Important Bird Areas (IBAs)

For a site to be chosen as a U.S. “Global” IBA (shown in solid colors), it must qualify under one or both of the categories below. The definition of an “Area” in this case is: a land management unit with singular (or primarily singular) ownership or management authority; or a clearly defined geographic feature such as a lake, island, peninsula, or ridge; that can be managed for bird conservation. Note that areas shown in a tinted color are not “sites” per se but more broadly defined areas such as corridors or marine zones that do not tend to be as discreet from a management or geographic perspective. These tinted areas also tend to be larger, and either seasonally important, or of most significance where appropriate habitat for the species of concern is found within them.

Category 1: It must be among the best sites (i.e. have a globally significant representative area of optimal habitat and the presence of the species within that habitat at a density appropriate for the species) for one or more WatchList species during the U.S. part of its/their life-cycle (the criteria for inclusion on the WatchList are set forth below).  

Category 2: It must contain a significantly large concentration of breeding, migrating, or wintering birds, including waterfowl, seabirds, wading birds, raptors, or landbirds (although we do not include super-abundant flocking species such as some of the blackbirds or those which are increasing their populations to the point where they, themselves, are presenting management problems, such as Snow and Canada Geese and some gulls).

Below are our numeric threshold criteria for including sites with significant congregations:

  1. For waterfowl, sites with more than 100,000 ducks, geese, or swans.

  2. For seabirds, colonies of 50,000 or more individuals, omitting concentrations of the most abundant increasing gull species.

  3. For shorebirds, sites at the international and hemispheric level in the Western Hemisphere Shorebird Reserve Network (WHSRN) and sites with 50,000 individual birds or more at some time of year.

  4. Congregations of raptors, with 25,000 or more individuals regularly counted during a season. It is important to note that these sites are generally “over-flight” sites, not used by migrant raptors for resting and feeding, and thus not important to them in the same way that many stopover sites are to migrating passerines and other landbirds. There are probably many other places in the United States that would qualify on the basis of 25,000 hawks passing over, but we include only those where long-term counts are available that prove their significance.

  5. For wading birds, the largest colonies, such as those with more than 1,000 individuals. For migrating landbirds other than raptors, including passerines, cuckoos, and hummingbirds, the sites we include are stopover sites, though there is a general lack of census data on numbers using such sites, and use can vary greatly from year to year, depending on weather conditions.

  6. For migrating landbirds other than raptors; including passerines, cuckoos, and hummingbirds, the sites we include are stopover sites, though there is a general lack of census data on numbers using such sites, and use can vary greatly from year to year, depending on weather conditions.

Many of the sites qualify in both categories. The “Highlight” given for each site in the Google Earth balloon makes it apparent why it was chosen, without the need to refer back to this section.

American Bird Conservancy has identified approximately 500 “Global” (those that are considered globally important) IBAs that cover the whole of the U.S. using the criteria cited above. National Audubon and its chapters have identified additional IBAs by state using criteria that can be found at: These state IBA programs have been completed for a majority of, but not for all states at the present time. Additional state-level sites will be added to the map as they become available.

The WatchList

The WatchList reflects the most advanced and consistent reasoning yet attempted concerning the assessment of the status of birds in the United States. In order to focus on the most important conservation objectives, Partners in Flight (PIF) developed a species assessment process. From the beginning, the criteria used included range size, population size, population trend, and threats. Initiatives dealing with shorebirds, waterbirds, and waterfowl all created variations of these criteria, as did increasing involvement by Canadian and Mexican conservationists, and the criteria continue to evolve as new ideas develop.

A list such as this is an interpretation of assessments that includes all of those species that exceed a selected level of cumulative concern on a national or continental scale. There have been a number of WatchLists produced over the years, most recently in 2007 (click here). Prior to 2000 the lists were somewhat inconsistent, in part because divergent interpretations of the various initiatives (shorebirds, waterbirds, etc.) were respected, meaning that different groups of birds were evaluated differently and independently of each other.

PIF in the three North American countries has since made great advances in the science and application of species assessment. The WatchList now applies the latest thinking to all birds, including shorebirds, waterbirds, waterfowl, and other gamebirds such as grouse and quail. 

Wind Development Bird Risk Map