Many development sites will fall within the impact zones of important habitats for overwintering birds and/or the flight paths of birds migrating to and from such habitats.
As a general rule of thumb the following periods are relevant to wintering bird surveys albeit it should be noted that times will vary depending on the target species and to some extent according to the current weather in the countries of origin.
- Autumn migration surveys should be undertaken during all or part of the period August-November.
- Winter surveys cover October-March.
- Spring migration surveys should include all or part of March-May.
Greenwillows Associates' personnel include experienced ornithologists with many years experience of bird identification field craft and extensive knowledge of birds' behavior and ecological needs to undertake the relevant surveys and advise on mitigation to avoid or ameliorate adverse impacts on wintering bird populations.