IWC Sites and Waterbird Census

International Waterbird Census

The waterbird counts are bi-annual counts done around mid-month in January and July. Regular counts are regarded as a minimum standard; however, we do encourage counters to survey their wetlands on a more regular basis as this provides more accurate data.

It is necessary for us to improve our data quality by adopting various protocols regarding sites and counting methods. There is nothing too complicated about this.

Contact Ian Riddel at for any kml boundary files and if anything needs clarification.

Aims and Protocols

Goal: To act as an effective long-term waterbird monitoring tool, benefiting conservation efforts worldwide.


  • Coordinate, prioritise and expand waterbird surveys on a national scale with the emphasis on long-term monitoring;
  • Submit census data towards the African Waterbird Census Programme in part fulfilment of South Africa’s contribution to international agreements such as Ramsar, Bonn and AEWA.

Regular counts: counts will take place twice a year. For the summer season, wetlands are surveyed on any single day between 15 January and 15 February. For the winter season, counts can take place on any day during the month of July. The importance of these dates lies in the need to minimize the chances of counting the same birds twice at different sites and in making comparisons between years as valid as possible. The ideal is for all counts to be performed on the same day each year. In practice this is never possible so limits are set. These limits will always include four weekends and all counts must take place within the limits. It is very important that all sites be counted regularly every summer and winter. Breaks in the series of counts make it difficult to analyse the data statistically and detect patterns of change through time.

Additional counts: Apart from the regular counts described above, people are encouraged to count their wetlands more often where possible – quarterly or monthly. The above mentioned regular counts may not be applicable for many of the ephemeral wetlands in the country. In cases where wetlands are dry for long periods of time it is worthwhile counting them whenever there is an influx of waterbirds. Often in such cases it is also a good idea to survey such a wetland on a regular basis for the entire duration it is wet; often only a few weeks.

Consistency and standardization: Analyses of the data will involve comparisons between sites and between seasons and between years. If these comparisons are to be valid and informative they must be based on data which were collected consistently for the same geographical areas, using the same methods of data collection. These two issues require separate consideration:

Site definition: What constitutes an appropriate site is discussed in the CWAC Information Sheet No.1. Once a site has been selected its boundaries must be clearly defined and marked on a map (1: 50 000 or smaller scale). A copy of this map must be supplied to the National Coordinator. The importance of this exercise lies in (a) knowing the spatial limits within which counts are to be done and (b) ensuring that the whole area is covered during each count. Do not change these boundaries from count to count because of temporary conditions or organizational circumstances. Factors such as water level will necessitate some changes in approach but nevertheless, every effort should be made to collect data from the whole defined area and only from that area.

Sites: site boundaries on Google Earth (recommended) are useful to work from. If anyone has GE the kml files can be emailed, otherwise jpg files can be sent. Many of these boundaries cover the ‘largest’ area and some may be impractical and can be altered. Large sites can be broken up into manageable sectors that come under a Parent Site. In this case you need a big enough team to cover these sectors at the same time; counting on another date and/or time will obviously result in recounts of the same birds and is to be avoided. So too is breaking up your count over different periods of the day or over more than one day.

The IWC site map app shows current and old sites. The zoom buttons at bottom left change your view – as you zoom in, the box at the top right displays the site names, which are also marked on the map. Drag the map and the box updates.

Use the search box for a known site name. If an imprecise name is used, you will be taken to a general area and may need to zoom out to show sites.

Method definition: methods need to be defined and used consistently. It is easy to imagine how drastic changes in counting methods could affect results and thereby make comparisons between counts invalid. Please examine your sites carefully with this and the points above in mind. When the best method is established, commit the route, timing and viewing points to a map – a GPS can be used to track your route.

Lake Kariba, for one, presents some complications because of the potentially large changes in water level and thus your route. A route set up at full supply level could leave you out of sight of any waterbirds if the level drops drastically. In this case it is acceptable to have the same start/end points, which can also be adjusted to a suitable distance from the water, and follow a parallel route. You don’t want to be too close and flush birds unnecessarily.

The aspects of the method for counting a particular site which should be standardized are the following:

  1. Number of counters – The number of counters should be fixed such that the job can be done in a reasonable amount of time but without excessive disturbance of the birds.
  2. Routes followed – The routes which the counters follow should be fixed and marked on the site map. The route should be laid out to afford the best possible coverage of the area without repetition. Routes should always be followed in the same direction.
  3. Time of day – Counts should always be conducted during the same hours of the day.
  4. Viewing technique – An appropriate viewing technique should be chosen and used consistently, e.g. stationary from a hide, mobile on foot, mobile from a vehicle, mobile from a boat, aerial survey or some combination of these.
  5. Viewing aids – Appropriate aids should be chosen and used consistently, e.g. binoculars and telescopes of particular magnification, photography from particular vantage points, aerial photography. It is important not to use inadequate equipment, e.g. binoculars across long stretches of open water or shore where telescopes are essential for proper identification of species.
  6. Personnel – If possible counters should be experienced in identifying waterbirds. If necessary, training should be provided, particularly in identifying waders. Counts will benefit from repeated use of the same counters who know the area, know the techniques and know the birds.
  7. Counting techniques – The manner in which the actual counting is done and recorded should be standardised as far as possible. Again this may require some training and will benefit from personal experience. Factors which cannot be standardised such as weather conditions and water levels should be recorded and reported so that account can be taken of their effects.

Compilers may need the experience of one or two counts before they are able to decide on which methods to use but these decisions must be made and when they are they should be written down, indicated on maps, copies made and provided to the National Coordinator and to the relevant counters. This probably seems like a lot of work but in most cases it will be very straightforward and will need to be done only once. The subsequent benefits in the form of smoothly run counts will make it well worthwhile.

Submission of results: Once field data has been collected, transfer your count data onto the appropriate census form. We encourage compilers to use the electronic means of submitting results as this is a far more efficient way of dealing with the data. The census form is available for download with this link. Please submit your data as soon as possible after completion of your count.

Please contact me at for any kml boundary files and if anything needs clarification.

Ian Riddel