Publication details
ALTERATIONS IN THE HEALTH OF HIBERNATING BATS UNDER PATHOGEN PRESSURE
| Authors | |
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| Year of publication | 2018 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | In underground hibernacula, temperate northern hemisphere bats are exposed to Pseudogymnoascus destructans, the fungal agent of white-nose syndrome. Following the emergence of WNS and recognition of its impact on North American bat populations in 2006, chiropterologists concerned with European bat conservation have asked one essential question: are Palaearctic bat populations and communities threatened by this fungal disease? Pathological and epidemiological data suggest that Palaearctic bats tolerate this infection. There is mounting evidence for virulent skin invasion and pathognomonic lesions in many hibernating Eurasian bat species. As these findings have not been associated with mass mortalities and/or population declines, research should be directed toward examining health consequences in terms of trade-off mechanisms modulating investment into host response to infection. In this study, we were 26 able to show variation in fungal pathogen pressure in relation to hibernaculum-dependent physiological effects of P. destructans infection. We report blood profiles, along with body mass index (BMI), infection intensity and hibernation temperature, in greater mouse-eared bats (Myotis myotis). We sampled three European hibernacula that differ in geomorphology and microclimatic conditions. Skin lesion counts differed between contralateral wings of a bat, suggesting variable exposure to the fungus. Analysis of blood parameters suggests a threshold of c. 300 skin lesions on both wings, combined with poor hibernation conditions, may distinguish healthy bats from those with homeostatic disruption. Physiological effects manifested as mild metabolic acidosis, decreased glucose and peripheral blood eosinophilia which were strongly locality- dependent. Hibernating bats displaying blood homeostasis disruption had 2°C lower body surface temperatures. We conclude that European M. myotis survive P. destructans invasion, despite showing deterioration in health, with infection intensity dependent on hibernation conditions. Disruption in blood homeostasis was observed in bats, even with a low threshold number of skin lesions on both wings. We argue that overwintering in underground hibernacula colonised by this virulent pathogen is associated with health-related costs for European bats. Further research should aim to quantify levels of homeostasis disruption in terms of constrained energy reserves and compatibility for survival. Conservation measures should minimise additional stressors to conserve constrained body reserves of bats during hibernation. |