Q-What makes this new research so important?
A-This is almost certainly the most comprehensive analysis of bird movements over the past forty years and what they reveal about the effects of climate change. It tells us that those who think climate change will be felt far from home and far off in the future had better think again. Its impacts are being seen here and now - and they are a warning that we must act immediately to stem the causes of global warming and to take conservation action to help habitat and species where changes cannot be avoided.

Q- What does this movement tell us about our environment?
A-It shows us that climate change is having a serious and pervasive impact on our country and the natural world right now. What we have detected is, at least in part, a response from birds to the disruption of healthy, functioning ecosystems caused by climate change. In essence, climate change is conducting an uncontrolled experiment on birds, other wildlife, their habitats and ours.

Q. How can you be sure that this movement is being caused by climate?
A. There is a strong correlation between shifting ranges and winter temperature trends. Specifically, annual latitudinal distributions of birds are correlated with annual temperatures; in other words, birds are found further north in warmer winters than they are in colder winters. Similarly, many birds are moving away from coastal areas, where oceans help moderate temperatures, and are being seen farther inland - as temperatures rise. In both cases, they are following the biological imperative to move into areas with suitable climate-and providing compelling evidence that we are seeing the impact of climate change play out across the continent. While it is true that birds alter their ranges for a variety of reasons, including successful reintroductions, habitat loss, recovery from DDT, loss of food supplies, etc., the fact that northward or inland movement is being seen for so many different species in different habitats points to climate change as a primary cause.

• Among all the species in our study, twice as many bird species moved north as south; twice as many species moved inland as moved coastally. Both of these directional movements are consistent with a climate change model.
• An equal number of birds moved east as moved west. This is also consistent with a global warming model - movements away from the Atlantic and Pacific should be about equal, with no other expectation of differences in east-west movement.
• There is a high correlation between the rate of winter population change for species in states, and the rate of winter temperature change in those states - and this is the case regardless of state or province latitude.
• While birds found only in a few southern states were not included in the main part of this study, they have been observed in increasing numbers, suggesting that they have moved north from south of the United States.

Q - How were Audubon's scientists able to determine that many bird species are showing significant northward and inland movement?
A. Researchers pooled thousands of Christmas Bird Count observations and used them to calculate the center of abundance for each bird species in the study. (In simplified terms, half the individuals of a species are found south of the center of abundance, and the other half are found to the north.) They then measured the direction and distance of any changes in these centers of abundance over the last 40 years. The resulting numbers are approximations, but taken together, they give striking evidence that our wintering birds are indeed shifting their ranges toward the north and farther inland.

Q: Didn't some species fare really well over the past 40 years (even showing population increases)?
A-Yes, many of the species that moved north and inland increased in population at the same time. But it would be short-sighted to focus on what may appear to be short-term gains. Where food or habitat is available, species may do well in the short term, but ultimately the need to adjust to changing climate conditions can put species in peril in a variety of ways. Some will move into areas where an unusually harsh winter will still bring conditions they cannot survive. Others may be unable to find food or suitable habitat (especially if the healthy habitats they need, like grasslands) are already being decimated by overuse, pollution, and other threats. Even species that fare well amid the changes are likely to force out other, less adaptable birds, taking a long-term toll on ecological health and all it supports.

Q-Did any species move south, and if so, why?
A-Yes, about one-quarter of the species moved south. Birds frequently alter their ranges due to many factors, especially habitat changes and interactions with other species. Audubon does not suggest that all the birds that moved north or inland did so in response to climate change; a wide variety of other factors play a contributing role and explain why a minority of species showed no movement or even shifted southward.

Q- Is this simply evidence that nature is adaptable?
A- Some birds are among the most adaptable creatures on earth, and they're warning us about just how much movement may be needed - not just by birds but by all kinds of wildlife. Unfortunately, many species will not have the ability to make the moves the climate requires; their habitats or their own numbers or their sedentary nature or the necessary corridors may be too limited. They may face too much competition, or they could be decimated by sudden changes in weather that defy the long-term trends. Even though many species can adapt to change, we have to be careful about creating change that is beyond what they - and we - can handle.

Q-What groups of birds are at greatest risk?
A-Tundra species such as Snowy Owl and American Golden-Plover simply cannot go much farther north. Grassland species are also at particular risk because their habitats have been so decimated by human over-use that they have few other places to go to find more suitable climate-indeed that is why many did not show much movement in our study. Coastal species face two major issues. Many will lose their habitats due to sea-level rise. Others will lose their food supply because of the disruption of ocean currents that bring their foods near to the ocean surface where they can be caught by birds.

Q-What birds are likely to be forced toward extinction?
A-We are concerned about ice-loving birds such as Ivory and Ross's Gulls that share habitat with polar bears and Arctic-breeding shorebirds such as American Golden-Plover and Buff-breasted Sandpiper. We are very concerned about coastal birds such as Piping Plover and Saltmarsh Sparrow and coastal seabirds like Kittlitz's Murrelet and Ashy Storm-Petrel. We are also concerned about mountaintop birds such as Brown-capped and Black Rosy-Finches and Bicknell's Thrush.

Q-Many of the citizen scientists who participate in the Christmas Bird Count are volunteers. Is the data still reliable?
A-Extremely. While most "counters" are not professional scientists, they follow a carefully-developed and reporting protocol developed by Audubon scientists to ensure the quality of the data, which are also analyzed by professional scientists and statisticians. The headline of a January, 2009 editorial in the authoritative journal, Nature, proclaimed: "The Christmas Bird Count is a model to be emulated in distributed, volunteer science." The editorial noted that "[CBC] data have informed reams of peer-reviewed work…" Indeed, more than 200 scientific papers have been based on its well-respected data since the CBC began in 1900, serving as a vital foundation for conservation planning and policy development.

Q- What can concerned people do to help?
A. Everyone can make a difference, from encouraging our government representatives to adopt energy policies that curb climate change and support science-based conservation action to reducing our own use of fossil fuels. For more information visit Legislative Priorities and What You Can Do.