WASHINGTON, DC, February 10, 2009-The northward and inland movement of North American birds, confirmed by thousands of citizen-observations, provides new and powerful evidence that global warming is having a serious impact on natural systems, according to new analyses by Audubon scientists. The findings signal the need for dramatic policy changes to combat pervasive ecological disruption.
Analyses of citizen-gathered data from the past 40 years of Audubon's Christmas Bird Count (CBC) reveal that 58 percent of the 305 widespread species that winter on the continent shifted significantly north since 1968, some by hundreds of miles. Movement was detected among species of every type, including more than 70 percent of highly adaptable forest and feeder birds. Only 38 percent of grassland species mirrored the trend, reflecting the constraints of their severely-depleted habitat and suggesting that they now face a double threat from the combined stresses of habitat loss and climate adaptation.
Population shifts among individual species are common, fluctuate, and can have many causes. However, Audubon scientists say the ongoing trend of movement by some 177 species-closely correlated to long-term winter temperature increases-reveals an undeniable link to the changing climate.
"Birds are showing us how the heavy hand of humanity is tipping the balance of nature and causing ecological disruption in ways we are just beginning to predict and comprehend," said report co-author and Audubon Director of Bird Conservation, Greg Butcher, Ph.D. "Common sense dictates that we act now to curb the causes and impacts of global warming to the extent we can, and shape our policies to better cope with the disruptions we cannot avoid."
Movements across all species-including those not reflecting the 40 year trend-averaged approximately 35 miles during the period. However, it is the complete picture of widespread movement and the failure of some species to move at all that illustrates the potential for problems.
Purple Finch, Pine Siskin, and Boreal Chickadee have retreated dramatically north into the Canadian Boreal, their ranges moving an estimated 313, 246, and 211 miles respectively over 40 years. Continuing warming and development are predicted to have adverse impacts on the Boreal forest and the species that depend on it.
Red-breasted Merganser, Ring-necked Duck, and American Black Duck, normally found in southern-tier states, have all taken advantage of warmer winter waters and have shifted their ranges north by an estimated 244, 169, and 141 miles. Still, they are likely to be negatively impacted by the increased drought expected in many parts of North America as global warming worsens.
Only 10 of 26 grassland species moved north significantly, while nine moved south. Species such as Eastern Meadowlark, Vesper Sparrow, and Burrowing Owl were likely unable to move despite more moderate northern temperatures because essential grassland habitat areas have disappeared, having been converted to intensive human uses such as row crops, pastures, and hayfields. In combination, global warming and ongoing overuse of grasslands by humans will doom grassland birds to continued population declines.
"Experts predict that global warming will mean dire consequences, even extinction, for many bird species, and this analysis suggests that that the process leading down that path is already well underway," warned Audubon President John Flicker. "We're witnessing an uncontrolled experiment on the birds and the world we share with them."
Butcher explains that many birds move great distances to find suitable food and habitat, but questions how far they will be able to move in the face of climate change before they run out of habitat, food or even luck. "The long term picture is not good for many species, and even in the short term, a single harsh winter could have a devastating impact on birds that have moved too far," he adds.
New forward-looking research from Audubon California reinforces the national findings, predicting that about 80 of that state's native bird species will experience significant climate-driven reductions in their geographic range over coming decades.
Scientific models indicate that the magnitude of losses in California depends largely on steps taken now to reduce greenhouse gas emissions. The California Gnatcatcher could lose as much as 56 percent of its range, or as little as 7 percent, depending on how climate change is addressed. Projected range losses for the Bay area's popular Chestnut-backed Chickadee vary from 49 percent to as little as 16 percent.
Detailed GIS maps produced using the California research project where the birds are likely to be in 50 to 100 years. Findings will help policymakers and land managers augment efforts to mitigate the severity of global warming impacts with better habitat conservation investments to address changes that can't be avoided.
"The birds are giving us yet another warning that it's time for urgent action," added Flicker. "People hear about melting glaciers and changing weather, but now they can witness the impact global warming is having with the birds they see or don't see right outside their doors. These birds are our 'canaries in the coal mine' and they're telling us that we'd better do something fast to curb global warming and to protect habitat."
Scientists say bold action is needed to overcome threats from global warming. Audubon calls on Congress and the administration to advance policies that will drastically reduce global warming pollution, cut oil dependence in half, and invest in a clean energy future and the economic benefits it offers. Americans can sign a petition at http://www.birdsandclimate.org/ to demand aggressive federal policy action.
Habitats already under siege from development, energy production, agricultural expansion and other human uses will require enhanced protection and restoration to sustain bird populations and provide ecological benefits essential to human health, economic prosperity and quality of life. Conservation efforts based on forward looking projections such as those from Audubon California are essential.
Audubon anticipates that the new avian evidence will help attract attention and spark action among more than 40 million U.S. bird-watchers, including tens of thousands who contributed to the Christmas Bird Count data on which the studies are based. The 109-year-old census provides the world's longest uninterrupted record of bird population trends. "Citizen Science is allowing us to better recognize the impacts that global warming is having here and now. Only citizen action can help us reduce them," said Butcher.
All of us have a role to play in reducing the worst impacts of global warming. As individuals and engaged citizens, we can all take steps to reduce our energy use, switch to cleaner sources of power, conserve habitat and encourage our leaders to take immediate action. Here's a short list:
1. Be an Active Citizen
Join Audubon's activist team and urge our elected official to make global warming a top priority by signing our petition at http://www.birdsandclimate.org/. Voice your support for new approaches to help solve global warming, move us toward a 100 percent clean energy future, reduce our dependence on oil, and protect our environment. Stay informed, write letters to your leaders, and support candidates who promise to take the aggressive and farsighted actions necessary to curb global warming.
2. Get Involved in Your Community
Support conservation efforts that protect and restore essential bird habitat, keeping it healthy to better withstand global warming. Visit http://www.audubon.org/ to learn how the Important Bird Areas program is building a national network of conservation stewards. And join in "Citizen Science" efforts like the Christmas and Great Backyard Bird Counts http://www.audubon.org/bird/citizen/index.html
3. Determine Your Energy Profile and Carbon Footprint
An energy audit assesses how much energy you consume. A carbon footprint shows how much greenhouse gas you emit into the atmosphere. These figures can help you determine steps you can take to make your home, school, or office more energy efficient. Many footprint calculators are available online.
4. Reduce Energy Consumption
Save money and energy by switching to compact fluorescent light bulbs and maximize the use you natural sunlight for daytime lighting needs. Reduce excessive use of home heating and cooling and weatherize your home. Buy energy efficient appliances such as those that are "Energy Star" compliant.
5. Eat Locally Grown and Organic Produce
The fewer miles your products travel, the less energy is used for refrigeration and transport. And buy organic. That reduces the use of pesticides that kill the organisms which help keep carbon in the soil.
6. Shop Smarter
Manufacturing, packing, transporting, and selling goods not only use huge amounts of energy but also release excessive amounts of greenhouse gases. When shopping, always ask, "Do I really need this? Does the Earth really need this?" You'll probably save money as well.
7. Save Gas and Money
Use public transportation, ride your bicycle, walk, carpool, and drive a more energy-efficient vehicle. Keep tires properly inflated to increase fuel efficiency-it will lower your fuel costs.
8. Plant More Trees and Buy Good Wood
An average tree absorbs ten pounds of pollutants from the air each year, including four pounds of ground level ozone and three pounds of particulates. So, plant leafy trees around your house to provide windbreaks and summer shade. When shopping for wood, ask about certified wood to support sustainably managed forests that are bird-friendly.
9. Switch to Green Power
Power plants are the single largest source of heat-trapping gases in the United States, but in some states you can switch to utilities that provide 50 to 100 percent renewable energy. You may also want to consider installing solar panels on your home.