Why apply criteria

The selection of Important Bird and Biodiversity Areas (IBAs) is achieved through the application of quantitative ornithological criteria, grounded in up-to-date knowledge of the sizes and trends of bird populations. The criteria ensure that the sites selected as IBAs have true significance for the international conservation of bird populations, and provide a common currency that all IBAs adhere to, thus creating consistency among, and enabling comparability between, sites at national, continental and global levels.

It is crucial to understand why a site is important, and to do this it is necessary to evaluate its international significance in terms of the presence and abundance of species that occur there, year round or seasonally. Historically, IBA site selection criteria were developed at the global level and for some regions at sub-global levels, including region (Europe and Middle East) and sub-region (European Union, South Africa and the Caribbean). These criteria were recently revised in consultation with our Regional Coordinators, and adopted in 2020. The following pages provide a summary of these revised IBA criteria.

A main aim of the IBA Programme of BirdLife International is to secure the long-term conservation of sites that are of significant importance for birds and biodiversity. The provision of robust bird data and the application of scientific criteria to identify IBA trigger species are essential for the identification of IBAs. Ongoing and regular up-dates permit not only the assessment of changes in species’ numbers but also an examination of how these changes impact on the overall importance of the site. Together with the implementation of the IBA Monitoring Protocol that assesses the state, the extent of pressures and the responses implemented (arising actions, management etc.), help to interpret these changes and to guide the management and conservation of the area.

There are more than 13,000 IBAs identified so far through the application of the IBA criteria and this information is stored in the World Database of Key Biodiversity Areas (WDKBA) and is available on the BirdLife Data Zone and on the Key Biodiversity Areas Website. The more specific, quantitative and comprehensive is the information available on IBAs, with links showing the fulfilment of obligations laid out in various international conventions, the stronger is the case for protection. To this end, the criteria build upon existing international legal instruments such as the EC Birds Directive, which obliges the designation of Special Protection Areas in the European Union, and the Ramsar Convention under which contracting parties must designate at least one Ramsar Site (wetland of international importance) in their territory. IBAs form a subset of Key Biodiversity Areas (KBAs) that have been embedded in various international agreements and safeguard mechanisms and serve as indicators for the biodiversity policy framework of the Convention on Biological Diversity (CBD) and the Sustainable Development Goals (SDGs).


Click on any of the pages below to review the more detailed descriptions of the relevant IBA criteria. Detailed guidelines can be downloaded here.

Global IBA Criteria
Regional IBA Criteria
Sub-regional IBA Criteria