Optimal blood handling for measures of ecological immunology and diet choice

Abstract

In wildlife blood is a much used diagnostic tool to investigate health status and lately also to investigate foraging habitat and trophic position. Under field circumstances however, direct centrifugation of blood isn’t always an option. The aim of this study was to investigate whether or not delayed centrifugation influences the outcome of a range of common ecological assays. We took single blood samples from 9 mallards (Anas platyrhynchos) and 9 Bewick’s swans (Cygnus bewickii), which we centrifuged after 0, 2 and 4 hours, to perform 4 commonly used ecological assays; antibodies to avian influenza, haptoglobin, hemolysis and hemagglutination and stable isotopes of Carbon and Nitrogen. We also aimed to investigate whether the type of fluid component used (sera or plasma) influences the outcome of these assays. Results of the assays showed no significant differences between different time points. Type of fluid component did influence some outcomes. Significant differences were found for hemagglutination and stable isotopes assays. Results of this study suggest that when performing a hemagglutination or stable isotopes assay only one type of fluid component should be used in order to get comparable results.