American Scientist

May-June 2011

Volume: 99 Number: 3

Female loons typically lay two eggs, a day apart. By the time the second hatches, the first chick is usually already on the water; it is rare to see two chicks in the nest at the same time. If food is plentiful and luck is running with the family, the adults may raise both chicks but often only the dominant chick survives, generally the older one. The presence of two chicks with the loon on the cover means that they have already passed the riskiest part of reproduction; most predation occurs at the egg stage. Yet threats remain from snapping turtles, big muskies, eagles and other predators. In "Marking Loons, Making Progress," Walter Piper, Jay Mager and Charles Walcott present the arresting results of nearly two decades of studying banded loons in the wild. Their work retires misconceptions, raises new research questions and sharpens our picture of this symbol of the Northern wild.