Ornis Polonica 2023, 64: 1–16
Distribution, number and species composition of large gulls Larus sp. breeding in Belarus in 2018–2022
Irina Samusenko, Alexander Pyshko
Abstract: For the first time since 2009, the population status and dynamics of large white-headed gulls from the genus Larus have been assessed based on all known breeding cases in Belarus. We collated all the available (both published and unpublished) data and results of our own censuses in most important breeding sites. The total population size was estimated at 8,000–9,500 breeding pairs in 2018–2022 and have increased about 3.5 times since 2009. 70–80% of gulls nested in 8 large colonies with more than 100 pairs, including the largest Gatovo colony, which grew to 5,000 pairs. About 75% of gulls nested on the roofs in 9 cities and towns, and 25% in the natural habitats. During the study period, there were at least 4,800 pairs of Caspian Gulls L. cachinnans and 800 pairs of Herring Gulls L. argentatus. Several Lesser Black-backed L. fuscus and Yellow-legged Gulls L. michahellis nested in Gatovo colony, mostly paired with other species. The rest of the estimated population may include both mixed and ‘pure’ pairs, as well as hybrids, the number of which could not be more accurately determined. Two numerous species entered Belarus in the 1980s: Herring Gulls – probably from the north, Caspian Gulls – from the south. By now, the Caspian Gull can be found almost all over the country and dominates most of the known nesting sites, except for a few sites on raised bogs and lakes in the north, where the Herring Gull can still be the most numerous. The increase of the Herring Gull’s population was much stronger until the 2000s and has slowed down more recently, but the growth rate of the Caspian Gull exceeded it by more than an order of magnitude in the last two decades. The newly observed rooftop nesting of the Caspian Gull contributed to the rapid expansion and current high numbers of this species in Belarus, and, interestingly, this phenomenon is extremely rare elsewhere. The rapid growth of populations of large gulls in the area of Minsk city is most likely linked to the vicinity of an abundant foraging ground in the largest landfill in the country as well as availability of secure nesting sites (rooftops).
Key words: abundance, distribution, breeding pairs, population trends, Caspian Gull, Larus cachinnans, Herring Gull, Larus argentatus, Lesser Black-backed Gull, Larus fuscus, Yellow-legged Gull, Larus michahellis, Belarus
Ornis Polonica 2023, 64: 17–30
Autumn migration of birds of prey in the Western Sudetes
Kamil Struś
Abstract: In years 2001–2022, survey of raptor autumn migration was conducted in the Western Sudetes, comprising 203 counts (677 h of observation) on the Mysłowska Pass in the Kaczawskie Mountains. In total, there were 9 659 migrating individuals recorded, on average 14.3 ind./h. Maximum daily number was in the range of 101–703 ind. Two most numerous species were the Common Buzzard Buteo buteo (79.7 % of the total number) and the Sparrowhawk Accipiter nisus (10.7%). The only species close to 3% threshold was the Marsh Harrier Circus aeruginosus (2.8%). The other species were less frequently observed, apart from the Kestrel Falco tinnunculus (1.3%) and the Honey Buzzard Pernis apivorus (1.3%), and did not exceed 1% of the community. Main passage occurred from the last decade of September until mid-November, with peak abundance between 10th and 30th of October. The highest recorded daily numbers were 758 ind., 703 ind., 404 ind., 351 ind. and 327 ind. The observed birds migrated mainly alone or in small groups of few individuals. The highest recorded abundance of the Common Buzzard amounted to 100 ind. Intensity of birds of prey migration in the Kaczawskie Mountains was higher compared to other Western Sudetes ranges and the Carpathians. It may stem from the fact that the local migration routes are shaped by terrain relief and system of main migration flyways in Central and Eastern Europe.
Key words: migration, birds of prey, Sudetes, Carpathians, Poland
Ornis Polonica 2023, 64: 31–51
Do Magpies Pica pica use trash bins as source of anthropogenic food in a city? A case study from Poznań (W Poland)
Kamil Kaczmarek
Abstract: In order to determine whether Magpies Pica pica use dustbins as sources of readily available anthropogenic food, litter bins were observed in two housing estates in Poznań city (532,000 inhabitants; W Poland) between December 2021 and November 2022. Twice a month, 252 single baskets and 30 collective rubbish bins, consisting of several containers, were inspected. The total time of Magpies observation on single baskets exceeded only in two months 1% of the total observation time for this type of bins. The same indicator for collective baskets, generally available to the public, was usually above 10%. Each month Magpies were found mostly on 2–5 baskets. Observations revealed that the garbage cans were visited by single individuals or pairs of Magpies. No positive correlation was found between the number of trash bins or their quality, and the stability of the Magpie territory. Both the observation of baskets and additional data obtained as a result of observations of Magpies feeding on the food left by the inhabitants indicate, that in autumn and winter, the Hooded Crow Corvus cornix may be a food competitor for Magpies. The low overall level of observations suggests that anthropogenic food from trash bins does not serve as an important diet component for Magpies as it is generally believed, or that they use other sources of such type of food.
Key words: Magpie, Pica pica, anthropogenic food, food competition
Ornis Polonica 2023, 64: 52–70
Changes in the distribution, numbers and ecology of the House Martin Delichon urbicum in Lublin in 1964–2016
Tomasz Buczek
Abstract: The study of the House Martin population was carried out in Lublin (SE Poland) within the administrative boundary of the city of (147.47 km2) in 2016, and then in 2018–2021 in order to determine the impact of thermo-modernization on the number of selected colonies. The obtained results of the number and distribution of martins were compared with the results of unpublished studies from the 1960s, 1980s and 1990s. Historical data on the distribution of swallow colonies were plotted on the maps of urban development in particular periods that were reproduced by the author. The studied population consisted of 655 breeding pairs, including 520 pairs inhabiting high-rise buildings (at least 4-storey buildings). From the early 1960s to 2016, the area of high buildings increased five times, and the number of House Martins 15 times, from 35 to 520 pairs with the most intense increase recorded at the turn of the 1970s and 1980s. For the location of the colony, martins preferred areas with a high rate of biologically active area or their vicinity. The relationship between the location of the colony and the areas with a high biologically active surface coefficient was observed. In the last three decades martin colonies disappeared from central districts and moved to housing estates located on the outskirts of the city, which can be associated with changes in the availability of rich feeding grounds and nesting material. The abandonment of colonies on renovated and thermo-modernized buildings was also observed. On housing estates, House Martins nested in densities of 4.0–72.6 pair/10 ha. In suburban areas, the densities were much lower (1.2 pair/km2). In selected housing estates with 5-storey buildings, 74% of martins (N=86 nests) chose the 3rd and 4th storey. In housing estates with mixed 5- and 12-storey buildings, they occupied the 3rd, 4th and 8th storey (respectively: 12%, 15% and 15%; N=218 nests). In one of the districts, where the buildings have not changed in time, the House Martins changed their preference from the 3–6-storey in 1991 (56%; N=71) to the 7–10-storey in 2016 (66%; N=43) what may have been caused by the growth of trees in this district. In high-rise housing estates, House Martins most frequently placed nests in window openings (82.4%; N=675 occupied and unoccupied nests), and in suburban areas under the eaves of the roof (64.1%; N=117). In high buildings, 42.0% (N=520) of House Martins nests were built on walls facing east, 22.8% north, 18.0% south and 17.2% west. In two housing estates where buildings were insulated in 2016, after two years, the number of occupied nests decreased from 27 to 7 and from 12 to 2. The nesting success of pairs nesting in high-rise housing estates was 88% (N=344). The main cause of brood losses was deliberate or accidental damage to the nest (34.1%; N=41).
Key words: House Martin, Delichon urbicum, population number, changes in the number, causes of changes in the number, bird synurbization, breeding ecology, Lublin
Ornis Polonica 2023, 64: 71–74
The first record of the Trumpeter Finch Bucanetes githagineus in Poland
Wojciech Guzik
Ornis Polonica 2023, 64: 74–80
Nesting of the Rook Corvus frugilegus in Siedlce County in the period 1970–2022
Andrzej Dombrowski, Łukasz Trębicki
