Agata J. Krawczyk

Local and Landscape-Level Factors Affecting the Density and Distribution of the Feral Pigeon Columba livia var. domestica in an Urban Environment

Abstract. 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 successful 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 Poznań (Western Poland). Three counts were made in summer 2010 in 60 0.5 km × 0.5 km plots (25 ha) distributed 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.

Diet of the American mink Neovison vison in an agricultural landscape in western Poland

Abstract. We studied the diet of the American mink (Neovison vison) in small artificial watercourses located in a farmland area of the valley of the River Barycz in Poland. Rodents, mainly Microtus spp., were the most frequent prey identified, occurring in 88.3 % of all analyzed mink scat. Minks also fed willingly on fish, birds and amphibians, whereas insects, crayfish and reptiles accounted for only a small part of the biomass of food consumed. The food niche breadth of the minks diet was wide, and varied significantly between seasons; in spring and autumn minks preyed mainly on rodents and fish, while the winter and summer diets consisted of a broad characterization of prey items. The proportion of mammals in the diet also decreased significantly during the summer months. These patterns differ from those previously reported in Europe, and demonstrate the plasticity of the mink diet across habitats.

Is baculum size dependent on the condition of males in the polecat Mustela putorius

Abstract. The allometry between baculum size, body size and body condition was studied in the polecat (Mustela putorius). The aim of this study was to investigate whether penis size is dependent on body size. We also calculated the correlation between the size of the baculum and body condition. Our research was based on 107 bacula and skulls from a museum in Slovakia. Individual traits describing the sizes of the body, skull and baculum were moderately to strongly correlated (r between 0.16 and 0.72). Condition was expressed as residuals from a regression analysis of body mass on structural body size. The size of the baculum was correlated with other measurements of body size and with body mass. Analysis revealed that the strongest positive correlation with condition of males was with the size of the baculum. Because the baculum varies between individuals and grows throughout life, the relationship between its size and condition confirms that the baculum may be a suitable indicator of male quality.

Cranial lesions caused by helminth parasites and morphological traits in the European polecat Mustela putorius

SummaryWe investigated the occurrence of cranial lesions caused by helminth parasites in the European polecat Mustela putorius in a museum collection in Slovakia. Selected traits of polecat body morphology and condition were studied with respect to the prevalence of the parasites, and number and extent of helminth-caused lesions in crania of 183 adult polecats. The trematode Troglotrema acutum was identified as the parasitic agent (prevalence 62.6 %), with a strong relationship between number of lesions and extent of cranial damage (surface of cranium). Prevalence of infection did not differ significantly between sexes (68.9 % in females, 51.1 % in males). Females with lesions by Troglotrema acutum have significantly greater braincase breadth than uninfected ones. Among males, infected individuals were generally significantly heavier and larger than uninfected individuals. Therefore, contrary to assumptions, it seems that parasites did not influence significantly body measurements of the animals, and differences are probably rather a result of an intra-sample age variation among infected polecats (older individuals are bigger, more probably infected and damage is more pronounced).

Diet of the Eurasian otter Lutra lutra on small watercourses in Western Poland

No abstract available

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

Abstract 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.

Nests of the harvest mouse (Micromys minutus) as habitat for invertebrates.

Abstract The nests of the harvest mouse (Micromys minutus) from an extensively used farmland in Western Poland were recognized as a place of occurrence of a large group of invertebrates. In total, from 42 nests 6,544 individuals of invertebrates were extracted. The number of invertebrates was positively correlated with mass of mouse nests. There were found arthropods belonging to the following groups: Arachnida: spiders, mites and pseudoscorpions; Entognatha: springtails; Insecta: Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Psocoptera, Siphonaptera and Thysanoptera. The most numerous groups were mites (Acari, 5,800 individuals) and fleas (Siphonaptera, 415 individuals). Among mites Astigmatida, Mesostigmata and Oribatida were identified. One species, Tyrophagus curvipenis (Acari: Astigmatina), was found in Poland for the first time. The study clearly showed that nests of the harvest mouse are often inhabited by invertebrates, and looks like some of them are characteristic to this particular kind of habitat.

Garbage in the diet of carnivores in an agricultural area

Abstract Human food waste is considered to be richer in carbohydrates, lipids and proteins than most natural food supplies; however, it is very well digested in scats. So, as an indication of this kind of food in the diet, we have used each indigestible, anthropogenic origin element found in faeces (e.g., glass, plastic, rubber, etc.). There are few studies discussing the importance of garbage in the diet of mammalian predators living in farmland; definitely, most focus on this issue in urban areas. We studied the contribution of garbage in the diet of raccoon dog (Nyctereutes procyonoides), red fox (Vulpes vulpes), marten (Martes sp.), polecat (Mustela putorius), stoat (Mustela erminea), American mink (Neovison vison) and Eurasian otter (Lutra lutra) in the agricultural areas of western Poland in 2006-2010. In addition, we examined the spatial changes in the diet of red fox and polecat. The largest contribution of garbage was found in scats of raccoon dog (8.8%), red fox (4.8%) and marten (4.3%). The diet of polecat, stoat and Eurasian otter contained 2.5%, 1.7% and 0.2% garbage items respectively. The most frequent item was plastic. Our analysis showed that garbage consumption by red fox and polecat was greater closer to human settlements. The results reveal a continuous gradient in the garbage consumption that corresponds with the degree of synanthropization of particular species.