The Desert Southwest has grown hotter over the years. Proof of the warming trend comes in the form of birds’ movements, according to bird scientists.
After analyzing data collected over the past 40 years, Audubon Society scientists have found that several of Arizona’s resident “forest birds” have shifted their ranges northward, some by hundreds of miles.
In particular, the Arizona populations of four birds — pygmy nuthatch, spotted towhee, northern pygmy-owl and American dipper — have decreased by 49 percent to 72 percent in the past four decades, according to Audubon data released last month.
As temperatures rise, especially in Southern Arizona, the farther north these birds must make their homes. If the trend holds, some species may vanish from the state in the coming decades.
Nationwide, 58 percent of 305 widely spread species that spend winters on the continent have shifted their ranges ever northward over the last 40 years, according to Audubon.
The effects of climate change on birds weighed on the minds of people who attended the Arizona Audubon Conservation Summit last Saturday at the Arizona-Sonora Desert Museum.
The purpose of last week’s gathering was twofold — to outline the biggest threats to regional conservation efforts, and to determine how local Audubon groups could lobby on behalf of the environment.
“Audubon is as much about people as it is about birds,” said Paul Green, executive director of the Tucson Audubon Society. “We use birds as a hook to get people.”
And, in birds, the group has an all-powerful hook, suggested Les Corey, a senior vice president with National Audubon.
“Birds are, in fact, becoming a real barometer for us,” Corey said. “They are the canary in the coal mine.”
The northward creep of many species points to a direct link between the natural environment and climate, he added.
The Audubon Society should bring data of such alarming trends to bear in the fight to protect sensitive lands and the environment as a whole, Corey and others suggested last Saturday.
Throughout the day, groups met separately to discuss three particular areas of concern — the loss of land and water habitats in Arizona and climate change, particularly how it relates to the Southwest.
The end goal of the gathering, Audubon leaders suggested, would involve marshalling a variety of forces, led by Audubon, to push for legislation designed to protect wild lands and waters and the climate.
“The birds are a great message,” said Tice Supplee, director of bird conservation at Audubon Arizona.
The plight of birds can aid scientists in making the case for swift action to combat climate change, said Betsy Loyless, Audubon’s national lobbyist and the summit’s keynote speaker.
“Science, in and of itself, cannot accomplish this,” Loyless warned. Grass-roots activism and local action can, she added. State by state, county by county, groups desiring stricter environmental protections can be successful.
Specifically in Arizona, summit attendees pointed to the need for tighter water regulations that ensure continued access not only for people, but for animals as well.
The group also sought to push for limits to development, particularly suburban sprawl.
Carolyn Campbell, executive director of Coalition for Sonoran Desert Conservation, touted the success of Pima County’s efforts to protect large swaths of desert acreage, thereby preserving animals’ natural habitats.
The Audubon Society, Campbell suggested, could lend cachet to any major conservation effort in the area.
“Audubon is trusted. Polling shows that,” she explained. “In a crass, sort-of political, way, Audubon is the messenger for this.”
Her words resonated with the group, which in the coming months would look for more aggressive ways to lobby for conservation measures here and nationwide.
Tucson Audubon’s Green said last weekend’s summit was but a start. “I’d like to see a major shift in mindset as we approach climate change.”
A number of factors have contributed to the decline in prevalence of many area birds in recent years, according to scientists. Threats include:
SPRAWL: Increased development throughout the state has supplanted prime desert, woodland and grassland habitats.
LOSS OF RIPARIAN HABITAT: The channeling of waterways and other diversions of surface water have eliminated more than 70 percent of the state’s riparian areas, according to Katharine Jacobs, executive director of the Arizona Water Institute. Riparian areas, including the region’s perennial and dry riverbeds, encapsulate entire ecosystems and serve as important buffers between land and water environments.
CLIMATE CHANGE: Scientists suggest the Desert Southwest will experience the effects of global warming to a greater degree than most areas on the continent. Changes likely will include hotter summers with more volatile storms and prolonged phases of drought.