How should we manage a strong Eurasian Beaver population? A comparison of population trends in Poland and Belarus.

The Eurasian beaver is currently found in at least 32 European countries, with many of these populations being established in the 1960s. In most European countries, the beaver is under protection, however, when the population is strong, the beaver becomes a game species. In Poland, the beaver is partially protected despite the species having a strong population. In this study we aimed to compare the development trends of Eurasian beaver populations in two management regimes, in Poland (protected) and Belarus (hunted), between 2004 and 2019. We compared beaver population trends in both countries, and analyzed the factors that could impact population growth. In Poland, during this period the population increased 3.5 times, while in Belarus it was only 20%. Distinct differences in the rate of population numbers increase were also observed between regions in Poland, but a stable, slight increase similar in all regions in Belarus. Our study did not show that precipitation or the density of this species influenced the rate of population development in Poland. During this period, hunting and wolf density significantly and negatively impacted beaver population growth in Belarus, but in the long-term analysis, hunting had a lower impact on beaver population growth. We concluded that we can expect a further increase in this population in Poland. Long-term hunting at a level of 13,7% (based on the analysis of population dynamics and hunting bags for Belarus) of the annual population seems to be a safe value for the beaver population. Nevertheless more detailed analysis should be carried out in the face of the large differences between regions.

Human Decision-Making as a Key Factor in the Risk of Wolf-Dog Interactions during Outdoor Activities.

As a result of species protection in Poland, wolves now appear in places that are attractive for human recreation, increasing their exposure to dogs. This creates a risk of spontaneous direct interactions between these two canine species. Aggressive interactions between the gray wolf and the domestic dog lead to human-large predator conflicts. This study examined wolf-dog interactions using data collected in an online questionnaire and included questions related to factors that might influence the likelihood of interactions between these canines. One of the most important factors affecting the likelihood of interaction between a dog and a wolf was the distance between the dog and the human. The number of wolves was also important-the more wolves, the more likely they were to interact with dogs. The risk of interaction also significantly increases with decreasing distance to human settlements. There were also statistical differences in terms of the type of outdoor activity being engaged in. Hunting was seven times more likely to result in a wolf-dog interaction than normal walk. We postulate that the choices made by the human (dog control and type of recreation) caring for the dog are an important factor that can reduce the risk of direct contact between dogs and wolves.

Human and the beast-Flight and aggressive responses of European bison to human disturbance.

Large mammals are often a source of conflict, and consequently there has been increasing interest in close encounters with them. Knowledge of wildlife responses to human disturbance is crucial for the management of increasing and expanding populations of large animals. We investigated flight initiation distance (FID) and aggressive responses of the European bison-the largest terrestrial mammal of Europe-to human disturbance in the Bialowieza Forest (NE Poland). When encountered by humans, bison usually flee. Aggression was observed in only 0.4% of approach attempts. Mean FID was 77±46 m and was influenced by habitat, sex, and supplementary feeding intensity. Females showed greater timidity than males, FID was lower in forest than in open habitats, and supplementary feeding caused a drop in FID. In 84.5% of all documented aggression cases, bison attacks were provoked by humans approaching too close to the bison or by deliberate scaring them. Males were more aggressive than females, and attacked mainly during the rut, while females attacked during the winter and calving. Bison attacked in built-up areas significantly more often than expected. The mean critical distance of attacks was 21±2 m. Most attacks took the form of a short chase preceded by warning signs. Goring was observed in 22.7% of all aggression cases and no fatalities were recorded. Our study shows that bison are not dangerous animals and only manifest aggression in response to prolonged disturbance at close ranges. The education of people and recommendations for minimum approach distances should ensure a low rate of disturbance and safety when encountering large mammals.

Habitat preferences of two sparrow species are modified by abundances of other birds in an urban environment.

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 Poznan (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.