Artykuły naukowe (WB)
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Browsing Artykuły naukowe (WB) by Author "Broniszewska, Monika"
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Item Effect of urbanization and feeding intensity on the distribution of wintering Mallards Anas platyrhynchos in NE Poland(Sveriges Omitologiska Foerening/Swedish Ornithological Society, 2010) Polakowski, Michał; Skierczyński, Michał; Broniszewska, MonikaUrban areas are alternative wintering sites for species with ability to exploit the new conditions that cities offer, such as food, shelter and reduced predation. During four winters (November–February), we recorded the number of Mallards along 108 km of rivers within an urbanization gradient from city centre to rural in north-east Poland. In the urban area, but not in the suburban and rural areas, there was an increase of numbers through winter with highest numbers in February, the coldest month. However, we found no correlation between numbers and ice cover. The only correlation was with feeding intensity by humans, and we suggest that intensity of feeding and the location of the feeding sites is the main factor determining number of wintering Mallards. This was supported by recoveries of ringed birds. Mallards ringed at good feeding sites in the city centre were recovered at the same sites whereas birds ringed in the periphery of the city tended to move to the centre in subsequent winters.Item Sex and age composition during autumn migration of Pygmy Owl Glaucidium passerinum in Central Sweden in 2005(Sveriges Omitologiska Foerening/Swedish Ornithological Society, 2008) Polakowski, Michał; Broniszewska, Monika; Skierczyński, MichałDuring an invasion in 2005, 164 Pygmy Owls were trapped and ringed at Hammarö Bird Observatory on the north coast of lake Vänern between 28 August and 31 October using play-back of territorial male calls. The most intensive migration was recorded in the third decade of September. Eighty percent of the owls were females. There was no difference in the timing of migration of males and females. More than eighty percent were yearlings, and they were migrating earlier than adults. Most Pygmy Owls were trapped at dawn, but some also in the evening, at night and during the day. Two recoveries were received, an immature bird controlled 123 km to the west in the same autumn and another immature individual from Nordre Osen, Hedmark, Norway in March 2008 (247 km to NNW). Twelve re-traps were made at the ringing site, each bird only once and on average one week after ringing with the longest staying bird controlled 22 days after ringing. The paper also shows photographs demonstrating the different wing patterns of yearling and adults.