Issue 2018-3

Ornis Polonica 2018, 59: 171–182

The breeding population of the Rook Corvus frugilegus in Warmia and Mazury

Adam Zbyryt, Dawid Cząstkiewicz, Sebastian Menderski, Marian Szymkiewicz

Abstract: During the survey conducted in 2017 in the area of 23 661 km2 in Warmia and Mazury (NE Poland) a total of 105 colonies of the Rook Corvus frugilegus, containing 8660 nests, were found. In addition we found 6 breeding sites with 1–2 nests. The mean density of the rookeries was 0.4 colony/100 km2, and the breeding population density was 36.6 nests/100 km2. Mean colony comprised 83.9 nests (SD=113.1). Small rookeries (≤50 nests) constituted 60.0% (N=63), medium (51–100 nests) 10.5%; (N=11), and large (>100 nests) 29.5% (N=31) of all. The 55% of the breeding population (N=61) was located in cities, 18.9% in towns (N=21), 17.1% in villages (N=19), and 9.0% in non-urbanized areas (N=10). No significant difference in the colony size between cities and villages was found. The total number of nest trees equalled 2224, and they represented 23 taxa (species or genus). Deciduous trees constituted 95.4% and conifers 4.6% of all the trees with the Rook nests. The distribution of Rook colonies was similar to that found in 1985–1993 in the same area, but recent data indicate a decline in the size of the breeding population.

Key words: Rook Corvus frugilegus, corvids, breeding colony, population size

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Ornis Polonica 2018, 59: 183–196

Population size of the Red-breasted Flycatcher Ficedula parva in the SPA Darżlubska Forest (N Poland)

Arkadiusz Sikora, Grzegorz Neubauer, Waldemar Półtorak, Zenon Rohde

Abstract: Red-breasted Flycatcher Ficedula parva population was estimated with replicated point counts in the SPA Darżlubska Forest (6453 ha, N Poland). 178 observation points located within 20 study plots (1 km2) were surveyed twice in May 2016. 67 and 93 singing males (102 males in total) were recorded during the first and the second survey, respectively, on 19 out of 20 plots. Habitats suitable for the species (deciduous, mostly beech forests aged 70 years or more) held much higher densities (1.46 males/10 ha, 95% CI: 1.03–1.95) than unsuitable ones (remaining stands; 0.12 males/10 ha, 95% CI: 0.01–0.30). Population size was estimated at 284 males/pairs (95% CI: 193–387), after accounting for imperfect detection and habitat suitability, significantly more than previous, census-based estimates. This represents 0.7% (95% CI: 0.2%–1.4%) of the national population. Favourable species status in the SPA can only be maintained with the appropriate forest management: strong reduction of cuts and thinnings in old-growth beech forests, which constitute the most important habitat for the Red-breasted Flycatcher.

Key words: Red-breasted Flycatcher, Ficedula parva, beech forests, Special Protection Area, Natura 2000 network, Darżlubska Forest

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Ornis Polonica 2018, 59: 197–210

Occurrence of the Taiga Bean Goose Anser fabalis and Tundra Bean Goose A. serrirostris in the Biebrza Basin (NE Poland)

Łukasz Krajewski

Abstract: In 2011–2018 we identified geese observed in 274 flocks of the Bean Goose complex in the Biebrza Basin (NE Poland). Among 47,501 individuals recorded in these flocks, 9,991 were identified to the species level. The autumn migration of Bean Goose complex was truncated, and the number of individuals staying in the area was related to the presence of floodwaters. The largest autumn flock comprised 500 ind. The Tundra Bean Goose Anser serrirostris was the dominant species in autumn, making up 99.7% of individuals identified to the species level. Wintering Bean Geese were recorded only in milder winters (3 out of 6 winter seasons) with the largest flock of 250 inds. The Taiga Bean Goose A. fabalis accounted for 5.4% of wintering birds identified to the species level, and the Tundra Bean Goose for 94.6%. The spring migration was much more intense. The largest flock of the Bean Goose complex during this period consisted of 5,000 ind. The Taiga Bean Goose accounted for 10.9% of all individuals present in February and 2% in March, with the most numerous flock of 190 inds observed in early March. The last spring observation of the Taiga Bean Geese was recorded in late March. The Tundra Bean Goose was much more numerous than the Bean Goose. Tundra Bean Geese constituted 89.1% of all individuals recorded in February, 98% in March, and 100% in April and May.

Key words: Bean Goose complex, Taiga Bean Goose Anser fabalis, Tundra Bean Goose Anser serrirostris, Biebrza Basin, migration, wintering

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Ornis Polonica 2018, 59: 211–221

Occurrence of the Pink-footed Goose Anser brachyrhynchus in Pomerania

Arkadiusz Sikora, Zbigniew Kajzer

Abstract: In 1931–2016 a total of 224 records of 466 individuals of the Pink-footed Goose Anser brachyrhynchus were made in Pomerania (N Poland). Only two birds were observed in the first half of the 20th century: in 1931 and 1937 near the Gulf of Gdańsk. In 1975–2003 a total of 13 individuals were recorded nine times. During subsequent years the numbers steadily increased, from 10 birds observed in 2004 to 68, 61 and 64 birds in 2013, 2014 and 2015 respectively. Pink-footed Geese were observed from September to May. The species was most frequently noted in spring (41.8%) and winter (41.2%). Between October and December numbers fluctuated, and from mid-February increased to reach a peak in the first decade of March. Afterwards the numbers declined, and in May the birds were observed only 6 times. Pink-footed Geese were recorded in 105 places, mostly (78.1%) in the western part of Pomerania (eastern part – 20.5%, central part – 1.3%). Observations included single birds (54.6%) or flocks of 2 to 29 individuals (45.4%) mainly mixed with Bean and Greater White-fronted Geese. Before 2009 only 22.5% of all identified birds were found in flocks of more than 3 birds, while in 2010–2016 this proportion reached 40.2%. The largest flock of 29 birds was recorded on 11 January 2015 at Osłonino near the Gulf of Gdańsk. The increase in the numbers of detected Pink-footed Geese in Pomerania is a result of breeding population growth, higher numbers of visitors during the non-breeding season, as well as increased study effort in Pomerania.

Key words: Pink-footed Goose, Anser brachyrhynchus, migration, wintering

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Ornis Polonica 2018, 59: 222–225

High densities of the European Nightjar Caprimulgus europaeus territories in windthrow areas of the Przedbórz Forest (Central Poland)

Piotr Dębowski, Marcin Wężyk

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Ornis Polonica 2018, 59: 226–229

Records of the Bearded Vulture Gypaetus barbatus in the Tatra Mountains (Poland)

Antoni Zięba, Filip Wacyk

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