The First Data on Parasitic Arthropods of the European Bison in the Summer Season with a World Checklist

The European bison (wisent) <i>Bison bonasus</i> is not only the largest terrestrial mammal in Europe, but also an example of the successful restitution and reintroduction of a species that became extinct in nature at the beginning of the 20th century. Even so, it remains a rare, protected species, and one susceptible to varied threats, including diseases. It has a specific parasitofauna, comprising only a few specific species retained with the last hosts in the restitution process, and some others acquired from other ungulates, or via environmental interactions. The current data on parasitic arthropods originated from the winter season, and less frequently, from autumn and early spring. The present study contains the first information on the occurrence of arthropods in the European bison (<i>n =</i> 6) in the summer season, which is the period of their increased activity. Data on the seasonal and populational dynamics of ectoparasites have been verified; specific parasite species (<i>Demodex bisonianus, Bisonicola sedecimdecembrii,</i> and recently described <i>Demodex bialoviensis</i>) and typical parasite species (<i>Chorioptes bovis, Ixodes ricinus</i>) have been recorded. The data refer to the information from other study periods, summarizing and valorizing data on parasitic arthropods in the form of a global checklist. These arthropods occur in European bison frequently (prevalence reaches up to 100%), but they are present in small numbers, and do not present a burden for the host; only sometimes, with high intensity of infection, they cause parasitoses (<i>chorioptosis, mallohagosis</i>). However, as an effect of regular activity, by penetrating the skin of the host, they create gateways for secondary infections, and hematophagous parasites (e.g., ticks) can be vectors of pathogens that can be hazardous, even at low infection levels. The identification of the parasitological threats faced by European bison is not only important from the standpoint of the study object, i.e., the Białowieża Forest European bison population, from which the existing bison population of Europe has been derived, but also the fact that their transfer to different parts of Europe can entail the additional transfer of their parasites.