The constitutive immune response of Long-nosed bats (Leptonycteris yerbabuenae) does not vary with sex, age, reproductive activity, and migratory habits

Abstract In contrast to birds, the relationship between migration and immune response has been scarcely studied in bats. We examined how the expression of the humoral portion of the constitutive immune response varied in a bat with partial and differential migration: the Lesser longed-nosed bat Leptonycteris yerbabuenae (Phyllostomidae). The Lesser longed-nosed bat is a nectarivorous species in which pregnant females migrate ~ 1,500 km along the Pacific Coast to northern Mexico and southern USA in spring-summer where they have their young, while males and some females remain throughout the year in west-central Mexico. We measured bacterial killing ability (BKA) in plasma of males and females throughout the year and along its geographic distribution in the Pacific coast. We also examined if BKA varied with sex, age category and reproductive activity. We found that BKA values did not vary significantly with reproductive activity, migratory behavior, sex and age. However, big interindividual variation indicates that other intrinsic factors not examined in our study might play a role in bactericidal activity. Our findings and those of previous bat studies indicate that, in contrast to other migratory vertebrates, migratory bats do not regulate the humoral portion of the constitutive immunity during migration.