Wyniki wyszukiwania

1

Genetic diversity of the Azores Blackbirds Turdus merula reveals multiple founder events

100%

Rodrigues P., Lopes R. J., Resendes R., Ramos J. A., Cunha R. T.

Acta Ornithologica

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2016

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tom 51

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nr 2

We assessed the genetic diversity and phylogeography of the Azores Blackbird Turdus merula, based on sequences of two mitochondrial genes (Cytochrome b and NADH Dehydrogenase subunit 2) and one nuclear gene (Aconitase 1 - intron 9) from 45 individuals and an outgroup of 15 birds from Madeira, continental west Europe and north Africa. Our results revealed the lack of genetic structure on these islands and the presence of, at least, two different lineage groups that may indicate two different founder events of the Azores by Blackbirds.

2

Nest sharing by two Blackbird Turdus merula females

100%

Wysocki D., Walasz K.

Acta Ornithologica

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2004

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tom 39

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nr 1

Two cases of nest sharing by two Blackbird pairs each were recorded during a long-term urban study. In the first case, two females simultaneously incubated eggs in the same nest. The nestlings were later seen to be fed by the two pairs of adult birds. In the second case, a nest containing 4 eggs laid by one female wastaken over by another which, having chased the nest owner away, laid 5 eggs of her own. The likely cause of nest sharing in the first case was the loss of eggs at an early stage of laying by the second female. In the second case, nest sharing seems to have been caused by nest competition. The details of the parents and siblings of the females involved in the first case permits the conclusion that the absence of competition between the females (and even their co-operation in feeding the young) was not caused by their genetic affinity.

3

Evaluation of the applicability of polymerase chain reaction [PCR] to sex identification in Eurasian blackbirds [Turdus merula]

84%

Dybus A., Siemierz A., Wysocki D., Szatkowska I., Muszynska M., Guenzel S.

Biological Letters

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2009

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tom 46

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nr 1

17-22

4

Blackbirds mate choice: dependence of male social status on age and morphology in an urban population of the European Blackbird, Turdus merula L.

84%

Jarska K., Jankowiak L., Smietana P., Wysocki D.

Polish Journal of Ecology

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2015

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tom 63

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nr 3

The differences in morphology and age between single and paired males of an urban population of the European Blackbirds (Turdus merula) were studied in Żeromski park in the city of Szczecin (NW Poland) spanning 11 breeding seasons since 1998. The proportion of single to paired males in different age groups was established. Also, morphology features like the length of tail, wing and tarsus of 45 single males and 475 paired males were collected. We found that old males (after second year of life) formed pair bonds more often than the young males (in their second year of life). The probability of being a paired male in case of young males increased along with the tarsus length.

5

Urban and forest-living blackbirds Turdus merula as hosts of Borreliella spp. infected ticks

84%

Gryczynska A.

Polish Journal of Ecology

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2018

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tom 66

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nr 3

The effect of urbanisation on parasite prevalence, especially these associated with human diseases, such as Lyme borreliosis, is of high interest. The blackbird Turdus merula is a ground-feeding species particularly predisposed to constitute a Borreliella spp. (Lyme borreliosis causative agent) reservoir. So, the aim of the study was to examine if the tick infestation level and their Borreliella spp. infection prevalence differs in blackbirds resident in two disparate habitats in Poland – one highly urbanized (in Warsaw agglomeration) and the other forested (in Mazurian Lake region). The infection in ticks feeding on blackbirds was ascertained based on detection of bacterium DNA (PCR). The prevalence of tick infestation in urban and forest-living blackbirds was similar (90 and 91.7%, respectively) but the mean number of parasites per bird was markedly greater in the forest (4.0 ind.) than in the urban populations (1.5 ind.). Even though, the Borreliella spp. infection of the ticks was significantly greater in the urban (46.7%) than in forest habitat (35.4%). Additionally, in the urban site more birds carry at least one infected tick than in the forest. The results of the study seem to confirm the role of blackbirds in establishing Borreliella spp. reservoir. Special regard should be given to highly urbanized areas, where the relative increase in the relevance of birds as tick hosts and pathogen transmitters may pose high risk to public health. Thus, the study constitutes a small-scale but an important contribution to our understanding of the role of birds in maintenance of Borreliella spp. foci in urban habitats.

6

First report of fishing in the European Blackbird Turdus merula

84%

Raes A., Lefebvre L., Jordaens K.

Acta Ornithologica

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2008

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tom 43

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nr 2

231-234

During two hours of observation, a female Blackbird made approximately 30 attempts to catch fish, 20 of which were successful. The bird watched and followed a minnow shoal in shallow parts of the river, hopping from stone to stone in a way that resembled its normal behaviour when catching earthworms. The bird only caught small individuals (5-7 cm). Larger individuals were present in the river but were not seen within the shoal and were not attacked.

7

Nest site selection in the urban population of Blackbirds Turdus merula of Szczecin [NW Poland]

84%

Wysocki D.

Acta Ornithologica

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2005

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tom 40

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nr 1

61-69

Nest site selection in the Blackbird was investigated in two urban parks in Szczecin from 1997 to 2003. The age structure of the tree stands, the area of shrub coverage and the number of predators (apart from squirrels) were similar in both parks. 95% of the nests discovered at the beginning of the breeding season were found again in June and July. Any increase in the heights of the nest sites in successive periods of the breeding season and any changes in the type of vegetation selected for nest construction were recorded. In April, Blackbirds most often used coniferous trees. At the start of the season, when deciduous plants began sprouting leaves, Blackbirds preferred those whose leaves appeared earlier. But later in the season, no difference was found between the numbers of nests in trees developing their crowns earlier or later. The shorter period of nest use in conifers is probably due to their selective penetration by corvids. The selective penetration of such trees by predators probably reduces the frequency of nest building in them between the first (pentads 1-3) and second (pentads 4-6) period of the breeding season, despite the fact that they provide better concealment for nests. The selection of nest sites by the Blackbirds in this study confirms both the predator-pressure and the nest-concealment hypotheses.

8

Nest re-use by Blackbirds - the way for safe breeding?

84%

Wysocki D.

Acta Ornithologica

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2004

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tom 39

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nr 2

The biology of individually colour-ringed European Blackbirds inhabiting two city parks in Szczecin (NW Poland) was studied in 1997-2003. In each park one to three observers watched the behaviour of Blackbirds every other day from dawn till afternoon (6-8 h a day); in this way almost all of their nests were discovered. 35 cases were recorded where pairs re-used their own nests, as well as two cases where the nest of another Blackbird pair and one Fieldfare nest were re-used. In 33 out of 81 cases observed, the re-use occurred after the brood had been successfully reared, while in two cases out of 378, female Blackbirds initiated the second breeding attempt in the same nest after the loss of the first one. The re-used nests were better concealed (80 ± 19% and 69 ± 18%, respectively) and had been built at greater heights than those abandoned after breeding (9.0 ± 5.0 m and 6.5 ± 4.2 m, respectively). No shortening of the interval between successive clutches was noted in the case of nest re-use (re-used nests 36.8 ± 4.9 days, newly-built nests 37.7 ± 8.0). The more and more frequent re-use of nests where breeding had been successful, their better concealment and higher sites, and also the lack of any differences in the intervals between successive clutches of pairs occupying old nests and those building new ones before the next breeding attempt, suggest that in the investigated population the basic reason for nest re-use was the insufficient number of safe nesting sites.

9

Juvenile Blackbird [Turdus merula] moulting primaries and secondaries

84%

Zielinska M., Zielinski P., Mokwa T.

The Ring

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2005

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tom 27

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nr 1

10

Winter breeding by the Blackbird Turdus merula L. during harsh weather conditions

67%

Wuczynski A.

Polish Journal of Ecology

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2010

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tom 58

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nr 4

Birds may occasionally breed far beyond the average breeding time for particular species. Nesting attempts in winter during unfavorable weather and unfavorable environmental conditions, however, are particularly rare events. In this note I report an unsuccessful attempt of a Blackbird Turdus merula L. observed in January, 2009 in SW Poland. The clutch was abandoned at the final stage of incubation. Unlike other reported cases, it had been started on the outskirts of an average-sized town, in a period of harsh weather– low ambient temperature and snow cover present. This is the first winter brood of this species recorded in Poland and probably the easternmost in Europe. It is suggested that winter breeding by Blackbirds may occur more regularly and in wider areas than previously reported.

11

Survival and site fidelity of urban Blackbirds Turdus merula - comparison of Cormack-Jolly-Seber and Barker models

67%

Jankowiak L., Wysocki D., Greno J.

Acta Ornithologica

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2016

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tom 51

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nr 2

Studies dealing with the individual survival of birds in open populations usually estimate survival according to capture-recapture models like the Cormack-Jolly-Seber (CJS). In fact, these models estimate local apparent survival (φ), which is a combination of the probabilities of true survival (S) and site-fidelity (F), i.e. death and emigration are confounded. These S and F parameters can be estimated by using 'robust' models (e.g. Barker's model), which use additional resighting and dead reports data. We aim to compare the results (and associated biological implications) obtained by analysing juvenile and adult survival in a Polish urban population of Blackbirds Turdus merula using both the CJS and Barker models. Our CJS models estimated high φ values for both juvenile and adult birds (0.48 and 0.62, respectively). The lower scores for juveniles could be interpreted as low juvenile overwintering survival. By fitting Barker models to the same dataset we determined that juvenile site fidelity was lower than that of adults (0.91 and 0.93, respectively), so natal dispersal was slightly greater than breeding dispersal. The high fidelity causes similarity between apparent survival and true survival parameters (S: 0.51 for juveniles, 0.64 for adults). The results are comparable with data from other urban populations. Thus, using robust models certainly allows one to reduce the noise of movements confounding and/or masking survival probabilities, but one can also determine the individual or environmental variables affecting any of them separately.

12

Effect of change in land use on breeding bird communities in a Silesian farmland [SW Poland]

59%

Kopij G.

Polish Journal of Ecology

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2008

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tom 56

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nr 3

511-519

Two study areas, 210 ha (A) and 120 ha (B), have been selected. Arable grounds dominated (92%) in the study area A, while meadows (63% in 1989 and 47% in 2003) – in the study area B. The changes in land use in both study areas have occurred in 2003 comparatively with 1989. In the study area A, an increase of the area with maize (from 1.1 ha to 38.4 ha) and oat (from 5.6 to 28.4 ha), and decrease in area of the rape (from 41.3 to 0.3 ha) and root plants (from 16.7 to 6.4 ha) have been recorded, while the clover and broad bean have totally disappeared as cultivated plants. In the study area B, a conversion of some dry meadows into arable grounds and an abandonment of more than half of the remaining area of meadows has been carried out. The landscape in the study area A was more fragmented in 1989 than in 2003, while in the study area B the reverse was true. On average, cereal areas increased – especially wheat (from 1.5 to 2.4 ha), maize (from 0.6 to 3.8 ha) and oat (from 0.6 to 1.9 ha), while rape areas decreased (from 2.0 to 0.3 ha). The mapping method has been employed to show the effect of these changes on breeding bird community in both years (1989 vs. 2003). In the study area A, density (pairs × 100⁻¹ ha) of the Skylark Alauda arvensis (28.1 vs. 17.1) and Marsh Warbler Acrocephalus palustris (12.9 vs. 2.4) has significantly decreased; while that of Corn Bunting Miliaria calandra (1.4 vs. 8.1) and gallinaceous birds (2.9 vs. 8.1) has significantly increased over the last 14 years. The most numerous species in the group of gallinaceous birds, the Common Quail Coturnix coturnix, probably benefits from the enlargement of oat and barley cultivations. The Skylark was negatively affected by the enlargement of study areas with cultivated plants, especially with the wheat and maize. The Corn Bunting has been, probably, positively affected by the enlargement of maize and barley cultivations, as well as from the warming effect. The decline of the Marsh Warbler could have been caused by the decrease of the area with rape cultivations but it may also reflect short-term fluctuations. In the study area B, only densities of the Chaffinch Fringilla coelebs and Blackbird Turdus merula have significantly increased, and no statistically significant declines were recorded. These increases can be linked to changes in the age structure of tree and shrub stands in the existing small forests, clumps and hedgerows, but these species show probably a general increase in numbers over large areas of farmlands in Poland and possibly in some other European countries.

13

Point transect counts of wintering birds in The Netherlands 1978-1992

51%

Sierdsema H., Hagemeijer W., Hustings F., Verstrael T.

The Ring

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1995

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tom 17

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nr 1-2

Ograniczanie wyników

Genetic diversity of the Azores Blackbirds Turdus merula reveals multiple founder events

Nest sharing by two Blackbird Turdus merula females

Evaluation of the applicability of polymerase chain reaction [PCR] to sex identification in Eurasian blackbirds [Turdus merula]

Blackbirds mate choice: dependence of male social status on age and morphology in an urban population of the European Blackbird, Turdus merula L.

Urban and forest-living blackbirds Turdus merula as hosts of Borreliella spp. infected ticks

First report of fishing in the European Blackbird Turdus merula

Nest site selection in the urban population of Blackbirds Turdus merula of Szczecin [NW Poland]

Nest re-use by Blackbirds - the way for safe breeding?

Juvenile Blackbird [Turdus merula] moulting primaries and secondaries

Winter breeding by the Blackbird Turdus merula L. during harsh weather conditions

Survival and site fidelity of urban Blackbirds Turdus merula - comparison of Cormack-Jolly-Seber and Barker models

Effect of change in land use on breeding bird communities in a Silesian farmland [SW Poland]

Point transect counts of wintering birds in The Netherlands 1978-1992