It is well known that agricultural intensification has caused severe population declines among bird species which use farmland for breeding and overwintering, while migrating bird species may benefit from intensive farming, but in turn damage crops. Knowledge of the habitat selection of migrating birds is important from both a conservation and agro-economic point of view. We investigated the habitat preferences of three common migrating goose species: White-fronted Goose Anser albifrons, Bean Goose A. fabalis and Greylag Goose A. anser during the autumn of 2009 in western Poland. A total of 24 flocks of these species were identified. Geese preferred large, elevated fields that were remote from forests and human settlements but in close proximity to a lake. Geese selected maize stubbles and avoided winter cereals. They selected sites in landscapes with a lower diversity of crops. Flock size was negatively correlated with the proportion of pastures in the landscape, but it increased with field size, distance to forest and distance to town. Our results are in contrast with the paradigm that less intensive farmland positively influences habitat use by birds during foraging. We advise the delayed ploughing of stubbles with the aim of creating appropriate foraging habitats for geese and minimizing damage to cereal crops.

The knowledge and conservation of diminishing valuable habitats in agricultural landscapes are of key importance in saving declining farmland biodiversity. One of these habitats is the traditional orchard whose role in supporting birds is still poorly known, especially in winter. We counted birds in 106 orchards differing in management intensity (abandoned, traditional, and intensive) during December 2009 and January 2010 in Wielkopolska, western Poland and measured site characteristics and composition of surrounding landscapes for every orchard. Old abandoned and traditionally managed orchards had significantly higher bird species richness than intensive ones. Irrespective of orchard type, bird species richness as well as density were positively influenced by the cover of unmown herb layer in orchards and tree diversity. Tree and fruit densities positively affected bird species richness and density mainly in abandoned orchards while in other orchard types the effect of these variables was less pronounced. Land cover diversity in a landscape had a positive effect on species richness and density mostly in abandoned orchards and we believe that this effect reflects the elevated utilization of such orchards by birds from the surrounding landscape. Thus, abandoned, as well as traditionally managed orchards seems to be especially important habitats that offer food source and refuge for wintering birds and should be protected. We propose to diversify fruit production by planting various tree species, leaving part of the herb layer unmown and several trees unharvested in intensive orchards in order to improve suitability of modern orchards for birds.

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Roosting site selection by geese is a key factor for survival during migration and wintering. Birds should select sites that minimize thermoregulation demands and predation risk, and maximize foraging efficiency. We used data on the spatial location of geese roosting sites in Poland to compare landscape features and the conservation status of roosting and non-roosting sites at different scales ranging from 5 to 50 km. Logistic regression revealed that the sites selected by geese had larger waterbody size than non-selected sites, and surrounded by a smaller coverage of woodland at the scale of 50 km. They also were more often Natura 2000 sites. The most important factors positively affecting the abundance of geese were the size of waterbody and low coverage of artificial area (mostly urban) within a 50 km radius. Several further factors also influenced the roosting site selection. Regardless to the scale a large coverage of farmland (mostly rapeseed) positively affected roosting geese whereas forest coverage had a negative effect. Spatial hierarchical clustering analysis showed that the roosting sites were densely located in regions characterized by the most intensive agriculture. Farming intensity therefore seems to increase the abundance of geese, and consequently, to increase a possible conflict between goose conservation and food production. To alleviate the conflicts we delineated areas that may be most affected and where the conservation measures should be implemented first. As geese respond to environmental factors at different spatial scales this scale-dependency should be included in the conservation and management of goose populations.

Every species has certain habitat requirements, which may be altered by interactions with other co-occurring species. These interactions are mostly ignored in predictive models trying to identify key habitat variables correlated with species population abundance/occurrence. We investigated how the structure of the urban landscape, food resources, potential competitors, predators, and interaction between these factors influence the abundance of house sparrow Passer domesticus and the tree sparrow P. montanus in sixty 25 ha plots distributed randomly across residential areas of the city of Poznań (Poland). The abundance of the house sparrow was positively correlated with the abundance of pigeons but negatively correlated with human-related food resources. There were significant interaction terms between abundances of other urban species and habitat variables in statistical models. For example, the abundance of house sparrow was negatively correlated with the abundance of corvids and tree sparrows but only when food resources were low. The abundance of tree sparrows positively correlated with density of streets and the distance from the city center. The abundance of this species positively correlated with the abundance of corvids when food resources were low but negatively correlated at low covers of green area. Our study indicates that associations between food resources, habitat covers, and the relative abundance of two sparrow species are altered by the abundance of other urban species. Competition, niche separation and social facilitation may be responsible for these interactive effects. Thus, biotic interactions should be included not only as an additive effect but also as an interaction term between abundance and habitat variables in statistical models predicting species abundance and occurrence.

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