Suchergebnisse

Pseudogymnoascus destructans is an ascomycetous fungus responsible for the disease dubbed white-nose syndrome (WNS) and massive mortalities of cave-dwelling bats. The fungus infects bat epidermal tissue, causing damage to integumentary cells and pilosebaceous units. Differences in epidermal lipid composition caused by P. destructans infection could have drastic consequences for a variety of physiological functions, including innate immune efficiency and water retention. While bat surface lipid and stratum corneum lipid composition have been described, the differences in epidermal lipid content between healthy tissue and P. destructans–infected tissue have not been documented. In this study, we analyzed the effect of wing damage from P. destructans infection on the epidermal polar lipid composition (glycerophospholipids [GPs] and sphingomyelin) of little brown bats (Myotis lucifugus). We hypothesized that infection would lead to lower levels of total lipid or higher oxidized lipid product proportions. Polar lipids from three damaged and three healthy wing samples were profiled by electrospray ionization tandem mass spectrometry. We found lower total broad lipid levels in damaged tissue, specifically etherlinked phospholipids, lysophospholipids, phosphatidylcholine, and phosphatidylethanolamine. Thirteen individual GP species from four broad GP classes were present in higher amounts in healthy tissue. Six unsaturated GP species were absent in damaged tissue. Our results confirm that P. destructans infection leads to altered lipid profiles. Clinical signs of WNS may include lower lipid levels and lower proportions of unsaturated lipids due to cellular and glandular damage. ; "This project was funded by an Arkansas State Wildlife Grant, the National Speleological Society, the Graduate Program of Environmental Science at Arkansas State University (ASU), the US Fish and Wildlife Service, a Government of Canada Postdoctoral Fellowship (PDRF), the Natural Sciences and Engineering Research Council (NSERC; Canada), the German Academic Exchange Service (DAAD), and the Center for North American Bat Research and Conservation at Indiana State University. Instrument acquisition and method development at KLRC was supported by NSF grants MCB 0455318, MCB 0920663, and DBI 0521587; Kansas Networks of Biomedical Research Excellence (INBRE; National Institutes of Health grant P20 RR16475 from the INBRE program of the National Center for Research Resources); National Science Foundation Experimental Program to Stimulate Competitive Research grant EPS-0236913; Kansas Technology Enterprise Corporation; and Kansas State University." ; https://www.journals.uchicago.edu/doi/10.1086/681931

White-nose syndrome (WNS) has caused dramatic declines of several cave-hibernating bat species in North America since 2006, which has increased the activity of non-susceptible species in some geographic areas or during times of night formerly occupied by susceptible species-indicative of disease-mediated competitive release (DMCR). Yet, this pattern has not been evaluated across multiple bat assemblages simultaneously or across multiple years since WNS onset. We evaluated whether WNS altered spatial and temporal niche partitioning in bat assemblages at four locations in the eastern United States using long-term datasets of bat acoustic activity collected before and after WNS arrival. Activity of WNS-susceptible bat species decreased by 79-98% from pre-WNS levels across the four study locations, but only one of our four study sites provided strong evidence supporting the DMCR hypothesis in bats post-WNS. These results suggest that DMCR is likely dependent on the relative difference in activity by susceptible and non-susceptible species groups pre-WNS and the relative decline of susceptible species post-WNS allowing for competitive release, as well as the amount of time that had elapsed post-WNS. Our findings challenge the generality of WNS-mediated competitive release between susceptible and non-susceptible species and further highlight declining activity of some non-susceptible species, especially Lasiurus borealis, across three of four locations in the eastern United States. These results underscore the broader need for conservation efforts to address the multiple potential interacting drivers of bat declines on both WNS-susceptible and non-susceptible species. ; U.S. Fish and Wildlife Service White-nose Syndrome Grant Program [4500900398]; Fort Drum through the U.S. Army Corps of Engineers' Cooperative Agreement [W9126G-15-2-0005]; Southern Appalachian Cooperative Ecosystems Study Unit Program ; Published version ; Funding for this study was provided by the U.S. Fish and Wildlife Service White-nose Syndrome Grant Program Agreement #4500900398 to the U.S. Geological Survey South Carolina Cooperative Fish and Wildlife Research Unit and the Virginia Cooperative Fish and Wildlife Research Unit. Additional support came from Fort Drum through the U.S. Army Corps of Engineers' Cooperative Agreement W9126G-15-2-0005 and the Southern Appalachian Cooperative Ecosystems Study Unit Program to the Virginia Tech Department of Fish and Wildlife Conservation. We thank P. White and the Wisconsin DNR for providing long-term acoustic data from Wisconsin. Fieldwork assistance was provided by L. Coleman, T. Nocera, J. Rodrigue, A. Silvis, and C. Whitman. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. All authors conceived the ideas and designed methodology; Robin Russell, Michael St. Germain, Chris Dobony, Mark Ford, Susan Loeb, and David Jachowski collected the data; Sara Bombaci and Robin Russell analyzed the data; Sara Bombaci and David Jachowski led the writing of the manuscript. All authors contributed critically to the drafts and gave final approval for publication.

Abstract ContextPseudogymnoascus destructans is the fungus responsible for white-nose syndrome (WNS), which has killed millions of hibernating bats in North America, but also occurs in bats in Europe and China without causing large-scale population effects. This is likely to be due to differences in species susceptibility and behaviour, and environmental factors, such as temperature and humidity. Pseudogymnoascus destructans is currently believed to be absent from Australia. AimsTo ascertain the level of risk that white-nose syndrome poses for Australian bats. Methods This risk analysis examines the likelihood that P. destructans enters Australia, the likelihood of the fungus coming in contact with native bats on successful entry, and the potential consequences should this occur. Key results This risk assessment concluded that it is very likely to almost certain that P. destructans will enter Australia, and it is likely that bats will be exposed to the fungus over the next 10 years. Eight cave-dwelling bat species from southern Australia are the ones most likely to be affected. ConclusionsThe risk was assessed as medium for the critically endangered southern bent-winged bat (Miniopterus orianae bassanii), because any increase in mortality could affect its long-term survival. The risk to other species was deemed to range from low to very low, owing to their wider distribution, which extends beyond the P. destructans risk zone. Implications Although Australia's milder climate may preclude the large mortality events seen in North America, the fungus could still significantly affect Australian bat populations, particularly bent-winged bats. Active surveillance is required to confirm Australia's continuing WNS-free status, and to detect the presence of P. destructans should it enter the country. Although White-nose Syndrome Response Guidelines have been developed by Wildlife Health Australia to assist response agencies in the event of an incursion of WNS into bats in Australia, these guidelines would be strengthened by further research to characterise Australian cave temperatures and hibernating bat biology, such as length of torpor bouts and movement over winter. Risk-mitigation strategies should focus on education programs that target cavers, show-cave managers and tourists, particularly those who have visited regions where WNS is known to occur.

We assessed the sampling effort requirements for detecting the presence of extant bat species following the impact of white-nose syndrome in the mid-Atlantic region of the United States. We acoustically sampled 27,796 nights across 846 sites between 15 May and 15 August 2016-2018 within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. We developed simulations to determine the number of sites required to document bat species when each site was sampled different numbers of nights. We examined these simulations with respect to land cover, physiographic region, and time period. We generally found that sampling a greater number of sample sites within a survey area increased detection more than increasing the number of nights at individual sampling sites. The sampling effort required to detect a given bat species varied by species, as well as land-cover type and physiographic region. Our results suggest that land managers and researchers should use caution in using protocols developed with other objectives, e.g., the U.S. Fish and Wildlife Service endangered and threatened bat species and the North American Bat monitoring programs? methods are designed relative to their specific needs. Unfortunately, neither protocol may be adequate for accurately detecting bat communities within all mid-Atlantic areas. ; National Park Service National Capital and Northeast Region; U.S. Fish and Wildlife Service Virginia Ecological Services Office; U.S. Army Installation Command; National Aeronautics and Space Administration Wallops Flight Facility; Virginia Tech Department of Fish and Wildlife Conservation ; Published version ; We thank T. Calhoun, S. Dermody, R. Lesagonicz, G. Mosley, A. Freeze, A. Scott, H. Taylor, L. Rohrbaugh and V. Wolfgang for their assistance with fieldwork. Funding was provided by the National Park Service National Capital and Northeast Region, the U.S. Fish and Wildlife Service Virginia Ecological Services Office, the U.S. Army Installation Command, and the National Aeronautics and Space Administration Wallops Flight Facility through numerous cooperative agreements with the Virginia Tech Department of Fish and Wildlife Conservation. ; Public domain authored by a U.S. government employee

Changes to hat distribution and habitat associations at the local to sub-landscape scale in the post white-nose syndrome (WNS) environment have received little attention to date despite being critical information for managers. To better understand the spatial nature of hat population declines, we modelled both activity patterns and occupancy from acoustic surveys for the Myotis lucifugus (little brown hat) on Fort Drum Military Installation in New York, USA over 15 summers (2003-2017) that span the pre-WNS, WNS-advent (2008) and post-WNS periods, using a set of generalized linear mixed models and geospatial analysis. Our best supported model indicated significant differences between years with significant declines in activity post-WNS. M. lucifugus activity was most closely associated with woody wetland habitats over the study period, however, the spatial patterns of high activity areas were variable over years, with the areal extent of these high activity areas decreasing post-WNS. Our best supported occupancy model varied by year. However, the null occupancy model [Psi(.)] was either competing (within 2 Delta AIC units) or was the best supported model. Meaning that none of our environmental variables seemed to impact occupancy, and when they did, these differences were not significant. There was high disagreement between our relative activity models and predictions compared to our occupancy models, suggesting that geographic spatial scale and the resolution of the data impacts model outcome. Our results indicate that continued acoustic monitoring of hat species in the Northeast to assess ongoing temporal and spatial changes in habitat associations and to provide direction for future mist-netting studies should rely more on relative activity as the metric of choice rather than site occupancy. ; U.S Army Corps of EngineersUnited States Department of Defense [W9126G-15-2-0005]; Southern Appalachian Cooperative Ecosystems Study Unit Program ; This work was supported by the U.S Army Corps of Engineers [W9126G-15-2-0005] through the Southern Appalachian Cooperative Ecosystems Study Unit Program. We thank C. Whitman for field assistance. Earlier drafts of this manuscript were reviewed by B. Carstensen. and K. Powers. The use of any trade, product or firm names does not imply endorsement by the U.S. government. ; Public domain authored by a U.S. government employee

Previous acoustic surveys, netting, and count data have shown that overall bat activity patterns have shifted among most species between pre- and post-white-nose syndrome (WNS) years in much of North America where WNS has occurred. However, the significance of these changes is based on the species-specific susceptibility to WNS. We used acoustically recorded echolocation passes obtained at Fort Drum, New York to describe changes in bat activity pre-WNS (2004-2007) to post-WNS (2008-2018). We examined seasonal and yearly changes in bat activity as they relate to the presence of WNS at hibernacula near (<25 km) Fort Drum. A priori, we expected that overall activity for communal hibernating species would be less in years following WNS, and migratory bats or those hibernating bats that are less affected by WNS would show no response or a positive response, due to niche relaxation/competitive release. Our results indicated both an overall and seasonal decrease in activity for Myotis spp. post-WNS. For WNS-susceptible species, our results reflect the high level of mortality in regional winter hibernacula post-WNS and possibly variable reproductive effort and recruitment thereafter. Although migratory bats did show increases in post-WNS activity throughout the summer, we found little evidence that community displacement was occurring on a nightly level by any species. The continuous spread of WNS across North America has had strong negative effects on bat populations of affected species, and our research identifies how individual species (both impacted and non-impacted) respond to WNS. Published by Elsevier B.V. ; U.S Army Corps of Engineers' Cooperative Agreement through the Southern Appalachian Cooperative Ecosystems Study Unit Program [W9126G-15-2-0005] ; This work was supported by the U.S Army Corps of Engineers' Cooperative Agreement W9126G-15-2-0005 through the Southern Appalachian Cooperative Ecosystems Study Unit Program to the Virginia Tech Department of Fish and Wildlife Conservation. We thank C. Whitman for field assistance. Earlier drafts of this manuscript were reviewed by B. Carstensen, L. Coleman and two anonymous reviewers. ; Public domain authored by a U.S. government employee