Uvac Special Nature Reserve

There are 219 plant species in the reserve. Of them, 3 are of international importance, 3 are listed in the Red list, 25 are placed under the controlled regime of picking and trading and 50 are believed to have medicinal properties.[1]

In the Uvac river and its tributaries within the reserve, there are 24 species of fish. Clean water in rivers and reservoirs are natural spawning locations for huchen, brown trout (borth faria and lacustris morphs), brook trout, zander, Mediterranean barbel, common nase and European chub.[1]

Mammalian fauna includes wolves, bears, wild boars, foxes, hares, badgers and European pine martens, some of which are declared rare and endangered in Serbia.[1]

Uvac meanders

The main attraction in the reserve is the avifauna, with 172 bird species. The most important inhabitant of Uvac is the griffon vulture, one of two remaining vulture species which nests in Serbia. Large bird, with a wingspan of up to 3 m (9.8 ft), it has a unique place in the ecosystem's food chain as it feeds solely on carcasses, providing the "natural recycling". In the years after the World War II, the species was on the brink of extinction. In order to save the birds, an area of the Uvac gorge was protected in 1971, but still, number of birds reduced to only 7 in the 1970s and 10 in 1990. At that moment, it appeared that the species will go extinct as it already disappeared from eastern Serbia, Romania, Albania, Bosnia and Herzegovina and Montenegro. Situation began to improve when in 1994 the Manastirina feeding ground was established. By 2017, the number of griffon vultures grew to 110 nesting couples and almost 500 birds altogether. That is the largest colony of griffon vultures in the Balkans and one of the largest in Europe, with probably only colony in Spain being larger.[1][4][6][7]

The griffon vultures from Uvac roam all over the Europe and Middle East. Birds tagged in Uvac have been spotted in 18 countries, ranging from Spain on the west to Yemen, 4,000 km (2,500 mi) on the southeast. Seven birds have been detected in 2,000 km (1,200 mi) away Israel which later returned to Uvac. For example, a female named Sara, which hatched in Uvac in 2011, was caught and satellite-tagged in Israel in 2012. After reaching sexual maturity, she returned to Serbia in 2017. Tracking devices showed that some birds were flying high up to 10 km (6.2 mi). One male flew north to Poland and got injured there. Polish ambassador transported it back to the Uvac by plane, it was healed and named Uroš the Weak, after the last Serbian emperor. He became a touristic attraction.[4] Another celebrity resident was a female named Dobrila. She hatched in 2018 in the Orlovica locality and on her maiden long-distance voyage that same year, she flew to the Turkish-Syrian border where she was found completely exhausted. In the spring of 2019, a special flight was arranged for her and she was transported back to Uvac by the plane. In December 2020 she was found dead in the reserve, stuck between the four entangled hornbeam canopies.[8]

As the population is thriving, there are less and less suitable locations for the nesting in the reserve. In 2009, a project for reintroduction of the griffon vultures to the Stara Planina was prepared. The birds used to live in this area of Eastern Serbia, on the border with Bulgaria, but went extinct in the late 1940s. Due to the financial difficulties, the project was put on hiatus, though not scrapped.[6] The reintroduction program continued in 2017 within the scope of a wider European program. Among other things, the feeders will be placed along the vultures' migratory route.[9]

An island in the Uvac gorge

The camera, which is installed at the feeding ground, recorded the showing of two other vulture species which were extinct from these areas: cinereous vulture and Egyptian vulture. The administration of the reserve, in association with the "Siniša Stanković Institute for Biological Research" and the "Institute for nature conservation of Serbia", wishes to implement the reintroduction project of another vulture species which went extinct in the region, the bearded vulture. Other birds in the protected area include many species of hawks, owls and, especially, eagles: white-tailed eagle, golden eagle, common buzzard and short-toed snake eagle. Uvac is also one of the rare nesting areas of goosander in Serbia and location of the largest recorded population of this bird in the Balkans.[1]

In 2017 the environmentalists warned that excessive tourism endangers the griffon vultures. The touristic guides often divert from the boat touristic routes, bring the tourists closer to the nests and even scare the birds so that they would fly and tourists can photograph them. In 2016/17, of the nests along the boat route, 12 were abandoned, 6 collapsed and from 2 the chicks fell out.[9] Still, the birds got accustomed to the visitors. When tourists visit the lookouts, birds began to fly above, as they are expecting food. The chicks are so well fed, that instead of weighing 8 to 9 kg (18 to 20 lb), some weigh up to 12 to 13 kg (26 to 29 lb) and fall into the lakes. The rangers pick them up and return to the nests, until they lose some weight and learn to fly. In the summer season of 2017 there were 12,000 visitors.[4]

By the late 2018 there were almost 150 nesting couples of various vultures, and 600 individual birds. Tracking shows that, on average, one vulture flies for some 40 km (25 mi) daily, in the circling patterns. The massive terrace-like bolder which birds use to take off, is called the "Castle of griffons".[2]