Researcher studies communal nesting in birds

Balanced in a small boat on the reedy edge of a Panama lake, Christina Riehl rigged a camera above the nest of a bird called the greater ani, a species of cuckoo that lives in Central and South America. Checking the footage a few days later, she saw something that had never before been documented in the species. A female ani landed on the nest, cocked her head to inspect the single egg, and then pushed the egg out of the nest and into the water below.