Date of this Version
Erforschung biologischer Ressourcen der Mongolei (2012) 12: 183-191.
A common inhabitant of East Siberian larch forests, the Siberian or black-billed capercaillie (Tetrao urogalloides) ranges south to the limits of the boreal forests in the northern Mongolian mountains and east to the very coast of the Asian continent (KLAUS et al. 1989). Tetrao urogalloides MIDDENDORF (1851) has priority over T. parvirostris BONAPARTE (1856). Therefore, we prefer the T. urogalloides.
The subspecies T.u. stegmanni was first described on the basis of morphological differences by POTAPOV (1985) using specimens collected during Russian expeditions by KOZLOVA (1930). This description was based on 18 males in the collection at the Zoological Institute of Sankt Peterburg. Compared to the nominate and the Kamtschatkan subspecies, the males are larger, of generally darker plumage with a longer, wedge-shaped tail and many lateral white spots on the belly, resembling the Siberian spruce grouse (Falcipennis falcipennis). However, knowledge of the ecology and behavior of this subspecies living at the southernmost edge of its range is very limited (NADLER, WIESNER in KLAUS et al. 1989, BOLD 1984). To expand this knowledge, we carried out field work over three weeks including the “high season” of display (when females appeared on the lek) in the Gorchij-Terelsh National Park in the Khentej Mountains. The field work included photo and video recordings. We describe the aggressive and the courtship behavior of the Mongolian subspecies as well as the properties of the habitat in the Khentej Mountains. We compare our findings with our earlier studies of the nominate form T. u. urogalloides in the Magadan region (62° N) by ANDREEV (1975, 1977, 1979, 2002), KLAUS et al. (1989) and KLAUS & ANDREEV (2001).
During one field season (29 April – 20 May 2011) territorial and courtship behavior of the black-billed capercaillie at one lek (6 males, 3 females) was studied 150 km north-east of Ulan-Bataar in the Gorchij-Terelsh National Park. The lek was found in an old-growth forest of Siberian larch, only 200 m from the southern edge of the forest with transition to open grassland, where the birds preferred to feed on the first shoots of grass and forbs. The first female was visiting the arena on 3 May, copulations occurred on 7, 8 and 9 May. Fighting between males was observed 4 times. One serious combat was documented and described. In contrast to common capercaillie, aggression between females was never observed. The milder climate and often missing snow cover allowed the birds much earlier to feed on ground vegetation and copulations occurred one week earlier as in the Magadan region. The protection of old-growth forest is basic for conservation of the Mongolian subspecies of T. urogalloides.