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Stress in paradise: effects of elevated corticosterone on immunity and avian malaria resilience in a Hawaiian passerine


Names, Gabrielle et al. (2021), Stress in paradise: effects of elevated corticosterone on immunity and avian malaria resilience in a Hawaiian passerine, Dryad, Dataset,


Vertebrates confronted with challenging environments often experience an increase in circulating glucocorticoids, which result in morphological, physiological, and behavioral changes that promote survival. However, chronically elevated glucocorticoids can suppress immunity, which may increase susceptibility to disease. Since the introduction of avian malaria to Hawaii a century ago, low elevation populations of Hawaii Amakihi (Chlorodrepanis virens) have undergone strong selection by avian malaria and evolved increased resilience (the ability to recover from infection), while populations at high elevation with few vectors have not undergone selection and remain susceptible. We investigated how experimentally elevated corticosterone affects the ability of high and low elevation male Amakihi to cope with avian malaria by measuring innate immunity, hematocrit, and malaria parasitemia. Corticosterone implants resulted in a decrease in hematocrit in high and low elevation birds but no changes to circulating natural antibodies or leukocytes. Overall, leukocyte count was higher in low than high elevation birds. Malaria infections were detected in a subset of low elevation birds. Infected individuals with corticosterone implants experienced a significant increase in circulating malaria parasites while untreated infected birds did not. Our results suggest that Amakihi innate immunity measured by natural antibodies and leukocytes is not sensitive to changes in corticosterone, and that high circulating corticosterone may reduce the ability of Amakihi to cope with infection via its effects on hematocrit and malaria parasite load. Understanding how glucocorticoids influence a host’s ability to cope with introduced diseases provides new insight into the conservation of animals threatened by novel pathogens.

Usage Notes

The corresponding AMAKIHI_CORT_EXPERIMENT_readme.txt file contains information about each variable included in the dataset, including units, how it was obtained and/or how it was calculated. NA represents data that is not available. Additional information about how data was obtained can be found in the corresponding manuscript.


Achievement Rewards for College Scientists Foundation, Award: ARCS Fellowship

U.S. Department of Agriculture, Award: NE-1834 Program

University of California, Davis, Award: College of Biological Sciences

University of California, Davis, Award: Animal Behavior Graduate Group

University of California, Davis, Award: Office of Graduate Studies

University of California, Davis, Award: Discretionary funds for Thomas P. Hahn

University of California, Davis, Award: Endowed Chair in Physiology to John C. Wingfield