The threat that domestic cats pose to wildlife has gained increased recognition by researchers and conservationists, and in this study, we investigated the seasonal variability and the effects of environment type (rural vs. urban) on the prey composition of free-ranging house cats in Poland. We analysed the variability in 307 monthly prey samples of different prey items killed by cats and brought to their owners (i.e., prey brought home by cats living in one home in one month) between 2002 and 2007 at 26 rural and urban sites. The variability in prey composition over time was analysed using additive models and canonical correspondence analysis. In total, we recorded 1348 prey items. Rodents were the most common prey in both environments, but shrews and reptiles were killed by cats more often in the rural environment while birds (mainly sparrows and pigeons) were more common in the urban environment. Additionally, prey composition changed seasonally. The pooled number of vertebrates killed by cats was largest in September and lowest in January, and rodents were killed most often in September, shrews and birds in June, and reptiles in April. The seasonal variation in the prey composition of cats was relatively high in the rural environment and more stable in the urban environment. Prey composition seemed to follow temporal and spatial variations in prey availability, thus confirming a facultative feeding strategy in free-ranging house cats.

Examples of interspecific interactions have been described for mammalian predators, but less is known regarding disturbances of native predator guilds by domestic predators. We investigated intraguild interactions among three opportunistic predators (dog ( Canis lupus familiaris L., 1758), cat ( Felis catus L., 1758), and red fox ( Vulpes vulpes (L., 1758)) co-occurring in the extensive farmlands of central Poland. Their space use was monitored using tracking stations distributed in field and forest plots along a distance gradient from buildings and analyzed using the occupancy-modeling framework. For all three species occupancy decreased with increased distance from buildings, although for the fox the pattern was relatively weak. The occurrence of cats at the stations was higher in the forest than in the field; for fox and dog, there was a strong variation between study plots. For all three predators, the probability of detection was higher during the night than during the day and varied between the seasons; however, the exact patterns were species-specific. The presence of one predator was also linked to the presence of the other two species—generally, a given species was detected more frequently in the absence of the other two species. We recorded spatiotemporal niche segregation among the three species. We conclude that interspecific antagonistic interactions and differences in foraging ecology are the main drivers shaping co-occurrence of the three species in the agriculture landscape.

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Red squirrels (Sciurus vulgaris) successfully inhabit cities, utilize urban structures and adapt to alternative food sources such as supplemental anthropogenic feeding. Here, we compared two urban populations: one in a busy park and another in an urban forest. The first was expected to be highly influenced by human presence (and food delivered by park visitors), and the other was hypothesized to be unaffected by human disturbance. Our goal was to determine how they differed in terms of spatial organization, behaviour and food habits. The populations were monitored using radio‐tagging. Squirrels in the park had significantly smaller home ranges than those in the forest. In both areas, they had multi‐nuclear home ranges, but the number of nuclei in the park was lower than that in the forest. This probably reflects more homogenous food availability (i.e. supplemental feeding). Squirrels in the park spent more time on the ground throughout the year than squirrels in the forest. This was probably related to their dependence on human‐supplemented food. Park squirrels often interacted with park visitors throughout the year – this involved approaching and taking food in 60% of the interactions. Hazelnuts and walnuts (food most often supplied by humans) dominated the diet of park squirrels, whereas pine and hornbeam seeds dominated the diet of forest squirrels. Overall, the study showed how living in the park with year‐round access to supplementary food changed the spatial organization and behaviour of red squirrels compared to that of the population from the urban forest reserve.

Studies of cat trophic behaviour can be based on collections of the prey brought home or the prey eaten by cats (i.e. analyses of scat/gut contents). Both methods involve biases with respect to palatability, prey size and assessment of hunting rates. Furthermore, these methods are often used on different groups of cats (i.e. house‐based vs. feral), thus results are difficult to compare. In the present study, cats from the same area (rural areas in central Poland) were studied by both methods: prey brought home and prey eaten (scat and gut analyses). Both methods identified mammals as the most frequent prey (followed by birds). However, differences occurred in the percentages of the four main vertebrate groups brought home versus eaten by cats: reptiles tended to be brought home, whereas amphibians tended to be eaten. No such difference was found for birds and mammals. Second, the relative proportions of presumably more palatable and presumably less palatable prey differed. The relative proportions of mice and voles (the latter eaten more frequently) and the relative proportions of soricomorphs and rodents (the latter eaten more frequently) were different. Finally, small prey items (i.e. invertebrates) were recorded incompletely for the brought‐home method. Overall, the prey‐brought‐home method underrepresented small prey and underestimated the predation rate for cats, whereas the prey‐eaten method was less likely to record unpalatable prey. We thus recommend to combine these two methods to obtain fuller and truer assessment of cat predation.