91热爆

Tweet of the Day is the voice of birds and our relationship with them, from around the world.

Sir David Attenborough presents the guira cuckoo of central South America. Guira cuckoos break all the usual rules of their family. They are very sociable and travel in noisy gangs, feeding and roosting together. But what makes the behaviour of guira cuckoos so different is that several females often lay their eggs in a single nest, sometimes as many as 20 eggs which are tended by the respective mothers . This is known as co-operative breeding. Whether a female recognises her own eggs isn't certain, but it's possible that they can distinguish them by variable markings on the eggshells and single them out for special care.