Strix uralensis Pallas, 1771
Syrnium uralense (Pall.): Klain, 1909: 90.
Conservation status: in Bulgaria: Endangered species EN D, BDA-II, III; International: CITES-II, BeC-II.
General distribution. A Siberian species distributed in Northern and Eastern Europe, in some mountains of Central and Southeastern Europe, where it is a relict from post-glacial time, Siberia, Manchuria, Korea, Japan .
Distribution and abundance in Bulgaria. Resident. The birds shot at until 1978 were considered wintering migrants from the north [2, 3, 4]. In 1979-1985, breeding was recorded in the Central Balkan range [5, 6, 7, 8, 9]. Since 1985it has been breeding in the same region and at places in the Central Balkan National Park [9, 10, 11, 12, 13,]. It obviously breeds in Sredna Gora Mountain , possibly in the Vrachanski Balkan Nature Park  and in the Western Balkan range (V. Ivanov, N. Spasov, G. Spiridonov, unpubl. data). The numbers in the known places are 30-50 pairs, but it is possible that they are twice larger.
Habitats. Old beech and fir-beech forests at altitudes between 1 250 – 1 650 m, distanced from urban settlements, in the vicinity of areas of felling and meadows.
Biology. Monogamous, the pair probably stays for life . Breeding starts at the beginning of March. It uses the nests of birds of prey, also stumps, hollows in trees and nest-boxes [16, 17]. In Central Europe it lays 2-4 eggs in the second half of March or in April , incubation lasts for 27-29 days, the nestlings fledge at the age of one month but they are able to fly well after another week . Flying young birds in neoptyle plumage appear in the middle of May . It is active also during the day. Its breeding territory is over 400 ha. It remains permanent, all the year round and in time, if the environment is not disrupted. In Central Europe the food mainly consists of rodents and insectivorous mammals, less so of birds and insects .
Similar species. The Eurasian Tawny Owl (Strix aluco) .
Negative factors. Felling old beech forests and fragmentation of their massifs. Urbanization, disturbance and poaching.
Conservation measures taken. Protected according to the Biological Diversity Act. Included in the Red Data Book of Bulgaria (1985). The Central Balkan National Park was established with a network of strict reserves, holding about 70% of the breeding birds.
Conservation measures needed. Declaration of Nature Parks in the mountains Western Balkans and Sredna Gora. Conservation of the breeding habitats. Inclusion of more than 60% of the beech and fir forests in the country in the Natura 2000 network. Ban on felling in old natural forests in the protected territories and zones.
References. 1. Voous, 1960. 2. Klein, 1909. 3. Boev, Simeonov, 1967. 4. Donchev, 1970. 5. Spiridonov et al., 1979. 6. Spiridonov et al., 1982. 7. Spiridonov, 1985. 8. Spiridonov et al., 1987. 9. Spiridonov, Mileva, 1988. 10. Kouzmanov et al., 1995. 11. Pacenovsky, 1996. 12. Nikolov et al., 2001. 13. Spiridonov, 1999. 14. Petrov, 1979. 15. Nankinov, 2002. 16. Mikkola, 1983. 17. Geroudet, 1979. 18. Makatsch, 1976.
Authors: Geko Spiridonov, Petar Shurulinkov, Boris Nikolov