• In the entire AEWA region, estimates are now available for 98% of the 522 waterbird populations covered by the Agreement. This is satisfactory, but the quality of many of the estimates remains low. Population trend estimates (whether decreasing, stable or increasing) are available for 71% of these populations.
• The quantity and quality of waterbird population estimates and trends in 2008 was considerably higher in Europe, and particularly in northern and western Europe, than in the rest of the AEWA region.
• Overall the trend status of waterbirds in the Agreement area worsened between 1999 and 2006. The state of knowledge of waterbird trends improved considerably, however, and the number of populations for which there is no estimated population trend decreased from 41% in 1999 to 29% in 2008. The result of this is that the proportion of known populations that was estimated to be increasing declined from 25% in 1999 to 21% in 2008, the proportion estimated to be stable increased from 33% to 37%, and the proportion estimated to be decreasing stayed at about the same level, decreasing from 42 to 41%.
• A total of 92 populations that showed a decreasing trend in both 1999 and 2008 are still considered to be decreasing. By comparison, only 47 populations that were increasing in 1999 were still considered to be increasing in 2008.
• Improvements in the quality of IWC data allowed the first comprehensive trend analysis of IWC data from the East Mediterranean/Black Sea region and revealed that many more populations in this region are in decline than in other parts of the Europe.

Priority Geographic areas

• The quality of population estimates is high for non-breeding waterbirds in northern western and central Europe. In most other regions, there is a need to improve the quality of estimates, and this need is greatest in the Asian and sub-Saharan African portions of the AEWA region.
• In the AEWA region as a whole, of populations covered by the Agreement with known trends, nearly twice as many show decreasing trends (41%) as increasing trends (21%). In the part of the Agreement Area in Asia, the situation is much worse: only 11% of populations are known to be increasing, but five times as many, fully 55% of populations are known to be decreasing. 42% of population trends in Asia remain unknown, however, and the need to improve knowledge of population trends is greatest in this part of the AEWA region, where the proportion of decreasing populations is also the highest.
• Altogether, 30 of the 34 AEWA Globally Threatened or Near Threatened species are found in Africa, 17 in the part of the Agreement Area in Asia and only 14 in Europe. Africa holds the highest proportion of populations recognised as being Globally Threatened – 11.5% of all AEWA populations occurring there are Globally Threatened or Near Threatened.

Status of different waterbird groups

• A Red List Index (RLI) prepared by BirdLife International shows that, overall, AEWA species are less threatened than all birds (i.e. RLI values are greater), but between 1988 and 2008 their status has deteriorated faster (i.e. the RLI slope is steeper).
• The AEWA region holds 19 species which are Globally Threatened according to IUCN Criteria, and a further 15 which are Near Threatened. The four most endangered species covered by the Agreement, appearing in the Critically Endangered category, are Northern Bald Ibis, Siberian Crane, Sociable Lapwing and Slender-billed Curlew. There are five species in the Endangered category: Bank Cormorant, Madagascar Pond Heron, Red-breasted Goose, White-headed Duck and White-winged Flufftail. The nine most endangered species in AEWA thus each belong to a different family.
• Families with a high proportion (100% to 35%) of unknown population trends are, in descending order, as follows: thick-knees, divers, plovers, crakes & rails, coursers & pratincoles, gulls & terns, herons & egrets.
• Families with a high proportion of their populations (50% or more) showing decreasing trends are, in descending order, as follows: penguins, boobies, shoebill, skimmers, oystercatchers, coursers & pratincoles, crakes & rails, cranes, grebes, plovers, and divers.
• Families in both categories (i.e. having a high proportion of populations with unknown trends, and a high proportion of those with known trends in decline) are perhaps most in need of baseline information: divers, plovers, crakes & rails, and coursers & pratincoles.

Causes of population changes

• Our ability to describe the distribution, numbers and population trends of waterbirds is improving steadily, but our ability to explain them remains limited. This report is largely descriptive and in future it may be possible to include information on the causes of changing population status and trends.

Priorities for further Conservation work

The high number of populations whose trends were still unknown or decreasing in 2006, and the relatively low numbers that were stable or increasing give considerable cause for concern. Preparation of this report has identified or confirmed a number of priorities that should be addressed by AEWA.

1. Enhance the quality and quantity of monitoring and surveillance of waterbirds

The largest single source of data on waterbird numbers, distribution and trends for AEWA is the International Waterbird Census (IWC). In order to produce more data of higher quality that better serves the needs of AEWA, the following improvements in IWC are needed:

• Expansion of IWC into a representative set of sites in all countries in the AEWA region.
• Counts at times of year other than January, to allow monitoring of waterbirds during migration and breeding seasons.
• Special surveys of species not well monitored by IWC methodology, especially cryptric species, nocturnal species, colonially nesting species and species with dispersed distributions.

• Internationally coordinated monitoring of productivity of a wide selection of species. A relatively high proportion of waterbird populations have centres of breeding distribution in Arctic and Boreal Russia, and the inclusion of Russia in AEWA processes should remain a high priority.
• Internationally coordinated monitoring of mortality of as many species as possible, including hunting mortality, and making use of data derived from bird ringing.

• Full analyses of existing ringing data and their use in preparation of flyway atlases for all waterbird species in the AEWA region; as well as enhancement of bird ringing programmes wherever necessary.
• Satellite telemetry studies of selected species.

2. Improve knowledge of the causes of changes in waterbird status and trends

• Systematic, comprehensive literature reviews.
• Improved analyses of data derived from waterbird counting and ringing. This will include the use of GIS to allow spatial analysis of bird count and movement data in relation to land use, climate and many other relevant datasets.
• Work on habitat use by waterbirds. The inclusion of habitat data in a GIS directory of count sites will allow better understanding of ecological processes influencing waterbird demography. Habitat types that are currently inadequately covered by waterbird survey work include offshore marine areas, wetlands in arid regions, grasslands and steppes, and African swamps.
• Increasing numbers of waterbirds can indicate underlying environmental problems as well as decreasing ones, and research into the species and habitats involved should be a priority.

Implementation of these priorities will require large-scale capacity development in most countries in the AEWA region.

¹Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA),www.unep-aewa.org