as part of the Ropotamo Complex that also includes the swamps Alepu, Arkutino and several smaller protected areas. In the lower course there are rock formations, such as the Lion's Head, small caves, and the highest dune in the Balkans. The most important mammal species are red deer, fallow deer, roe deer, wild boar, grey wolf, red fox and golden jackal. The largest birds of prey are the white-tailed eagles with a wing-span of over two meters, and the Eurasian eagle-owl. The river is located on the Via Pontica bird migratory route. There are about 50 fish species, such as flathead grey mullet, big-scale sand smelt, European eel, round goby, Caucasian dwarf goby, as well as abundant populations of European pond turtle. Citations References External links Rivers of Bulgaria Bulgarian Black Sea Coast Tributaries of the Black Sea Landforms of Burgas Province Strandzha Ramsar sites in Bulgaria