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Unpredictable resources in seasonal environments may favour innovative individuals that efficiently explore and exploit such resources. We tested the hypothesis that potential intraspecific abundance is a more powerful predictor of detection of a novel food source than interspecific abundance and predation risk. The hypothesis was tested using latency of Great Tits Parus major to find bird-feeders in relation to the abundance of Great Tit and other birds, as well as cats recorded close to novel feeders in urban and rural habitats. Data were collected during winter 2013/2014 in eight cities and nearby rural areas across Poland. Generalized linear models, multimodel inference and hierarchical partitioning showed that the probability that Great Tits used a novel birdfeeder was positively correlated both with the number of Great Tits and all other tits combined in the vicinity of feeders. Latency in feeder usage was negatively related to the number of conspecifics, and it was less strongly negatively related to the number of other tits and the abundance of all other species. The effect of the number of other tits interacted with the environment; the number of tits positively correlated with latency in rural areas, while this relationship was negative in urban areas. Latency until arrival at a feeder was shorter for males than for females. The effect of cats at feeders on bird behaviour was statistically non-significant. Thus, latency until arrival at novel birdfeeders was predicted by local population size and abundance of other bird species, but not mammalian predators, and this relationship may be altered by the environment.

Urbanization is the most dynamic phenomenon worldwide and many species colonize urban environment. Some of these species became so abundant in towns and cities that they are regarded pests, are human health hazard, causes damage to buildings and affect other urban species. Therefore, it is important to understand how such success- ful colonizers utilize urban environment and which factors affects their population densities. One of such species is the most common urban pest bird in the world, the Feral Pigeon Columba livia var. domestica. The aim of this study was to investigate how local food resources and the composition of the urban landscape affects densities of Feral Pigeon in the city of Poznan (Western Poland). Three counts were made in summer 2010 in 60 0.5 km x 0.5 km plots (25 ha) distrib- uted randomly across residential areas in the city. The density of pigeons showed significant spatial autocorrelation, both positive and negative one. The density of pigeons was highest in plots with more tall buildings (over four floors), a large number of human-related food resources, schools, and a high proportion of green space. The density of pigeons was lower in plots with a higher density of streets and located further from the city centre. The solution to the pigeon problem appears to be to plan residential areas with low-rise buildings. To control the number of pigeons in urban areas, we suggest preventing access to local food resources by using litter-bins that are inaccessible to animals. The public should also be educated to behave appropriately towards pigeons and refrain from feeding them intentionally.

The density and behavior of the Mistle Thrush in Niepolomice Forest (southern Poland) and adjacent open areas were studied during winter (December—February) in 1996/97, 1998/99 and 2000/01. Mistle Thrush densities differed significantly from winter to winter, and the abundance of thrushes decreased as the season progressed. Bird density and mistletoe clump density were correlated positively. Birds held territories or congregated in flocks. The latter were sighted in the forest only during winter 1996/97, when the largest density of birds was noted. Flock size decreased progressively during that winter, but at the same time, the number of territorial birds remained stable. This suggests that by the end of the winter 1996/97 some birds from the flocks had begun to hold territories. Flocks were also seen in open areas, and displayed a preference for foraging on pastureland. Each individual territory in the forest consisted of several clumps of mistletoe on a few adjacent trees, which were defended ...