The purpose of this document is to identify migratory and non-migratory birds of the United States and its territories that are of conservation concern so as to stimulate coordinated and proactive conservation actions among Federal, State, Tribal, and private partners. The conservation concerns may be the result of population declines, naturally or human-caused small ranges or population sizes, threats to habitat, or other factors. The primary statutory authority for Birds of Conservation Concern 2008 (BCC 2008) is the Fish and Wildlife Conservation Act of 1980 (FWCA), as amended; other authorities include the Endangered Species Act (ESA) of 1973, the Fish and Wildlife Act of 1956, and 16 U.S.C. § 701. The 1988 amendment (Public Law 100-653, Title VIII) to the FWCA requires the Secretary of the Interior, through the United States Fish and Wildlife Service (USFWS), to "identify species, subspecies, and populations of all migratory nongame birds that, without additional conservation actions, are likely to become candidates for listing under the Endangered Species Act of 1973." BCC 2008 is the most recent effort by the USFWS to carry out this proactive conservation mandate and update Birds of Conservation Concern 2002 (USFWS 2002). The overall goal of this report is to accurately identify those species (beyond those already federally listed as threatened or endangered) in greatest need of conservation action at three different geographic scales. A primary goal of the USFWS is to conserve avian diversity in North America (USFWS 1990, 2004). This goal includes reducing or removing threats that may necessitate that a species be considered for listing under the ESA. The Birds of Conservation Concern are largely a subset of a larger list known as the Birds of Management Concern (BMC). The BMC is a subset of all species protected by the Migratory Bird Treaty Act (MBTA, see 50 CFR 10.13), and includes those which pose special management challenges due to a variety of factors (e.g., too few, too many, conflicts with human interests, or societal demands) (USFWS 2004). The BMC includes both game birds below their desired condition and nongame birds. As indicated in its strategic plan (USFWS 2004), the Migratory Bird Program places priority emphasis on these birds in its activities. The philosophy underlying this report is that proactive bird conservation is necessary at a time when human impacts are at an all-time high. We strongly believe that a well-designed program that addresses resource-management issues up front will prevent or remove the need to consider listing species as threatened or endangered, and will promote and conserve long-term avian diversity in the United States. In addition, proactive conservation clearly is more cost-effective than the extensive recovery efforts required once a species is federally listed under the ESA. Our intent is for BCC 2008 to stimulate coordinated efforts to develop and implement comprehensive and integrated approaches for the study, management, and protection of "non-ESA listed" bird species deemed to be in the most need of additional conservation actions. It should also be noted that, while the inclusion of native species not listed under the MBTA is beyond the scope of the FWCA, the USFWS has an incentive to encourage proactive management of these species by State agencies and other partners to prevent the need for listing them as endangered or threatened.