Over the last 20 years the Cheetah Research Project (CRP) has built a solid, reliable and powerful infrastructure for various questions of wildlife research. This includes an extensive network of partners within Namibia, the development of modern wildlife traps and a fully equipped field laboratory to conduct various analyses regarding the immune system, identification of pathogens or determination of diet composition. In 2016, the CRP hosted fellow scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) for the investigation of immune marker variance in a native population of Egyptian geese in Namibia. The birds were successfully live trapped using the CRP’s cheetah traps and expertise. Blood samples for immunological assays and serology were taken, centrifuged and transferred with an uninterrupted cooling chain to the Leibniz-IZW where they were analysed and compared to similar samples from the invasive population in Germany. We are proud that the CRP regularly facilitates research of fellow colleagues of the lively and inspiring research cosmos that is the Leibniz-IZW and that we collaborated with the Namibia Bird Club for this study.
Leibniz-IZW scientists Hanna Prüter and Gábor Á. Czirják capturing Egypian geese at the CRP field facilities.
Abstract of the paper “Increased immune marker variance in a population of invasive birds”: 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.
Egyptian goose (Alopochen aegyptiacus) By Carlos Delgado - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=44418830
Publication: Prüter H, Franz M, Twietmeyer S, Böhm N, Middendorff G, Portas R, Melzheimer J, Kolberg H, von Samson-Himmelstjerna G, Greenwood AD, Lüschow D, Mühldorfer K, Czirják GA (2020): Increased immune marker variance in a population of invasive birds. Scientific Reports, volume 10, article number: 21764 (2020). https://www.nature.com/articles/s41598-020-78427-7