Study of the helminth fauna in booted eagle (Hieraaetus pennatus) in the south of Spain

Studies on the helminth fauna of the booted eagle ( Hieraaetus pennatus ) remain limited, with only four parasitic species previously described and a single study reporting prevalence data. Accordingly, the objective of the present study was to characterize the helminth community parasitizing H. pennatus individuals from southern Spain (Andalusia). Between 2008 and 2023, a total of 28 specimens were examined. Recovered parasites were taxonomically identified, and prevalence, intensity, and mean abundance were calculated. The overall parasitism rate was 67.8%, comprising nematodes (53.5%), trematodes (21.4%), cestodes (25.0%), and acantocephalans (7.1%). Twelve genera of helminth were detected, eight of which are reported for the first time in this host. Among the eight helminths’ genera identified, six were fully identified and newly documented in H. pennatus . Physaloptera alata was the most prevalent species (25.0%), followed by Capillaria tenuissima (17.9%). Other detected taxa with lower prevalence (7.1%) included Porrocaecum angusticolle , Platynosomum illiciens , Strigea falconis , Matabelea fuhrmanni , and Centrorhynchus buteonis . The helminth community exhibited low diversity, with species richness of 1.6 (95% CI: 1.2-1.9), total abundance of 7.1 (95% CI:3.5-12.7), a Brillouin diversity index of 0.3 (95% CI: 0.09-0.35), and a Berger-Parker dominance index of 0.84 (95% CI: 0.74-0.95). These metrics reflect a depauperate parasitic community, with P. alata and C. tenuissima as dominant species that do not achieve the status of core taxa. This study represents the largest parasitological survey of helminths infecting booted eagles in Europe and the first conducted in southern Spain.