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
Common ground dove common ground dove has a yellow beak with a black tip. Feathers surrounding the beak are pink in colour. The feathers on the head and the upper breast have a scale like appearance. The tail feathers are very short and similar colour to the back. The plumage on the back of the bird is brown. The coverts and wing feathers are also brown but have black spotting on them. The common ground dove has chestnut primaries and wing borders, which can only been seen when the bird is flying. The common ground dove shows some sexual dimorphism in their plumage.