The Physiological Ecology of White-Nose Syndrome (WNS) in North American Bats

Craig L. Frank

doi:10.5772/intechopen.100369

Abstract

White-nose Syndrome (WNS) is an emergent mycosis in North America that is caused by a severe cutaneous infection with the fungus Pseudogymnoascus destructans (Pd) during hibernation. Pseudogymnoascus destructans (Pd) was first observed in North America at a single site during the winter of 2006–2007 and has since spread to 39 U.S. States and 7 Canadian provinces. This fungus was introduced to North America from Europe, where it is endemic. WNS has thus far been observed to occur only in hibernating bats and has caused the populations of 4 North American bat species to decline by more than 84% within 7 years. Field studies have revealed that 4 other North American bat species are not afflicted with WNS when hibernating in areas where Pd occurs. The physiological and biochemical adaptations that permit some bat species to resist Pd infections are starting to be elucidated but are still poorly understood. A total of 47 different bat species are found in North America, about half of which hibernate during the winter. The potential future effects of WNS on 13 of these hibernating bat species remains to be determined.

Highlights

White-nose Syndrome (WNS) is an emergent mycosis that affects some bat species in North America and is caused by an extensive cutaneous infection with the fungus Pseudogymnoascus destructans (Pd) during hibernation
77% of the bats tested had Pd DNA on their skin, none of them had Pd skin lesions [40]. These findings indicate that M. austroriparius was exposed to propagules of Pd, this fungus did not invade the skin of this bat species during hibernation, WNS does not develop
Four species of North American bats develop severe Pd infections during hibernation which result in WNS, whereas 4 other bat species develop only moderate Pd infections during this period and do display that abnormal torpor patterns and mortality associated with WNS

Summary

Introduction

White-nose Syndrome (WNS) is an emergent mycosis that affects some bat species in North America and is caused by an extensive cutaneous infection with the fungus Pseudogymnoascus destructans (Pd) during hibernation. It was first observed at a single cave in New York State during the winter of 2006–2007, and spread to 5 more caves/mines in New York State during the winter of 2007–2008 [1]. Pseudogymnoascus destructans (Pd) has since spread to 39 U.S States and 7 Canadian provinces, and it was introduced to North America from Europe [2] This fungus grows on the muzzle, wings, and ears of afflicted bats during hibernation, with hyphae penetrating both the epidermis and dermis, consuming hair follicles, sebaceous and sweat glands [3–5]. The mechanism by which an extensive cutaneous infection with Pd leads to WNS and subsequent death during hibernation in some North American bat species is due to the effects of these infections on the hibernation energetics of small bats

Hibernation physiology and white-nose syndrome

The susceptibility to Pseudogymnoascus destructans

Impacts of WNS

Cutaneous lipids

Findings

Conclusions