Sumer is icumen in,/ Lhude sing cucu, begins one of the oldest songs in English. The distinctive call of the male Common Cuckoo, just returned from winter in sub-Saharan Africa, has long marked the return of spring to Europe. People used to write to the Times to report the date they first heard it for the year.
In studying the curious life history of the Common Cuckoo, Nick Davies asks many intriguing questions about brood parasitism and co-evolution. Moralists have, of course, been appalled for centuries about the Cuckoo’s way of doing things. The more interesting thing is how they do it—including careful observation of the host’s nest and the lightning fast laying of “forged” eggs—and what the host species do to defend themselves.
There seem to be a lot of advantages of brood parasitism. Female Common Cuckoos are, for instance, well on their way back to Africa while other species raise the next generation of Common Cuckoos. Yet only about 1% of all bird species are brood parasites. Why should this be so? Not even all cuckoos do it: only 59 of the 141 cuckoo species in the world, in the family Cuculidae, are brood parasites.
For instance, the cuckoos found in the Northeast U.S. are the Black-billed and Yellow-billed. Both are parental, meaning they build their own nests. They will occasionally lay their eggs in each other’s nests. And the Black-billed female will sometimes lay her eggs in the nests of other bird species. But this isn’t their usual way of reproducing, and any hatched young of theirs don’t dispose of the host’s hatchlings, as the Common Cuckoo does.
Of the other brood parasite species, best known to North Americans is the Brown-headed Cowbird. I’ve seen Chipping Sparrow parents feed the enormous cowbird chicks here in Brooklyn. It’s quite amazing to see.
You should definitely explore along with Davies, his co-researchers, their fake eggs, stuffed birds, and decades of experiments in the fens. For those who want the audiovisual version, he presents his research at the Royal Society.