Ornis Polonica 2010, 51: 1–13
The Black Woodpecker Dryocopus martius and the European Beech Fagus sylvatica as keystone species for the Stock Dove Columba oenas in western Poland
Ziemowit Kosiński, Elżbieta Bilińska, Julian Dereziński, Joanna Jeleń, Marcin Kempa
Abstract: The research was aimed at recognition of the factors which determine the abundance of the Black Woodpecker Dryocopus martius and Stock Dove Columba oenas in the forests of western Poland. In the period 2003–2007, 33 territories of the Black Woodpecker and 98 pairs of the Stock Dove were recorded from seven study plots (jointly 3164 ha). The Black Woodpecker density amounted to 0.3–2.3 ter./100 ha of forest area, while the Stock Dove reached a density of 0.5–12.6 pairs/100 ha of forest area. The densities of both species increased with the growing share of tree-stands dominated by the European Beech Fagus sylvatica and European Hornbeam Carpinus betulus over 80 years old. The density of trees with nest-holes made by Black Woodpeckers, which is potential breeding sites for Stock Doves, ranged from 2.7 to 16.4/100 ha of forest area, whereas the density of nest-holes equalled 4.3–45.7 per 100 ha of forest area. The density of trees with nest-holes and that of the nest-holes themselves were found significantly correlated with the Black Woodpecker density (r=0.81; P=0.028 and r=0.87; P=0.011 respectively). The majority (84%) of nest-holes excavated by Black Woodpeckers were situated in beech trees. The proportion of nest-holes occupied by the Stock Dove on particular study plots amounted to 5–24%, which yields an average of 16% (SD=7.4). Stock Doves most frequently occupied the nest-holes in the beeches; in pine trees, rarer than it would follow from the availability of trees with nest-holes. The Stock Dove density was increasing with the growth in the density of trees containing nest-holes (r=0.79; P=0.033) and in the density of nest-holes (r=0.85; P=0.015). When the nest-holes excavated in pine trees were excluded from analysis, the correlation between the Stock Dove density and the density of nest-holes obtained was even stronger (r=0.98; P<0.001). These results indicate that both the activity of the Black Woodpecker and occurrence of the beech in the tree-stands of western Poland play an important role in the maintenance of the Stock Dove populations.
Ornis Polonica 2010, 51: 14–20
Numbers and distribution of the Common Whitethroat Sylvia communis
in the farmland landscape of south-western Wielkopolska in 1998–2008
Abstract: The aim of the study was to assess the numbers and distribution of the Common Whitethroat in the agricultural landscape near Leszno in south-western Wielkopolska. The research was conducted in 1998–2000 and 2007–2008 on the Dąbcze study plot (10 km²) with the use of the combined version of the mapping method. During the study, an average of 36.2 breeding territories per season were recorded – from 23 in 1998 to 46 in 2000. The density varied from 0.23 to 0.46 territory/10 ha of total area. No clear trend in the changes of abundance was recorded for the local population and, similarly, no effect of changes in the local landscape structure on the Common Whitethroat numbers was observed. Changes in breeding territories distribution were caused mainly by plant succession and afforestation with the Scots Pine Pinus sylvestris. The results suggest that the Common Whitethroat population on the research plot was stable across the study period.
Ornis Polonica 2010, 51: 21–29
Biometric analysis of the Coot Fulica atra from northern Poland
Abstract: The paper provides an analysis of the biometric traits of the Coots caught in 1990–2009 in northern Poland. No significant differences have been found between the first-year individuals and adults with respect to the mean length of the head with the bill, of the bill, wind or tarsus with a toe. Juveniles were lighter than the adult birds examined. They also had a smaller frontal shield. Both in the young and adult individuals, the body mass was gradually declining from autumn to spring. Before the spring migration, no increase in the weight was noted, which may have been caused by a high (93%) proportion in the sample of birds caught at the same place (Sopot). This suggests that at this particular site there were birds which did not undertake long routes. The length of the frontal shield underwent seasonal changes. In adult individuals, its length and breadth were observed to be decreasing from autumn to winter, whereas in spring the frontal shield was found enlarging both in adult and juvenile birds. The mean nail length in the Coots from Sopot and Nowogard was significantly higher than in the individuals caught on the river near the village of Swornegacie. This difference stemmed from the fact that the birds in Sopot and Nowogard were intensely fed by people, and, staying on sandy (Sopot) or concrete-asphalt (Nowogard) substratum, they wore their nails down. This indicates low usefulness of this particular measurement for biometric analyses.
Ornis Polonica 2010, 51: 30–42
Number and distribution of the Grey Heron Ardea cinerea colonies
in northern Poland
Katarzyna Żółkoś, Włodzimierz Meissner, Marek Kalisiński, Ewa Górska, Maria Mellin, Iwona Ibron, Dariusz Wysocki
Abstract: The present paper discusses the results of the censuses updating the information about the colonies of the Grey Heron Ardea cinerea in northern Poland for the period 1999–2009. In the decade mentioned, 76 heronries were noted: most of them in the western part (29 colonies), slightly fewer in the eastern (26 colonies) and central (21) section of northern Poland. The colonies under analysis comprised a total of 4654 nests of the Grey Heron, their number was evenly distributed in the three distinguished regions. The average size of the colonies (the median) in northern Poland amounted to 37 nests. Among the 76 colonies recorded, 16 were established on islands on lakes, and their proportion differed significantly between the regions: the highest was noted for the eastern region (50%), and a clearly lower in the western and central (10% each). Of the16 colonies situated on islands, as many as 15 (94%) represented mixed colonies of the Grey Heron and the Cormorant Phalacrocorax carbo. Among the colonies situated on the land, merely 4 out of 60 were mixed (7%). All the heronries were established in trees, the greatest number of them in pine stands (43%). The highest number of the colonies were found in tree-stands aged 81–100 years, yet, quite a substantial share (9%) of the youngest stands category (21–40 years) is worth noting. Of the 76 colonies, 10 (13%) have been taken under protection within nature reserves. In those reserves 2 of the 4 largest colonies, grouping over 200 nests, are situated.
Ornis Polonica 2010, 51: 43–55
Avifauna of the Middle Noteć River Valley and Bydgoszcz Canal – current state and changes in abundance
Przemysław Wylegała, Andrzej Batycki, Bogdan Rudzionek, Karol Drab, Mariusz Blank, Teresa Blank, Justyna Barteczka, Wiesław Bagiński, Andrzej Konopka
Abstract: In 2003–2009 censuses of selected bird species were performed in the Noteć River valley along its section between Bydgoszcz and Ujście, the site constituting a Natura 2000 bird refuge of European rank named The Valley of the Middle Noteć River and Bydgoszcz Canal. The Middle Noteć valley belongs to the most important refuges of waders in Poland both due to the fact of its housing numerous breeding populations of some species, e.g. the Corncrake Crex crex (124 males), Curlew Numenius arquata (10–12 pairs) and Bluethroat Luscinia svecica (250–280 pairs), and owing to the occurrence in the area of marked concentrations of birds during the migration and wintering periods, including the Tundra Swan Cygnus columbianus (550–600 inds.), Whooper Swan C. cygnus (700–750), Bean Goose Anser fabalis and White-fronted Goose A. albifrons (jointly up to 20 000), Great White Egret Egretta alba (350–400), White-tailed Eagle Haliaeetus albicilla (70–75 inds), Lapwing Vanellus vanellus (9 000–10 000) and Golden Plover Pluvialis apricaria (5 500–6000). Within this refuge, one of the largest in Poland roost of the Common Cranes Grus grus (up to 6 650 inds.) was observed in autumn, and an exceptionally abundant assemblage of moulting Mute Swans C. olor (up to 2 000). In comparison with 1983–1984, among the 40 species under comparison (the majority linked with marshlands), for 17 an increase in the breeding population was recorded and a decrease for 16. The remaining 7 species did not show any trends in number fluctuations. Such trends followed mostly the environmental changes – decline in the intensity of agricultural use of the valley and its secondary turning into marshland. The highest drop in numbers was observed in birds associated with seasonally flooded marshy meadows (wildfowl and waders) and in species connected with fishponds (grebes, diving ducks Aythya, the Coot Fulica atra and Black-headed Gull Larus ridibundus). The increase in abundance concerned mainly species whose population grows in the whole territory of Poland. Also, a strong growth in the numbers of the Bluethroat was noted.
Ornis Polonica 2010, 51: 56–57
Mystery bird 58: Black-eared Wheatear Oenanthe hispanica
Ornis Polonica 2010, 51: 58–62
Numbers of waterfowl species on the Bay of Gdańsk in the period
from September 2008 to April 2009
Włodzimierz Meissner, Piotr Rydzkowski
Summary: In the season 2008/2009 censuses of waterfowl were carried out for the 25th time in the western part of the Bay of Gdańsk. That winter ranked among the mild; the longest span of temperatures below zero fell mainly on the first decade of January, when the bay was frozen to a very limited extent. The highest ever recorded abundance of the Mute Swan Cygnus olor (almost 13 000 inds.) was noted in the study season, which constitutes 5% of the population of this species wintering in north-western and central Europe), and also high numbers of the Whooper Swan C. cygnus, Smew Mergus albellus, Tufted Duck Aythya fuligula and Goosander M. merganser. Recent data indicate a constant decrease in the proportion of the Herring Gull Larus argentatus on municipal refuse grounds near the Bay of Gdańsk.
Ornis Polonica 2010, 51: 63–76
Critically about some counts of breeding bird assemblages
Summary: The paper reminds the rules helping to increase the comparability of breeding bird counts, once agreed upon during a series of IBCC conferences. Recently, a trend to simplify the counting methods, or a switch to semi-quantitative atlassing, has been prevailing. On the example of papers by G. Kopij, it has been documented that the principles of these two approaches are confusingly mixed when too simplified – and empirically never tested – variants of the mapping technique are being used. This is chiefly when they rely on very superficial penetration of too large (even up to 1000 ha) census plots. Although such variants are referred to as the mapping technique, their results do not produce the actual density picture (available only from close-to-absolute data) or true dominance indices (which would require making up for different species detectability). Only the true mapping technique increases cumulatively (after subsequent visits) the accuracy of the final abundance estimates, and reflects a nearly-true share of particular species in a community due to compensation for their different detectability. Quick relative methods are devoid of such corrective mechanisms. To be justifiable, the use of approximate data from the quick methods should be restricted to internal (within own papers) “monitoring” comparisons, or treated as yielding a rough distribution pattern for different species within an area (more detailed than the qualitative faunistical data), but not assumed as a means to obtain reliable figures of bird abundance.
Ornis Polonica 2010, 51: 63–76
Critique of judgment
Summary: Quantitative studies under the critique were conducted on very large plots. These studies were based on methodology widely accepted and commonly used by most ornithologists. Furthermore, L. Tomiałojć has failed to point out that, the most common species were excluded from counting (these often comprised more than 70% of all breeding pairs) in all these studies, that the habitat was much simply in comparison with mature forests, and that the study period extended from March to the end of July (150 days). These factors can greatly reduce the time required for counting. The standard mapping method is design to count common territorial bird species, preferably in forest habitats. It is rather not suitable in assessing densities of less common species (e.g. Locustella sp., Cethia sp., Luscinia sp.), those that do not show much territorial behavior (e.g. Apus apus, Passer domesticus, Columba spp.), semi-colonial (Fringillidae, Sturnus vulgaris) and those that do not sing (e.g. Pyrrhula pyrrhula, Lanius sp.). However, there is an urgent need (e.g. to establish the European network of protected areas, so called Special Protection Areas of the NATURA 2000) to count the less common species, even some common ones (e.g. Emberiza hortulana, Ficedula albicollis, Lanius collurio) on much larger areas, using much simplified versions (e.g. four counts and most common species excluded from studies) of the mapping method.