Spread of white-nose syndrome on a network regulated by geography and climate

Abstract

Wildlife and plant diseases can reduce biodiversity, disrupt ecosystem services and threaten human health. Emerging pathogens have displayed a variety of spatial spread patterns due to differences in host ecology, including diffusive spread from an epicentre (West Nile virus), jump dispersal on a network (foot-and-mouth disease), or a combination of these (Sudden oak death). White-nose syndrome is a highly pathogenic infectious disease of bats currently spreading across North America. Understanding how bat ecology influences this spread is crucial to management of infected and vulnerable populations. Here we show that white-nose syndrome spread is not diffusive but rather mediated by patchily distributed habitat and large-scale gradients in winter climate. Simulations predict rapid expansion and infection of most counties with caves in the contiguous United States by winter 2105-2106. Our findings show the unique pattern of white-nose syndrome spread corresponds to ecological traits of the host and suggest hypotheses for transmission mechanisms acting at the local scale.

Potential for spread of the white-nose fungus (Pseudogymnoascus destructans) in the Americas: use of Maxent and NicheA to assure strict model transference

“…Although multiple climatic (including microclimatic), behavioural and physiological factors have combined to produce the catastrophic effects of P. destructans on bat populations in North America, previous modelling efforts indicate further potential for the spread of P. destructans across the Midwest in the USA in the near future (Maher et al, 2012) with correct anticipation of recent reports (USGS, 2013). Bat species with broad distributions are more likely to overlap and thus be exposed to P. destructans-infected sites (Wilder et al, 2011).…”

“…We used a buffer distance of 500 km around European and North American occurrences (M; Fig. 1), as this distance has been observed yearly from one infected county to the next (Maher et al, 2012); all analyses were carried out within the areas delimited by these buffers. We generated ecological niche models independently for North America and Europe and also for the two continents pooled.…”

“…The fungus has been confirmed in the north-eastern part of the United States of America (USA) (Maher et al, 2012;National Park Service, 2013) and southeastern Canada (Turner et al, 2011). Evidence suggests that the pathogen is native to Europe (Wibbelt et al, 2010), where it is showing increasing incidence (Martínková et al, 2010) and some evidence of spread (Martínková et al, 2010;Puechmaille et al, 2010b;Wibbelt et al, 2010): its translocation to the Americas was apparently via anthropogenic activity (Frick et al, 2010).…”

“…Evidence of this new disease was established in North American in early 2006; infected bats displayed a white fungal growth in mouth, muzzle, ears and wings (Blehert et al, 2009). At fine scales, disease caused by P. destructans can be considered density-dependent or frequencydependent according to the species involved (Langwig et al, 2012); across broader regions, it is density-dependent (Maher et al, 2012;Thogmartin et al, 2012), causing the white-nose syndrome (WNS) in native bat populations in North America (Lorch et al, 2011).…”

“…Evidence suggests that the pathogen is native to Europe (Wibbelt et al, 2010), where it is showing increasing incidence (Martínková et al, 2010) and some evidence of spread (Martínková et al, 2010;Puechmaille et al, 2010b;Wibbelt et al, 2010): its translocation to the Americas was apparently via anthropogenic activity (Frick et al, 2010). A major unknown is the degree to which other sectors of the Americas are susceptible to this pathogen (Fenton, 2012), an important matter in light of its broad spread to date of >2,220 km from where the epizootic initiated (Maher et al, 2012). For concerns of both biodiversity conservation and ecosystem benefits of bats , we address two questions: (i) do ecological differences in abiotic factors (i.e.…”