title: Measuring physiological stress in Australian flying-fox populations.
abstract: Flying-foxes (pteropid bats) are the natural host of Hendra virus, a recently emerged zoonotic virus responsible for mortality or morbidity in horses and humans in Australia since 1994. Previous studies have suggested physiological and ecological risk factors for infection in flying-foxes, including physiological stress. However, little work has been done measuring and interpreting stress hormones in flying-foxes. Over a 12-month period, we collected pooled urine samples from underneath roosting flying-foxes, and urine and blood samples from captured individuals. Urine and plasma samples were assayed for cortisol using a commercially available enzyme immunoassay. We demonstrated a typical post-capture stress response in flying-foxes, established urine specific gravity as an attractive alternative to creatinine to correct urine concentration, and established population-level urinary cortisol ranges (and geometric means) for the four Australian species: Pteropus alecto 0.5-305.1 ng/mL (20.1 ng/mL); Pteropus conspicillatus 0.3-370.9 ng/mL (18.9 ng/mL); Pteropus poliocephalus 0.3-311.3 ng/mL (10.1 ng/mL); Pteropus scapulatus 5.2-205.4 ng/mL (40.7 ng/mL). Geometric means differed significantly except for P. alecto and P. conspicillatus. Our approach is methodologically robust, and has application both as a research or clinical tool for flying-foxes, and for other free-living colonial wildlife species.
authors.affiliation: Queensland Centre for Emerging Infectious Diseases, Biosecurity Queensland, Department of Agriculture, Fisheries and Forestry, Brisbane, QLD, 4108, Australia, lee.mcmichael@uqconnect.edu.au.
authors.forename: Lee A
authors.initials: LA
authors.lastname: McMichael
authors.forename: Daniel
authors.initials: D
authors.lastname: Edson
authors.forename: Hume
authors.initials: H
authors.lastname: Field
mesh_terms: D000818:Animals; D001315:Australia; D002685:Chiroptera / Q000378:metabolism* / Q000652:urine; D006854:Hydrocortisone / Q000652:urine*; D012307:Risk Factors; D013046:Specific Gravity; D013312:Stress, Physiological / Q000502:physiology*; D059349:Urine Specimen Collection
chemical_list: D006854:Hydrocortisone