Western Black-eared Wheatear on Helgoland, Germany, in October 2002 and lessons for identification of autumn females

This document with public access URL https://doi.org/10.5281/zenodo.19201780 was prepared as supplementary information to the following article to appear in Dutch Birding: Western Black-eared Wheatear on Helgoland, Germany, in October 2002 and lessons for identification of autumn females; written by Manuel Schweizer & Jochen Dierschke.