The Banded Bay Cuckoo, or Bay-Banded Cuckoo, is a small, striking bird with a distinctive appearance. Adults boast a bright rufous or bay coloration on the head and back, with dark brown bars adding a bold pattern to their plumage. Their long, slightly curved bill is black, with a greenish-grey base on the lower mandible. A white supercilium stands out above a dark eye-line, while the wings are darker and the tail is graduated with a dark brown center, a subterminal black band, and white-tipped feathers. Both sexes are similar in appearance, with yellow irises and grey tarsi. Juveniles resemble adults but have a pale lower mandible and white fringes on their upper body feathers. At about 22 cm in length, they are comparable in size to other Cacomantis species but can be distinguished by their supercilium, long beak, and barred tail.
When identifying the Banded Bay Cuckoo, look for the white eyebrow-like supercilium, the rufous upperparts with regular dark bands, and the whitish underside with fine striations. The long, slightly curved bill and the distinctive tail pattern with a subterminal black band and white tips are also key features to note.
This species is typically found in well-wooded areas, favoring the lower hills where the canopy provides cover and feeding opportunities.
The Banded Bay Cuckoo is native to the Indian subcontinent and Southeast Asia, with its range extending from India and Nepal through Thailand and the Malay Peninsula, to Java, Bali, Sumatra, Sri Lanka, and parts of the Philippines.
The Banded Bay Cuckoo exhibits brood parasitism, laying its eggs in the nests of other bird species such as the common iora and various bulbuls. The host's fledglings are evicted, and the cuckoo's breeding habits remain somewhat enigmatic. This species is known to be migratory or partially migratory, with movements often linked to the monsoon season in India.
The call is a high-pitched, four-note whistle, reminiscent of "wee-ti wee-tee" or "smoke-yer-pepper," starting at 2.4 kHz and descending in pitch, each strophe lasting about a second.
Breeding seasons vary by region, with egg-laying observed from February to August near Bombay, April to August in Assam, and adults singing from January to May in the Malay Peninsula. In Sri Lanka, young have been seen in June and October.
The Banded Bay Cuckoo may be confused with the hepatic forms of Cacomantis merulinus and Cacomantis variolosus, but it can be distinguished by its supercilium, long beak, and barred tail.
Insects form the primary diet of the Banded Bay Cuckoo. It employs both gleaning and aerial sallying techniques to capture its prey.
The Banded Bay Cuckoo is currently classified as Least Concern on the IUCN Red List, indicating that it is not at immediate risk of population decline or habitat loss.