Hematology of the long-distance migrant red knot (Calidris canutus rufa) in three sites of the northward migration

D'AMICO, VERÓNICA L.; BERTELLOTTI M.; BAKER A. J.

Barcelona, España

Congreso; 31st Annual Meeting of the Waterbird Society; 2007

Plasmatical parameters related to the body condition were analyzed for long-distance migrants Red knots, Calidris canutus rufa in three sites during the north migration to the arctic breeding grounds: the wintering area, Río Grande, Argentina (67,5º W, 54º S) in November 2005,  the first stopover site San Antonio Oeste, Argentina (64,55º W, 40,45º S) in March 2006, and the last stopover site, Delaware Bay, USA (75.1º W, 39.1º N) in May 2006. Birds were captured with cannon net and blood samples were collected from the brachial vein using microcapillary tubes. Biochemical analyses were performed using colorimetric and enzymatic methods. Body index was obtained as ratio of weight and bill length. Total proteins, albumin, globulin, cholesterol, triglycerids and body index showed significant differences between sites (K-W test, P<0.05). Also, glucose showed differences (M-W test, P<0.05). Total proteins, albumin, globulins and cholesterol were positively correlated with body index (Spearman, P<0.05). Concentrations of total protein, globulins, cholesterol and triglycerids were higher in both stopover sites where birds accumulate reserves for onward migration. Glucose, was higher in the wintering site and it is consumed very fast, almost all is used to energetic storage for the migratory flight. Body index was higher in Delaware Bay where birds have to fuel up for the breeding period. These values are the first report of plasmatical parameters for free-living Red knots in the north flyway and they can serve as a benchmark to evaluate nutritional and health condition of birds in future.