In the tropical jungle of Central America where predators abound, a species of cuckoo has found safety in numbers by building communal nests guarded by two or three breeding pairs.
In the tropical jungle of Central America where predators abound, a species of cuckoo has found safety in numbers by building communal nests guarded by two or three breeding pairs.
Why then do these agreeable avians sometimes ditch the collaborative lifestyle and instead deposit eggs into nests outside the communal group, acting like social parasites, in the hopes that other females will raise the chicks as their own?
In a paper published online in the journal Nature, Princeton researchers show that the cuckoos, known as greater anis (Crotophaga major), act collectively for the most part but can become social parasites after their communal nest is destroyed. They start the breeding season placing all their eggs in one basket, but if predators intervene, the birds switch to a strategy of spreading the eggs around in other nests.
“When different females in a population pursue different reproductive tactics, like cooperative and parasitic nesting, this poses an evolutionary puzzle. We wondered why some females lay their eggs into other groups’ nests, whereas other females never do,” said Christina Riehl, assistant professor of ecology and evolutionary biology. She and co-author Meghan Strong, a research specialist in the Department of Ecology and Evolutionary Biology, conducted the study with help from undergraduates, graduate students and interns, including several from the Princeton Environmental Institute (PEI).
Read more at Princeton University
Image: Princeton researchers found that greater anis, which normally nest communally in groups of two to three females, can become social parasites and start laying their eggs in the nests of other groups after their own nests are destroyed. (Credit: Christina Riehl)
