Climate changes, habitat loss cited as threats to 314 bird species
If bird watchers in Pennsylvania think they are seeing less of some species — the ruffed grouse, scarlet tanager, wood thrush and Baltimore oriole — they are right.
Those birds could go the way of the once-prevalent Passenger Pigeon and are among hundreds at risk of disappearing, according to a report by the Audubon Society and another jointly prepared by the Fish & Wildlife Service and the Cornell University Lab of Ornithology.
The projected declines, the studies each say, reflect climate changes and the disappearance of natural habitats.
“They are more of a wake-up call than an absolute and concrete prediction,” said Margaret Brittingham, a professor of Wildlife Resources and bird habitat expert at Penn State University, which was not involved in either study.
Birds are important because they provide free ecological services, she said. Warblers feed on insects in forests. Birds contribute to forest health, clean air and clean water and protect timber resources.
Of 588 bird species examined in the seven-year Audubon study, 314 species are at risk, the report concluded. Of those, 126 species are at risk of severe declines by 2050, and 188 species face the same fate by 2080, according to the Audubon study.
The Audubon report analyzed more than 40 years of historical North American climate data and millions of historical bird records.
Changes in rainfall, temperature and the seasons — building blocks for ecosystems and species survival — may have catastrophic consequences, the study said.
“The greatest threat our birds face today is global warming,” said Audubon Chief Scientist Gary Langham, who led the investigation. “That’s our unequivocal conclusion.”
Birds such as cardinals and Carolina wrens are wintering farther north than they did as little as 20 years ago, the Audubon study said. Pennsylvania and Maryland could lose the orange-and-black Baltimore oriole, mascot of the major league team, before the end of this century.
Minnesota’s state bird, the common loon, an iconic species across much of the northern United States, may not be able to raise its young anywhere in the lower 48 states by 2080, according to the study.
Experts say that development and habitat loss play just as large a role in shrinking bird populations. The steepest declines are in the Western states, according to “The State of the Birds 2014” prepared by the federal government, Cornell and 13 other organizations.
“Species that can do well around people have increased — blue jays, mockingbirds, morning doves. Cardinals are more abundant,” Brittingham said.
Destruction of arid lands, largely because of development, has resulted in a 46 percent decline in the bird population since 1968 in Utah, Arizona, New Mexico and other Western states, the report said.
“There are a lot of things that people can do to reduce stress on bird populations, such as wetland conservation and landscaping suburban backyards and planting trees and shrubs that support native birds,” Brittingham said.
Rick Wills is a staff writer for Trib Total Media. He can be reached at 412-320-7944 or [email protected].