Adam Zbyryt, Jarosław Banach
Ornis Polonica 2014, 55: 105–114
https://doi.org/10.12657/ornis.2014.2.2
Abstract: In 2013, in the city of Białystok (53°07’N; 23°10’E, 102 km2) 219 nests of Magpie were found, including 149 inhabited. The total breeding population has been estimated at 149–157 pairs. The average density was 1.5 pairs/km2. Differences in densities of Magpie nests among the 3 major types of habitats in Białystok have been shown (I – open areas without buildings: x=1.4 pairs/km2, SD=2.2; II – villa type allotments and dispersed development: x=4.0 pairs/km2, SD=2.5; III – apartment blocks allotments and industrial areas: x=0.4 pairs/km2, SD=0.4). A total of 21 tree and shrub taxa were chosen as nesting sites. The most frequently occupied tree species were Salix sp. (22.8%), Betula pendula (18.8%), Picea abies (17.4%), Alnus glutinosa (8.1%) and Cerasus vulgaris (5.4%). Mean nest height above the ground was 11.1 m (SD=5.46) and the height increased along the gradient of increasing urbanisation (habitat I: x=9.7 m, SD=5.2; habitat II: x=11.5 m, SD=4.9; habitat III: x=14.0 m, SD=6.1). The vast majority of nests (138, 92.6%) were covered with a roof, and only 11 stayed open (7.4%). The latter type of nests was located mainly in the first habitat (72.7%), and they were placed usually lower than nests with a roof. Nests were located the most often among groups of trees (92.6% of nests), while single trees and tree avenues were occupied less frequently – 20.1% and 9.4%, respectively. The Magpie in Białystok colonized all the available urban habitats, suggesting that it can be considered as an urban species at an intermediate level of urbanisation process.
Keywords: habitat selection, Magpie, Pica pica, urban habitats
