Cover Caption

Cover: Muskoxen (Ovibos moschatus) in Arctic Alaska. For muskoxen and other large mammals, trait sizes can be measured noninvasively and relatively inexpensively in photographs. Such data are highly accurate and can be used to inform conservation policy (see pages 769‐777). Photographer: Art Wolfe ( http://www.artwolfe.com ) has worked in hundreds of locations spanning all continents. His photographic style draws on both art and journalism to document his subjects and educate his viewers. His goal is to obtain public support for conservation by focusing on what is beautiful on Earth. Wolfe has published over 60 books for adults and children, including The Living Wild, Vanishing Act, Edge of the Earth—Corner of the Sky, and The Art of Photographing Nature. His book Light on the Land was a gift of state during the Clinton administration, and he has received awards from diverse organizations, including the National Outdoor Book Awards and Graphis. Wolfe is a recipient of the Photographic Society of America's Progress Medal and the . rst Rachel Carson Award from the National Audubon Society.