Domestication Effects on Immune Response: Comparison of Phytohemagglutinin‐Induced Skin Swelling in Domesticated Bengalese Finch and Its Wild Ancestor, White‐Rumped Munia

ABSTRACT The domesticated Bengalese finch ( Lonchura striata var. domestica ) exhibits more complex songs and altered physiological and behavioral traits compared with its wild ancestor, the white‐rumped munia ( Lonchura striata ). Domestication has been suggested to be associated with immune function, and domestication‐related physiological and behavioral traits are thought to co‐vary with immune traits. Comparing immune responses between the Bengalese finch and the white‐rumped munia provides an opportunity to explore phenotypic differences associated with domestication. In this study, we assessed cell‐mediated immune responses using phytohemagglutinin (PHA), a lectin that induces local skin swelling. This PHA‐induced swelling (PHA response) is a widely used index of T cell‐mediated immunity in ecological immunology. Our results showed that the Bengalese finch exhibited a significantly greater PHA response than the white‐rumped munia, indicating higher cell‐mediated immune activity in the domesticated birds. These findings suggest a possible association between immune function and domestication‐related phenotypic changes, including fearfulness, song complexity, and stress responsiveness.