Dataset on blood parameters including leukocyte profiles of eastern European vespertilionid and rhinolophid bats.

Understanding the immunological profiles of wild bats is crucial for monitoring population health, disease dynamics, and stress responses in changing environments. Here, we present a dataset of 747 blood smear samples collected from 19 European bat species between 2017 and 2023 in Ukraine. For a substantial portion of individuals, red and white blood cell counts were assessed, and for most, differential leukocyte profiles were recorded, including segmented and band neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The dataset is accompanied by rich metadata, which, among other aspects, includes species, sex, age class, life-cycle stage (e.g., hibernation, migration, breeding), capture location, habitat type and others. Most individuals were sampled during the hibernation period in urban environments. The dataset offers a valuable baseline for comparative hematology, eco-immunology, and bat conservation research. By sharing detailed leukocyte profiles and standardized metadata, this dataset facilitates cross-species comparisons, contributes to wildlife health surveillance, and supports future studies on the impacts of environmental stressors and zoonotic risks in European bats.