Low bird numbers blamed on climate change
LAS VEGAS: Climate change could be to blame for the collapse of bird populations in the desert along the NevadaCalifornia border, scientists say.
The number of bird species has fallen by an average of 43% over the past century at survey sites across an area larger than New York state, according to a new study by researchers at the University of California, Berkeley.
The study shows almost a third of species are less common and widespread than they once were.
Authors Steven Beissinger and Kelly Iknayan point to less hospitable conditions in the Mojave Desert as the probable cause.
‘‘California deserts have already experienced quite a bit of drying and warming because of climate change, and this might be enough to push birds over the edge,’’ said Iknayan, who conducted the research for her doctoral thesis. ‘‘It seems like we are losing part of the desert ecosystem.’’
‘‘The Mojave Desert is now nearly half empty of birds,’’ said Beissinger, a professor of environmental science, policy and management.
The researchers spent three years searching for birds at 61 locations, including survey sites in the Spring Mountains, the Desert National Wildlife Refuge just outside Las Vegas, the Death Valley and Joshua Tree national parks and Mojave National Preserve.
Iknayan revisited the same sites UC Berkeley biologist Joseph Grinnell and his colleagues surveyed between 1908 and 1947.
Iknayan and Beissinger found that areas with reduced rainfall lost more birds species than sites that remained wetter.
Their findings were published earlier this month in Proceedings of the National Academy of Sciences .—AP