Dietary effects on innate immune state among individuals of Diuca diuca

Immune function shows intraspecific variation, with diet being a crucial factor that could explain such variation. Using the isotopic signature δ¹⁵N and C:N ratio, we evaluated the relationship between immune state (hemolysis and hemagglutination score) and natural variation in resource use in individuals of the species Diuca diuca. We found that some components of the immune state, specifically the hemagglutination score, correlated positively and significantly with the incorporation of animal material (high levels of δ¹⁵N), while the hemolysis score correlated positively with the C:N ratio. In this sense, we conclude that individuals of Diuca Finches that fed with a variety of prey exhibit a better immune state.