Hematology and Plasma Biochemistry of Wild Spectacled Flying Foxes (Pteropus conspicillatus) in Australia

Abstract

The spectacled flying fox (Pteropus conspicillatus) is listed as vulnerable to extinction in Australia. The species' restricted population is in decline, putatively attributed to decreasing habitat, climatic extremes, anthropogenic activities, and more recently, mass mortality events associated with tick paralysis and neonatal cleft palate syndrome. Knowledge of fundamental physiologic parameters of the species is limited. To address this knowledge gap, we sampled 50 wild-caught adult spectacled flying foxes in June (winter) in Far North Queensland, Australia. Hematologic and plasma biochemistry reference ranges were established, and a suite of urine biochemistry analytes were measured. Analyte values were compared within spectacled flying fox sex cohorts and between the spectacled flying fox and the paraphyletic black flying fox (Pteropus alecto). Significant differences in multiple analytes (including erythrocyte, leucocyte, plasma, and urine biochemistry) were found between spectacled flying fox sex cohorts. The majority of spectacled flying fox analyte values did not differ significantly from black flying fox values. Of those analytes that differed between species (erythrocyte, platelet, eosinophil, liver enzyme, and triglyceride levels), the majority were plausibly explained by intraerythrocyte parasite burden and food resource type. Our findings provide baseline data essential to measure and meaningfully interpret flying fox population health in ecologic, conservation, and epidemiologic contexts.