Common hawk-cuckoo

The common hawk-cuckoo (Hierococcyx varius), popularly known as the brainfever bird, is a medium-sized cuckoo resident in the Indian subcontinent. It bears a close resemblance to the shikra, even in its style of flying and landing on a perch. The resemblance to hawks gives this group the generic name of hawk-cuckoo; like many other cuckoos, these are brood parasites, laying their eggs in the nests of babblers. During their breeding season in summer males produce loud, repetitive three-note calls that are well-rendered as brain-fever, the second note being longer and higher pitched. These notes rise to a crescendo before ending abruptly and repeat after a few minutes; the calling may go on through the day, well after dusk and before dawn.