By Susan Milius
A coot may tally the eggs in her nest, a rare example of an animal counting in the wild, suggests a new study.
American coots (Fulica americana) wage covert egg wars among themselves, sneaking into a neighboring nest to deposit an egg for the other family to raise, explains Bruce E. Lyon of the University of California, Santa Cruz. He’s made an unusually detailed study that shows that coots do fight back. They often count up the rightful ones and move or destroy the suspect eggs, Lyon contends in the April 3 Nature.