Volume 47 • Number 3 • 2006

147 State of the population of the Little Owl Athene noctua in Poland.
Grzegorz Grzywaczewski

Abstract: In the 1990s the Little Owl was most abundant in the eastern and south-eastern part of the country: starting from the southern section of the Podlasie region, through Masovia, the provinces of Łódź and Kielce up to that of Lublin . The species abundance in Poland on the turn of the 20th century was estimated at 1000-1500 territories. In the last decades a clear decrease in the Little Owl numbers was noted, the most marked in the agricultural landscape within river valleys. In 1980-2003 the density of the species ranged between 0 and 6.8 ter./10 km 2 (4 study plots) in river valleys, from 0 to 2.0 ter./10 km 2 in agricultural landscape (16 plots), amounting to 0.7-5.3 ter./10 km 2 in small and medium-size towns of Lublin area (9 plots). The natural declines of the Little Owl population are linked with frosty and snowy winters. Probably, the species numbers are also reduced due to the predation by martens Marten sp., Domestic Cats Felis catus and Tawny Owls Strix aluco. Besides, some birds are killed having collided with motor vehicles, others get drowned or fatally crash against windows of buildings, and young birds die having fallen down from the nest onto concrete ground. The Little Owl in Poland breeds in dwelling houses, cowhouses, barns, warehouses, farm buildings, hospitals, schools, sacral objects and, exceptionally, hollows in willows, fruit trees or pillows, and also transformers and dovecots. In buildings the broods are most commonly situated in ventilation holes, in attics and garrets, or crevices.

159 Avifauna of the Ner River valley in 1984-2005.
Sławomir Mielczarek, Jerzy Grzybek, Tomasz Janiszewski, Paweł Michalak, Radosław
      Włodarczyk, Zbigniew Wojciechowski

Abstract: In 1984-2005 observations were carried out in the Ner River valley within the Warsaw-Berlin Glacial Stream Valley between Rzuchów and Łęczyca. The Ner valley ranks among the most important refuges of waterbirds, with 210 bird species recorded, the number including 141 breeding or probably breeding species. Among the breeding avifauna the following species should be mentioned: the Little Bittern Ixobrychus minutus, Montagu's Harrier Circus pygargus, White-tailed Eagle Haliaeetus albicilla, Curlew Numenius arquata, White-winged Tern Chlidonias leucopterus, Whiskered Tern Ch. hybrida and Aquatic Warbler Acrocephalus paludicola. The observations made in the breeding season indicate also possible irregular nesting of the Pintail Anas acuta, Wigeon A. penelope and Red-crested Pochard Netta rufina. Within the study season significant fluctuations in the abundance of some breeding species were recorded, the most substantial in the eastern, reclaimed, section of the valley, where the numbers of many species decreased dramatically (Shoveler A. clypeata, Garganey A. querquedula and most waders). However, some of the changes were more general in character, concerning also the part of the valley which had not been drained. The Ner River valley is also an important roosting and foraging ground of migrating waterbirds - spring concentrations of geese, ducks and waders regularly exceed 10,000 inds.

175 The usefulness of the mapping method with playback in estimation of the numbers
      of the Syrian Woodpecker Dendrocopos syriacus.

      Jerzy Michalczuk, Monika Michalczuk

Abstract: By means of the combined form of the mapping method with playback, the distribution of the Syrian Woodpecker's territories in Łaszczów and Telatyn communes (238 km 2 , Lublin region) in 2003 and 2004 was determined and detectability assessed. The territories were searched for in agricultural landscape with cultivated fields and meadows predominating (86.2%) and a low percentage of woods (4.9%) and built-up areas (8.9%). The research was conducted from March till July. There were 8 controls made in 2003 and 11 in the next season. During these two years of research respectively 39 and 53 Syrian Woodpecker's territories were discovered, which gives an average density of 1.6 and 2.2 territories/10 km 2 of the whole area and 18.6 and 25.2 territories/10 km 2 of optimal habitats (about 21 km 2 ) that is orchards, tree lines and stands of sparsely grouped trees near built-up areas. In some of the villages even 3-5 pairs were discovered, whereas in others there was no evidence of these birds' presence. It may point to the fact that the colonization of this area by the Syrian Woodpecker had not been finished yet. A precise assessment of the species breeding population can be made by spending about 1 hour on controlling 10 ha of optimal habitats. In order to do this, 6 controls during March-April period are needed.

185 Sexual dimorphism and sex identification of the Herring Gull Larus argentatus group
      using biometric measurements.
Grzegorz Neubauer, Magdalena Zagalska-Neubauer

Abstract: Species-specific biometric criteria are necessary when sexing gulls from the Herring Gull complex. The paper offers a discriminant function, not requiring identification of species, which is based on molecular determination of sex made for 63 individuals breeding in a mixed colony of L. argentatus and L. cachinnans at the Włocławski Reservoir. The equation is D = -36.913 + 0.116 × HE + 1.245 × HBIN, where D is the discriminant score, HE is the total head length and HBIN is the minimal depth of the bill between the gonys and feathering. The cut-off point is 0.518, and birds whose discriminant score is higher are classified as males, and those of a lower discriminant score - as females. The function gives 97% of correct classifications in the sample from the mixed colony in central Poland , where the two species hybridize, and 100% of correct classifications for allopatric populations of L. argentatus and L. cachinnans.


192 First record for Poland and the second for the Western Palearctic of the Rufous-tailed Robin
      Luscinia sibilans.
Grzegorz Grygoruk, Tomasz Tumiel

Summary: On 30th December 2005 an unknown bird was seen and photographed along the Biała River in Białystok , where it stayed until the next day. The bird was later identified as a Rufous-tailed Robin. The record has been accepted by the Avifaunistic Commission as the first for Poland . The single previous record of this species in the Western Palearctic was made in October 2004 at Fair Isle of the Shetlands.

194 Second record of the Ring-necked Duck Aythya collaris in Poland.
Paweł Kmiecik, Radosław Gwóźdź, Jacek Betleja, Szymon Beuch, Krzysztof Henel

Summary: During 26th April -1st May 2005 an adult drake of the Ring-necked Duck was observed and photographed on the water reservoirs and fish-ponds between Dąbrowa Górnicza and Siewierz in southern Poland ( Upper Silesia ). Later, most probably the same bird was relocated about 76 km south-west, in fish-ponds at "Łężczok" reserve near Racibórz, where it stayed during 6th-19th May. It is the second record in Poland . Accepted by the Avifaunistic Commission.

196 Expansion and increase in numbers of the Stonechat Saxicola rubicola in Western Pomerania.
Łukasz Ławicki

Summary: In 1992-2005, in Western Pomerania 61 breeding sites of the Stonechat were noted, at 24 of which confirmed breeding (adults with fledglings, birds carrying food observed) and at 37 anxious pairs or singing females were recorded. The greatest number of breeding sites were discovered in the western section of the region, with the maximum near Szczecin (13 sites/18-19 pairs), Police (13 sites/14-15 p.), Świdwie Reserve (9 sites/9-11 p.) and in the Odra River valley (7 sites/7 p.). In the central part of the region single sites were discovered, grouped mainly around Goleniów, Stargard Szczeciński and Nowogard, and in Świnoujście and three places near Kołobrzeg on the seaside. Abundance of favourable habitats for the Stonechat in Western Pomerania (ruderal terrain, young pine stands, meadows, etc.) suggests that the actual species numbers can be higher than indicated by the obtained data.

199 Decrease in the Curlew Numenius arquata numbers in chosen meadows of Western Pomerania in
Łukasz Ławicki, Bartosz Racławicki

Summary: In the last fifteen years a critical decline of the Curlew population has been recorded in the studied meadows of Western Pomerania . In 1990-1996, 20-35 pairs bred in the Szczecin Firth region, whereas in 2006 there were merely 6-8 pairs observed. The most significant decrease, reaching 75-90% and with some breeding sites having even disappeared, was found at Lakes Dąbie and Płoń. The decline of the Curlew population observed recently concerns nearly all localities of this species in Western Pomerania . The largest and most stable breeding ground are the meadows surrounding Lake Miedwie . The main factors which are responsible for the Curlew withdrawal from the Western Pomeranian meadows are the cessation of meadow use (no grazing, the land lying fallow) and, consequently, reed succession, ground over-drying and transformation of the meadows into arable land.

203 The Little Owl Athene noctua diet in Central Poland.
Jerzy Romanowski, Michał Żmihorski

Summary: We analyzed Little Owl pellets, collected in agricultural landscape of Central Poland from March to July 1982-2005. We recorded 310 prey items. The Common Vole Microtus arvalis was the predominating species among vertebrates, and beetles Coleoptera among invertebrates. The Little Owl food composition indicates that the owl preys mainly on ground-living vertebrates and invertebrates (e.g. Carabidae, Gryllus campestris). And thus changes in the plant layer height and density, caused by an increasing proportion of fallow-land in the agricultural landscape of central Poland , can negatively affect the Little Owl hunting success.

207 Untypical food of the Bearded Tit.
Janusz Stępniewski, Adrian Surmacki

Summary: The diet of adult Bearded Tits in spring and summer is composed of small invertebrates. In autumn the share of seeds, mostly of Phragmites australis, increases to constitute nearly the sole food item of these birds in wintertime. On 5th February, 2005, three Bearded Tits were observed collecting from the iced Lake Wojnowickie (Wielkopolska region) beetles of the family Staphylinidae (genera Paederus, Atheta and Stenus), which occurred at abundance of ca 60 inds/m2. This observation indicates that this bird species is able to exploit various and unexpected food resources irrespective of the season.

208 Diet of the Red-backed Shrike Lanius collurio in the agricultural landscape of eastern Poland.      Artur Goławski

Summary: In 1999-2003, the Red-backed Shrike diet was investigated in an agricultural landscape of extensive farming 10-15 km north-south of Siedlce. In the food, 5298 remnants of animals and three seeds of the Black Cherry Padus serotina were discovered. The predominating food items were insects representing the orders Coleoptera, Hymenoptera and Orthoptera, which accounted for 94.8% items of prey. Vertebrates constituted merely 0.5% of prey items, among which Microtidae made up 0.2%. All the four methods of food analysis showed predominance of coleopterans. Compared with other methods, the pellets revealed relatively abundant hymenopterans, whereas in food storage places numerous orthopterans were found. In the agricultural landscape of eastern Poland the Red-backed Shrike diet does not differ markedly from those in other regions of Europe . The bird feeds on a wide spectrum of prey, particularly coleopterans, which, along with hymenopterans, are preferred items of food.

214 Mystery bird 44: Pallid Swift Apus pallidus.
     Jan Lontkowski

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