Favourable Reference Values. Establishing favourable reference values for each population covered by the Action Plan, as well as for the management units thereof (if applicable), is a crucial step as it provides the reference for assessing whether a population is in a favourable conservation status as per the legal requirements of AEWA. Numerical target thresholds will also allow for better monitoring of progress towards the Action Plan goal. • The approach for establishing the favourable refence values will need to be agreed amongst the respective Range States for each population, as it will vary depending on the distribution of the population during its annual cycle and the data available for the species. Favourable reference values for AEWA-listed populations will be established in accordance with the CMS definition of Favourable Conservation Status which has four criteria (population dynamic, range, habitat and historical levels) and the population is considered to be in unfavourable status if it does not meet any of the criteria or its future prospects are negative. More detailed guidance on the interpretation and establishment of favourable reference values is under development by the AEWA Technical Committee building on existing work under other relevant international frameworks6. • Establishing favourable reference values for migratory waterbird populations is time consuming and it usually requires the establishment of national favourable reference values by Range States (at least by the identified Principle Range States). It may not be possible to be carried out within the regular action-planning process itself. If this is the case, the standard text providing the mandate to establish favourable reference values should be included in the Action Plan as per the format above. Note that management units will most likely only be established for populations subject to Adaptive Harvest Management Programmes. The reference to management units can therefore be omitted for populations which are not foreseen to be subject to adaptive harvest management. • Ideally, however, the favourable reference values should be established before the adoption of the Action Plan whereby these could be included directly into the Plan itself already during the drafting phase, directly under the Action Plan Goal and Purpose.
