Issue 2011-1

 

Ornis Polonica 2011, 52: 1–25

Changes in breeding bird communities of two urban parks in Wrocław across 40 years (1970–2010): before and after colonization by important predators

Ludwik Tomiałojć

Abstract: Bird censuses were carried out in two parks of Wrocław, a down-town one (Słowacki Park, 7–7.5 ha) and in a 17 ha section of the larger Szczytnicki Park, once a riparian forest. In the first one, counts were performed each year in 1970–1999 and 2008–2010, while in the second one during 1970–1974, 1986–1988, 2000–2002 and 2009–2010. Territory mapping method (8–10 to 10–12 visits/season) was applied by the same observer, recently using a hearing apparatus and visiting plots more often. The parks differ by: (a) Słowacki Park – tree stand with few bushes planted before 1900, intensive human presence, with Hooded Crows Corvus cornix present since 1972, (b) Szczytnicki Park – high luxuriant tree stand with few bushes on alluvial soils, moderate numbers of visitors and predators arrived mostly in the late 1970s (two marten species, sporadic raptors and Hooded Crows). In both areas usually a few to a dozen of artificial nest boxes were present. Due to war devastations, both parks were in a “wild” state till the 1960s. After restored predation an overall density of breeding birds dropped in Słowacki Park from c. 294 to 173 p/10 ha, with significant declines of previously abundant species (Wood Pigeon Columba palumbus, Collared Dove Streptopelia decaocto, Rook Corvus frugilegus, Jackdaw C. monedula, Blackbird Turdus merula, Tree Sparrow Passer montanus). Reduction of prey species was diversified in time: vulnerable (Wood Pigeon) declined soon after arrival of crows, other ones after their replenishment. In Szczytnicki Park, with a more stable tree stand, avifauna has changed considerably: over a dozen of species have disappeared, some are close to local extinction, while 6–8 new ones have settled. After arrival of predators some common species ceased to breed (Tree Sparrow, Jackdaw) or their abundance declined by 2–3 times (turdids, columbids). Overall density has dropped from 230 to 145–149 p/10 ha. Main declines in this bird assemblage occurred during the 1980s (arrival of Pine Martens Martes martes) and in 2008–2010 (replenished Hooded Crows). Records of predator attacks on bird nests/broods confirmed this pressure. Antipredator behaviour in some prey species persisted for years after Pine Marten disappearance.

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Ornis Polonica 2011, 52: 26–39

Wintering of the Lapwing Vanellus vanellus and the Golden Plover Pluvialis apricaria in Poland in 1990–2008

Włodzimierz Meissner, Arkadiusz Sikora, Sebastian Guentzel, Jacek Antczak

Abstract: 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 67 records of 11,656 Golden Plovers). Both species were traditionally considered rare during winter, and the numbers were rather stable until 2006. However, a clear increase was evident since 2007, and this was most likely not related to increasing observers’ activity. At the level of the whole country, numbers of both species appeared unrelated to mean winter temperatures, but during winters of 2000/01 to 2007/08 the number of wintering Lapwings was positively correlated with average December and January temperature in north-western Poland. Both species were more numerous in western Poland during winter, while records from the eastern part of the country were scarce. Flocks up to 50 birds were most frequent (61% and 58% of all records of Lapwing and Golden Plover, respectively), while biggest flocks accounted for 1,000 Lapwings and 1,200 Golden Plovers. Lapwings most frequently wintered at the bottom of fish ponds, reservoirs and meadows, while Golden Plovers were found at fish ponds and plowed fields in the majority of cases.

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Ornis Polonica 2011, 52: 40–52

Decline in the numbers of the Eurasian Curlew Numenius arquata in western Poland in 1980–2010

Łukasz Ławicki, Przemysław Wylegała

Abstract: During last 30 years a distinct decrease in the numbers of the Eurasian Curlew in western Poland (west of the Vistula River) has been recorded. Breeding population size declined by over 70%, from 293–365 pairs in 1980–1996 to 84–109 pairs in 2004–2010. The most important decrease was found at the key breeding sites of the species in Wielkopolska Region (decline by 77%), Pomerania (81%) and Lubuskie District (40%). Only in Świętokrzyskie Region some increase was recorded, while population fluctuations were recorded near Łódź. Of 33 analysed sites, at 26 (79%) declines or population disappearance were recorded. At 6 sites (18%) numbers has increased, and fluctuated at one site (3%). Key breeding sites of the Eurasian Curlew, holding 80% of its population in western Poland are situated at present in river valleys of the Noteć, Ner, lower and middle Warta, Obra and in the Włoszczowska Basin. The most likely reasons for the species decline are low breeding success affected by high predation rate, and habitat loss, as it has been found in western Europe. Data from a few regions in eastern part of the country suggest that the decrease is widespread within the whole area of Poland. Similar trend has been detected at the majority of European breeding sites of the species.

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Ornis Polonica 2011, 52: 53–61

Relationship between the quality of song and condition
and immunocompetence in songbirds

Magdalena Herdegen

Summary: Condition and immunocompetence are related to the quality of male song in songbirds. However, this does not necessarily involve a direct, cause-effect relationship. In most cases the indirect relationships are determined by various environmental or genetic factors, or both. Among these factors are e.g. androgen level, the development of brain and nervous system affected by external conditions during an organism development (the level of nutrititional stress, parasite load, brood size). The genetic component seems to be of great importance. It’s worth mentioning that the results of various studies and their interpretations, though concern different aspects of an organism functioning, do not exlude each other. Almost all hypotheses explaining relationships between bird song, condition and immunocompetence imply the trade-offs between different body functions as a results of related costs. The high number and diversity of hypotheses may better reflect the complexity of real relationships between condition and immunocompetence, and the attractivenes of epigamic traits in songbirds, than one simplified model.

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Ornis Polonica 2011, 52: 62–67

Distribution, numbers and habitats of the Ring Ouzel Turdus torquatus
in the Beskid Wyspowy Mts.

Łukasz Kajtoch

Summary: Distribution, numbers and habitat preferences of Ring Ouzel Turdus torquatus breeding population from Beskid Wyspowy Mts. (about 400 km² of managed forests situated between 500 and 1170 m a.s.l.) were described. Field work was conducted mainly in 2007–2010 years. 34–45 Ring Ouzel territories were found and the total size of population was estimated at 40–50 pairs (2–4% of Polish population). Most of territories (71%) were located in southern-central part of mountain range. Ring Ouzel inhabits here mainly coniferous forests: fir or fir-spruce (53% of territories) and spruce (25%) and also fir-beech forests (22%), between 650 and 1170 m a.s.l. In the vicinity of its territories, glades, forest clearings, rocky debris, peatbogs and/or springs are frequently present. Ring Ouzel inhabits both semi-natural uneven-aged forests (18% of territories in reserves) and mosaic forests composed of patches of different age. In territories of that species frequently were present berries, junipers and rowans. Densities of Ring Ouzel (calculated for the total forest area) were very low (0.1–0.3 territories/1 km2), but in optimal habitats they reached 3.5–22.0 territories/1 km².

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Ornis Polonica 2011, 52: 67–69

High densities of the Aquatic Warbler Acrocephalus paludicola
in the Biebrza Marshes in spring 2010

Michał Polakowski

Summary: Two censuses carried out on 28th May and 2nd July 2010 at the plot “Pogorzały” (Biebrza river Valley, 53°29′N, 22°53′E) revealed extremely high densities of Aquatic Warbler. 130–139 and 138–142 singing males were counted during the first and second census, respectively, producing densities of 10.3–11.0 and 11.0–11.3 males/10 ha, which represents one of the highest densities ever recorded on small plot. Such a high density may be the result of two compounding factors, supporting an optimal nesting habitat for Aquatic Warbler at the time of the study. These were (1) removing most of bushes and reedbeds from the plot during the preceding winter and (2) only a moderate water levels in spring 2010. It also seems likely, that birds from traditional breeding grounds located close to the river, flooded for a long time in spring 2010 could have arrived to the studied plot.

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Ornis Polonica 2011, 52: 69–71

Reuse of a nest in Reed Warbler Acrocephalus scirpaceus

Lucyna Hałupka, Ewelina Klimczuk

Summary: Most passerines, including Reed Warblers, do not reuse their nests, even when nest structure remains intact, and nest failure occurs at the beginning of the nesting cycle (e.g. on the day of laying of the first egg). For seven years (1994, 2005–10) we studied a colour-ringed population of Reed Warblers Acrocephalus scirpaceus breeding in extensive reedbeds on a fish pond Słoneczny in the nature reserve Stawy Milickie (SW Poland). Each year we found ca. 85 nests (65–120) containing clutches, and up to 20 nests deserted at the building stage. In each clutch found at the laying stage each successive egg was marked with a small colour dot. In 2010 we observed a single case of reuse of a nest by a pair of Reed Warblers. On 11 July the pair started building their third nest (two previous broods failed). The female laid the first egg on 15 July, but the second egg was taken by a predator on 16 July, which resulted in nest desertion. The pair started building a new nest nearby, but it was destroyed by an intense rain. On 19 July the pair was observed in the vicinity of their previous nest, adding some new nest material, which was confirmed by camera recording. The female laid 4 new eggs (starting on 20 July), but the nest contained 5 eggs as one old egg from the previous clutch still remained. A few day later, on 27 July, two eggs disappeared (including an old one), but remaining eggs survived until hatching. We suspect that this unusual behaviour was affected by late season and hence dramatically declining renesting potential. This was one of the last broods of 2010, and the pair saved c. 3 days by using of an old nest instead of building of a new one. Such a behaviour has never been reported in the species before.

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Ornis Polonica 2011, 52: 72–73

Mystery bird 62: Dunlin Calidris alpina

Jan Lontkowski

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