Arkadiusz Sikora

• Ornithological Station, Museum and Institute of Zoology, Polish Academy of Sciences, Gdansk

In July 2024, a breeding survey of the White Stork Ciconia ciconia was carried out in an area of 1,742 km2 of the Lower Warta and Noteć River valley. The study area was designated based on a grid of 1 × 1 km squares and divided into 5 sections: Lower Warta River valley (DDW), Lower Noteć River valley (DDN), Noteć River valley from Drezdenko to Wiel...

The highly pathogenic avian influenza virus (HPAIV) A(H5N1) has caused the most extensive and severe epizootic event affecting both poultry and wild birds globally. This study investigated the impact of HPAIV on the breeding population of the Black-headed Gull Chroicocephalus ridibundus, the most abundant gull species in Poland. During the 2023 out...

Raport podsumowuje wyniki zebrane w Kartotece Rzadkich Ptaków dotyczące gatunków lęgowych w Polsce w roku 2022. Scharakteryzowano populacje lęgowe 32 rzadkich taksonów.

Monitoring of Birds of Poland has been carried out since 2006 by the Chief Inspectorate for Environmental Protection and financed by the National Fund for Environmental Protection and Water Management. The programme implements the provisions of the Birds Directive, the Marine Strategy Framework Directive and the European Biodiversity Strategy. Duri...

Abstrakt: W piątym raporcie Kartoteki Rzadkich Ptaków za rok 2022 przedstawiono występowanie 42 gatunków ptaków w Polsce. Rok ten, na tle danych wieloletnich, był bardzo dobry lub rekordowy dla bernikli rdzawoszyjej Branta ruficollis (61 stw./89 os.), gęsi krótkodziobej Anser brachyrhynchus (470/979), gęsi małej A. erythropus (35/42), gęsiówki egip...

In the years 2020–2022, the state monitoring of the European Bee-eater took the form of a full census, during which all known sites in the country were visited. Since 2023 the methodology was changed to a survey, limited to 120 randomly selected sample plots. In the years 2020–2022, a total of 777 breeding sites of the European Bee-eater were found...

Słonka Scolopax rusticola to jeden z niewielu gatunków ptaków lęgowych w Polsce, o których brak podstawowej wiedzy dotyczącej liczebności i trendów krajowej populacji. Stan ten wynika z trudności w uzyskaniu wiarygodnych wyników badań ilościowych – gatunek wymaga dedykowanej metodyki – wieczornych liczeń terenowych, których w szerszej skali w kraju...

Raport podsumowuje wyniki zebrane w Kartotece Rzadkich Ptaków dotyczące gatunków lęgowych w Polsce w roku 2021. Scharakteryzowano populacje lęgowe 32 rzadkich taksonów (30 gatunków i 2 podgatunków) opisując ich liczebność, rozmieszczenie i trendy. Rekordową liczebność odnotowano dla: łabędzia krzykliwego Cygnus cygnus (308 par), gęsiówki egipskiej...

W czwartym raporcie Kartoteki Rzadkich Ptaków za rok 2021 przedstawiono występowanie 38 gatunków ptaków w Polsce. Rok ten, na tle danych wieloletnich, był bardzo dobry lub rekordowy pod względem liczby stwierdzonych osobników dla gęsiówki egipskiej Alopochen aegyptiaca (598), szczudłaka Himantopus himantopus (121), biegusa morskiego Calidris marit...

In the 21st century, an increase in the breeding population and territorial expansion of the Pygmy Owl Glaucidium passerinum in Pomerania has been recorded. In the late 1990s, the first territorial male was recorded, and since 2006 the species has been recorded annually. In years 2016–2022, its occurrence was revealed in 15.8% of squares (N=80) out...

This research was carried out in north-eastern Poland, where Whooper Swan Cygnus cygnus is a sparse breeder. Whooper Swan is timid and exhibits a tendency to hide in emergent vegetation. A drone was used to improve the effectiveness of research into its breeding success and offspring productivity. The breeding density of Whooper Swan in the study a...

Binomial N-mixture models are commonly applied to estimate abundance unaffected by imperfect detection, but are known to be sensitive to violations of assumptions. One of the model's assumptions, the independence of detections has rarely been tested. It requires that during a survey, detection of one individual does not affect detection of another...

Abstract: In the year 2021, in water bodies at Górowo Heights (402.4 km2) in north-eastern Poland 91 breeding pairs of two species of swans were recorded, including 35 pairs of the Whooper Swan Cygnus cygnus (density 8.7 pairs/100 km2) and 56 pairs of the Mute Swan C. olor (13.9 pairs/100 km2). In the study area, 31% of 2 x 2 km sample plots were i...

W niniejszym, trzecim raporcie Kartoteki Rzadkich Ptaków przedstawiono występowa-nie 38 rzadkich, nielęgowych gatunków w Polsce w roku 2020. W roku tym dokonano rekordo-wej liczby stwierdzeń następujących gatunków: gęsi małej Anser erythropus, gęsiówki egipskiej Alopochen aegyptiaca, szczudłaka Himantopus himantopus, rybitwy popielatej Sterna parad...

Awifauna Zatoki Puckiej charakteryzuje się wyjątkowym zróżnicowaniem. Spośród 24 rzędów ptaków stwierdzonych w Polsce odnotowano na tym terenie przedstawicieli 22 z nich. Również pod względem zróżnicowania grup morfoekologicznych obszar ten wyróżnia się bogactwem rzadko spotykanym w kraju. Warunkują to cechy siedliskowe terenu, w tym szczególnie do...

Analizowany materiał dotyczący gniazdowania mewy czarnogłowej Ichthyaetus melano-cephalus w Polsce został w większości zebrany w ramach Monitoringu Mewy Czarnogłowej jako część Państwowego Monitoringu Środowiska prowadzonego przez Główny Inspektorat Ochrony Środowiska. W latach 2006-2020 jej liczebność w kraju wahała się między 50 a 100 par. Stałe...

In 2021, an assessment of the breeding population of the Common Crane Grus grus was carried out in the part of the Noteć valley protected as the Natura 2000 Special Protection Area Nadnoteckie Łęgi PLB300003. The population of the species increased there rapidly from 7 pairs in 1990 to 34 pairs in 2003 and 143 pairs in 2021 (95 pairs/100 km2). The...

Raport podsumowuje wyniki zebrane w Kartotece Rzadkich Ptaków dotyczące gatunków lęgowych w Polsce w roku 2019. Scharakteryzowano populacje lęgowe 32 rzadkich taksonów (30 gatunków i 2 podgatunków), w tym ich liczebność, rozmieszczenie i trendy. Zróżnicowane okresy do oceny trendów podano w przeglądzie gatunków. Wysoką lub rekordową liczebność odno...

Abstrakt: Niniejszy, drugi raport podsumowujący działanie Kartoteki Rzadkich Ptaków w Polsce obejmuje rok 2019. W raporcie omówiono występowanie 38 rzadkich gatunków nielęgowych. W roku 2019 odnotowano wysokie lub rekordowe liczby pojawów m.in. bernikli rdzawoszyjej Branta ruficollis, bernikli kanadyjskiej B. canadensis, gęsi małej Anser erythropus...

Abstract: The Savannah Sparrow Passerculus sandwichensis from subspecies labradorius / savanna was recorded in the dune area of Jastarnia in the Hel Penninsula (N Poland, the Baltic coast) on 26 June 2020. It was the first record of this Nearctic species in Poland (observation accepted by the Avifaunistic Commission) and the sixth in the Western Pa...

1. Czerwone listy to opracowania szacujące ryzyko zagrożenia wymarciem taksonów poddanych analizie. Wyniki czerwonych list są jednym z głównych elementów budowania strategii ochrony gatunków rzadkich i zagrożonych – zarówno globalnie, jak i na poziomie regionalnym. 2. Poprzednia krajowa czerwona lista analizująca status gromady ptaków została opubl...

The report of the Rare Birds Panel presents abundance estimates for 17 rare breeding species in Poland in 2018. These include: Whooper Swan Cygnus cygnus (153–178 pairs, increasing 11% per year in 2007–2018), Ferruginous Duck Aythya nyroca (100 p., stable in 2007–2018), Eurasian Oystercatcher Haematopus ostralegus (26–28 p., stable in 2010–2018), E...

Abstrakt: Pierwszy raport podsumowujący działanie Kartoteki Rzadkich Ptaków w Polsce obejmuje rok 2018 oraz dla wybranych gatunków również dane z lat poprzednich. W raporcie omówiono występowanie 35 rzadkich gatunków nielęgowych. W omawianym okresie odnotowano wysokie lub jak dotąd rekordowe liczby pojawów m.in. bernikli rdzawoszyjej Branta ruficol...

We investigated the performance of hierarchical distance sampling (HDS) versus binomial N-mixture (binmix) models, both aiming at abundance (or, equivalently, density) estimation. We tested the accuracy of density estimates using simulated data and compared them to the estimates coming from a Red-breasted Flycatcher (Ficedula parva) point count sur...

The population size and distribution of the European Nightjar Caprimulgus europaeus were studied in 2018 in forests of the SPA Wielki Sandr Brdy (hereafter WSB, 371 km2, N Poland), dominated by the Scots Pine Pinus sylvestris. Two point counts were performed during night-time at 180 observation points located within 30 study plots of 2×2 km between...

Liparus glabrirostris is one of the largest European weevils, and it has been recently proposed as the flagship species for threatened riparian habitats in mountains. For effective conservation of its populations (and associated habitats), it is crucial to understand its history, contemporary distribution, genetic diversity and predict changes in t...

A Whiskered Tern in the first winter plumage was observed in winter 2017/2018 (1 and 9 Jan 2018) at the unfrozen Siemianówka reservoir (Narewka community, Podlasie Province, NE Poland). In previous years the species was noted twice in December, both times in Eastern Poland. These records are the first known attempts of the Whiskered Tern wintering...

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...

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 r...

Population size of the Red-breasted Flycatcher Ficedula parva in the SPA Darżlubska Forest (N Poland). 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 km 2) were surveyed twice in May 2016...

Until recently the Siberian Accentor Prunella montanella was recorded extremely rarely outside its breeding areas in Russia. In 1800–1974 the species was observed only 5 times. In 1975–2015 the number of European records (outside Russia) increased: the species was observed 29 times (31 ind. in total). In autumn 2016 an unprecedented irruption of th...

A fraction of White-throated Dippers Cinclus cinclus breeding in Scandinavia migrate south over the Baltic Sea during their short-distance migration to the winter quarters. The aim of our study was to investigate patterns of body mass changes between arrival to and departure from the wintering grounds in northern Poland. From a cost-benefit perspec...

Abstrakt. Płochacz syberyjski Prunella montanella jest gatunkiem wyjątkowo pojawiającym się w Europie poza stałymi lęgowiskami w Rosji. W okresie 1800-1974 został stwierdzony tylko 5 razy. W latach 1975-2015 liczba stwierdzeń w Europie (poza Rosją) wzrosła i odnotowany został 29 razy (łącznie 31 os.). Jesienią 2016 roku miał miejsce niespotykany na...

Projekt „Atlas ptaków lęgowych Pomorza” realizowany w ramach działań Pomorskiego Regionu Ornitologicznego rozpoczęto w roku 2016. Jego celem jest zebranie danych o rozmieszczeniu ok. 200 gatunków ptaków lęgowych na Pomorzu. Dane te zostaną opracowane i przedstawione w monografii, zawierającej m.in. informacje o rozmieszczeniu, zmianach rozmieszczen...

Key words: White Stork, river delta, depressed area, short- and long-term population decline, nesting success. In 2013, 473 breeding pairs of the white stork Ciconia ciconia (26.5 pairs/100 km2) were observed in the mesoregion of Żuławy Wiślane (the alluvial delta area of the Vistula; 1783 km2), including 68 pairs (16.5 pairs/100 km2) in Żuławy Gd...

Estimation of density and abundance of the Red-breasted Flycatcher Ficedula parva in the Tricity Forest (N Poland) using replicated point-counts. Abstract: The paper presents density and abundance estimates of the Red-breasted Flycatcher Ficedula parva in the southern part of Tricity Forest called Oliva Forest. Tricity Forest is a 210 km2 complex b...

Abstrakt: W roku 2011 przeprowadzono inwentaryzację wybranych gatunków ptaków lęgowych w obszarze specjalnej ochrony Natura 2000 Puszcza Borecka (190 km 2). Wśród stwierdzonych cen-nych gatunków wyróżniają się dzięcioły – białogrzbiety Dendrocopos leucotos (12–18 par; 1,3% populacji krajowej; dalej pk), trójpalczasty Picoides tridactylus (1–5 par)...

In autumn 2014 the third census of Lapwings Vanellus vanellus and Eurasian Golden Plovers Pluvialis apricaria was carried out. A total of 113,254 Lapwings and 43,138 Golden Plovers were recorded at 368 sites in October, while in November 293 sites hosted 21,029 Lapwings and 27,036 Golden Plovers. Both species were more common in northern Poland, co...

During 23 winters (1994–2015) probably the same individual of the Glaucous Gull Larus hyperboreus was observed annually at the Hel Peninsula. This assumption gains some support from the fact that the individual had successive stages of immatural plumage during first three winters, and an adult plumage in the following years. Moreover, it stayed in...

The paper presents population size estimates of selected bird species in the lower part of the Łeba River valley (N Poland, central Pomerania). Night surveys were conducted twice in 2013 (late May/early June and late June/early July) on 35 randomly chosen plots (1 km2 squares). Surveyed area accounted for 11%–23% of the whole valley area (125 km2),...

In this paper we present new estimates of breeding bird populations in Poland for 2008–2012. The estimates are based on both published and unpublished data, as well as information from experts. Most data come from four basic sources: (1) Monitoring of Birds of Poland, (2) data collected by the Polish Avifaunistic Committee, (3) species specific ass...

The Bearded Tooth Hericium erinaceus is one of the rare species of macrofungi in Poland. Due to its rarity, the fungus is strictly protected and red-listed in many European countries, including Poland. Despite the relatively large size of fruiting bodies, and their unique appearance, only 23 localities are known from Poland from the period of 1951–...

Liparus glabrirostris (Coleoptera: Curculionidae) is a rare species occurring locally in Northern Poland. Six sites were reported by 2014. During intensified observations in 2015, the species was reported from 7 new sites and confirmed at 4 previously known sites. Altogether, the species was found at 13 sites in Northern Poland: Tuchola Forest (1),...

To estimate numbers and distribution of Common Cranes Grus grus during autumn migration in Poland, counts of the species at 88–103 roosting sites were performed in 2009–2013. In 2009 two counts were carried out, and in subsequent years – three counts each season. A total maximum number of Cranes at all roosting sites was 93.000–120.000, and the num...

EU Bird Directive regulations oblige member states to effectively conserve all bird species and to monitor favorable conservation status of endangered species. To fill these requirements, the system of bird monitoring, commissioned by the Chief Inspectorate of Environmental Protection (GIOŚ) since 2006 is being continued in 2013–2015. The Monitorin...

Rare and uncommon breeding birds in the Special Protection Area Napiwodzko-Ramucka Forest (N Poland). Abstract: In 2012, a total of 152 breeding bird species were found in the Special Protection Area (SPA) Napiwodzko-Ramucka Forest PLB280007 (1,166 km2, northern Poland). Either censuses or survey sampling methods (counts on 35 random plots of 4 km2...

Two new sites of the country red-listed, rare basidiomycete, Climacocystis borealis, are presented from northern Poland. The fungus decomposes conifer wood and requires large-size wood trunks to grow. Its distribution in the country reflects the distribution of natural and semi-natural habitats so that the species is known mainly from mountain fore...

This paper describes the occurrence of the Ring Ouzel Turdus torquatus in northern and central Poland (above 51°30’ N). In 19th century the species was probably much more abundant than at present. In 1950–2014 it was observed 171 times (in total 227 individuals), but only since 1980 it has been recorded almost annually. The number of observed birds...

In October 2015, a single individual of harbour seal Phoca vitulina was observed on the inland waters of the Vistula river near Wielkie Walichnowy (the 888th km of the river). Previously one individual of this species was observed near the same place (Polskie Gronowo, the 883rd km of the Vistula) in July 2012.

In 2007–2014 within the area of SPA Lower Vistula River Valley near Gniew exceptionally large flocks of migrating birds were observed, including Eurasian Golden Plovers Pluvialis apricaria – up to 11,000 ind., Northern Lapwings Vanellus vanellus – up to 10,000 and the Eurasian Curlews Numenius arquata – up to 950 ind. Autumn migration was more inte...

In winter 2013/2014 in the Vistula Valley near Gniew in Pomerania a total of 280 Eurasian Curlews Numenius arquata were present. During the same period in the whole country a total of about 510 individuals were recorded, which probably was related to an extremely warm December of 2013. Birds spent the day in the fields and green areas, and nights a...

This study analyses records of the Great White Egret Ardea alba in Warmia and Masuria (NE Poland) in 1989–2012. Most data come from accidental observations of non-breeding birds. In 1989–2000 the Great White Egret was recorded at only 10 sites. However, after several years its numbers started to increase dynamically, and the species appeared in man...

We investigated factors affecting the detection probability of the Collared Flycatcher Ficedula albicollis, a secretive forest passerine, whose range is confined to central and eastern Europe. With a robust design sampling protocol, 78 sites were surveyed four times in spring 2012 for the presence of singing males in the Las Warmiñski nature reserv...

In this paper we present data on rare breeding birds in Pomerania in 2000–2012. We discuss 50 species and one subspecies, the population of which in Pomerania is either to 100 pairs or occurrs in no more than 10 localities. The Pomeranian populations of seven species are characterized by high numbers (over 20% of the Polish population): Sandwich Te...

EU Bird Directive regulations oblige member states to effectively conserve all bird species and to monitor favourable conservation status of endangered species. To fill these requirements, the system of bird monitoring, commissioned by the Chief Inspectorate of Environmental Protection (GIOŚ) since 2006 is being continued in 2012–2013. The Monitori...

There were 13 records of Greater Spotted Eagle Aquila clanga in Pomerania in 1985, 1986 and 2007–2012 – nine from spring, three from autumn and one from winter. Greater Spotted Eagles were recorded 8 times in Gdańsk Pomerania but just once in Central Pomerania. In Western Pomerania this species was not seen, but a bird with a satellite transmitter...

The breeding bird community of the Jar Rzeki Raduni nature reserve (84.2 ha, ca 20 km SW of Gdańsk) was studied in 2011. The reserve encompasses the stretch of the River Radunia flowing through a forested ravine up to 40 m deep. Birds were counted three times in spring at 20 points located every 200–300 m along the river valley; rare species were s...

(1) EU Bird Directive regulations oblige member states to effectively conserve all bird species and to monitor favourable conservation status of endangered species. To fill these requirements, in 2006 the system of bird monitoring, commissioned by the General Inspectorate of Environment Conservation (GIOŚ) was implemented in Poland and is being con...

Breeding population of the Whooper Swan Cygnus cygnus in Poland. Abstract: Whooper Swan breeds in almost all regions of Poland except the mountains and foothills. In years 1973–2011 the annual average growth rate of breeding population was 12%. In 2007 the national breeding population was estimated at the level of 43–52 pairs, while in 2011 at 73–8...

A census of Boreal Owl Aegolius funereus was conducted during the 2012 breeding season in two forest plots in eastern Pomerania: the Tuchola Forest National Park (4613 ha) and the Darżlubska Forest Natura 2000 Special Bird Protection Area (6453 ha). The vast majority of the Tuchola Forest National Park consists of pines, whereas the Darżlubska Fore...

The Common Breeding Bird Monitoring (CBBM; Polish acronym: MPPL) has been conducted in Poland since 2000. In 2000–2010 results were obtained from 110 randomly selected 1x1 km survey plots located in Pomerania (north-west Poland). During eleven years, 174 bird species were recorded on the survey plots in this region, on average 35 (7–65) species per...

In the first half of the 20th century breeding Red-breasted Merganser Mergus serrator was found in Pomerania on 7 lakes. During the next several decades its nesting was not confirmed in the region; in 1980–2000, however, it was definitely breeding in 5 localities and probably breeding in another 3. In the mid-1990s the number of Red-breasted Mergan...

In the 19th century and at the beginning of the 20th century European Roller was less numerous in Pomerania than in other Polish regions. After the 1930s it became to be rare. The species nested longest in the Tuchola Forest near Czersk (1–3 pairs in 1988–1995). The last clutch of European Roller in Pomerania was recorded in Rzepiczna near Tuchola...

Maintenance of biodiversity requires spatial planning for the conservation of species habitats. In this study, the distribution of the White-backed Woodpecker (Dendrocopos leucotos) in Poland was used to assess the usefulness of a demographic model compared to an area-based model for predicting the occurrence of breeding pairs in local landscapes....

A national census of Bewick’s Swans took place in Poland in spring 2010 with three counts conducted (13–21 March, 27 March–4 April and 10–18 April), which in total covered 338 sites. During subsequent counts 1,122, 1,214 and 253 swans were recorded on 74, 44 and 18 sites, respectively. Most of Bewick’s Swans were observed in lowlands (71–92% of all...

In 2009–2010, four new breeding sites of the Citrine Wagtail Motacilla citreola on Pomerania, were confirmed: in Gdańsk-Górki Zachodnie (3–4 pairs in 2009–2010), at the Rewa near the Puck Bay (2 pairs in 2009–2010), on the Miedwie Lake (1 pair in 2010) and one breeding female on the Vistula Lagoon near the Pasłęka River mouth in 2009. All breeding...

Following the first survey in 2003, in autumn 2008, Lapwings and Golden Plovers were counted in Poland. In October (282 sites surveyed), nearly 120 thousands of Lapwings and 52.6 thousands of Golden Plovers were counted, while respective numbers in November (151 sites surveyed) were 28.8 and 22.8 thousands. Both species were most numerous in northe...

(1) EU Bird Directive regulations oblige member states to effectively conserve all bird species and to monitor favourable conservation status of endangered species. To fill these requirements, in 2006 the system of bird monitoring, commissioned by the General Inspectorate of Environment Conservation (GIOŚ) was implemented in Poland and is being con...

This paper presents a new to Poland method of estimation ofMute Swan population basing on the analysis of aerial photographs. Here we present the data from the city of Gdańsk gathered in 2008 and 2010. Aerial digital photographs were taken on 9 and 10 May 2008 at the height of 1000 m. The photos were ortorectified with a pixel-size of 10 cm. All si...

By the year 2010 the Pygmy Owl has been noticed ca 55 times in Pomerania. In the years 1890-–1950 it was observed 7 times and after a few decades it was found again (8 birds caught on the coast: including 5 in spring and 3 in autumn). In 1999-–2009, 21 records in 17 sites (20 males, 2 unsexed) were noticed in their breeding habitats in Pomerania. I...

The paper describes the trends in numbers of wintering Lapwings and Golden Plovers in Poland during two recent decades. In total, 197 records involving 19,351 Lapwings and 122 records involving 15,749 Golden Plovers were obtained (using only peak numbers from a given site and season, respective numbers dropped to 94 records of 12,804 Lapwings and 6...

Wintering of Water Rail, Snipe and Woodcock was studied during 12 winters (1998–2010) in Gdańsk Pomerania and western part ofWarmia and Masuria (northern Poland). All three species wintered regularly in the area, but they were a few times more numerous in Gdańsk Pomerania than in Warmia and Masuria. In total, 52 wintering Water Rails, 173 Snipes an...

Wintering of Water Rail, Snipe and Woodcock was studied during 12 winters (1998–2010) in Gdańsk Pomerania and western part ofWarmia and Masuria (northern Poland). All three species wintered regularly in the area, but they were a few times more numerous in Gdańsk Pomerania than in Warmia and Masuria. In total, 52 wintering Water Rails, 173 Snipes an...

The Blyth’s Reed Warbler is being recorded with increasing frequency in Poland, with 79 records (80 individuals) made between 1967 and 2009. Most (94%) observations refer to singing males in spring, while the remaining four are of birds trapped in mist-nets during the ringing actions in July–August. The earliest singing male was recorded on 7th May...

Important migratory routes of the Common Crane Grus grus run across Poland. During the peak of the species autumn migration, ca 100 thousand individuals in total may stop to roost within the Polish territory. A substantial part of Common Cranes migrating in autumn remain for a longer time at higher concentrations. In the 21st century, 91 roosts of...

(1) OSOP Ostoja Warmińska jest najważniejszą krajową ostoją bociana białego podtrzymującą 2% jego krajowej populacji oraz jedną z dwóch najważniejszych ostoi orlika krzykliwego, podtrzymującą 5% polskiej populacji gatunku. Celem opracowania jest ocena potencjalnego wpływu wykonanych w ramach PROW 2004-2006 zalesień na gruntach prywatnych na korzyst...

Breeding ranges of Scandinavian and central European subspecies of the White-throated Dipper (Cinclus cinclus cinclus and C. c. aquaticus) are geographically separated by uninhabited lowlands. Between 1990 and 2006, 25 confirmed and 4 probable breeding cases of 23 individual dipper pairs were recorded in northern Poland. Dippers breeding in Norther...

Jack Snipe Lymnocryptes minimus is a small wader showing sexual monomorphism in plumage and some dimorphism in size. To study whether parameters of body size may be used to reliably sex individuals of this species, a discriminant function analysis was applied to a set of morphometric traits measured in birds caught during migration and the winterin...

The hitherto available data about the breeding avifauna of the Wysoczyzna Elbląska upland have been occidental in character. The study carried out in 2004–2007 was aimed at estimation of the abundance of selected breeding bird species, endangered ones in particular. Most data were gathered during counts performed in 2004–2006 within 100 randomly ch...

Counts of the Golden Plover and Lapwing were performed on 11th October and 9th November 2003 (the day after a full moon), with a tolerance of 5 days. In total, ca 22 and 9 thous. Golden Plovers, and ca 51 and 12 thous. Lapwings were recorded respectively in October and November. The greatest number of Golden Plovers were observed in the northern pa...

Numbers and distribution of the Grey-headed Woodpecker Picus canus in the Elbląg Plateau and its expansion in Varmia and Masuria. Abstract: In 2004–2005 the abundance, distribution and habitat selectivity of the Grey-headed Woodpecker Picus canus breeding in the Elbląg Plateau (ca 420 km 2) were studied against the background of the species expansi...