Thick-billed Cuckoo vs Asian Koel

In short

The Thick-billed Cuckoo and the Asian Koel can be distinguished primarily by their bill structure and plumage patterns. The Thick-billed Cuckoo has a notably robust bill, while the Asian Koel features a more slender bill. Plumage differences are also significant, with the Thick-billed Cuckoo generally having more uniform coloration compared to the Asian Koel's sexually dimorphic plumage.

Identification tips

1. Bill Structure: Look for the Thick-billed Cuckoo's robust bill compared to the Asian Koel's slender bill. 2. Plumage: Note the uniform coloration of the Thick-billed Cuckoo versus the sexually dimorphic plumage of the Asian Koel. 3. Habitat: Consider the habitat; presence in urban areas may suggest Asian Koel. 4. Vocalization: Listen for the loud, distinctive calls of the Asian Koel.

Size

Both species are similar in size, but the Asian Koel is generally slightly larger.

Plumage

The Thick-billed Cuckoo has a more uniform and less contrasting plumage, while the Asian Koel exhibits marked sexual dimorphism: males are glossy black, and females are brown with white spots and streaks.

Behaviour

Both species are known for their secretive behavior, often staying hidden in dense foliage. However, the Asian Koel is more likely to be seen in urban areas.

Habitat

Thick-billed Cuckoos are typically found in forested areas, while Asian Koels are more adaptable and can be found in a variety of habitats, including urban environments.

Voice

The Asian Koel is known for its distinctive, loud calls, which are more frequently heard than those of the Thick-billed Cuckoo, whose calls are less well-documented.