Barn Owl
Tyto alba (Scopoli, 1769)
Strix alba, Scopoli, 1769, Annus Historico Naturalis, 1: 21; Strix flammea L.: Klain, 1909: 87.
Order Strigiformes
Family Tytonidae
Conservation status: in Bulgaria: Vulnerable VU B2 + C, BDA-II, III; International: CITES-II, BeC-II, ECS Spec 3.
General distribution. A cosmopolitan species distributed in Europe (without its northeastern parts), Africa and Madagascar island, Central Asia, America to the south of Canada, Indonesia and Australia. In Europe, two subspecies are found: T. alba alba and T. alba guttata. The former is distributed in Great Britain, Western Europe and the Scandinavian peninsula, the latter in central Europe and the Balkan peninsula. In Bulgaria it is the T. alba guttata that breeds, and T. alba alba is registered only in the autumn-winter period [1]. Hybrids between the two subspecies have also been found [2].
Distribution and abundance in Bulgaria. Resident and passage migrant. According to Patev (1950), it is very rare and perhaps in Southern Bulgaria it is T. alba alba that breeds. According to Peshev and Boev, this subspecies "rarely breeds in Bulgaria", but they do not mention concrete habitats. A rare breeding species for the country, represented by the subspecies T. alba guttata [5], registered in six breeding habitats: the cities of Sofia and Sliven, Atanasovko Ezero lake, the village of Hadzhidimitrovo (Yambol region), the towns of Lom and Ivaylovgrad. At present, 75 certain breeding habitats have been found, the species being distributed throughout the country [7]. According to other authors [10], the number of the habitats is 48. The data show that Southeastern Bulgaria (the regions of Yambol, Burgas and Plovdiv) is the most suitable area for breeding [7, 10, 11]. There is a concentration of habitats also in the Sofia region, and sporadic breeding has been registered in separate places in Northern Bulgaria, specifically Dobrudzha [7]. The estimates of the numbers vary: from 100-500 pairs [8] even to 1 300 – 1 700 [9], and according to [7] they are 200-700 pairs. According to our data, the breeding numbers are about 600 pairs. On the territory of Bulgaria and the neighbouring countries, there are wintering individuals flying in from Germany, the Czech Republic, Slovacia, the Netherlands and Hungary [6].
Habitats. Open landscapes, the environs of small towns and villages and deserted buildings around towns.
Biology. In Bulgaria it is understudied. It breeds in large hollows of trees at the edges of forests, and around urban areas in dark ceiling spaces or in special bird houses, not disturbed by people. In other parts of the breeding area the courting cry is registered at the beginning of March, and the female lays at the end of April. The full clutch contains from 3 to 8 eggs; in unfavourable years it breeds only one or two young ones [1]. In Bulgaria, in two breeding habitats (Atanasovsko Ezero lake and the town of Lom), a second clutch was proved [5]. In Bulgaria the species has an extended breeding period: the feeding of pluming young birds has been observed (I. Vatev, personal communication) at the end of August (Atanasovsko Ezero lake) and the beginning of September (near the wall of Studen Kladenets Reservoir). Found in the food are 71 nutrition components, small mammals having the major share [12, 13].
Negative factors. Disturbance during the multiplication period and illegal shooting.
Conservation measures taken. Protected according to the Biological Diversity Act (2002). The habitat in Atanasovsko Ezero lake is within a Protected Territory.
Conservation measures needed. Studying the distribution and the biology of the species in the country. Increase of the nature preservation awareness of the population.
References. 1. Simeonov et al., 1990; 2. Georgiew, 1998; 3. Patev, 1950; 4. Peshev, Boev, 1962; 5. Simeonov et al., 1981; 6. Nankinov, 2002; 7. BSPB, in press; 8. Kostadinova, 1997; 9. Nankinov et al., 2004; 10. Miltchev et al., 2002; 11. Miltschev et al., 2004; 12. Miltschev et al., 2006a; 13. Miltschev et al., 2006b.
Authors: Iliya Vatev, Nevena Kambourova
