Hummingbird
Hummingbirds are birds native to the Americas and constitute the biological family Trochilidae. They are among the smallest of birds, most species measuring in length. Indeed, the smallest extant bird species is a hummingbird, the bee hummingbird weighing less than .
Mixed-species foraging flock
African rainforests also hold mixed-species flocks, the core species including bulbuls and sunbirds, and attendants being as diverse as the red-billed dwarf hornbill and the tit-hylia, the smallest bird of Africa. Drongos and paradise-flycatchers are sometimes described as the sentinels of the flock, but they are also known to steal prey from other flock members. Acanthizidae are typical core members in New Guinea and Australia; in Australia, fairy-wrens are also significant. The core species are joined by birds of other families such as minivets.