Issue 2016-2

Ornis Polonica 57, 2016: 83–106

The importance of the Biebrza Basin for ducks Anatinae during their spring migration

Michał Polakowski, Monika Broniszewska, Łukasz Krajewski

Abstract: The regular monitoring of ducks was conducted during spring migration in the Biebrza Basin in 2013–2015. The results were supplemented with data from irregular counts made in 1994–2015. In total, 452,292 individuals from 18 species were recorded in 2013–2015, and ca 1.5 million birds representing 25 species in 1994–2015. At the peak of spring migration the Biebrza Basin held the maximum of 60,000–90,000 ducks, yet the figures may be underestimated. The dominant species was the Eurasian Wigeon Anas penelope (60.3% of the recorded birds, 37,000–50,000 individuals during the migration peak). Other numerous species were the Mallard A. platyrhynchos (15.0%, up to 12,000–23,000 ind.) and the Northern Pintail A. acuta (10.4%, up to 7,000–10,000 ind.). The most important stopover sites were situated in the lower Biebrza Basin (mainly near Chyliny, Brzostów and at the mouths of the Kosódka and the Wissa rivers), in the Wizna Basin (the area of Grądy Woniecko and Wizna), and, prior to the dredging of the local streams, near the mouth of Brzozówka in the Middle Basin. This study confirmed the significance of the Biebrza Basin as the major national area of a global importance for the Eurasian Wigeon and Northern Pintail. According to the findings of this study, the site is also important for the Northern Shoveler A. clypeata, Mallard, Common Teal A. crecca and Garganey A. querquedula at the national scale.

Key words: ducks, spring migration, Biebrza Basin, stopover site

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Ornis Polonica 57, 2016: 107–116

Distribution and numbers of the Grey Heron Ardea cinerea in Podlasie Province (NE Poland)

Adam Zbyryt

Abstract: The distribution and numbers of the Grey Heron Ardea cinerea colonies were studied within Podlasie Province (20,187 km2). In 1980–2014 at least 31 heronries were recorded in the studied area, but in 2015 the presence of only 12 active heronries (39%) was confirmed. The average breeding density was 0.6 colony per 1000 km2. In total 455 pairs nested there, with the average density of 23 pairs per 1000 km2. The average colony contained 38 nests. Small (≤50 nests) and big (> 100 nests) heronries made up 75% and 17%, respectively. Grey Herons bred most frequently in small (mean area 2.2 ha) single-species (92%) forest patches with dominating pine (58%) and alder forests (17%) of 46 years on average. Colonies were located in the vicinity of rivers and oxbows (50%), lakes (33%) and ponds (17%), at an average distance of 1441 m from a nearest water body. The majority of colonies (83%) were situated close (< 200 m) to the buildings (mean distance 434 m). Grey Herons used 12 species of nesting trees and bushes, mainly Scots’ pines Pinus sylvestris (40%), willows Salix sp. (21%), and European elders Sambucus nigra (17%). The number of colonies and breeding pairs of the Grey Heron declined in the central and southern part of the area during the study period. This may have resulted from deliberate disturbance and excessive shooting.

Key words: Grey Heron, Ardea cinerea, breeding colony, Podlasie, mixed colony, colony size

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Ornis Polonica 57, 2016: 117–147

Rare birds recorded in Poland in 2015

Komisja Faunistyczna

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Ornis Polonica 57, 2016: 148–154

Territory mapping technique versus quick mapping

Ludwik Tomiałojć

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Ornis Polonica 57, 2016: 155–162

The story of one individual of the Glaucous Gull Larus hyperboreus wintering at the Hel Peninsula over 23 years

Arkadiusz Sikora, Zbigniew Kajzer, Waldemar Półtorak

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Ornis Polonica 57, 2016: 162–165

Second record of the Great Knot Calidris tenuirostris in Poland

Anna Włodarczak-Komosińska

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Ornis Polonica 57, 2016: 166–167

Mystery bird 83

Jan Lontkowski

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