The grey-bellied cuckoo (Cacomantis passerinus) is a cuckoo with widespread occurrence throughout Asia.
It comes here in the Northern India at the time of outset of the summers. It is a small sized cuckoo. During this time of year another cuckoo known as the Jacobin Cuckoo also arrives.
Grey Bellied Cuckoo pic by Ranjit
Unlike Jacobin Cuckoo which migrates here in summers from Africa, Grey Bellied Cuckoo is short distance migrant.
It comes here for breeding. It is a brood parasite. It lays its eggs by replacing the eggs in the nests of babblers who then raise its brood. This strategy is just akin to the Koel using Crows to raise its chicks.