An Overview of the IBA Programme

Using Birds as Indicators

Important Bird Areas (IBAs) are sites of global, regional, or sub-regional biodiversity conservation importance that are chosen using internationally agreed, objective, quantitative, and scientifically defensible criteria (eg Bennun & Njoroge, 1999, Fishpool & Evans, 2001, Heath & Evans, 2000, Islam & Rahmani, 2004). The IBA process uses birds to select key sites for conservation. IBAs are selected because they may hold threatened birds, birds restricted to particular regions or biomes, or significantly large populations of congregatory waterbirds. Through this process, sites directly important for bird conservation are identified and prioritized for conservation actions. In addition, birds have been shown to be extremely good indicators of overall biodiversity, and throughout the world, IBAs themselves protect a high percentage of many nations’ total biodiversity (Stattersfield et al, 1998; Bennun & Njoroge, 1999).

Birds serve as a good indicator for several reasons. In certain places birds are some of the largest terrestrial species, and thus are sensitive to changes throughout their ecosystems. Multiplying effects from less visible biodiversity in lower trophic levels may be manifested and then observed in birds. Birds also play a role in maintaining biodiversity through their ecological role as pollinators and seed dispersers, and thus a change in bird biodiversity may indicate a change in overall biodiversity. Birds also tend to be well studied and well understood, and because they are larger, aesthetically pleasing fauna, they lend themselves easily to many community-based research and monitoring programs. Thus birds, for the inherent biodiversity and ecosystem service value they hold and the popular appeal they hold to people, serve as good indicator species for overall biodiversity and ecosystem health. In addition, conserving a site because it holds bird species of concern will most probably lead to conservation of other important plant and animal species as well.

International IBA Programme

The IBA Programme has been developed by BirdLife International and used throughout the world. IBAs have been identified in Europe, Africa, and in parts of Asia, North America, South America, the Pacific Islands and Australia.

The International IBA Program is designed to identify areas of global significance. To be listed as an IBA of global significance, sites must meet one or more of four criteria. These criteria are listed in Table 5. In some cases, quantitative thresholds are set to aid site selection and to help define the concept of “significant numbers” of species. (Thresholds for waterbirds and seabird in the Pacific region can be found here). The application of the criteria involved assessing the data provided for each relevant bird species at a site with whether the population represented 1% of the regional population of the species (A4), or whether the known presence of a species at a site implied that it occurred there regularly and/or in significant numbers (A1). As a rule of thumb, the regular presence of all species classed as Critically Endangered or Endangered, meant that the site qualified under A1. Similarly, the presence of at least 30 individuals, or 10 pairs, of a Vulnerable or Near-threatened species qualified the site under A1. For category A2, the presence of a suite of Restricted-range species, the application process required assessments of the assemblages of relevant species at a given site, in comparison with those same assemblages at other sites potentially qualifying for the same category. Category A3, the assemblage of Biome-restricted species has not been used on the Pacific Islands, but may be important in assessing sites in large, continental, landmasses such as Papua New Guinea and Australia.

Table 5. Criteria for selection of Important Bird Areas of global significance (Bennun & Njoroge, 1999)

Category	Criterion	Notes
A1. Globally-threatened Species	The site regularly holds significant numbers of a globally threatened species, or other species of global conservation concern.	Globally threatened species are those listed on the IUCN Red List. Sites qualify if they are known or thought to hold a population of Critically Endangered or Endangered species. Population-size thresholds are set for species classified as Vulnerable, Conservation Dependent, Data Deficient, and Near Threatened. Thresholds may be set (1% of global population, >10 pairs or 30 individuals).
A2. Restricted Range species	The site is known or thought to hold a significant component of the restricted-range species whose breeding distributions define an Endemic Bird Area (EBA) or Secondary Area (SA)	Restricted-range species are defined as all landbirds which have had, throughout historical times, a total global breeding range estimated at below 50,000 km². EBAs are defined as an area which encompasses the overlapping breeding ranges of restricted-range bird species, such that the complete ranges of two or more restricted-range species are entirely included within the boundary of the EBA. EBAs capture endemic birds and other birds with limited ranges.
A3. Biome-restricted species	The site is known or thought to hold a significant component of the group of species whose distributions are largely or wholly confined in one biome.	This applies to species that share a distribution of greater than 50,000 km² and occur within a biome, defined as a major regional ecological community characterized by distinctive life forms and principal plant species.
A4. Congregations	(i) The site is known or thought to hold, on a regular basis, >1% of a biogeographic population of a congregatory waterbird species.	Thresholds may be set regionally or inter-regionally. Pacific Island thresholds, and sources of data, can be found here.
	(ii) The site is known or thought to hold, on a regular basis, >1% of the global population of a congregatory seabird or terrestrial species.	Thresholds may be set regionally or inter-regionally. Pacific Island thresholds, and sources of data, can be found here
	(iii) The site is known or thought to hold, on a regular basis, >20,000 waterbirds or >10,000 pairs of seabirds of one or more species.	Follows the Ramsar criterion for waterbirds.
	(iv) The site is known or thought to exceed thresholds set for migratory species at bottleneck sites.	Thresholds may be set regionally or inter-regionally.

In addition to the criteria, site selection requires the following:

IBAs should, as far as possible, have a clear border, such that the IBA is different in habitat or character from surrounding areas;
IBAs should be small or cohesive enough to act as a management unit;
IBAs should, either alone or with other sites, be a self-sufficient area that provides the requirements of the birds that use it during the time they are present; and
Selection of a set of IBAs in an Endemic Bird Area[1] should also be designed to ensure that all restricted-range species are present in significant numbers in one or more sites (Bennun & Njoroge, 1999).

· Where extensive tracts of continuous habitat occur which are important for birds, only characteristics 2 to 4 need apply.

· Practical consideration of how best the site may be conserved are the foremost considerations.

· Simple, conspicuous boundaries such as roads or rivers can often be used to delimit site margins, while features such as watersheds, ridge-lines and hilltops will help in places where there are no obvious discontinuities in habitat (transitions of vegetation or substrate). Boundaries of ownership may also be relevant.

· There is no fixed maximum or minimum size for IBAs – the biologically sensible should be tempered with the practical. Neither is there a definitive answer on how to treat cases where a number of small sites lie near each other. Whether these are best considered as a series of separate IBAs, or as one larger site containing areas lacking ornithological significance, depends upon the local situation with regard to conservation and management.

[1] An Endemic Bird Area (EBA) is defined as an area which encompasses the overlapping breeding ranges of restricted-range bird species, such that the complete ranges of two or more restricted-range species are entirely included within the boundary of the EBA (Stattersfield, et al., 1998).

IMPORTANT BIRD AREAS IN THE PACIFIC: A COMPENDIUM - Birdlife Pacific (2010)