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 ostrich racing. Chandler, Arizona, hosts the annual "Ostrich Festival", which features common ostrich races. Racing has also occurred at many other locations such as Virginia City in Nevada, Canterbury Park in Minnesota, Prairie Meadows in Iowa, Ellis Park in Kentucky, and the Fairgrounds in New Orleans, Louisiana. Common ostrich The common ostrich ("Struthio camelus"), or simply ostrich, is a species of large flightless bird native to Africa. It is one of two extant species of ostriches, the only living members of the genus "Struthio" in the ratite order of birds. The other is the Somali ostrich ("Struthio molybdophanes"), which was recognized