115 Views 3 Downloads
Immunity and parasites have been linked to the success of invasive
species. Especially lower parasite burden in invasive populations has been
suggested to enable a general downregulation of immune investment (Enemy
Release and Evolution of Increased Competitive Ability Hypotheses).
Simultaneously, keeping high immune competence towards potentially newly
acquired parasites in the invasive range is essential to allow population
growth. To investigate the variation of immune effectors of invasive
species, we compared the mean and variance of multiple immune effectors in
the context of parasite prevalence in an invasive and a native Egyptian
goose (Alopochen aegyptiacus) population. Three of ten immune effectors
measured showed higher variance in the invasive population. Mean levels
were higher in the invasive population for three effectors but lower for
eosinophil granulocytes. Parasite prevalence depended on the parasite taxa
investigated. We suggest that variation of specific immune effectors,
which may be important for invasion success, may lead to higher variance
and enable invasive species to reduce the overall physiological cost of
immunity while maintaining the ability to efficiently defend against novel
parasites encountered.
115 views reported since publication in 2020.