Birds of a Feather...

• Author: Gonzalez, Nicolas
• Position: THE ENVIRONMENT

AN AVERAGE of 25% of the bird species found in some of the U.S.'s most well-known national parks could be completely different by mid century because of a changing climate, according to a study by scientists from the National Audubon Society and the National Park Service. The peer-reviewed study appeared in PLOS ONE and delivers another sobering reminder of the threat climate change poses to birds.

The study authors analyzed 274 sites managed by the National Park Service and overlaid them with climate suitability models for birds known to spend summers and winters within the parks. The suitability models then were linked to two different trajectories of greenhouse gas emissions representing low-and high-emissions paths. The low-end pathway incorporates the most-stringent mitigation scenario, whereas the high-end represents our current trajectory.

In scenarios with lower carbon emissions, there are fewer projected changes found in parks but, on the high end of emissions--or "business as usual"--bald eagles may leave the Grand Canyon during the winter and mountain bluebirds may stop breeding in Badlands National Park over the summer.

"These drastic climate projections underscore the important role our national parks play as habitat for birds, today and tomorrow" says Joanna Wu, Audubon biologist and lead author on the study. "Scenarios with lower greenhouse gas emissions result in a lower average bird turnover. If we want to reduce the impact in these protected places, lowering carbon pollution is an integral part of the equation."

Because more birds have the potential to move into national parks than move out, public lands will continue serving as important bird habitats despite a changing climate. Each site will receive a "climate brief," outlining which bird species currently are found within the park, which new species may colonize the park, and which current species may be extirpated locally.

"With new birds coming in and familiar birds heading out, the stewards of America's public lands will need to prepare for substantial changes in the near future," maintains study coauthor Gregor Schuurman, National Park Service ecologist.

The parks are grouped into five trend categories: high turnover overall, high potential extirpation, high potential colonization, intermediate change, and low change. Understanding the characteristics of the trend groups will serve to inform the management of individual parks for the benefit of the entire National...