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Population trends of the common murre (Uria aalge californica)

January 1, 2001

Population trends for the common murre (Uria aalge californica) were determined from available whole-colony counts of murres in California, Oregon, Washington, and British Columbia from 1800 to 1995.From 1800 to 1978, historical counts were sporadic and not standardized. From 1979 to 1995, standardized whole-colony counts from aerial photographs were conducted in many years in California, Oregon, and Washington. In contrast, no aerial photographs of murre colonies in British Columbia have been taken and only a few other whole-colony counts have been conducted. Direct comparisons and statistical treatment of whole-colony counts were conducted using 1979-95 data. Complete data for all colonies were available only in 1988-89 when the breeding murre population was estimated to be 1.1 million, about 5-8% of the world population and 13-28% of the Pacific Ocean population. A summary of various natural and anthropogenic factors affecting murre populations in western North America since 1800, and particularly in 1979-95, also is provided.

Publication Year 2001
Title Population trends of the common murre (Uria aalge californica)
Authors Harry R. Carter, Ulrich W. Wilson, Roy W. Lowe, M.S. Rodway, David Allen Manuwal, Jean E. Takekawa, Julie L. Yee
Publication Type Report
Publication Subtype Federal Government Series
Series Title Information and Technology Report
Series Number 2000-0012
Index ID 87377
Record Source USGS Publications Warehouse
USGS Organization Western Ecological Research Center