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Urban environments cover vast areas with a high density of humans and their dogs and cats causing problems for exploitation of new resources by wild animals. Such resources facilitate colonization by individuals with a high level of neophilia predicting that urban animals should show more neophilia than rural conspecifics. We provided bird-feeders across urban environments in 14 Polish cities and matched nearby rural habitats, testing whether the presence of a novel item (a brightly coloured green object made out of gum with a tuft of hair) differentially delayed arrival at feeders in rural compared to urban habitats. The presence of a novel object reduced the number of great tits Parus major, but also the total number of all species of birds although differentially so in urban compared to rural areas. That was the case independent of the potentially confounding effects of temperature, population density of birds, and the abundance of cats, dogs and pedestrians. The number of great tits and the total number of birds attending feeders increased in urban compared to rural areas independent of local population density of birds. This implies that urban birds have high levels of neophilia allowing them to readily exploit unpredictable resources in urban environments.

Bird feeding is one of the most widespread direct interactions between man and nature, and this has important social and environmental consequences. However, this activity can differ between rural and urban habitats, due to inter alia habitat structure, human behaviour and the composition of wintering bird communities. We counted birds in 156 squares (0.25 km(2) each) in December 2012 and again in January 2013 in locations in and around 26 towns and cities across Poland (in each urban area, we surveyed 3 squares and also 3 squares in nearby rural areas). At each count, we noted the number of bird feeders, the number of bird feeders with food, the type of feeders, additional food supplies potentially available for birds (bread offered by people, bins) and finally the birds themselves. In winter, urban and rural areas differ in the availability of food offered intentionally and unintentionally to birds by humans. Both types of food availability are higher in urban areas. Our findings suggest that different types of bird feeder support only those species specialized for that particular food type and this relationship is similar in urban and rural areas.

Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas). The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (± SE) 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments.

Climate conditions may determine the foraging strategy of migratory birds at spring stopovers. For geese, this period is a crucial time for acquiring energy to fuel onward migration and ensure future breeding success. Our study, analysing the influence of weather factors on numbers of geese and foraging sites, was conducted in the Biebrza Basin (north-eastern Poland) during the spring migration period in 2007-2013, when a total of 116 counts were carried out. A total of 741,865 White-fronted Geese and 20,871 Greylag Geese were counted. Numbers of geese differed among habitat types; Greylag Geese used arable lands more frequently than Whitefronted Geese, which in turn preferred grasslands. Two climate factors affected numbers of the latter: the impact of mean 10-day temperature was positive but that of snowfall was negative. Neither of these factors affected the former. We conclude that changeable climate conditions in the temperate climatic zone may force a more flexible response in terms of habitat use during stopovers from short-distance migrants like Greylag Geese than from longer-distance migrants like White-fronted Geese. [ABSTRACT FROM AUTHOR]

Winter is one of the crucial periods of the bird's year-round life cycle. Fat reserves in bird species are prone to a wide range of factors, with weather conditions and a bird's social status being two major ones. In our study we analysed the variation in fat reserves in birds with stable, constant access to food resources in three of the most common wintering species: the great tit Parus major, the blue tit Cyanistes caeruleus and the greenfinch Chloris chloris. The highest mean value of fat score was found in the greenfinch, whereas in both species of tits these values were equally lower. For all three species the amount of fat reserve was correlated with the same factors. It increased together with the decrease of mean average temperature, and with the course of daytime as well as the season-site index (calculated as data collected at a given site in a particular year). Contrary to many previous surveys we did not find dependence of the fat score level on individual dominance status, which is probably linked to the abundance of food in catching sites. [ABSTRACT FROM AUTHOR]

Animals respond to approaching predators by taking flight at a distance that optimizes the costs and benefits of such flight. Previous studies have shown that urban populations of birds have shorter flight initiation distances than rural populations of the same species, that this difference is partly explained by differences in the community of predators, and that a longer history of urbanization implies a greater reduction in flight initiation distance in urban populations. The use of birdfeeders may be an additional factor reducing flight initiation distance not only in cities but also elsewhere by among other effects increasing body condition, increasing availability and reliability of food, and hence reducing the relative cost of flight. Here, we tested the prediction that urban habitats and presence of feeders independently accounted for reductions in flight initiation distance using extensive samples from different cities in Poland. We found independent significant effects of urban habitat and presence of feeders on flight initiation distance. These findings suggest that different factors have contributed to the "tameness" of urban birds. [ABSTRACT FROM AUTHOR]

The migratory behaviour of a subpopulation of Whooper Swans breeding in highlands of southern Poland was studied over a 17-year period, from 1997 to 2013. Birds ringed in their breeding area spent winters and moulting periods in the vicinity of their natal sites, and the mean distance between breeding area and wintering sites was only 149.1 ± 11.7 km. Moreover, 57.0% of all winter re-sightings were obtained within 100 km of the study area. There was an increase in winter site fidelity by individual Whooper Swans over their life-time (R2 = 0.09, p = 0.019), reflected by a linear decrease in the distance travelled between two consecutive winters (β = -0.22 ± 0.09). We did not find any association between winter severity and the birds' migratory behaviour, neither in the distance travelled nor the location of winter recoveries. The mean distance between the study area and the moulting site was 142.7 ± 34.6 km and c. 66.6% of ring re-sightings during the moulting period were within 100 km of the study area. During autumn many immature birds were observed close to their parents' breeding territory and this could help them reunite with parents or siblings from other seasons. The apparent reduction of migratory behaviour compared with representatives of northern populations indicates behavioural plasticity in the Whooper Swan, which may facilitate further southward expansions of the species. [ABSTRACT FROM AUTHOR]