Innate immune function varies within individuals over time in Dark-eyed Juncos (2013)

Undergraduates: Mary Wurzelmann, Rachel Hanauer (Graduate Student advisor at Indiana University)

Faculty Advisor: Ellen Ketterson
Department: Biology

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Immune function is an important, but costly, physiological activity in all organisms. Resource availability and activities, such as reproduction, vary over time leading to variable investment in immune function. Consistency in immune function over time was tested by performing bacteria killing assays (BKA) of ten individual Dark-eyed Juncos (Junco hyemalis) by measuring them at two time-points. We found no correlation in immune function between the first and second measurements. Additionally, we found no seasonal pattern. These results suggest that using a BKA to measure immune function at one time-point may not provide information to describe that individual¿s immune function in general. Further knowledge of the individual¿s physiological state (i.e. breeding, molting, infection), along with a larger sample size could determine if there is a some pattern underlying the variation that was not elucidated in this experiment.