Abstract. We tested whether reduced parasite loads might contribute to high post-fire abundances of deer mice (Peromyscus maniculatus). We performed parasite examinations of 54 mice captured in burned forest in the area of Davis Fire (western Montana, USA), and 26 mice captured in nearby unburned forest. Mean abundance of ectoparasites (fleas, ticks, and lice) was lower in burned than in unburned forest. The difference was particularly pronounced for fleas, which were reduced by 70% in burned forest. Endoparasites (i.e., nematodes and cestodes) were unaffected. Mechanisms for the lower mean abundance of fleas in burned areas are not known, but might involve flea mortality in burrows during fire or decreased transmission, survival, or both in the post-fire environment. We propose several hypothetical pathways through which reduced ectoparasite loads could cause an increase in deer mouse abundance, such as improved health status or increased foraging efficiency of mice, both of which could translate into the increased reproduction that has been reported in mice from burned forest. We encourage experimental tests of the ectoparasite release hypothesis of the post-fire increase in deer mouse abundance.

We investigated abundance and prevalence of ticks and fleas infesting urban populations of two species of hedgehogs: the northern white-breasted hedgehog (Erinaceus roumanicus) and the European hedgehog (Erinaceus europaeus). The hedgehogs were captured in the city of Poznań (western Poland) over the period of 4 years. Both species of hedgehogs were infested with the castor bean tick (Ixodes ricinus), the hedgehog tick (Ixodes hexagonus), and the hedgehog flea (Archeopsylla erinacei). The northern white-breasted hedgehog had higher loads of I. ricinus and A. erinacei than the European hedgehog. The abundance and prevalence of I. hexagonus were similar on both species of hosts. Co-infestation with the two species of ticks was more frequent on the northern white-breasted hedgehog than on the European hedgehog. Therefore, these two closely related species of hedgehogs differ in their importance as hosts of arthropod vectors of pathogens in urban areas and might play a different role in the dynamics of zoonotic diseases.

Diet variation of the long-eared owl (Asio otus Linnaeus, 1758) was investigated on the basis of pellets collected in winter season 2007/2008 from a communal roosting site in a municipal cemetery in Rzeszów (a city in south-eastern Poland). We assumed that the proximity of human settlements would affect the diet composition of this predator, resulting in a higher proportion of species associated with urban habitats. Although voles, especially the common vole Microtus arvalis, were still the most important prey, mice constituted approximately 17% of all prey items, with the field mouse Apodemus agrarius being most frequent. Food niche breadth was wider in December than in March. Our results suggest that owls from Rzeszów hunt mostly in open habitats surrounding the city, where they can still capture their basic prey species. Yet, they can broaden their diet with species of murids associated with the mosaic urban and suburban habitats.

Infestation by the nest-dwelling Ixodes hexagonus Leach and the exophilic Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) on the Northern white-breasted hedgehog, Erinaceus roumanicus (Erinaceomorpha: Erinaceidae), was investigated during a 4-year study in residential areas of the city of Poznań, west-central Poland. Of 341 hedgehogs, 303 (88.9%) hosted 10 061 Ixodes spp. ticks encompassing all parasitic life stages (larvae, nymphs, females). Ixodes hexagonus accounted for 73% and I. ricinus for 27% of the collected ticks. Male hedgehogs carried significantly higher tick burdens than females. Analyses of seasonal prevalence and abundance of I. hexagonus revealed relatively stable levels of infestation of all parasitic stages, with a modest summer peak in tick abundance noted only on male hosts. By contrast, I. ricinus females and nymphs peaked in spring and declined steadily thereafter in summer and autumn, whereas the less abundant larvae peaked in summer. This is the first longterm study to evaluate the seasonal dynamics of both tick species on populations of wild hedgehogs inhabiting urban residential areas.