both species in predator avoidance. The Brown Tanager also commonly associates with Orthogonys chloricterus in mixed species flocks (Legal and Kohler 2008).