Bat with white-nose syndrome. Photograph by U.S. Fish & Wildlife Service.
White-nose syndrome (WNS) and/or Pseudogymnoascus destructans (P.d.), the causal agent, has spread westward across 26 states and 5 provinces within the eastern United States and Canada, respectively, over a short period of time. In 2015, three tri-colored bats (Perimyotis subflavus), a species found primarily in the eastern United States, tested positive for P.d. in eastern Oklahoma. Until March 2016, the discovery of WNS and P.d. in Washington state, these records represented the westernmost occurrence of the disease causing fungus. In addition, records of P.d from eastern Oklahoma are also on the same latitude and trajectory as a possible corridor to the western United States via northeastern New Mexico and southeastern Colorado. In 2003, tri-colored bats were discovered in northeastern New Mexico, thus suggesting that this species is moving into the West via the riparian corridors of northeastern New Mexico.
Given the proximity of Bent’s Old Fort National Historic Site (BEOL, approx. 135 km away) in southeastern Colorado and Capulin Volcano National Monument (CAVO, approx. 75 km away) in northeastern New Mexico to the record of P. subflavus recorded in 2003, these two monuments are at the frontline to the introduction of P.d. and WNS. Further, Pecos National Historic Park (PECO) is at an ecotone between grassland-woodland and montane forest relative to the two aforementioned national parks and likely possess a greater diversity of bat species that could be affected by WNS. Overall, these sites serve as critical locations prior to exposure to P.d. for the diagnosis of naturally occurring microbiota that could act as natural defenses against WNS.
During the spring and summer of 2016, FORT Scientist Dr. Ernie Valdez and his collaborators at the University of New Mexico sampled bats from all BEOL, CAVO, and PECO in an effort to document naturally occurring bacteria belonging to the group known as Actinobacteria. In general, this particular group of bacteria is known for producing many of the world’s antibiotics. As shown in previous research by Dr. Valdez and his collaborators, some Actinobacteria sampled from the external surfaces of western bats produce antifungal properties that impact the growth of P.d. (see figure 1). The discovery and future testing of the anti-fungal properties from these bacteria may lend themselves as possible bio-control agents against WNS.
Pathophysiology of white-nose syndrome in bats: a mechanistic model linking wing damage to mortality
Warnecke, L., J.M. Turner, T.K. Bollinger, V. Misra, P.M. Cryan, D.S. Blehert, G. Wibbelt and C.K.R. Willis
White-nose syndrome is devastating North American bat populations but we lack basic information on disease mechanisms. Altered blood physiology owing to epidermal invasion by the fungal pathogen Geomyces destructans (Gd) has been hypothesized as a cause of disrupted torpor patterns of affected hibernating bats, leading to mortality. Here, we present data on blood electrolyte concentration, haematology and acid–base balance of hibernating little brown bats, Myotis lucifugus, following experimental inoculation with Gd. Compared with controls, infected bats showed electrolyte depletion (i.e. lower plasma sodium), changes in haematology (i.e. increased haematocrit and decreased glucose) and disrupted acid–base balance (i.e. lower CO2 partial pressure and bicarbonate). These findings indicate hypotonic dehydration, hypovolaemia and metabolic acidosis. We propose a mechanistic model linking tissue damage to altered homeostasis and morbidity/mortality.
Continental-scale, seasonal movements of a heterothermic migratory tree bat
Long-distance migration evolved independently in bats and unique migration behaviors are likely, but because of their cryptic lifestyles, many details remain unknown. North American hoary bats (Lasiurus cinereus cinereus) roost in trees year-round and probably migrate farther than any other bats, yet we still lack basic information about their migration patterns and wintering locations or strategies. This information is needed to better understand unprecedented fatality of hoary bats at wind turbines during autumn migration and to determine whether the species could be susceptible to an emerging disease affecting hibernating bats. Our aim was to infer probable seasonal movements of individual hoary bats to better understand their migration and seasonal distribution in North America. We analyzed the stable isotope values of non-exchangeable hydrogen in the keratin of bat hair and combined isotopic results with prior distributional information to derive relative probability density surfaces for the geographic origins of individuals. We then mapped probable directions and distances of seasonal movement. Results indicate that hoary bats summer across broad areas. In addition to assumed latitudinal migration, we uncovered evidence of longitudinal movement by hoary bats from inland summering grounds to coastal regions during autumn and winter. Coastal regions with nonfreezing temperatures may be important wintering areas for hoary bats. Hoary bats migrating through any particular area, such as a wind turbine facility in autumn, are likely to have originated from a broad expanse of summering grounds from which they have traveled in no recognizable order. Better characterizing migration patterns and wintering behaviors of hoary bats sheds light on the evolution of migration and provides context for conserving these migrants.
Ecology and distribution of Geomyces fungi: an introduction for bat researchers and wildlife managers
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North American Symposium on Bat Research—Program and Abstracts, October 24-27, 2012, San Juan, Puerto Rico
From late winter to summer 2011, the U.S. Geological Survey Arid Lands Field Station conducted mist-netting efforts at El Malpais National Monument and on adjacent lands belonging to Bureau of Land Management and U.S. Forest Service to detect the occurrence of white-nose syndrome or causal fungal agent (Geomyces destructans). During this assessment, 421 bats belonging to 8 species were documented at El Malpais National Monument and adjacent lands. None of these captures showed evidence for the presence of white-nose syndrome or G. destructans, but it is possible that the subtle signs of some infections may not have been observed.
Throughout the field efforts, Laguna de Juan Garcia was the only water source located on El Malpais National Monument and was netted on June 20 and 27, July 25, and August 2, 2011. During these dates, a total of 155 bats were captured, belonging to eight species including: Corynorhinus townsendii (Townsend’s Big-Eared Bat), Eptesicus fuscus (Big Brown Bat), Lasionycterics noctivagans (Silver-Haired Bat), Myotis ciliolabrum (Small-Footed Myotis), M. evotis (Long-eared myotis), M. thysanodes (Fringed Myotis), M. volans (Long-Legged Myotis), and Tadarida brasiliensis (Brazilian Free-Tailed Bat). Overall, Laguna de Juan Garcia had the greatest number of captures (79 bats) during one night compared to the other sites netted on adjacent lands and had the greatest species diversity of 8 species netted, not including Euderma maculatum (Spotted Bat) that was detected by its audible calls as it flew overhead. Laguna de Juan Garcia is an important site to bats because of its accessibility by all known occurring species, including the less-maneuverable T. brasiliensis that is known to form large colonies in the park. Laguna de Juan Garcia is also important as a more permanent water source during drought conditions in the earlier part of the spring and summer, as observed in 2011.
Lights, camera, action: behaviors of hibernating bats before and after WNS revealed by surveillance video
Cryan, P., J. Boyles, G. McCracken, K. Castle, D. Dalton, J. Yanez, J. Beeler, A. Wilson, A. Hicks, C. Herzog, R. vonLinden, S. Johnson, C. Hudson, T. Shier, and J. Coleman
White-nose syndrome (WNS) is an emerging disease of hibernating bats associated with cutaneous infection by the fungus Geomyces destructans (Gd), and responsible for devastating declines of bat populations in eastern North America. Affected bats appear emaciated and one hypothesis is that they spend too much time out of torpor during hibernation, depleting vital fat reserves required to survive the winter. The fungus has also been found at low levels on bats throughout Europe but without mass mortality. This finding suggests that Gd is either native to both continents but has been rendered more pathogenic in North America by mutation or environmental change, or that it recently arrived in North America as an invader from Europe. Thus, a causal link between Gd and mortality has not been established and the reason for its high pathogenicity in North America is unknown...