This paper examines 167 records of 14 bat species killed on roads in Poland. Regional differences in the species composition of road traffic accident records resulted from differences in the structure of local bat faunas. Young-of-the-year individuals (ind.) were killed significantly more often than adults. The highest mortality occurred in August and in the first half of September during intense dispersal of young bats. The highest incidence of road casualties was noted in places where roads crossed bat flyways, especially at junctions with forest edges and tree alleys. The rate of mortality depended on the habitat. It was highest where roads approached tree stands (up to 6.8 ind./km/year) or crossed a forest (2.7 ind./km/year) and lowest within densely built-up areas of Warsaw (0.3 ind./km/year). The mean was 1.5 ind./km/year in an 8-km section of a road near Warsaw. Road mortality depended on the hunting strategy of bats, in particular on the height of their flight. Road casualties were frequent for the low-flying gleaner, Myotis daubentonii (39.5% of the records), but rare for the high-flying aerial hawker, Nyctalus noctula (1.9%).

A year-round study was conducted on a 16.6-km road section crossing Kampinos National Park near Warsaw (central Poland). We found 61 road-killed bats belonging to seven species. The most abundant were: Nyctalus noctula, Plecotus auritus, and Barbastella barbastellus. Bats were found between the middle of April and the end of October with peaks in July/August and October. The density of bat casualties differed slightly in various habitats surrounding the road—lower values than expected were found only for windbreaks and bushes. The prediction that low-flying species are killed more frequently was not confirmed—the most abundant N. noctula usually flies at heights over 10 m above the ground. N. noctula, Myotis nattereri, and Pipistrellus nathusii were killed more frequently while Eptesicus serotinus less frequently than could be expected from the frequency with which they were captured in mist-nets on forest lanes.

Differences in the frequency with which bats feature in the diet of tawny owls Strix aluco were studied, as these relate to types of habitat occupied (i.e. urban park, suburban forest, non‐urban land outside forest, and non‐urban forest as divided into forest edge or forest interior). The pellets collected at 152 sites in central and north‐eastern Poland in the years 1990–2008 comprised 17,908 items of vertebrate prey, of which 115 (0.64%) were bats. Tawny owls caught 11 bat species, most frequently Nyctalus noctula, Plecotus auritus and Eptesicus serotinus. The analysis revealed habitat‐related differences to the proportions of all tawny owl prey items accounted for by bats, being the highest in urban habitats (2.0%) and suburban forests (0.8%), and the lowest in forest interiors (0.1%). Bat frequency in the diet of tawny owls correlated negatively with that of other mammals pooled together with amphibians. Myotis nattereri and “aerial hawkers” (vs. “gleaners”) were taken significantly more often in habitats associated with a large city (parks and suburban forests), and P. auritus in non‐urban habitats.

The raccoon Procyon lotor is an invasive species inhabiting Europe and its impact on local populations, particularly on endangered species, is not well known. The aim of the study was to determine whether raccoons pose a threat to bats wintering in the Nietoperek nature reserve, one of the largest hibernation sites in Central Europe. In the winter of 2016–2017, 67 raccoon scats were collected in one of the main underground corridors in the reserve. It was confirmed, with the use of molecular methods, that the scats belonged to raccoons. Raccoon prey was identified based on the features of skulls, jaws or hair found in the scats. Analysis of the determinable remains indicates that bats (including Daubenton’s bat/Natterer’s bat/Brandt’s bat M. daubentonii/nattereri/brandtii, Natterer’s bat Myotis nattereri, greater mouse-eared bat Myotis myotis, brown long-eared bat Plecotus auritus) made up the largest percentage of raccoon diet (96%). Remains of other mammal species, lizards Lacerta spp., plant materials and anthropogenic food were also identified in raccoon scats. The results of the research indicate that predation by raccoons can constitute a significant factor in the increasing mortality of bats wintering in Nietoperek.