A splash of black and a bubbly call means you are looking at an Asian Koel hiding in tree foliage

A splash of black and a bubbly call signals an Asian Koel hidden in tree foliage. The male, with a ruby‑red eye and blue‑black sheen, skulks in thick foliage and is a familiar songster, while the female lays eggs in the nests of other birds, such as crows. The Koel is a brood parasite, known for its melodious call that is celebrated in India. The male prefers shaded groves before calling loudly, and the species is shy, often calling from hidden locations within foliaged trees.