New paper in Ecologia Balcanica


Habitat Selection of ‘Mad Cocks’ of the Western Capercaillies Tetrao urogallus (Galliformes: Phasianidae) from the Fringe of the Range: A Case Study from Rila Mts. (Bulgaria)

Plachiyski D, Popgeorgiev G, Avramov S & Kornilev YV.
Ecologia Balkanica 12 (1): 155–69. Published June 2020.


We investigated the habitat selection of “mad” Western Capercaillies males from the isolated and threatened Rila-Rhodope population. These “mad” Capercaillies are highly territorially aggressive individuals, that approach and attack people; this abnormal behavior, rarely occurs beyond single individuals in one lek and no studies that we know of have been published on such cases. In 2014–2015, we tagged with GPS transmitters three adult “mad” males associated with one lek. We evaluated the temporal variation in the Capercaillie habitat selection based on three periods (“summer”, “winter”, and annual). Based on Manly’s selection ratios (design III), at the home range scale, males used measured habitat variables non-randomly. Birds selected forests dominated by Scots pine (annually) and Macedonian pine (summer). Males used forest stands in the age class “81 to 120” years more than the availability. They highly avoided stands dominated by Norway spruce, bare rocks and ski slopes, as well as forest stands less than 81 years old (summer and annually). The birds demonstrated significant avoidance of flat and highly sloped terrains as well as those with northern and northwestern exposure. Notwithstanding the abnormal aggressive behavior of Capercaillie males and their affiliation with an edge population, the habitat selection of “mad cocks” in the Rila Mts. is consistent with the principal habitat preference of the species.