Easily recognized by their black plumage, and distinctly long, typically forked tail, the drongos constitute a very homogeneous Old World family of 26 species, the majority of which are to be found in tropical and subtropical regions of Africa, India and Southeast Asia. Though traditionally grouped with orioles and crows, molecular-genetic studies have shown that these families are phylogenetically unrelated to drongos, whose closest relatives are the monarchs and fantails. Drongos are also characterized by their upright stance, and a stout, arched, black bill with a hooked tip and with well-developed rictal bristles at its base. They are mainly insectivorous, and like flycatchers, typically hunt by watching from a prominent perch, then darting out after insects, such as cicadas and dragonflies, and often chasing them in the air, before returning to their launch pad. Other foraging techniques include snatching insects from foliage, sometimes whilst hovering, and swooping onto tree trunks or, occasionally, even the ground. Drongos often associate with mammals to capture prey that are flushed by them. More frequently, however, they join and even attract other birds in mixed species flocks, sometimes by mimicking their calls. The feeding success of drongos has been shown to clearly increase when following other species. Yet it not a parasitic relationship as drongos provide “sentinel” services through their raucous alarm calls, warning other species of the approach of a predator. Drongos, themselves, appear fearless, often boldly and aggressively attacking predators much larger than themselves, especially when defending their nests, which are shallow bowls suspended in a forked branch. Of the 26 species worldwide, six occur in Java, and
two of these occur in Baluran
Agile and maneouvrable, capable of aerial acrobatics while foraging; in normal flight, shallow, rather slow wingbeats. Shallow undulating.