Brood parasitism in action. A Malaysian Pied-fantail parent feeding a Rusty-breasted Cuckoo fledgling beside the nest. The Fantail has no idea that the baby bird was not genetically related to her; the Fantail mama continued to feed the Cuckoo chick for weeks till the latter grew even bigger than its foster parent. A 500mm telephoto was used to provide adequate distance and avoid disturbance to the nesting.