Diet and Foraging

Almost all information on the diet of Yellow-throated Toucan refers to swainsonii. These toucans are largely frugivorous. Being generalists, they eat from a wide variety of fruiting trees and play a vital role in seed dispersal. Preferred food sources include Virola, Casearia, Cecropia, Protium, Hampea, and Trophis spp. (Howe 1977, 2004; Skutch 1980). Virolas are especially important food sources for Yellow-throated Toucans. For example, 43% of V. sebifora fruit eaten by birds is consumed by this toucan (Howe 1981). Casearia corymbosa is also a vital food source for toucans since it fruits throughout months when very little else is available. Howe (1977) observed Yellow-throated Toucans feeding extensively on Casearia during Costa Rica’s early dry season, but noticed virtual abandonment when other fruits (Virola and Protium) came into season.

Yellow-throated Toucans also sometimes take lizards, large insects, and the eggs and young of other birds. Insect prey includes cicadas and walking sticks (Howe 1977). They have also been recorded attempting to chase and snatch flying termites out of the air (Skutch 1972, Short and Horne 2001). Mindell and Black (1984) observed a pair of toucans cooperatively hunt and consume a small lizard (see Behavior). Yellow-throated Toucans also raid the nests of Social Flycatchers (Myiozetetes similis), Tropical Kingbirds (Tyrannus melancholicus), Boat-billed Flycatchers (Megarynchus pitangua), Collared Araçaris (Pteroglossus torquatus), and some woodpeckers (Picidae) (Skutch 1972, Short and Horne 2001). One toucan even drove a Double-toothed Kite (Harpagus bidentatus) from its nest and ate one of the eggs (Laughlin 1952).

Despite what may seem like a voracious appetite for meat, animal matter only makes up a tiny portion of the diet of Yellow-throated Toucan. Adult birds eat over 90% fruit and are thought to mainly catch prey for their young (which require extra protein for growth). In one study that analyzed stomach contents, none of the six Yellow-throated Toucan stomachs examined held any animal matter whatsoever (Remsen et al. 1993).

Yellow-throated Toucans mostly range in the treetops, where they forage singly, in pairs, or in small groups, although larger numbers may gather where food is plentiful. Reportedly forages higher than "keel-billed" Ramphastos (Hilty and Brown 1986) but occasionally takes fallen fruit from the ground. While foraging, toucans hop from branch to branch, reaching, hanging, plucking, and twisting off whatever fruit they can find. Their beak often helps in this respect since it allows the toucan to reach out and grab fruits while maintaining a center of gravity (Short and Horne 2002). Once fruit is in its possession, a toucan usually tosses its head back and swallows the fruit. For particularly large fruits and prey, toucans sometimes hold the item down with one foot while they feed (Short and Horne 2002).

Smaller, slow-moving prey (such as insects or frogs) is gleaned from branches and epiphytes. Bird nests are sought out during breeding season, where the toucan’s bill helps by allowing it to reach deep inside nest cavities (Short and Horne 2002). Yellow-throated Toucans are not usually known for pursuing mobile prey, although there is one record of a pair cooperatively hunting down a lizard (Dactyloa frenata): one toucan repeatedly flushed the lizard from hiding while the other pursued it lengthwise down a tree trunk (Mindell and Black 1984). Once prey is caught, it usually is killed by a crushing action of the beak.