The hawk-cuckoos are sometimes placed in a separate genus, Hierococcyx.
These are vocal species, with persistent and loud calls. They feed on large insects, with hairy caterpillars, which are distasteful to many birds, being a speciality. One or two species will also take some fruit.
Cuculus cuckoos are brood parasites, that is, they lay a single egg in the nests of various passerine hosts. The best-known example is the European Common Cuckoo. The female cuckoo in each case replaces one of the host’s eggs with one of her own. The cuckoo egg hatches earlier than the host’s, and the chick grows faster; in most cases the cuckoo chick evicts the eggs or young of the host species.
Cuculus species lay coloured eggs to match those of their passerine hosts. Female cuckoos specialise in a particular host species (generally the species that raised them) and lay eggs that closely resemble the eggs of that host.
A species may consist of several gentes, with each gens specialising in a particular host. There is some evidence that the gentes are genetically different from one another though other authorities state that as female cuckoos mate with males of any gens, genes flow between gentes.
Researchers from University of Granada provide details of new studies and findings in the area of life sciences.(Report)
Oct 13, 2008; New research, 'Egg colour mimicry in the common cuckoo Cuculus canorus as revealed by modelling host retinal function,' is the...
Nest defence, enemy recognition and nest inspection behaviour of experimentally parasitized Reed Warblers Acrocephalus scirpaceus
Nov 01, 2004; Capsule Reed Warblers in a regularly parasitized population do not recognize Cuckoo Cuculus canorus as a special enemy and do not...