Information for Observers

Have you seen a colour-marked shorebird in Europe or the East Atlantic Flyway?

If so, please follow this three-step-approach:

  1. Was it a Black-tailed Godwit Limosa limosa? Please directly contact the IWSG species coordinator for Black-tailed Godwit at
  2. Was it a Sanderling Calidris alba? Please report sightings of Sanderlings on – this requires creating an account on AnimalTrack which takes 1 minute. If for whatever reason this fails, contact the IWSG species coordinator for Sanderling at j.w.h.reneerkens<at>
  3. If it was not a Black-tailed Godwit or a Sanderling, please use the IWSG Colour Mark Register to find the project where the bird may have come from.

For tips on how to describe a colour-mark combination see here, and also some examples here. The latest version of the Register can be downloaded here.

Alternative options include: