The drongo is a member of the passerine order of birds, which includes perching songbirds. These birds are generally small to medium-sized, characterized by a glossy black, sometimes iridescent, plumage and a long, deeply forked tail. Drongos are found across a wide geographical distribution, inhabiting open woodlands, savannas, and forests throughout Africa, Asia, and Australia. They are known for their distinctive appearance and varied behaviors.
Standard Diurnal Foraging
The drongo’s daytime activities are largely centered on acquiring the insects that form the bulk of its diet, using a combination of active hunting techniques. Their primary method is aerial hawking, where the bird perches on an exposed, elevated vantage point, such as a dead tree branch or a fence post. From this high perch, the drongo maintains an erect posture while scanning the surrounding air and ground for movement. Once a flying insect is sighted, the drongo sallys out in a swift, acrobatic flight to intercept the prey mid-air before returning to its original or a new perch.
The birds also employ a method called gleaning, where they pluck insects directly from foliage or other surfaces while briefly hovering or landing. Sometimes a drongo will drop down from its perch to seize prey on the ground, a technique known as plunge diving. The diet of the black drongo and fork-tailed drongo consists predominantly of insects like grasshoppers, termites, butterflies, moths, and bees. They are sometimes observed following large mammals like cattle to catch insects that are flushed out by the animal’s movement.
Deceptive Tactics and Kleptoparasitism
Beyond honest hunting, a considerable part of the drongo’s day involves a complex and deceptive food-gathering strategy known as kleptoparasitism, or stealing food from other animals. This behavior is most refined in species like the African fork-tailed drongo, which targets species such as meerkats and pied babblers. The drongo will closely follow these foraging animals, waiting for them to catch a substantial meal. Kleptoparasitism is a reliable source of food, especially when the drongo’s own aerial hawking attempts are less successful.
When a target species secures food, the drongo emits a false alarm call, mimicking the specific predator call of the victim species. This mimicked alarm is acoustically indistinguishable from a genuine call, causing the victim to instantly drop its meal and flee to safety. The drongo then swoops down to snatch the abandoned food, which can include large insects, scorpions, or even small vertebrates. The rate of successful theft is high because the cost to the victim of ignoring a genuine alarm is potentially fatal, making a flight response the safer bet.
This deception requires significant cognitive flexibility; the fork-tailed drongo can learn and use dozens of different alarm calls, many of which are those of other bird and mammal species. The drongo must constantly vary its repertoire of false alarms because its victims will eventually learn to ignore a specific call if it is used too frequently without a genuine threat.
Daytime Social and Defensive Roles
The drongo’s day involves important social and defensive activities, contributing to its reputation as a fearless associate in its ecosystem. Drongos are known for their intensely aggressive defense of their nesting and foraging territories against intruders, including much larger birds and even mammals. This territorial defense often manifests as mobbing, where the drongo repeatedly dives at and harasses a perceived threat like a raptor, crow, or snake. This bold behavior provides a protective benefit that is exploited by other, less aggressive bird species, which often choose to build their own nests in close proximity to a drongo’s territory.
Beyond defense, drongos also act as sentinels, frequently perching high up where they can scan the environment for danger. They produce genuine, species-specific alarm calls when they spot a true predator, which alerts their foraging associates to the danger. The drongo’s role as a sentinel creates a fragile trust with species they also kleptoparasitize, such as the sociable weaver. They even produce a specific “all-clear” sentinel call when associating with certain species, which encourages their partners to increase foraging and decrease vigilance.