With great sadness we say goodbye to Dr. Zbigniew Krasiński, a former employee of the Białowieża National Park, who for several decades cooperated with Mammal Research Institute PAS, conducting jointly with prof. Małgorzata Krasińska research on the history and ecology of the European bison. Dr. Krasiński introduced many of us to the secrets of field work with European bison, offered advice and help. He was an expert and bison enthusiast, doctor of veterinary sciences, naturalist, photographer, collector, beekeeper. We will remember Zbyszek as an extremely open, kind and humorous man. He will remain forever in our memory.