Many bird species commonly found in California have suffered steep population declines, as much as 96%, part of a nationwide trend, according to a study that for the first time combines 40 years of data. The study, combining the National Audubon Society's Christmas season bird counts with summertime surveys by the U.S. Geological Survey, documented declines of 75% to 96% in several California species, including the northern pintail, horned lark and loggerhead shrike. Greg Butcher, Audubon bird conservation director and analysis leader, said of the birds surveyed nationally, "about half are in decline and of these half are in significant decline." Overall, Butcher said, his organization is concerned about decreasing numbers of 200 to 300 kinds of birds. Because they have been so numerous, the birds that were surveyed often don't get the attention that small, endangered populations such as California condors have received. However, Gary Langham, Audubon California's director of bird conservation, said that although many bird populations may number in the millions, the large reductions that were documented are statistically significant. Kimball Garrett, collection manager for ornithology at the Natural History Museum of Los Angeles County, said that while the surveys must be interpreted cautiously, they are in line with other studies that show steep declines. "Some trends are just undeniable," he said. The evening grosbeak (Coccothraustes vespertinus) fared the worst in Audubon's California survey, with a 96% decline statewide. Nationally, grosbeak numbers fell from 17 million 40 years ago to 3.8 million today, according to both surveys.
Source: Los Angeles Times, June 15th, 2015
http://www.latimes.com/local/obituaries/la-me-birds15jun15-story.html
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