Blue Rock-thrush

(Monticola solitarius)

Category of conservation concern (IUCN, 2020) – Least Concern

Population size: 2020: 67-132 pairs (2007: 250–450 pairs)

Distribution pattern

A rare breeding species with a small population found only in 27 squares 10X10 km during the reported period. Distributed only in the southernmost parts of the country. Breeds mainly in the Eastern Rhodopes and along the valley of the Struma River northward towards the Kresna Gorge, rarely – towards the Zemen Gorge. Small isolated localities have also been found in the Northern Rhodopes. The sites in the more northern parts of the country (Vratsa Balkan, Cape Emine, Cape Kaliakra, the Chepan ridge near Dragoman) are without evidence of breeding and are of temporary nature. 

Population estimation for the period 2013 – 2020: During the period 2013-2020, the species was not found in 17 squares, where it was found before 2013. Probably this is an indication of a decrease in the number of the species in some areas such as the valley of the Mesta River and the Western Rhodopes. New sites have been identified in eight squares. There is no clear trend of expanding the range to the north, as is the case with other bird species of southern origin.

Population size in Special Protection Areas of Natura 2000: 53-101 pairs (77% of the population). The highest numbers have been registered in the SPAs “Studen Kladenets” (16-30 pairs), “Madzharovo” (11-20 pairs), and “Most Arda” (7-12 pairs).

Comparative distribution of the species compared to the first breeding birds atlas (Iankov, 2007): Breeding locality until 2007 | Breeding locality until 2007, confirmed after 2015 – | New breeding locality after 2015. – The breeding localities after 2015 are identified on a base of raw data from smartbirds.org.

Habitats

Breeds mainly on inland cliffs and exposed rocks, and in some anthropogenic structures resembling rocks (dam walls and other concrete structures). Has clear predilection for river valleys.

Trends in population changes for the period 2013-2020

Threats 

Disturbance of breeding pairs by climbers. Hydro engineering / for example in the valley of the Vacha River /. Busy highways / Kresna Gorge /. Destruction of rocks with existing or potential breeding sites due to the mining industry / Zemenski Gorge /.

Petar Shurulinkov, Volen Arkumarev, Girgina Daskalova