Behavior

Reflecting adaptations to niche, behaviors are diverse. Tree-living butcherbirds, bristleheads, and New Guinean peltopses are perch-pouncers or salliers, using their feet for little else besides perching, coming to the ground only to snatch prey. All are sedentary, keeping to the same large foraging territories year-round, and are solitary, rarely gathering in groups larger than family parties. In flight, they move between trees in direct flight on rapidly and shallowly flapping wings. Similarly sedentary, the ground-feeding Australian magpie is more gregarious and has evolved a complex social organization; senior pairs or small breeding groups hold permanent territory in optimal habitat, while larger groups of juveniles and subordinate nonbreeders congregate in suboptimal areas. On the ground, magpies walk sedately, and their flight, direct as in butcherbirds, is far swifter. Currawongs are variably social, the gray being solitary at all times, while the other two species gather in large wandering bands when not breeding. At that time, their east coast populations make north to south migratory movements. Currawongs bound about all strata in the forest and hop and run on the ground. These long-tailed birds also fly in loping undulations.

Loud, carrying flutings, glottal (relating to the opening between the vocal chords and larynx) gargles, and bell-like whistles characterize the calls of all magpie-shrikes except the peltopses, which "tick" or "tinckle" mechanically. Australian magpies often chorus together in groups, and flocking curra-wongs call and answer constantly.

At night, all magpie-shrikes roost in tree foliage at mostly mid-height, Australian magpies and flocking currawongs doing so in loose groups.

0 0

Post a comment