Eurasian Siskin
Carduelis spinus (Linnaeus, 1758)
Order Passeriformes
Family Fringillidae
Conservation status: in Bulgaria: Vulnerable VU C, BDA-III; International: BeC-II.
General distribution. A Palearctic species. It inhabits Eurasia from Eire in the east to Sakhalin island, in the south to the mountains in Central Europe, the Pyrenees, the Balkan peninsula and the Caucasus Mountains.
Distribution and abundance in Bulgaria. Resident. In the past there were data of possible breeding in some low parts of the country – around Burgas and Sofia [1, 2], but there is proved breeding only in the mountains [3, 4, 5]. More habitats were known in the Rhodopes, Vitosha mountain and the Balkan range [6, 7]. At present, it has an "island" distribution with a high degree of isolation between the separate subpopulations [8]. It is found in the coniferous belt of the mountains Balkan range, Vitosha, Rila, Pirin, the Rhodopes and Slavyanka [9, 10, 11, 12, 13]. The breeding density is low but it may vary considerably, depending on the production of seeds [14, 15]. The breeding population is estimated at 2 000 – 4 000 pairs, and the wintering one at 10 000 – 50 000 individuals [8, 16].
Habitats. Different types of coniferous forests: spruce, white fir and black fir, Scotch pine and black pine, less often dwarf mountain pine and mixed formations with a considerable altitude [8, 17, 18]. Outside the multiplication period it is found throughout the country.
Biology. The beginning of incubation is influenced by the abundance of seeds, and in years rich in strobiles it begins in March, and in years poor in strobiles it begins in May [15]. The nest is cup-like, built out of grasses, bast fibre, cobweb and feathers, masked with moss and lichen. It is located on a branch of a coniferous tree. It lays 3-6 subelliptical, pale-bluish eggs, coloured with dark little spots. It has up to two clutches yearly. Incubation lasts for 12-13 days. The young ones leave the nest at the age of 13-17 days [19]. It mainly feeds on the seeds of coniferous trees, alder and birch, and during the multiplication period also on invertebrate animals [19].
Negative factors. Destruction of the habitats by deforestation and building, catching individuals.
Conservation measures taken. Protected according to the Biological Diversity Act. About 50% of the breeding population inhabits the territory of National Parks, some Natural Parks and Reserves.
Conservation measures needed. Study of the biology and the ecology of the species in the country; follow-up of the population trends; preservation of the habitats.
References. 1. Prostov, 1964; 2. Nankinov 1982; 3. Patev, 1950; 4. Balat, 1962; 5. Peshev, Boev, 1962; 6. Donchev, 1963; 7. Donchev, 1970; 8. Nikolov, 2006; 9. Iankov, 1996; 10. Shurulinkov and Hristov, 2001; 11. Iankov, 2003; 12. Popov et al., 2005; 13. Nikolov, 2005; 14. Newton, 1972; 15. Shaw, 1990; 16. Kostadinova, 1997; 17. Simeonov, 1975; 18. Spiridonov, 1999; 19. Cramp, 1994.
Author: Stoyan Ch. Nikolov
