Cover Caption


Cover: A poster of the Ivory-billed Woodpecker (Campephilus principalis) decorates the wall of a restaurant in Brinkley, Arkansas (U.S.A.). The town is located near where the bird was reportedly sighted in 2004, 60 years after its presumed extinction. Th ree papers in this issue present new methods to estimate whether species are extinct. On pages 47-56, Gotelli et al. introduce a statistical method for estimating the probability of species persistence from the temporal sequence of collection dates of museum specimens. Application of the method to a case study of the Ivory-billed Woodpecker suggests there is virtually no chance the species is currently extant within its historical range in the southeastern United States. On pages 180-184, Solow et al. describe a Bayesian method that formally accounts for species records of uncertain validity. They used a recently published record of sightings of the Ivory-billed Woodpecker to illustrate their method. Their results were consistent with the conclusion that the species is extinct, but did not provide a clear estimate of the time of extinction. On pages 57-67, Fisher and Blomberg outline how to estimate the probability that species with few records or recent last-sighting dates are extinct. Cover image © 2012 Joel Sartore.

Photographer: During more than 20 years with the National Geographic Society, Joel Sartore ( has covered topics from the Amazon rainforest to beer-drinking, mountain-racing. firefighters in the United Kingdom. His work focuses on endangered species, natural history, and land use. Joel's books include Photographing Your Family, Face to Face with Grizzlies, Nebraska: Under a Big Red Sky, RARE: Portraits of America's Endangered Species, and, most recently, Let's Be Reasonable. In addition to his work for National Geographic, Joel has completed assignments for Audubon Magazine, Time, Life, Newsweek, and Sports Illustrated and has contributed to numerous book projects. Joel and his work have been the subject of several national broadcasts in the United States, including National Geographic's Explorer, NBC Nightly News, NPR's Weekend Edition, and an hour-long PBS documentary. He is a regular contributor to the CBS Sunday Morning Show.