Tips from Kukua

2001/03/22 Imaz Amiano, Eneko - Elhuyar Zientziaren Komunikazioa

• Zoologia

But as you know, the cuckoo lays eggs in the nests of the other birds. In each of the nests puts an egg and the substitute parents grow the cuckoo chickens. Normally, in each region a certain species of bird is tended to parasite. And the cucos lay eggs similar to those of the species that most parasite in each region. In this way, they want to get the hostelero not to realize. Then, the first thing to be born and do is to throw off a nest other eggs or chickens so that he himself can get all the food. And it is that, often, the cucos are served of birds smaller than the own cuckoo chito.

However, sometimes the eggs do not resemble those of the hostelero (for example, when the cuckoo has laid the eggs in the nest of many species), but the birds do not realize or expel the new egg from the nest. How is it possible to deceive the hostelry with eggs so bad imitation? In an investigation conducted in Australia, spectrophotometer has been used to measure the tone of color and color saturation, both of visible light and of ultraviolet light, since birds see this entire spectrum. And to where, in our view, the eggs that do not resemble are seen in ultraviolet light and become quite similar. The cuckoo may use this trap to deceive the hosteleros.