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
Kite (bird) Kite (bird) Kite is a common name for certain birds of prey in the family Accipitridae, particularly in subfamilies Milvinae, Elaninae, and Perninae. Some authors use the terms "hovering kite" and "soaring kite" to distinguish between "Elanus" and the milvine kites, respectively. The groups may also be differentiated by size, referring to milvine kites as "large kites", and elanine kites as "small kites". A few of the traditional Perninae" "are also called kites. In 1824, Vigors proposed five divisions or "stirpes" of the family Falconidae: Aquilina (eagles), Accipitrina (hawks), Falconina (falcons), Buteonina (buzzards) and Milvina (kites, containing two genera "Elanus"