Waterbirds have been defined as “species of bird that are ecologically dependent on wetlands”. 1.This is the definition used by the Ramsar Convention on Wetlands. For the purposes of the International Waterbird Census, all species in the following families are considered by Wetlands International to be waterbirds: Gaviidae (Divers/Loons), Podicipedidae (Grebes), Pelecanidae (Pelicans), Phalacrocoracidae (Cormorants), Anhingidae (Darters), Ardeidae (Herons), Scopidae (Hamerkop), Ciconiidae (Storks), Balaenicipitidae (Shoebill), Ciconiidae (Storks), Threskiornithidae (Ibises and Spoonbills), Phoenicopteridae (Flamingos), Anhimidae (Screamers), Anatidae (Ducks, Geese and Swans), Gruidae (Cranes), Aramidae (Limpkin), Rallidae (Rails, Gallinules and Coots), Heliornithidae (Finfoots), Eurypygidae (Sunbittern), Jacanidae (Jacanas), Rostratulidae (Painted Snipes), Dromadidae (Crab Plover), Haematopodidae (Oystercatchers), Ibidorhynchidae (Ibisbill), Recurvirostridae (Stilts and Avocets), Burhinidae (Thick-knees), Glareolidae (Coursers and Pratincoles), Charadriidae (Plovers), Scolopacidae (Sandpipers, Snipes and Phalaropes), Pedionomidae (Plains Wanderer), Thinocoridae (Seedsnipes), Laridae (Gulls), Sternidae (Terns) and Rynchopidae (Skimmers). Only a few wetland birds are excluded by considering entire families in this way. Conversely, the inclusion of whole families results in the waterbird list containing a few non-wetland species such as some coursers and thick-knees. These rather minor anomalies are thought to be outweighed by the convenience of a whole-family approach to the definition of the term ‘waterbird’ and, in particular, considering the complications that would arise from applying the definition rigidly to every species.
The Ramsar Convention on Wetlands recently widened its approach to include more families traditionally regarded as seabirds, as well as certain raptors and passerines, and it is possible that a small number of additions will be made in the coming years to the families and species included in the IWC.
2. Why count waterbirds?
The International Waterbird Census uses information collected by four continental-scale censuses over the long term to provide crucial information which underpins conservation of waterbirds and their wetland habitats. The aims of the census are as follows: To monitor the numerical size of waterbird populations; To describe changes in numbers and distribution of these populations; To identify wetlands of international importance for waterbirds at all seasons; To provide information to assist protection and management of waterbird populations through international conventions, national legislation and other means. The rationale behind the census was summarised eloquently by Matthews (1967) at the time when international coordination of waterbird counting was beginning: “..while man is recklessly unleashing new insults on his environment, background monitoring of populations is essential to detect the threats as they develop and before they become catastrophes apparent to all”.
Waterbirds are well-known indicators of the quality of certain types of wetlands. A powerful tool which makes use of this characteristic is the so-called 1percent criterion, whereby any site which regularly holds 1percent or more of a waterbird population qualifies as a wetland of international importance under the Ramsar Convention on Wetlands. The 1percent criterion
has been adopted by the European Union to identify Special Protection Areas (SPAs) under the Birds Directive. It is also used by BirdLife International in the identification of Important Bird Areas (IBAs) in wetlands throughout the world.
Standardised monitoring of Arctic breeding species, and species dependent on inter-tidal habitats is even more important in the light of human induced climate change, the seriousness of which is now generally accepted (Houghton et al. 2001). Global warming is expected to have especially pronounced effects on tundra and other Arctic environments, and, through sea level rise, on intertidal habitats (Boyd & Madsen 1997). The IWC will play a significant future role in monitoring the effects of these changes on the millions of waterbirds which depend upon these habitats.
3. What is the International Waterbird Census?
The International Waterbird Census (IWC) is a site-based counting scheme for monitoring waterbird numbers, organised since 1967 by Wetlands International, formerly the International Waterfowl and Wetlands Research Bureau (IWRB). The Census operates at a global level, and the former division into four separate continental-scale surveys was superseded in 2003 by a new strategy for global coordination. Coordination at continental level takes place as follows:
• Global coordination, and the counts in the Western Palearctic and southwest Asia are organised from Wetlands International
headquarters in Wageningen, The Netherlands.
• The African Waterbird Census is coordinated from a sub-regional office in Dakar, Senegal, which began operating in 1998.
• The Asian Waterbird Census, which includes Oceania, is coordinated from Wetlands International’s Asia Pacific office in Kuala Lumpur, Malaysia.
• In the Americas, the Neotropical Waterbird Census is coordinated from the Americas office of Wetlands International in Buenos Aires.
• Establishment of IWC in North America began in 2003, from a new Wetlands International office in Washington DC. The census takes place every year in over 100 countries with the involvement of around 15,000 counters, most of whom are volunteers. More than half the effort is concentrated in Europe, but involvement in other parts of the world has increased markedly since 1990. Between 30 million and 40 million waterbirds are counted each year around the world, and details of the counts and the sites where they take place are held on the newly upgraded, state-of-the-art IWC database. The IWC is thus by far the longest running and most globally extensive biodiversity monitoring programme in the world.
4. How to count waterbirds.
Anybody who can identify birds can contribute to waterbird monitoring activities. Identification Correctly identifying all the waterbird species present at a site is the first necessity of waterbird counting. Bird identification is a skill which takes time to master and beginners make more mistakes and miss more scarce species than experienced observers. Correct identification includes a process of elimination, and knowing which species are most likely to occur at a site in a particular season reduces the number of species that need to be eliminated from consideration.
The best way to learn is to spend time in the field with an experienced observer who knows which species to expect and who is familiar with the field characteristics of each species. Careful and copious note-taking and field sketching also enhance an observer’s powers of observation and reinforce memory of field characteristics.
This manual is not an identification guide, and when learning to identify birds, time should be spent consulting identification guides and becoming familiar with the plumage patterns, behaviour and annual cycles of each species. Videos and CD RoMs are also available which provide additional “homework” material for those learning to identify birds, but there is really no substitute for experience in the field, preferably under the guidance of a knowledgable birdwatcher.
Any experienced birdwatcher can count waterbirds, and a count on foot of a small to medium sized site is quite a straightforward undertaking. The methods used to count waterbirds in the field depend on many factors, for example: - the species being monitored;
- the size of the site; - the accessibility of the shoreline; - the availability of vantage points from which the site can be scanned; - the amount of time available to complete the count; - the number of people involved; - the available equipment. The most important element of waterbird monitoring methodology is standardisation.
Want to know more?– check out Wetlands International online.