Łukasz Jankowiak, Michał Polakowski, Tomasz Kułakowski, Piotr Świętochowski, Tomasz Tumiel, Monika Broniszewska
Ornis Polonica 2013, 54: 77–95
https://doi.org/10.12657/ornis.2013.2.0
Abstract: To investigate changes in numbers of selected bird species during the non-breeding period (November–February), surveys were conducted in the river valleys of the central part of Północnopodlaska Lowland (a total of 107.5 km of routes along Narew, Supraśl and Biała rivers) in 2000–2011. 32 species were surveyed, mainly waterfowl and corvids and increasing trends were found for 13 of them. Significant declines were noted in the Kingfisher Alcedo atthis, while moderate decline was found in the Grey Partridge Perdix perdix, Rough-legged Buzzard Buteo lagopus and Great Grey Shrike Lanius excubitor. The occurrence of some invasive species has been described, especially most irruptive migrant like the Bohemian Waxwing Bombycilla garrulus and Common Redpoll Carduelis flammea.
Keywords: changes in numbers, Corvids, invasive species, non-breeding period, river valleys, waterbirds
