Population density, nesting sites and breeding success in Barn Swallows in urban habitats, SW Poland. - J. Niżyńska-Bubel, G. Kopij. - Berkut. 16 (2). 2007. - P. 232-239.
Studies were carried in the city of Wrocіaw, SW Poland, out during the years 2005–2006. Breeding densities increase along urban gradient: it does not breed in the city centre at all, it varies from 0.0 to 0.1 pairs/10 ha in old densely built-up areas in the inner parts, from 0.1 to 1.0 pairs/10 ha in built up areas in outer parts, and from 4.0 to 28 pairs per 10 ha in villages around the city. Barn Swallows nested in all kind of farm buildings such as stables (25.4 %), human houses (25.0 %), pigsties (14.4 %), sheds (11.0 %), poultry-houses (9.0 %) and other (12.5 %) (n = 201 nests). Nests were usually attached to an angle formed by the wall squared with the ceiling (56.0 %) or to a log under the roof (31.5 %) (n = 184). Out of 135 nests, which were aged, 17.8 % were one-year old, 8.1 % two-year old and 74.1 % were more than two-year old. The overall mean clutch size in all sites was 4.78 (n = 184 nests), being slightly higher for the first clutches (x = 4.80; n = 132) than for the second clutches (x = 4.73; n = 52). For the first clutches, hatching success was 76.5 %, while fledgling success – 89.3 %. For the second clutches these parameters were higher: 83.3 % and 93.2 % respectively. In comparison with rural populations, the mean clutch size and overall breeding success in urban population are, in general, similar, although breeding density is much higher in the rural than in the urban population. However, breeding success in the second clutches tend to be higher in urban than in rural population. [English].
Key words: Barn Swallow, Hirundo rustica, Poland, ecology, synurbanisation, clutch size, breeding success.
Address: G. Kopij, Institute of Natural Sciences, Wrocław University of Environmental & Life Sciences, Pl. Grunwaldzki 24a, 50-363 Wrocław, Poland; e-mail: grzegorz.kopij@up.wroc.pl.