Long‐Term Patterns of Immune Investment by Wild Deer Mice Infected with Sin Nombre Virus

Abstract Immunocompetence of animals fluctuates seasonally, However, there is little consensus on the cause of these fluctuations. Some studies have suggested that these patterns are influenced by changes in reproductive condition, whereas others have suggested that differences result from seasonal variations in energy expenditures. The objective of our study was to examine these contrasting views of immunity by evaluating seasonal patterns of immune response and reproduction in wild populations of deer mice Peromyscus maniculatus exposed to Sin Nombre virus (SNV). Over three consecutive fall (September, October, November) and three consecutive spring (March, April, May) sampling periods, we used titration enzyme‐linked immunosorbent assay (ELISA) to quantify virus‐specific antibody production in 48 deer mice infected with SNV. Levels of reproductive hormones were quantified using ELISA. SNV antibody titers reached their lowest level during November (geometric mean titer \documentclass{aastex} \usepackage...