Asian koel: where and when to see them

The Asian koel is a large, long-tailed cuckoo associated with wooded settlements, orchards and tropical forest edges. Males are glossy black, while females wear intricate brown-and-white spotting and barring. Its ringing calls often reveal a bird that remains concealed in foliage. Unlike many cuckoos, adults eat predominantly fruit. The species reproduces through brood parasitism, placing eggs in other birds' nests rather than building a nest and raising its own young.

Size

39–46 cm long

Weight

190–327 g

Lifespan

Not reliably established

Status

Least Concern

Koels move deliberately through tree crowns, pausing at fruiting branches and sometimes chasing one another during courtship. Males give repeated, rising whistles, while females produce sharper, rapid calls. Females monitor suitable host nests and lay when the hosts' breeding stage is appropriate. Crows are important hosts in parts of the range, although host use differs geographically. Young koels are fed by their foster parents and may remain dependent after leaving the nest. As brood parasites, females carefully observe potential host nests, often focusing on a single nest at a time before laying an egg, typically mimicking a host egg. Young koels grow rapidly, often outcompeting or evicting host nestlings to ensure they receive all the food from their foster parents.

• Male and female plumages differ so strongly that they can look like different species.
• Adults can disperse seeds after swallowing fruit.
• The familiar repeated koel whistle is primarily a male call.
• Unlike common cuckoo chicks, young Asian koels generally do not evict every nestmate.

Calls usually make koels easier to detect during local breeding activity, but timing varies across their extensive range. In the Maldives, the generally drier December-to-April travel period can suit patient garden birdwatching; it should not be interpreted as a confirmed local breeding season. In the Maldives, though not a confirmed breeding season, the drier months often coincide with increased fruit availability, which can make koels more active and visible. Migration patterns also influence their presence, with some populations undertaking long-distance movements that could bring them to the islands.

This cuckoo uses lowland woodland, mangrove margins, gardens and cultivated landscapes with substantial tree cover. Fruiting trees and available host birds are more important than untouched forest. On small tropical islands, leafy residential areas can provide suitable feeding and sheltering habitat. In the Maldives, they are often found in coastal vegetation, particularly on islands with human settlements, where food sources like fruit trees are abundant. Their adaptable nature allows them to thrive in human modified environments, unlike many forest specialist birds.

Adults consume figs, berries and other soft fruits, often swallowing smaller items whole. They also take insects and occasional other animal food. Nestlings receive whatever their host parents bring, so their early diet can differ markedly from the fruit-heavy diet of adults. Their gizzard structure is adapted for processing soft fruits and seeds, which are typically regurgitated, aiding in seed dispersal for many plant species. While insects are consumed, fruits form the bulk of their diet, especially during periods of high fruit availability.

Common name

Asian koel

Scientific name

Eudynamys scolaceus

Animal group

Birds

Size

39–46 cm long

Weight

190–327 g

Lifespan

Not reliably established

Status

Least Concern

Identification

A male's red eye, pale bill and long tail distinguish it from crows, while the heavily spotted female differs from the more boldly barred female Asian emerald cuckoo. The male's glossy black plumage, contrasting with its bright red eye, is quite striking and distinct from other common black birds in the region. Females have a brown upperpart with white spotting and a pale underside with heavy barring, offering good camouflage among leaves.