Effects of Age and Captivity on Plasma Chemistry Values of the Egyptian Vulture

• Published in: The Condor (Los Angeles, Calif.) Calif.), 1998-11, Vol.100 (4), p.719-725
• Main Authors: Dobado-Berrios, Pablo M., Tella, José L., Ceballos, Olga, Donázar, José A.
• Format: Article
• Language: English
• Subjects: Age; Age groups; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Aves; Biochemistry; Biological and medical sciences; Bird nesting; Birds of prey; Blood plasma; Calcium; Cholesterols; Fundamental and applied biological sciences. Psychology; Plasma chemistry; Vertebrata; Wild birds
• ISSN: 0010-5422; 1938-5129
• DOI: 10.2307/1369754

Despite the interest in blood chemistry for studying ecological and pathological characteristics of birds, sources of variability such as age and captivity are poorly understood, and reference values usually are obtained from adult captive birds. We determined 15 plasma chemical variables for 164 free-living Egyptian Vultures (Neophron percnopterus) of three age groups (nestlings, subadults, and adults), and for 9 captive adults. Free-living subadults and adults exhibited identical plasma chemistry values. Nestlings had significantly higher levels of creatinine, urate, urea, triglycerides, calcium, phosphorus, and alkaline phosphatase (AP) than both free-living subadults and adults, but lower values of glucose and aspartate aminotransferase (AST). Captive adults had significantly higher levels of total protein, albumin, creatinine, urate, cholesterol, calcium, phosphorus, and AST than free-living adults, which we attribute to differences in diet quality and physical activity. We conclude that future studies should consider age as a major source of variability in avian plasma chemistry, and that results obtained from captivity should be used cautiously to interpret plasma chemistry in the study and rehabilitation of wild birds.