Counting Coots

I photographed this lone coot at Sharon Wood's lake last week, which inspired me to learn a bit more about this odd rail. I found a report on a scientific study which suggests that coots can count, at least as far as the number of eggs in their own nest goes. Coots, like many other species of birds, practice a behavior known as brood parasitism. This involves a gravid female sneaking onto an unguarded but active nest and laying an egg within, leaving the owner of the nest to raise the sneak's offspring. Since this might be detrimental to the victim's own offspring, there is constant pressure to recognize that the parasitism has taken place and to counteract it afterwards. Coots apparently do this by counting the eggs in their nest once they are finished laying and rejecting any that appear later. They may push the offending egg out of the nest, bury it deep in the nest material where they will never hatch, or relegate it to the periphery of the nest where it will have a diminished chance of hatching.

I've come to expect brilliant behavior from birds like the crows and the parrots, but counting ability from a coot astounded me. They are somewhat comical birds and have been likened to a water-going pigeon due to their habit of pumping their head back and forth when they swim, much as pigeons do when walking.