Bats are a major global reservoir of alphacoronaviruses (alphaCoVs) and betaCoVs. Attempts to discover the causative agents of COVID-19 and SARS have revealed horseshoe bats (Rhinolophidae) to be the most probable source of the virus. We report the first detection of bat coronaviruses (BtCoVs) in insectivorous bats in Poland and highlight SARS-related coronaviruses found in Rhinolophidae bats. The study included 503 (397 oral swabs and 106 fecal) samples collected from 20 bat species. Genetically diverse BtCoVs (n = 20) of the Alpha- and Betacoronavirus genera were found in fecal samples of two bat species. SARS-related CoVs were in 18 out of 58 lesser horseshoe bat (Rhinolophus hipposideros) samples (31%, 95% CI 20.6–43.8), and alphaCoVs were in 2 out of 55 Daubenton’s bat (Myotis daubentonii) samples (3.6%, 95% CI 0.6–12.3). The overall BtCoV prevalence was 4.0% (95% CI 2.6–6.1). High identity was determined for BtCoVs isolated from European M. daubentonii and R. hipposideros bats. The detection of SARS-related and alphaCoVs in Polish bats with high phylogenetic relatedness to reference BtCoVs isolated in different European countries but from the same species confirms their high host restriction. Our data elucidate the molecular epidemiology, prevalence, and geographic distribution of coronaviruses and particularly SARS-related types in the bat population.

Białowieża Primeval Forest (BPF, approx. 1700 km²) is an important forest area in Europe from the point of view of the protection of natural diversity. BPF is covered with old mixed tree stands of mostly natural origin. Norway spruce is a tree species in BPF and covers approx. 27% of its area. Between 2012 and 2017 a large outbreak of the bark beetle Ips typographus (Linnaeus, 1758) took place in the forest, which transformed the stands and left many dead standing trees. At that time salvage logging had begun but was stopped due to protests by scientists and activists and for legal reasons. As a result of research conducted using a radiotelemetry method in 2020, we found that the Western barbastelle bat Barbastella barbastellus (Schreber, 1774) chooses nursery roosts in dead Norway spruce trees, showing ecological plasticity by colonizing a newly available resource. Based on this, we found that the Western barbastelle has a preference for a type of roost rather than a tree species. Insect outbreaks in forests of primary, natural, or semi-natural origin are one of the natural factors that shape the habitat. Removal of dead standing trees disrupts these processes, and in this particular case results in the disappearance of a newly appeared ecological niche.

Bats are the second most numerous group of mammals in the world, after rodents. About 1,400 species have been described, of which 27 occur in Poland. All bats found in Poland are subject to strict species protection. Therefore, activities related to detention, including the treatment of injured, ill, or malnourished individuals, require appropriate permits. Caring for these mammals also requires knowledge of the biology and ecology of native species. Surveys were conducted in Polish wildlife rehabilitation centres, as well as among bat workers. The described interventions took place from September 2015 to September 2017. During this period, a total of 962 bats were taken under care. Most of the specimens required feeding and/or watering (645 specimens), 137 specimens suffered from injuries and/or diseases, 97 specimens were given emergency care, 77 specimens were taken from the environment without justified cause, and six specimens were born in captivity. Most of the interventions (760 individuals) resulted in the bats being released, 84 individuals remained under treatment or rehabilitation, 69 died, and a further 49 were euthanized. Statistical analysis showed a difference in the reasons for intervention and the intervention outcome between the care provided by rehabilitation centres and bat workers.