An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations.
IBA was developed and sites are identified by BirdLife International. There are over 13,000 IBAs worldwide. These sites are small enough to be entirely conserved and differ in their character, habitat or ornithological importance from the surrounding habitat. In the United States the Program is administered by the National Audubon Society.
Often IBAs form part of a country's existing protected area network, and so are protected under national legislation. Legal recognition and protection of IBAs that are not within existing protected areas varies within different countries. Some countries have a National IBA Conservation Strategy, whereas in others protection is completely lacking.
IBAs are determined by an internationally agreed set of criteria. Specific IBA thresholds are set by regional and national governing organizations. To be listed as an IBA, a site must satisfy at least one of the following rating criteria:
The site qualifies if it is known, estimated or thought to hold a population of a species categorized by the IUCN Red List as Critically Endangered, Endangered or Vulnerable. In general, the regular presence of a Critical or Endangered species, irrespective of population size, at a site may be sufficient for a site to qualify as an IBA. For Vulnerable species, the presence of more than threshold numbers at a site is necessary to trigger selection.
The site forms one of a set selected to ensure that all restricted-range species of an Endemic Bird Area (EBA) or a Secondary Area (SA) are present in significant numbers in at least one site and preferably more.
The site forms one of a set selected to ensure adequate representation of all species restricted to a given biome, both across the biome as a whole and for all of its species in each range state.
The assessment by expert individuals is however not entirely reliable and a study in South America found that the coverage needed for at-risk bird conservation as chosen by computational algorithms rarely overlapped with IBAs and suggested that such methods should be used to complement expert driven IBA site choices.