Summer has brought wth it an abundance of food and water, and conditions for reproducing in all species is at its peak during this lucrative period. Of particular interest are the thousands of birds taking advantage of these prime conditions, and in particular the cuckoos who rely on other species of birds to rear their young.


It would seem that all these cuckoos would have to worry about would be finding a suitable mate and a suitable nest to lay their eggs in, and that would be all. This, however is not the case and one species, the Diederik cuckoo has a very interesting lifecycle.


When conditions are perfect for breeding to begin, the male cuckoos have to establish a territory and secure a mate. They have no other motive but to reproduce and regardless of who their host parents were is of little relevance to them. These Cuckoos have several hosts which they parasitize, and all these hosts lay eggs of a specific shape and colour and are able to distinguish between their eggs and a foreign egg. These hosts are known as discriminators. The female cuckoos have this information genetically imprinted and it is up to them, once they have mated to find a suitable host and their nest in which to lay their egg. The female cuckoo is able to almost identically match their egg to the egg of the host species who raised them. This matching improves from generation to generation.


Once a host has been found and the egg has been laid the cuckoo will evict the hosts eggs or chicks, by lifting them onto their backs and, by holding them in position with the wings will raise them to the edge of the nest and tip them out.


Below are two photographs of the beautiful Diederik cuckoo who seem to be having a very successfull season indeed.

Michelle Swemmer - Field Guide