Calculating Coots and Other Avian News
Recent scientific discoveries about various bird species are revealed
COOTS CAN COUNT, says University of California–Santa Cruz ecologist Bruce Lyon, who studied the birds’ nesting behavior for four years in British Columbia. He based the conclusion on his discovery, published in Nature, that a female American coot will still lay the appropriate number of eggs after rejecting those laid by neighboring coots—the two darker eggs in the photo—trying to fool her into raising their offspring. Females that are fooled, on the other hand, not only keep the invaders’ eggs, but lay fewer of their own to maintain the nest’s normal clutch size.
Male grouse looking for love gather in groups known as leks to display before prospective mates (see "Getting Down on the Ground With Grouse" in the issue). But because most females end up choosing the same one or a few suitors, biologist Robert Gibson of the University of Nebraska–Lincoln wondered if the birds were getting anything other than sex out of joining a lek. In the case of one kind of grouse, the greater prairie chicken, he found that males—which will even join leks of another species, the sharp-tailed grouse—were gaining protection from predators by belonging to the groups.
Bad news about birds emerged in a recent report from the Worldwatch Institute, which concludes that more than 12 percent of the earth’s 9,800 avian species are at risk of extinction. Major threats include chemical pollution, invasive species, climate change and, especially, habitat loss.