Locomotion: Giant Conebills are generally quiet and inconspicuous; their movement is described as slow and deliberate while moving from tree to tree during foraging bouts (Isler and Isler 1999).
Foraging Behavior: Giant Conebills forage for insects from near the ground, to the tops of trees as high as 12 m off the ground. O. fraseri primarily probes under the bark of Polylepis trees in search of insects, and is usually seen on the trunk or horizontally branching limbs. Also peels off loose bark in layers, oftentimes with neck far outstretched while clinging upside down or with legs spread out. Hitching behavior has been described as similar to Sitta nuthatches, although Ridgely and Tudor (1989) states that the Giant Conebill never hops down headfirst. Although they mainly probe bark on tree trunks, Giant Conebills have been also been observed foraging in other areas. Some individuals occasionally foliage glean in canopy level limbs. They have also been observed picking at moss and lichens, while gleaning aphids and sugary secretions from the undersides of Gynoxys leaves. In addition, they have been observed probing flowers of epiphytic mistletoe (data from Ted Parker cited in Isler and Isler 1999).
A brief video demonstrating singing and foraging behavior.
Observations of breeding pairs indicated that during incubation, one parent acts as a sentinel, perched on a high branch of Polylepis tree until the other returned with food. Parents did not emit songs while approaching the nest or during the provisioning process (Cahill et al 2008).
Little information on mating systems currently available. Giant Conebills form family groups and juveniles have been observed with parents during the first 3 weeks post fledging. Offspring have also been observed with both parents after 5 weeks of fledging, and are generally found in monospecific flocks of 4-7 individuals (Cahill et al. 2008). No information on extra-pair copulations or pair fidelity.
Social and interspecific behavior
Usually found in pairs or family groups of 4-5 individuals while foraging (Fjeldså and Krabbe 1990). Oftentimes found accompanying, and occasionally leading, conspecific or mixed-species flocks (Ridgely and Tudor 1989).
Predation by avian predators, such as the Yungas Pygmy-Owl (Glaucidium bolivianum), seems to be an imminent risk for the Giant Conebill because it sometimes forms and leads both conspecific and mixed-species flocks (Herzog et al. 2002).