Caucasian Black Grouse (Tetrao mlokosiewiczi) breeding display sites selection in Arasbaran Region, East Azerbaijan, Iran

Abstract

Micro-habitat characteristics of breeding display Sites (Leks) of Caucasian Black Grouse (Tetrao mlokosiewiczi) were studied in the mountains of Arasbaran Region, East Azerbaijan, from October 2006 to June 2008. We quantified micro-habitat characteristics around active and inactive Caucasian black grouse lek sites and random points in the 3 areas (Biosphere reserve, Kalan protected area (one of core zones of Arasbaran biosphere reserve) and unprotected areas)). Our objective was to compare micro-habitat characteristics among these sites. We also developed a logistic regression model to identify micro-habitat factors have important effect in the active lek sites. In the micro-habitat scale, we measured both biotic factors (canopy cover (%), height (cm) and frequency of vegetations) and abiotic (physical) factors (slope (%), altitude (m), aspect and etc.). Slope and altitude were different significantly between sampling sites (p = 0.05). Mean of slope in the active leks (= 57.9%) and inactive leks (= 52.0%) were higher than random sites (= 40.1%). The mean aspect differed between active leks (\( \bar X \) = 284°, S.D = 54.1°) and random sites (\( \bar X \) = 33°, S.D = 76.18°) (Watson’s U2-test, U0.05, 22, 272 = 0.717). Also, variance analysis (ANOVA) revealed that grasses and forbs cover, frequency of deciduous shrubs and forbs, canopy cover and frequency of deciduous woody plants > 12 cm diameter at breast height were different significantly between sampling sites. The best model for discriminating between active lek and random sites included rock-pavement cover (parameter estimate [B] = 0.286, SE = 0.219), canopy cover of grasses (parameter estimate [B] = 0.880, SE = 0.453), distance to the nearest tree (parameter estimate [B] = −0.047, SE = 0.027).