Biochemical parameters in free-living Olrog´s Gull (Larus atlanticus)

The determination of blood parameters in free-living animals is fundamental for the evaluation of the health status of their populations. The study of these parameters can provide important information in the promotion of management measures for threatened species. The Olrog’s Gull is endemic to the Atlantic coast of southern South America and one of the few globally threatened species of Larus, being listed as near threatened. Although several studies have evaluated the ecology and foraging behavior of this species, no studies about the blood parameters have been undertaken. As part of an long-term study on the ecology and conservation of the Olrog´s Gull, blood samples were collected to establish baseline values for biochemical parameters (glucose, urea, uric acid, total protein, albumin: globulin ratio, cholesterol, triglycerides, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, calcium, phosphorus). The individuals were captured during May-August 2016 at the Mar Chiquita Reserve (37°46′ S, 57°27′ W). All birds appeared to be in good body condition and no abnormalities were noted during physical examination. In general terms, we did not observe differences in the parameters studied as a function of the age classes. Body mass, total protein and calcium were higher in males than females. This study presents the first values of biochemical parameters for this species and contributes to our knowledge of its overall health status during the non-breeding season.