Locomotion: Azure-rumped Tanagers move rather quickly among twigs, but are not skulky.
Foraging: Tanagers pluck small fruit such as Perrottetia longistylis, rip off pieces of large soft fruit such as figs of Ficus aurea, look under leaves for larvae, and catch arthropods on sallying flights.
Self-maintenance: Routines of flights to attend the nest are often interrupted by breaks of several minutes for resting and preening.
Agonistic behavior: Azure-rumped Tanagers are aggressive against intruders in the nest territory, and at times also against other Azure-rumped Tanagers on food sources, indicated by chasing and uttering of a scratchy rrrb-rrrb-rrrb vocalization (Eisermann et al. 2011c).
At Atitlán volcano, nest density in forest was 2 nests / 10 ha, in non-intensive shade coffee plantation 5.3 nests / 10 ha, and in intensive coffee plantation 0.8 nests / 10 ha (Eisermann et al. 2011b). The shortest distance between synchronically active nests was 40 m (Eisermann et a. 2011b). Repeated nesting in the same tree in subsequent years suggest nest site fidelity (Eisermann et al. 2011b). Nesting Azure-rumped Tanagers are aggressive in the area surrounding the nest tree and were reported to chase away small birds that intrude the nest territory, including Paltry Tyrannulet (Zimmerius vilissimus), Band-backed Wren (Campylorhynchus zonatus), Rufous-and-white Wren (Thryothorus rufalbus), Brown-backed Solitaire (Myadestes occidentalis), Black-and-white Warbler (Mniotilta varia), Slate-throated Redstart (Myioborus miniatus), Yellow-winged Tanager (Thraupis abbas), White-winged Tanager (Piranga leucoptera), and Lesser Goldfinch (Spinus psaltria) (Eisermann et al. 2011b), and Elegant Euphonia (Euphonia elegantissima) (Gómez de Silva 1997). On some occasions, however, nesting Azure-rumped Tanagers did not react at all to intruding Paltry Tyrannulets, Yellow-winged Tanager, and Blue-tailed Hummingbird (Amazilia cyanura) (Eisermann et al. 2011b). Home range sizes during breeding and nonbreeding season remain unknown.
On a nest monitored from the first day of building to the fledging of the young, copulations have been observed in or near the nesting tree. Once the helper approached the copulating pair closely, but was chased away by the male (Eisermann et al. 2011b). Cooperative breeding has been observed in several occasions in Azure-rumped Tanager (Long and Heath 1994, Eisermann et al. 2011b); see Reproduction.
Social and interspecific behavior
Azure-rumped Tanagers move usually in pairs or family groups during the breeding season. After young fledged, birds form also larger flocks. Flocks of 14 (Eisermann et al. 2011a) or 16 birds (Hilty and Simon 1977) have been reported. On Atitlán volcano, however, Azure-rumped Tanager was never seen in true mixed flocks, which move together on the search for food. When Azure-rumped Tanagers were seen together with other species, such as Common Bush-Tanager (Chlorospingus ophthalmicus) or White-winged Tanager (Piranga leucoptera), they were apparently in the same tree by coincidence, but did not move on together (Eisermann et al. 2011a). In previous accounts, the species has been reported from mixed flocks (Hilty and Simon 1977, Cooper 2003), but it has not been mentioned if they were indeed moving with the flock.
Bushy-crested Jay (Cyanocorax melanocyaneus) is the only species reported predating on Azure-rumped Tanager. At Atitlán volcano, a jay was seen with a nestling of Azure-rumped Tanager in its bill. The adult tanagers were mobbing the jay (Eisermann et al. 2011b). At another nest, an Emerald Toucanet (Aulacorhynchus prasinus) was seen perched in the canopy at a distance of about 5 m apparently observing the nest. A day later the nest was abandoned, presumably predated (Eisermann et al. 2011b). When potential predators are detected, Azure-rumped Tanagers become alert, jumping nervously between twigs. At a nest on Atitlán volcano, adults stopped a routine of intensive feeding when a flock of Bushy-crested Jay was in the nest territory. They avoided attending the nest until the jays were gone (Eisermann et al. 2011b).