Ornis Polonica 2019, 60: 235–244
Numbers and distribution of breeding population of the Great Egret Ardea alba in Poland
Abstract: Research on the distribution and abundance of the breeding population of the Great Egret Ardea alba was carried out using an unmanned aerial vehicle (drone) in eastern Poland (east of the Vistula river) in 2018. Data from western Poland (west of the Vistula river) came from reports of the Polish Avifaunistic Commission and local observers. As only single pairs nested in western Poland, a detailed description and analysis of breeding sites have been made only for eastern Poland. In total, 496 breeding pairs were recorded in 8 colonies hosting from 13 to 248 pairs (mean = 62; SD=77; Me=40) in eastern Poland. Surveyed heronries were located on shrubs in wetlands (50%), in reedbeds (37.8%), in a young pine stand and on bushes on a lake island. In total 5 mixed colonies, where Great Egrets nested together with the Grey Heron A. cinerea or with the Grey Heron and the Great Cormorant Phalacrocorax carbo (one case), were recorded. The average distance between the Great Egret colonies and human settlements was 989 m (range: 63–3700; SD=441; Me=1245). The average distance of mixed colonies of the Great Egret and the Grey Heron to human settlements (909 m) was lower compared to single species colonies of the Great Egret (1227 m). A colony on Lake Gaładuś (248 pairs; about 50% the national population) and surrounding feeding grounds deserve protection as the SPA Natura 2000. In 2018 the breeding population of the Great Egret in eastern Poland probably included almost the entire Polish population of this species, as only 2 pairs were recorded in the western part of the country. Therefore it can be assumed that the national population of the Great Egret amounted to 498 pairs in 2018. It is postulated that Polish monitoring of the Great Egret breeding population planned to be launched in 2020 within the framework of Polish Birds Monitoring should be conducted with the use of drones, which are an efficient tool for the detection and inventory of breeding sites of this species.
Key words: Great Egret, Ardea alba, breeding colony, heronries, drone, UAV, survey
Ornis Polonica 2019, 60: 245–268
Distribution, conservation status and monitoring suggestions for the Bewick’s Swan Cygnus columbianus bewickii in Poland
Przemysław Wylegała, Arkadiusz Sikora, Tomasz Janiszewski, Wiesław Lenkiewicz, Grzegorz Grygoruk
Abstract: In 2011–2018 flocks of Bewick’s Swans Cygnus columbianus bewickii exceeding 20 individuals were recorded at 71 sites in Poland. The most important concentrations were located in Wielkopolska, Dolny Śląsk, Pomorze, Łódź, Lublin and Podlasie regions. In 2011–2018, 75.5% of observations were noted in the western part (Pomorze, Wielkopolska and Śląsk regions) and 24.5% in the eastern part (Podlasie, Łódź, Lublin, Warmia and Mazury regions) of the country. In the west the species was more numerous in autumn (82.7% individuals) and even more frequently in winter (91.8%) than in the east, while in spring there was no such a disproportion between these two areas. In the whole country most birds were recorded during the autumn and spring migration (up to 2 000 individuals); the species was less numerous in winter (300–500 individuals). The number of wintering birds has increased in recent years. The share of juvenile individuals in 2011–2018 was 10.4% in autumn, 13.2% in winter and 11.2% in spring. In comparison with 1961–2010 a decrease in the share of young birds has been observed. The mean number of young per family was 2.11 (SD=1.01; N=360). Flocks comprising 2–10 birds were the most common. Groups of more than 50 birds were noted mainly in autumn and spring, while much less often during winter. Most Bewick’s Swans were found at fish ponds (67%) and in farmlands (17%), while in natural habitats the species was most numerous at lakes and wet meadows (9%). Fields of corn stubble are very important for Bewick’s Swans during autumn and winter season. The paper discusses threats and suggestions for the species protection, as well as recommendations for monitoring during migration and wintering. Due to the conservation status of the species in Europe and possible growing importance of Poland as its wintering area, it is necessary to conduct actions that will induce the effective protection of the Bewick’s Swan as well as its habitats (mainly hunting restriction).
Key words: Bewick’s Swan, age structure, monitoring, migration, wintering, threats, key areas
Ornis Polonica 2019, 60: 269–284
Numbers, hunting behaviour and feeding preferences of birds of prey (Accipitriformes and Falconiformes) wintering in agricultural landscape in the Kotlina Sandomierska
Konrad Krasoń, Jerzy Michalczuk
Abstract: We studied numbers and feeding preferences of birds of prey wintering in the Kotlina Sandomierska (SE Poland) throughout the winter 2015/2016. Eight species of raptors were found during the study. Common Buzzard Buteo buteo (density of 15.5 individuals/10 km2 of the entire study area), Rough-legged Buzzard B. lagopus (1.0 ind./10 km2) and Common Kestrel Falco tinnunculus (2.5 ind./10 km2) were the most numerous species. Perching (respectively 74.5, 56.0 and 41.9% observations of studied species) was the most common hunting strategy. Buzzards chose mostly trees and the ground as perching sites, while Common Kestrel anthropogenic elements. The Common Buzzard was recorded in December more frequently than in other months, while the numbers of Rough–legged Buzzard and Common Kestrel were relatively constant in winter. Birds of prey most often hunted individually – respectively 70.1, 63.2 and 83.7% of observations for Common Buzzard, Rough-legged Buzzard and Common Kestrel. Groups of two individuals were noted less frequently (22.8%), the most often in December and in the second half of February, The most important conservation measure for birds of prey wintering in the agricultural landscape is to maintain a mosaic of diversified agrocenoses, containing a considerable part of stubble fields, meadows and pastures as well as scattered tree stands used by birds as perching sites. Although Common Buzzards and Common Kestrels often forage in the vicinity of roads, birds of prey seemed to avoid built-up areas, as well as winter corns and arable fields.
Key words: birds of prey, non-breeding period, habitat preferences, feeding behaviour, agriculture landscape, SE Poland
Ornis Polonica 2019, 60: 285–299
Changes in the number of Common Cranes Grus grus and Wood Sandpipers Tringa glareola in the Bielawa reserve in 1983–2019, and the effect of conservation measures on avifauna
Arkadiusz Sikora, Waldemar Półtorak
Abstract: A total of 43 pairs of Common Cranes Grus grus (density of 0.6 pairs/10 ha) were counted in the nature reserve Bielawa (721 ha), comprising the largest Polish peatbog. Six other pairs nested near the reserve border. This indicates an increase by 10 times compared to the early 1980s. In the eastern part of the reserve (72 ha) a colony of 26 pairs (3.6 pairs/10 ha) were found. In 1983–2018 the number of Cranes counted during autumn surveys increased by 5 times (max. 2220 ind. in 2018), and by 2–3 times in spring (max. 1320 ind. in 2014 and 1070 ind. in 2018). In January 2018 a total of 250 and in 2020 – 390 wintering individuals were recorded. In the early 1980s 10 pairs of Wood Sandpipers Tringa glareola nested in the reserve, while in 2018–2019 only 1–2 males exhibiting courtship displays were observed, which suggests a strong population decline. During the last 15 years breeding of single pairs was recorded in four seasons. Throughout the last decade a few other breeding species were recorded, including the Whooper Swan Cygnus cygnus (1 pair), Greylag Goose Anser anser (up to 10 pairs), Gadwall Anas strepera (1 pair) and Citrine Wagtail Motacilla citreola (10 pairs in 2014). Conservation measures undertaken in the reserve Bielawa, including the reduction of water outflow and evaporation, as well as logging of expansive birches, helped to improve conditions for the local avifauna.
Key words: Common Crane, Grus grus, Wood Sandpiper, Tringa glareola, population decline, population growth, colonial nesting, Atlantic peatbog, northern Poland, hydrological conditions
Ornis Polonica 2019, 60: 300–307
Abundance of the Black Woodpecker Dryocopus martius in the Sobibór Forest in 2013–2015
Oliwia Karpińska, Bartłomiej Woźniak, Mateusz Grzębkowski
Ornis Polonica 2019, 60: 307–313
The first and the second record of the Eastern Olivaceous Warbler Iduna pallida in Poland
Paweł Szymański, Adam Janczyszyn
Ornis Polonica 2019, 60: 314–316
Stawarczyk T., Cofta T., Kajzer Z., Lontkowski J., Sikora A. 2017. Rzadkie ptaki Polski. Studio B&W Wojciech Janecki, Sosnowiec