1. Department of Virology , National Veterinary Research Institute , Al. Partyzantów 57, 24-100 Puławy , Poland
2. Department of Epizootiology and Clinic of Bird and Exotic Animals , Wrocław University of Environmental and Life Sciences , Pl. Grunwaldzki 45, 50-366 , Wrocław , Poland
3. Białowieża National Park , Park Pałacowy 11, 17-230 , Białowieża , Poland
4. Institute of Forest Sciences , Faculty of Civil Engineering and Environmental Sciences , Białystok University of Technology , Wiejska 45 E, 15-351 Białystok , Poland