With apologies to a certain brooding California rock band, the real counting crows have feathers. Crows can count to three or four, whereas parrots - the Stephen Hawkings of the avian world - have them beat, grasping the concept of zero through six. And a recent study in the journal Behavioural Processes, which looked at the arithmetic abilities of the New Zealand robin, adds to the growing evidence that birds can count.
Researchers at the Victoria University of Wellington presented wild robins with a box that contained two mealworms, one of the birds' favorite treats. Alexis Garland, one of a pair of bird experts who authored the study, would then hide one of the mealworms behind a sliding floor - a bit like a stage magician's trick.
After eating the unhidden worm, the birds continued to peck at the box as if they were awaiting a second worm. If both worms were in sight, the birds left the box alone, indicating the birds can count, the authors said.
Garland told The New York Times that counting is a good skill to have if you're a New Zealand robin - these birds' mates often attempt to filch meals from one another. "If you've got a mate that steals 50 or more percent of your food," she told the Times, it pays to be able to count your inventory.
Bird arithmetic doesn't involve only food. Coots (who, though they may look a little like mallards, aren't ducks) count their eggs, bird experts discovered more than a decade ago. Before that, coots had a bit of a reputation as dumb birds, but the mathematical finding cast these animals in a new light. According to the ecologist who found out coots could count: "It's very satisfying to rescue a study animal from a bad rap."