Black Drongo

The black drongo (Dicrurus macrocercus) is a medium-sized drongo of open country across South, East and Southeast Asia. Adults are about 26–32 cm long and weigh roughly 40–60 g. The plumage is glossy black with blue-green iridescence in good light, the eyes are dark red, and the long tail ends in a deep, clean fork. Adults usually show a tiny white rictal spot at the base of the bill, a useful field mark when separating them from several other dark drongos.

The species is closely related to the African fork-tailed drongo (Dicrurus adsimilis), with which it was historically treated as conspecific. In Asia, the paler and usually slimmer ashy drongo (Dicrurus leucophaeus) can also cause confusion.

Black drongos favour open landscapes with scattered trees and exposed perches, including farmland, grassland, scrub, wetland margins, plantations and forest edges. Wires, fence posts, bare branches and dead snags provide particularly useful lookout points above open ground.

The species is highly tolerant of agricultural and other human-modified landscapes. Areas where livestock, cultivation or regular disturbance keep vegetation open can provide both abundant insects and suitable hunting perches.

Insects dominate the diet, including beetles, grasshoppers, crickets, moths, termites and many other arthropods. Small vertebrates are taken occasionally; unusual records include lizards, small fish and even small passerine birds, but such prey is not a normal basis of the diet.

Much foraging is based on exposed lookout perches. A drongo watches the surrounding air and ground, launches after passing insects or drops toward prey below, and often returns to the same or a nearby perch. It also exploits insects flushed by grazing livestock, agricultural machinery and other disturbance, sometimes following moving animals or equipment as new feeding opportunities appear.

Black drongos are famously bold toward larger birds. Raptors, crows and other potential threats may be met with sharp calls, repeated pursuit and close aerial attacks even outside direct nest defence. A field study in western Java found that mobbing changed with season, but the pattern differed between the two raptor species studied. The birds therefore do not respond to every large bird in the same way, and both breeding context and predator type can influence the response.

The species is also an accomplished vocal mimic and can copy calls of other birds. The famous use of deceptive false alarm calls to steal food is, however, far better documented in the African fork-tailed drongo than in the black drongo.

Most black drongos in tropical and subtropical parts of the range are resident or make relatively short local movements. Populations breeding farther north, especially in northern China and adjacent parts of East Asia, migrate south for the non-breeding season. Migrants pass through the Korean Peninsula and other East Asian stopover areas, while western populations also show seasonal movements around Pakistan and Afghanistan.

Migration can expose the species to unusual feeding opportunities. On a Korean stopover island, one migrating individual was documented catching and eating two small migratory passerines in succession. The observation suggests that black drongos can selectively hunt birds when the opportunity arises, despite an otherwise strongly insect-dominated diet.

Black drongos build a shallow cup nest high in an exposed fork of a tree, using fine twigs, grass fibres and cobwebs. Both adults take part in nest construction. Breeding timing varies geographically; a study in agricultural Punjab recorded nesting from May to August, with clutches of three to four eggs and an average incubation period of about 13 days. Both parents participate in incubation and later feed the chicks. The young usually remain in the nest for about 16–20 days before fledging.

Territorial defence becomes especially intense around the nest. Adults may repeatedly dive at crows, raptors and other intruders and pursue them well beyond the nest tree. In this context mobbing is a direct part of reproductive defence, protecting eggs and young in a conspicuous open nest that would otherwise be accessible to many avian predators.

The black drongo is classified as least concern on the IUCN Red List. It remains widespread and common across much of southern Asia and is well adapted to open agricultural and human-modified landscapes.

Indian monitoring data published in 2025 give a strongly positive long-term estimate of about +49%, although the long-term trend remains classified as inconclusive. The recent annual estimate is close to zero at about +0.2% and is classified as stable. The species remains in the low conservation-priority category and has a very large distribution in India.