HOW TO DISPLAY IN DENSE WOODLAND - VARIAB ILITY OF DISPLAY IN THE SIBERIAN SPRUCE GROUSE (FALCIPENNIS-FALCIPENNIS)

Territorial behaviour of the rare endemic Siberian Spruce Grouse was i ntensely observed and analyzed by means of modern technology for the f irst time ever. The most striking display element is the flutter jump. Moreover cocks showed various types of other displays. Flutter jumps are visually and acoustically conspicuous at high distances even in de nse forests. Despite their complex structure jumps are very much stere otyped. The different types of tail-fanning, however, are rather incon spicuous and serve their purposes at short distances. Most displays ar e stereotyped in duration, but not in sequence.