1. Swiss Ornithological Institute Sempach Switzerland
2. V.N.Karazin Kharkiv National University Kharkiv Ukraine
3. British Trust for Ornithology Thetford UK
4. Meudt Germany
5. Grafengehaig Germany
6. Balingen Germany
7. Zoology and Ecology Department Moscow Pedagogical State University Moscow Russia
8. National Institute of Biology Ljubljana Slovenia