Ornis Polonica 2010, 51: 241–251
Wide intersexual niche overlap of the specialized White-backed Woodpecker Dendrocopos leucotos under the rich primeval stands in the Białowieża Forest, Poland
Abstract: Foraging sites and foraging behaviour of the White-backed Woodpecker Dendrocopos leucotos females and males were compared within the year in primeval deciduous tree stands of the Białowieża National Park (BNP), NE Poland. The only significant difference was found during winter when females foraged more often on the branches while males used thicker parts of trees (mainly trunks). The strongest niche overlapping of sexes was observed during spring (Schoener’s overlap index OI = 0.87), while the weakest was in winter (OI = 0.78). As a rule females and males foraged separately. Relatively slight differences in foraging behaviour of both sexes could result from weak size dimorphism in this population or from high-quality habitats of BNP or both. Intersexual competition is minimized most likely due to abundant food resources in multispecies tree stands with high amount of dead wood. Habitat quality and possibly climate conditions could influence body size of females and males as well as related foraging behaviour. Differences between females and males of the White-backed Woodpeckers in Białowieża Forest were very small, compared to northern populations. The study showed that this highly specialized woodpecker species could modify its foraging behaviour in response to environmental conditions like food resources and climate.
Ornis Polonica 2010, 51: 252–261
Owls Strigiformes of the central part of the Kampinos National Park
Adam Olszewski, Bartłomiej Woźniak, Tomasz Chodkiewicz, Jerzy Lewtak
Abstract: The paper describes distribution and numbers of owls in the central part of the Kampinos National Park (KPN). The study was conducted in the years 2008–2009 within the area of 89 km² (23% of the area of KPN). In both seasons a census based on vocal stimulation was performed. Only two owl species were observed: the Tawny Owl Strix aluco and Long-eared Owl Asio otus. All observations were mapped. A total of 44–45 territories of Tawny Owls were detected during the first and second season respectively, producing the average densities of 4.9–5.1 and 4.4–4.6 territory/10 km², respectively. The Tawny Owl population reached the highest densities in tree stands more than 120 years old. The number of the Long-eared Owl territories found in 2008 was 11–12 (density 1.2–1.4 territory/10 km²). The density in a semi-open area “Mozaika” was much higher (3.1–3.4 territory/10 km²), suggesting a species preference for mosaic habitats composed of woodland and open areas. In 2009 only one territory of the Long-eared Owl was found (density 0.1 territory/10 km²). Data gathered during the study were combined with the results of earlier research to produce population size estimates for these two owl species in the whole KPN. The Tawny Owl population was estimated at 139–160 pairs and Long-eared Owl at 33–37 pairs (using data from 2008).
Ornis Polonica 2010, 51: 262–274
Occurrence of the Carrion Crow Corvus corone in Poland
Przemysław Żurawlew, Paweł Czechowski, Łukasz Ławicki
Abstract: This paper summarises the occurrence of the Carrion Crow Corvus corone in Poland basing on literature data as well as information from about 190 bird observers. The data cover the period from 19th century up to 2009. Hybridisation zone of the Carrion Crow and Hooded Crow C. cornix is situated in Germany and the Czech Republic. Therefore most breeding attempts of Carrion Crows and observations of non-breeding individuals have been recorded in western Poland. The only breeding record of the Carrion Crow pair occurred in 1890, but 9 cases of mixed broods of the Carrion and Hooded Crow have been found. Additionally, two broods at which at least one parent was Carrion Crow were recorded. Four times probable mixed breeding pairs were observed. Three nests belonged to the hybrids of C. corone × C. cornix and Hooded Crows. At one nest both parents were probably hybrids. In 19th century and first half of the 20th century Carrion Crow was recorded regularly but extremely rarely almost in the whole Poland. A marked increase since the 1980s has resulted probably from greater activity of bird observers. In 1954–2009 a total of 436 observations (612 ind.) of Carrion Crows were made, including 363 records (83%) from western Poland (Silesia, Lubuskie region, Wielkopolska region and Pomerania), while records from eastern Poland (east of the Vistula River) were very rare. Carrion Crows were observed mostly in spring (35% of records) and autumn (32%), while winter (18%) and summer records (15%) were much more seldom. In most cases up to 3 ind. were observed (96%), and the largest flocks comprised 9 birds. Carrion Crows were observed generally unaided (80% obs.), sometimes accompanied by Hooded Crows or (less often) by other corvids. Two individuals of Carrion Crow, ringed in Germany and Belgium, were subsequently caught in Poland, 434 km and 1010 km from the ringing site, respectively.
Ornis Polonica 2010, 51: 275–284
Seasonal changes in numbers and distribution of the Long-tailed Duck Clangula hyemalis, Common Scoter Melanitta nigra and Velvet Scoter
M. fusca near the Cape Rozewie
Abstract: In 2003–2004 a study was conducted aiming to assess the seasonal changes in number and distribution of the three common sea-duck species. The research was carried out on the Baltic Sea between Białogóra and Władysławowo in the two zones: coastal and open-sea zone. Birds were counted from a ship along the same routes. The number of Long-tailed Ducks Clangula hyemalis was the highest in autumn (maximum 42000 ind.), and subsequently declined. The species reached high numbers in both zones. The Common Scoter Melanitta nigra ocurred mostly in coastal zone. Its number fluctuated considerably throughout the season, and reached a peak of 3300 ind. (in both zones) on 5th April 2004. The Velvet Scoter M. fusca was much more abundant in open-sea zone, and reached a peak in autumn (9500 ind.). In autum the highest densities of the ducks were found in a narrow belt of shallow waters of coastal zone, while in winter and spring most birds were concentrated in north-eastern part of the studied area with deeper waters. The most plausible reason for the desertion of coastal-zone was over-exploitation of mussel populations, which constitute the main food of the ducks. Deeper waters in open-sea zone offer high densities of benthic organisms, although diving there is more costly in terms of energy. Changes in the numbers of Long-tailed Ducks could result from both the end of autumn migration and movements of some birds to open-sea zone.
Ornis Polonica 2010, 51: 285–295
Distortion of the rules of quantitative description of breeding bird communities
Summary: The tendency to use quick and simplified versions of the methods to characterize the composition of bird communities and for estimation of population densities violates the international recommendations once proposed by the IBCC. This is paralleled by a confusion in the purposes of counting work: some authors claim to collect data for nature conservation purposes, while the form of their publications negates this, being typical synecological descriptions of bird communities, usually devoid of endangered species. Also the claims of using the mapping technique have been found unjustified, as quick methods may map distribution of bird territories, but fail to do this in a way prescribed to the true mapping technique. Standard mapping technique and combined mapping technique are shown here to be variants of the same method, while quick mapping violates most of the criteria of this method category. Serious problems emerge from repeated claims that the breeding season suitable for counting birds lasts for 5–5.5 months, not solely for 3 months as in standard recommendations. Consequently, a quick counting over c. 150 ha of Wrocław urban park revealed the presence of just one pair of the Middle Spotted Woodpecker Dendrocopos medius, while the combined mapping method helped to find out 5–7 pairs in the same area (during preceding and following seasons). It is shown also that one large census plot (1000 ha) selected from a mosaic-like extensive urban development suggests wrongly the presence of just one bird community, while in fact there is a mosaic or a mixture of several communities there. Large single plot lowers also a possibility of future comparisons (too costly coverage, too uncertain bird numbers, an absence of similar mosaic elsewhere). Instead, more information would be obtained at a lower cost and/or higher accuracy from a set of single-habitat smaller census plots.
Ornis Polonica 2010, 51: 296–301
Changes in breeding bird community of an urban park of Gliwice during 1974–2005
Tomasz Grochowski, Dariusz Szlama
Summary: In 10.75 ha urban park of Gliwice (c. 200 thousand inhab., a part of Upper Silesian Agglomeration, S Poland) breeding bird counts following the combined mapping technique rules were conducted in 1974, 1988–1990 and 2005. As in other urban parks, the numbers of breeding species rose slightly while overall breeding density increased dramatically (from 79 to 278 p/10 ha), even though this park is not entirely isolated from suburban habitats. The strongest increase occurred among species showing a synurbic adaptation (Woodpigeon Columba palumbus, Fieldfare Turdus pilaris, Blackbird T. merula, Blackcap Sylvia atricapilla, Chaffinch Fringilla coelebs, Magpie Pica pica), and hole nesters (Starling Sturnus vulgaris, Great Tit Parus major, Blue Tit Cyanistes caeruleus, Nuthatch Sitta europaea, Short-toed Treecreeper Certhia brachydactyla). Growing numbers of the latter group resulted apparently from aging of the tree stand (c. 90 years old). Another important factor responsible for the growth in bird numbers seems to be the absence of many important nest predators (c.f. Tomiałojć 2007). Similar trends were detected in other long-term studies of bird communities of Polish parks (in Legnica and Warsaw), though each of them was also characterized by its own features.
Ornis Polonica 2010, 51: 302–304
Expansion of the Goosander Mergus merganser in the western Carpathians in 1999–2009
Łukasz Kajtoch, Tomasz Baziak, Szymon Mazgaj, Agata Piestrzyńska-Kajtoch
Summary: First breeding Goosanders in submountain river valleys of the western Carpathians were recorded in 1999. In 2000 the species occupied middle parts of the Raba and the Dunajec Rivers. Goosanders have expanded their breeding area and increased in numbers since then, being recorded in the two river basins. The species was also observed during some breeding seasons in other Carpathian valleys but much less numerous. At present there are about 70–100 breeding pairs of Goosanders in western part of the Polish Carpathians. Probably more pairs breed in eastern Carpathians. In the study area Goosanders breed mainly in semi-natural valleys, although recently some breeding females were recorded also in the vicinity of regulated rivers and streams.
Ornis Polonica 2010, 51: 304–306
High number of the Spotted Crake Porzana porzana in the Middle Noteć River Valley during floods in 2010
Przemysław Wylegała, Zuzanna Rosin
Summary: During drier seasons there were only 1–2 males of the species in the Middle Noteć River Valley. In 2010, before floods, during first brood (April–May) the number of the Spotted Crake was estimated at 12–14 males. In July, during the second brood, 145 males were recorded, and a total number was estimated at 160–170 males. Local density reached 33.8 males/km². Such a considerable increase was probably caused by birds which moved from other more flooded river valleys to the Noteć Valley, where suitable condition for breeding occurred.
Ornis Polonica 2010, 51: 307–309
Mystery bird 61: Siberian Chiffchaff Phylloscopus collybita tristis
Ornis Polonica 2010, 51: 310–313
Numbers of waterbirds on the Bay of Gdańsk in September 2009 – April 2010
Włodzimierz Meissner, Jakub Typiak, Szymon Bzoma
Summary: In September – April 2009/2010 waterbird counts in the western part of Gdańsk Bay were conducted. Birds were counted once a month (table 1). In January we counted additionally gulls on the coast of Gdańsk Bay as well as on big rubbish dumps (table 2). Winter 2009/2010 was exceptionally cold. During the time of January and February counts ice covered more than a half of the Bay, which resulted in a decline of most bird species, especially Cormorants Phalacrocorax carbo, Mute Swans Cygnus olor, Mallards Anas platyrhynchos and Coots Fulica atra. In December, before the period of low temperatures, the Bay supported large numbers of Mallard, whose numbers has been gradually rising since a clear drop at the end of 1990s (fig. 1). During the period of low temperatures numbers of Common Goldeneyes Bucephala clangula, Goosanders Mergus merganser, Tufted Ducks Aythya fuligula and Greater Scaups A. marila increased, which could have been a result of bird movements from frozen inland water bodies and northern parts of the Baltic Sea.
Ornis Polonica 2010, 51: 314–315
Delany S., Scott D., Dodman T., Stroud D. (eds). 2009.
An Atlas of Wader Populations in Africa and Western Eurasia. Wetlands International, Wageningen, The Netherlands
Łukasz Ławicki, Włodzimierz Meissner