From critically endangered to least concern?—A revised population trend for the Kittlitz's Murrelet in Glacier Bay, Alaska

摘要

ABSTRACT The Kittlitz's Murrelet (Brachyramphus brevirostris) has been proposed for listing under the U.S. Endangered Species Act, and is classified as critically endangered by the International Union for the Conservation of Nature (IUCN). A significant portion of the global population occurs in Glacier Bay, Alaska, where steep population declines have been previously reported. To further examine Kittlitz's Murrelet population trends we replicated a 1993 survey in 2009 and 2010 using the same lead observer, the same transect lines, and similar methods. We found the number of Kittlitz's Murrelets unchanged since 1993. Other seabird surveys were conducted in Glacier Bay between 1991 and 2008 by federal agencies, using a variety of sampling designs. We added our surveys to previously published surveys, correcting for percentage of murrelets identified to species to enable comparison. When all surveys were analyzed collectively, the Kittlitz's Murrelet population showed no significant trend between 1991 and 2...