What is the importance of using both Christmas Bird Count (CBC) and Breeding Bird Survey (BBS) data?
For the first time, this analysis includes 40 years of national-level data from two different surveys - BBS and CBC. Looking at, and, where appropriate, combining the data gives us the clearest possible picture of what is happening to these bird populations. Unfortunately, we found a lot of news that is not good and that means people need to take action to help the birds and the habitats they share with all of us.

Are the combined national declines simply the average of BBS and CBC findings?
Common Birds in Decline presents weighted averages for all species on the national list based on the extent to which a survey includes a larger proportion of the species range or otherwise provides more reliable information on its population. This way we get the most accurate sense of what is really happening to the species nationwide.

Why does some trend information reflect the aggregate of the BBS and CBC, while some focuses on only one source of data?
Some species breed in the United States but winter south of the United States. For these species, we provide trends based only on the BBS because there are no CBC data for them. Some species winter in the 48 contiguous states, but breed farther north (farther north than there are roads). For these species, there are no BBS data, so the trends are based only on the CBC. Other species, such as permanent resident species or short-distance migrants are entirely or partially covered by both surveys. For these species, our best estimate of their total population change is a combination of the BBS and CBC trends.

Looking at the counts individually and together helps us to better understand the differences in more local population trends as opposed to those observed across the lower 48. A local story that appears better than the national picture simply demonstrates that we can make conservation gains close to home but still need to act at the broader level to protect the birds, their habitats and the resources we all depend on.

This information comes from "citizen scientists," is it as reliable as "real science?
This is very real science. The tens of thousands of people who devote countless hours to counting these birds provide data that no individual scientist could ever collect alone. Participants in the Christmas Bird Count and the Breeding Bird Survey include experts in bird identification - they take their bird counts very seriously and provide high quality data.

What does it mean if a species shows big declines nationally, but fares better in at the state level or in the experience of "locals?"
Most species do not show uniform trends throughout their range - although many on this list do. Species doing particularly well in a given state may well indicate some specific local or regional conservation progress worthy of celebration. However, while conservation gains close to home are encouraging, a species' presence on the CBID list reminds us that birds still face significant threats across the continent and beyond. We need to act at the broader level to protect the birds, their habitats and the resources we all depend on. Everyone who cares about our state and our local habitats needs to take action here and to also work for better conservation policies nationwide.

What do the declining numbers indicate for human health, prosperity and quality of life?
They tell us we need to pay closer attention to the resources and environmental quality that are essential to all people and wildlife. Birds require healthy habitats. So do we. Birds require clean air and clean water. So do we. When we take care of what the birds need, we're often taking care of ourselves. The declines we are seeing show we're not doing a good enough job in safeguarding wetlands, forests, and grasslands that all provide critical benefits to people and wildlife. And they warn us to act more quickly on increasing threats from global warming, the spread of invasive species, expanding and spreading sprawl, industrial agricultural practices, and poorly controlled energy development.

Should we really worry about birds that still number in the millions?
Keeping common birds common is both a good way to protect our own health and habitat and a necessity for protecting the legacy we leave for future generations. Being on this list means that these birds are on the path from abundance toward rarity. If we don't do something about the causes of their declines, they can eventually move from common, to rare, to watch-list status, and beyond. We need to heed the warnings now to keep them common and to protect the world they share with all of us.

Will people really care when they can still see these birds every day?
We believe they will care more because they know and love the species that are vanishing before their eyes. We hope familiarity will breed concern and action.

What is the outlook for these birds?
It varies greatly. Some are being helped by human intervention. In other cases, the habitat loss and other factors that caused their initial declines are being exacerbated by factors like the rush for more oil and gas production, demand for corn to produce ethanol, and the mounting impacts of global warming. What happens next will depend a lot on all of us. But beyond the outlook for these birds is: what is the outlook for humans? Will we act now to save vital habitats and to fight global warming and reduce pollution, or will we wait until these issues threaten our health and well-being?

What is happening to the real backyard favorites like robins, blue jays and cardinals?
Robins, cardinals and blue jays are not on our list because they're among a special group of birds that can do well even in heavily disrupted environments, meaning they offer a very misleading picture of environmental health - but much as people love robins, it would be a tragic error to see them replace other species, just as it's a mistake to replace a healthy forest with a single kind of tree. Populations of generalist birds like robins, blue jays and cardinals were stable or even increased slightly over the past four decades because they can thrive, often at the expense of other species like our birds in decline - in the face of greater environmental disruption.

In contrast, the common birds in decline reflect broader environmental problems because they have specific habitat needs that are jeopardized by the combined impacts of everything from local development to global warming-they give us warnings when our environment is in trouble. Habitat disruption and other factors that jeopardize the common birds in decline could even benefit these generalist species in the future, but that would spell a loss of biological diversity and signal an environment that's seriously out of balance.