Like other species in the genus Tangara, the Beryl-spangled Tanager is an omnivore, eating both fruit and arthropods. In Valle, Colombia, 85% of 92 observations involved insect foraging (Hilty, cited in Isler and Isler). Naoki (2003, 2007) quantified foraging observations in Peru and Ecuador. In Ecuador, of 115 forgaging observations, 62% involved fruit and 38% involved arthropods (Naoki 2003, 2007). In Bolivia, 235 foraging observations were made and 80% involved fruit and 20% involved arthropods (Naoki 2003). In Ecuador, fruits eaten were almost exclusively (97%) from Miconia. In Bolivia, Miconia also were the most dominant fruit eaten (77%), but fruits of Trema (17%) were also eaten. In Ecuador, attack maneuvers used in fruit foraging included glean (70%), reach-up (9%), reach-out (8%), reach-down (5%), and hang-side (5%). In Bolivia, 90% of attack maneuvers were glean, with other maneuvers used being reach-up (4%) and reach-out (3%). When foraging for arthropods, gleaning also is the primary attack mode used. In Ecuador, arthropod foraging modes included glean (46%), reach-down (17%), hang-down (13%), and hang-side (8%). In Bolivia, arthropod foraging modes included glean (41%), hang-down (16%), and reach-down (9%). When hunting for arthropods, the Beryl-spangled Tanager searches primarily leaves and bare branches. In Bolivia, dead leaves were searched more often than they were in Ecuador (Naoki 2003).
Stomachs (n = 8) of Beryl-spangled Tanagers included vegetable matter (7) or both vegetable and animal matter (1). Specific contents included fruit pulp, seeds, and coleopterans (Isler and Isler 1987).