The Byala river valley and neighbouring hills, situated in the eastern Rhodopi mountains in southern Bulgaria. The vegetation is rich, consisting of old broadleaved deciduous forests of Fagus, Quercus and Carpinus, and sclerophyllous scrub (pseudo-maquis) of Juniperus, Phyllirea, Paliurus and Fraxinus, with Salix trees along the riverbanks. There are also coniferous plantations and rocky outcrops. Land-uses include hunting, forestry, fishing, extensive stock-rearing and cultivation. There is a small abandoned marble quarry, but drilling for minerals and other geological investigations still go on.
The site is important for its assemblage of Mediterranean-restricted species, and is one of the most important breeding areas in Bulgaria for raptors (Aegypius monachus, Circaetus gallicus, Accipiter brevipes, Hieraaetus pennatus, Otus scops) and Lullula arborea. Significant proportion (³1%) of national population breeding at site: Ciconia nigra (3-4 pairs), Neophron percnopterus (2 pairs), Aquila pomarina (1-3 pairs), Dendrocopos medius (5-10 pairs).
BirdLife International (2019) Important Bird Areas factsheet: Byala Reka. Downloaded from http://www.birdlife.org on 26/05/2019.