Assessing the potential distribution of the Caucasian black grouse Tetrao mlokosiewiczi in Turkey through spatial modelling

The Caucasian black grouse (CBG) is classified as “data deficient” by the IUCN. Lack of information to guide conservation measures is mainly due to the bird’s elusive behaviour for much of the year and to its remote distribution at higher altitudes of the Caucasus Mountains. In order to fill some of the knowledge gaps, we mapped potential suitable habitat across the Turkish part of the Lesser Caucasus using a spatial regression model, and estimated the total CBG population from alternative assumptions on population density and habitat separation. The CBG model was derived from 167 CBG records obtained during a survey in representative areas of the Turkish Caucasus, in conjunction with a supervised habitat classification of satellite images and with topographic parameters calculated from a digital elevation model. In total, approx. 5,000 km² of suitable habitat were predicted to exist within the borders of Turkey, including areas where the CBG has not previously been searched for. Under conservative assumptions, this area can carry more than 4,800 individuals, which is higher than previously estimated. The predicted distribution map can be used to select priority areas for conservation and to specify additional survey locations of the species in areas, which so far have been less well sampled.