Two recent scientific studies under a project led by the Wildlife Conservation Society have revealed new insights on where and when bats hibernate across their range, and subsequently predict continued extreme levels of mortality from white-nose syndrome.

White-nose syndrome has already killed more than 90 percent of some hibernating bat species east of the Mississippi. The disease is the result of a fungus that grows on a bat and damages tissues during hibernation. The fungus grows well in near-freezing and humid environments that bats use for hibernation, with the name ‘white-nose’ describing the appearance of fungal growth on infected bats. It usually kills susceptible bats before they emerge in the spring; and it’s thought that hibernation duration is a factor that influences who survives. The fungal infection also changes bat behaviors so that bat survival partially depends on having enough fat to survive winter, as well as the energetic cost of hibernating with the disease.

Using updated models of hibernation duration, or when bats hibernate, and relationships between body mass and body fat, researchers at Massey University were able to spatially estimate the energetic cost of hibernation with and without white-nose syndrome. The study, published in Ecology and Evolution, focused on the white-nose susceptible little brown bat (Myotis lucifugus), which ranges across most of North America, and found that the energetic cost of hibernating with white-nose syndrome is substantial. In support of prior findings, the researchers concluded little brown populations not yet been impacted will fair no better than populations first infected in the East, which were decimated.

The study’s lead author, Dr. Reed Hranac, now a Data Analyst at the Colorado Department of Public Health and Environment said: “Originally we hoped that colder temperatures in the northern part of the range or warmer temperatures in the southern part of the range would slow the disease process and allow bats there to survive. Unfortunately the energetics suggest little brown bats are going to suffer across their range.”

This news increases the importance of understanding the conservation needs of susceptible bat species, such as where species hibernate in the winter. Surprisingly, species level knowledge of where and when bats hibernate has received little attention.

A separate study, published in Journal of Biogeography, conducted by Conservation Science Partners, took a hybrid approach to answering this question. Instead of estimating winter distributions of five bat species using landcover and climate features alone, the researchers added in a spatial layer estimating winter survival based on energetics. Not surprisingly the contribution of factors like land cover, winter survival, topography, and subterranean features were significant, but the relative influence of these factors varied by species. The importance of winter survival based on energetics in predicting winter distributions indicates that mechanistic energetic models of hibernation are improving and valuable. Moreover, it is promising that there are data rich landscape features that correlate with winter species distributions, as opposed to just subterranean features that are typically very data poor.

Dr. Sarah Olson, Wildlife Conservation Society Health Program co-author and project Principle Investigator said: “Our unique approach to mapping winter distribution highlights the utility of blending mechanistic energetic models of survivorship with more traditional correlative approaches to map species distribution. Survivorship was retained as an important predictor of winter occurrence in all five species studied, showing that physiology can enhance our understanding a species’ environmental niche.”

Improving knowledge of what influences where and when bats hibernate contributes to addressing multiple threats like white-nose syndrome as well as habitat loss and climate change. Bats are critical to ecosystem health, keeping insects populations, including agricultural pests in check. As multiple threats can influence the energetic dynamics of bat hibernation, such the amount of fat taken into hibernation, another important outcome of these studies is the advanced model of winter survival based on energetics. For example, researchers measuring relationships of habitat loss and reduced insect abundance can anticipate what reduced body mass may mean for winter survival. By advancing our understanding of bats, land managers and the public can make more informed assessments of bat health and future interventions that support better conservation outcomes.

These studies (www.science4bats.org) were funded by an award from the Strategic Environmental Research and Development Program (SERDP; www.serdp-estcp.org) – the Department of Defense’s environmental science and technology program that is executed in partnership with the Department of Energy and the Environmental Protection Agency. The research involved a consortium of partners including Texas Tech University, Montana State University, Massey University in New Zealand, Wildlife Conservation Society Canada, Conservation Science Partners and the Wildlife Conservation Society.

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About the WCS (Wildlife Conservation Society)

The Wildlife Conservation Society (WCS) is a US non-profit, tax-exempt, private organization established in 1895 that saves wildlife and wild places by understanding critical issues, crafting science-based solutions, and taking conservation actions that benefit nature and humanity. With more than a century of experience, long-term commitments in dozens of landscapes, presence in more than 60 nations, and experience helping to establish over 150 protected areas across the globe, WCS has amassed the biological knowledge, cultural understanding and partnerships to ensure that vibrant, wild places and wildlife thrive alongside local communities. Working with local communities and organizations, that knowledge is applied to address species, habitat and ecosystem management issues critical to improving the quality of life of poor rural people whose livelihoods depend on the direct utilization of natural resources. WCS was the first conservation organization with a dedicated team of wildlife veterinarians and other health professionals deployed around the world. The WCS Health Program is central to delivering on our mission to save wildlife and wild places around the globe. Wildlife, livestock, and human diseases will likely have a significant impact on the future development of sustainable land uses, protected areas, transboundary natural resource management, other biodiversity conservation approaches, and livelihood opportunities in many of the landscapes and seascapes where we work. Our work at the interface of wildlife, domestic animal, and human health has demonstrated that a One Health approach can build new constituencies for conservation and strengthen existing ones, while mitigating a key threat to conservation. Today, WCS Health Programs are globally recognized for excellence in zoological and wildlife medicine, pathology, and global health conservation initiatives. Visit: newsroom.wcs.org Follow: @WCSNewsroom. For more information: 347-840-1242. 

About Austin Peay State University

Austin Peay State University (APSU; apsu.edu) is a moderately-sized state university located in middle Tennessee. APSU serves a large population of diverse students with several degree options at the associates, bachelor’s, master’s and doctoral levels. Many of these degrees can be pursued on campus and online. APSU is home to the state’s only Center of Excellence for Field Biology, which enables students to work with professional field biologists in the study of mammals, insects, fish, plants and more.

About WCS Canada

Wildlife Conservation Society (WCS) Canada was incorporated as a conservation organization in Canada in 2004. The mission of WCS Canada is to conserve wildlife and wild places by understanding the issues, developing science-based solutions, and working with others to carry out conservation actions across Canada. WCS Canada is distinguished from other environmental organizations through their role in generating science through field and applied research, and by using results to encourage collaboration among scientific communities, organizations and policy makers to achieve conservation results.

About TTU

A new era of excellence is dawning at Texas Tech University as it stands on the cusp of being one of the nation's premier research institutions. Research and enrollment numbers are at record levels, which cement Texas Tech's commitment to attracting and retaining quality students. In fall 2020, the university achieved a goal more than a decade in the making, reaching a total student population of more than 40,000. In 2018, the Carnegie Classification of Institutions of Higher Education again placed Texas Tech among its top doctoral universities in the nation in the “Very High Research Activity” category. Texas Tech is one of 94 public institutions nationally and 131 overall to achieve this prestigious recognition. Quality students need top-notch faculty. Texas Tech is home to a diverse, highly revered pool of educators who excel in teaching, research and service. The university strives to foster an environment that celebrates student accomplishment above all else. Texas Tech is large enough to provide the best in facilities and academics but prides itself on being able to focus on each student individually.
The momentum for excellence at Texas Tech has never been greater.

About MSU

Montana State University is a public university located in Bozeman, Montana. It was founded in 1893 as the state’s land-grant institution and prides itself on its tripartite mission of excellence in teaching and learning, research and creative projects and outreach and service. With an enrollment of more than 15,600 students, MSU is the largest university in the state. It is also the largest research university in Montana and the largest research and development entity of any kind in Montana, with annual research expenditures typically exceeding $100 million annually. Through its colleges, MSU offers baccalaureate degrees in more than 50 fields, master's degrees in more than 40 fields, and doctoral degrees in approximately 20 fields. To learn more, visit http://www.montana.edu/.

About Massey U

Massey University is New Zealand's largest and most influential educational institution with around 32,500 students. It calls itself New Zealand’s defining university because its areas of specialized teaching and world-class research reflect what New Zealand and New Zealanders are best known for – agrifood innovation and the associated disciplines such as public health, animal welfare, farming and food technology, design, creative arts, social sciences, and business. It has five colleges (faculties), around 3000 full-time equivalent staff and the nation’s largest university-based distance education program, allowing students to study from anywhere in the world.

About CSP

Conservation Science Partners (CSP; csp-inc.org) is a nonprofit scientific collective established to meet the analytical and research needs of diverse stakeholders in conservation outcomes on public and private lands. The mission of CSP is to apply human ingenuity to the preservation of species, populations, and ecosystems using scientific principles, innovative approaches, and lasting partnerships with conservation practitioners. CSP connects the best minds in conservation science to solve environmental problems in a comprehensive, flexible, and service-oriented manner. The core capabilities of CSP span a wide spectrum of geospatial and statistical techniques, from custom ecological and environmental data development (GIS and remote sensing based) to advanced analyses of landscape patterns and changes at multiple spatial and temporal scales.