Hodgson's Hawk-Cuckoo

Hodgson's hawk-cuckoo, also called the whistling hawk-cuckoo, is a cuckoo found in north-eastern India, Myanmar, southern China and Southeast Asia, and is a brood parasite. It was formerly regarded as having four subspecies (Wikipedia, general species account).

The chick evicts the host's own eggs and young, becoming the sole occupant of the nest. To counter the lower feeding rate that a single gape would bring, the chick displays gape-coloured patches of skin under its wing that simulate extra gapes, which appears to increase how often it is fed. The account opened does not name Bhutan.