Relationship between blood lead levels and clinical and physiological factors in Bonelli’s eagle (Villén-Molina et al., 2023).
Lead is a toxic metal that harms animal health, causing mortality at high exposures, physiological and behavioral effects at lower concentrations, and population declines in many species. Scavengers and predators, such as Bonelli's eagle (Aquila fasciata), are particularly vulnerable to lead toxicity due to behavioral and physiological factors, as well as long lifespans that increase cumulative exposure risk. This study analyzed blood lead levels in 54 wild and captive Bonelli's eagles admitted to a recovery center in Spain from May 2014 to July 2015, exploring the relationship between lead and physiological, clinical, and environmental variables. Blood lead was measured using anodic stripping voltammetry. Results showed no detectable lead in 100% of captive eagles (n = 22), while 21.9% of wild eagles (n = 32) had higher lead levels than captive birds (P = 0.020). Among wild eagles, 2 adults had detectable lead, the only eagle sampled in autumn had the highest levels (14.7 μg/dL), and 16.7% of nestlings had detectable lead. There were no differences between sexes. No symptoms of lead intoxication were observed, and no correlation was found between lead levels and hematological or biochemical values. However, subclinical lead exposure in early life could negatively impact neurological and bodily development. Further research is needed to assess whether lead exposure affects the conservation of Bonelli's eagle populations in Spain and elsewhere.