Biometric Analysis of Pipistrellus (Chiroptera; Vespertilionidae) Species Distributed in Türkiye

Abstract Statistical analyses were conducted on a total of 231 specimens belonging to Pipistrellus species recorded from Türkiye (P. pipistrellus, P. kuhlii, and P. nathusii), based on 40 morphometric characters. Intraspecific comparisons revealed pronounced sexual dimorphism with females morphometric measurements being significantly greater than those of males. Principal Component Analysis (PCA) extracted three principal components with eigenvalues >1, which together explained 66.7% of the total variance. It was determined that numerous characters, such as body length and skull measurements, had high loadings on the first principal component. Similarly, the results of the Discriminant Function Analysis (DFA) indicated a strong morphological differentiation among the species. In the model generated by Discriminant Function Analysis (DFA), 95.7% of the total specimens were correctly classified to species level; 100% of P. pipistrellus, 90.9% of P. kuhlii, and 83.3% of P. nathusii individuals were correctly identified. In the UPGMA dendrogram constructed based on metric characteristics, P. kuhlii and P. nathusii formed a closer cluster, whereas P. pipistrellus was connected to this group at a more basal position. Overall, the present study demonstrates that external and cranial morphometric characters provide reliable discrimination among Pipistrellus species in Türkiye and reveal significant geographic and sexual variation within populations.