Common cuckoo lay eggs that better imitate the host's eggs, the host species adapts and is more able to distinguish the cuckoo egg. A study of 248 common cuckoo and host eggs demonstrated that female cuckoos that parasitised common redstart nests laid eggs that matched better than those that targeted dunnocks. Spectroscopy was used to model how the host species saw the cuckoo eggs. Cuckoos that target dunnock nests lay white, brown-speckled eggs, in contrast to the dunnock's own blue eggs. The theory suggests that common redstarts have been parasitised by common cuckoos for longer, and so have evolved to be better
Bird reserve Bird reserve A bird reserve (also called ornithological reserve) is a wildlife refuge designed to protect bird species. Like other wildlife refuges, the main goal of a reserve is to prevent species from becoming endangered or extinct. Typically, bird species in a reserve are protected from hunting and habitat destruction. Because of the protection they provide from such threats, bird reserves also serve as excellent locations for bird watching. Normally, wildlife refuges are under the care of non-profit organizations and governmental institutions. A bird reserve is an area where steps have been taken to preserve a habitation that is vital