Paul Cryan is a Research Biologist at the Fort Collins Science Center.
Mysteries, underdogs, and gadgets have always fascinated me, so for the past two decades I have focused my research on using technology to reveal how some of the 43+ species of U.S. bats live their cryptic lives. My particular interests include uncovering bat migration behaviors and seasonal movements, discovering the details of their winter hideouts and survival strategies, and understanding how infectious diseases influence bat populations. What began as general interest in an understudied group of mammals has grown into a practical search for answers to two of the most pressing threats currently facing U.S. bats - fatalities at wind turbines and the emerging disease known as white-nose syndrome. My basic research approach is to start by synthesizing natural history and existing information, then test plausible new hypotheses in a scientifically defensible way through observational and experimental field studies. I gravitate toward new collaborations and technologies that take us beyond existing methods and expand our abilities to follow and discover what (and how) bats are doing out there in the dark.
Professional Experience
2003 to present, Research Biologist, USGS Fort Collins Science Center, Fort Collins, CO
1999 to 2003, Student Trainee (SCEP), USGS Arid Lands Field Station (Fort Collins Science Center), Albuquerque, NM
1994 to 1997 & 1999 to 2002, Graduate Teaching Assistant, University of New Mexico, Albuquerque, NM
1998 to 1999, Wildlife Biologist, USGS Arid Lands Field Station (Fort Collins Science Center), Albuquerque, NM
1995 to 1997, Biological Science Technician, USGS Arid Lands Field Station (Fort Collins Science Center), Albuquerque, NM
Education and Certifications
Ph.D. Biology, University of New Mexico, 2003
M.S. Biology, University of New Mexico, 1997
B.A. Biology, The Evergreen State College, 1991
Science and Products
Population Assessments of the Pacific Sheath-Tailed Bat and Mariana Swiftlet
Developing online integrated data visualization tools for WNS and NABat
Ecology of Wildlife Disease
Species Conservation
North American Bat Monitoring Program (NABat)
Non-invasive Surveillance of Bat Hibernacula to Investigate Potential Behavioral Causes of Mortality Associated with White Nose Syndrome
Ecological Investigations of White-Nose Syndrome in Bats
White-Nose Syndrome Threatens the Survival of Hibernating Bats in North America
Bat Fatalities at Wind Turbines—Investigating the Causes and Consequences
Bat Species of Concern: An Ecological Synthesis for Resource Managers
Animal Migration and Spatial Subsidies: Establishing a Framework for Conservation Markets
Gene annotations for the hoary bat (Lasiurus [Aeorestes] cinereus) and alignments with other bat gene sets for evolutionary analysis
Bat, insect, and bird activity at a wind turbine in Colorado experimentally illuminated with ultraviolet light at night in 2019 to try and deter bats
Genetic variation in hoary bats (Lasiurus cinereus) assessed from archived samples
Data Release: Possibility for reverse zoonotic transmission of SARS-CoV-2 to free-ranging wildlife: a case study of bats
Hawaii Island Hoary Bat Acoustic and Visual Surveys 2014
Radio telemetry data on nighttime movements of two species of migratory nectar-feeding bats (Leptonycteris) in Hidalgo County, New Mexico, late-summer 2004 and 2005
Long-term video surveillance and automated analyses of hibernating bats in Virginia and Indiana, winters 2011-2014.
NABat ML: Utilizing deep learning to enable crowdsourced development of automated, scalable solutions for documenting North American bat populations
Positively selected genes in the hoary bat (Lasiurus cinereus) lineage: Prominence of thymus expression, immune and metabolic function, and regions of ancient synteny
Influencing activity of bats by dimly lighting wind turbine surfaces with ultraviolet light
Historical effective population size of North American hoary bat (Lasiurus cinereus) and challenges to estimating trends in contemporary effective breeding population size from archived samples
Behavioral patterns of bats at a wind turbine confirm seasonality of fatality risk
Possibility for reverse zoonotic transmission of SARS-CoV-2 to free-ranging wildlife: A case study of bats
Assessing the risks posed by SARS-CoV-2 in and via North American bats — Decision framing and rapid risk assessment
Hawaiian hoary bat (Lasiurus cinereus semotus) behavior at wind turbines on Maui
United States bat species of concern: A synthesis
Landscape movements by two species of migratory nectar-feeding bats (Leptonycteris) in a northern area of seasonal sympatry
Do you hear what I see? Vocalization relative to visual detection rates of Hawaiian hoary bats (Lasiurus cinereus semotus)
Long-term video surveillance and automated analyses reveal arousal patterns in groups of hibernating bats
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
Population Assessments of the Pacific Sheath-Tailed Bat and Mariana Swiftlet
Using thermal cameras, we are determining the population size and cave occupancy of the Mariana swiftlet and Pacific sheath-tailed bat. Both species face extirpation from the Northern Mariana Islands and are listed as endangered. Understanding the species' population status can assist in planning recovery efforts for both species.Developing online integrated data visualization tools for WNS and NABat
Bat Research Research collaboration: Brian Reichert (FORT), Anne Ballmann (NWHC), Jeremy Coleman (USFWS), Paul Cryan (FORT), Wayne Thogmartin (UMESC), and Katherine Irvine (NOROCK) White-nose syndrome is caused by the fungal pathogen Pseudogymnoascus destructans (Pd), which has decimated hibernating bat populations across North America since it emerged 10 years ago in New York. While diagnostic...Ecology of Wildlife Disease
Some of the biggest challenges facing wildlife today are changes to their environment from both natural and anthropogenic causes. Natural resource managers, planners, policy makers, industry and private landowners must make informed decisions and policies regarding management, conservation, and restoration of species, habitats, and ecosystem function in response to these changes.Species Conservation
Large scale changes are occurring to our natural landscapes, often resulting in changes to the distribution and abundance of species living within these landscapes. Populations of many species affected by these natural or anthropogenic changes require focused management to ensure their conservation and sometimes recovery from the brink of extinction.North American Bat Monitoring Program (NABat)
North American bats face unprecedented threats including habitat loss and fragmentation, white-nose syndrome, wind energy development, and climate change. However, it is difficult to evaluate the impacts of these threats due to a lack of basic information about the distribution and abundance of bats across the continent. Although bat monitoring has long been conducted in individual areas and for...Non-invasive Surveillance of Bat Hibernacula to Investigate Potential Behavioral Causes of Mortality Associated with White Nose Syndrome
White-Nose Syndrome (WNS) is a devastating disease that threatens the survival of hibernating bats in North America. Since first documented in the winter of 2005/2006, WNS has spread from a very small area of New York across at least two thousand kilometers and half or more of states and provinces in the U.S. and Canada.Ecological Investigations of White-Nose Syndrome in Bats
White-Nose Syndrome (WNS) is a devastating disease that threatens the survival of hibernating bats in North America. Since first documented in the winter of 2005/2006, WNS has spread from a very small area of New York across at least two thousand kilometers in half or more of states and provinces in the U.S. and Canada. Over five million bats are estimated to have died during the past decade from...White-Nose Syndrome Threatens the Survival of Hibernating Bats in North America
During the winter of 2006–2007, an affliction of unknown origin dubbed “white-nose syndrome” (WNS) began devastating colonies of hibernating bats in a small area around Albany, New York. Colonies of hibernating bats were reduced 80–97 percent at the affected caves and mines that were surveyed. Since then, white-nose syndrome or its causative agent have consistently spread more than 2,000...Bat Fatalities at Wind Turbines—Investigating the Causes and Consequences
Wind energy is one of the fastest-growing industries in the world and represents an important step toward reducing dependence on nonrenewable sources of power. However, widespread deployment of industrial wind turbines is having unprecedented adverse effects on certain species of bats that roost in trees and migrate. Bats are beneficial consumers of agricultural insect pests and migratory species...Bat Species of Concern: An Ecological Synthesis for Resource Managers
A large number of bat species are considered “species of concern” in the United States and its Territories, and resource managers are increasingly interested in learning more about their distribution, status, and potential management.Animal Migration and Spatial Subsidies: Establishing a Framework for Conservation Markets
Migratory species may provide more ecosystem goods and services to humans in certain parts of their range than others. These areas may or may not coincide with the locations of habitat on which the species is most dependent for its continued population viability. This situation can present significant policy challenges, as locations that most support a given species may be in effect subsidizing th - Data
Gene annotations for the hoary bat (Lasiurus [Aeorestes] cinereus) and alignments with other bat gene sets for evolutionary analysis
Bats of the genus Lasiurus occur throughout the Americas and have diversified into at least 20 species among three subgenera. The hoary bat (Lasiurus cinereus, or synonymously, Aeorestes cinereus) is highly migratory and ranges farther across North America than any other wild mammal. Despite the ecological importance of this species as a major insect predator, and the particular susceptibility ofBat, insect, and bird activity at a wind turbine in Colorado experimentally illuminated with ultraviolet light at night in 2019 to try and deter bats
Certain species of tree-dwelling bats die after colliding with the moving blades of industrial wind turbines. Based on the speculation that these bats approach turbines after visually mistaking them for trees, we tested a potential light-based deterrence method. It is likely that the affected bats see ultraviolet (UV) light at low intensities. Here, we present the results of a multi-month experimeGenetic variation in hoary bats (Lasiurus cinereus) assessed from archived samples
Hoary bats are among the bat species most commonly killed by turbine strikes in the midwestern United States. The impact of this mortality on species census size is not understood, due in part to the difficulty of estimating population size for this highly migratory and elusive species. Genetic effective population size (Ne) could provide an index of census population size if other factors affectiData Release: Possibility for reverse zoonotic transmission of SARS-CoV-2 to free-ranging wildlife: a case study of bats
The table illustrates global patterns of betacoronavirus (β-CoV) associations in bats. The table lists bat species in which betacoronaviruses (β-CoVs) were detected, organized by viral subgenera and clade [for Sarbecorviruses], bat family, bat suborder, and general global region where the species of bat occurs. Reference to the published literature sources of information for each row are listed inHawaii Island Hoary Bat Acoustic and Visual Surveys 2014
Hawaiian hoary bat vocalization and visual detection records collected on Hawaii Island, Hawaii, September-October 2014. Bat echolocation was monitored with ultrasonic detectors and bat occurrence and behavior was monitored using thermal surveillance cameras.Radio telemetry data on nighttime movements of two species of migratory nectar-feeding bats (Leptonycteris) in Hidalgo County, New Mexico, late-summer 2004 and 2005
These bat location estimates have been reported by Bogan and others (In press) and come in the form of a GIS shape file. Three species of nectar-feeding phyllostomid bats migrate north from Mexico into deserts of the United States (U.S.) each spring and summer to feed on blooms of columnar cacti and century plants (Agave spp). However, the habitat needs of these important desert pollinators are pLong-term video surveillance and automated analyses of hibernating bats in Virginia and Indiana, winters 2011-2014.
This data release includes video files and image-processing results used to conduct the analyses of hibernation patterns in groups of bats reported by Hayman et al. (2017), "Long-term video surveillance and automated analyses reveal arousal patterns in groups of hibernating bats. Thermal-imaging surveillance video cameras were used to observe little brown bats (Myotis lucifugus) in a cave in Virg - Publications
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NABat ML: Utilizing deep learning to enable crowdsourced development of automated, scalable solutions for documenting North American bat populations
Bats play crucial ecological roles and provide valuable ecosystem services, yet many populations face serious threats from various ecological disturbances. The North American Bat Monitoring Program (NABat) aims to use its technology infrastructure to assess status and trends of bat populations, while developing innovative and community-driven conservation solutions.Here, we present NABat ML, an auAuthorsAli Khalighifar, Benjamin S. Gotthold, Erin Adams, Jenny K. Barnett, Laura O. Beard, Eric R. Britzke, Paul A. Burger, Kimberly Chase, Zackary Cordes, Paul M. Cryan, Emily Ferrall, Christopher T. Fill, Scott E. Gibson, G. Scott Haulton, Kathryn Irvine, Lara S. Katz, William L. Kendall, Christen A. Long, Oisin Mac Aodha, Tessa McBurney, Sarah McCarthy-Neumann, Matthew W. McKown, Joy O’Keefe, Lucy D. Patterson, Kristopher A. Pitcher, Matthew Rustand, Jordi L. Segers, Kyle Seppanen, Jeremy L. Siemers, Christian Stratton, Bethany Straw, Theodore J. Weller, Brian ReichertPositively selected genes in the hoary bat (Lasiurus cinereus) lineage: Prominence of thymus expression, immune and metabolic function, and regions of ancient synteny
BackgroundBats of the genus Lasiurus occur throughout the Americas and have diversified into at least 20 species among three subgenera. The hoary bat (Lasiurus cinereus) is highly migratory and ranges farther across North America than any other wild mammal. Despite the ecological importance of this species as a major insect predator, and the particular susceptibility of lasiurine bats to wind turbAuthorsRobert S. Cornman, Paul M. CryanInfluencing activity of bats by dimly lighting wind turbine surfaces with ultraviolet light
Wind energy producers need deployable devices for wind turbines that prevent bat fatalities. Based on the speculation that bats approach turbines after visually mistaking them for trees, we tested a potential light-based deterrence method. It is likely that the affected bats see ultraviolet (UV) light at low intensities. Here, we present the results of a multi-month experiment to cast dim, flickerAuthorsPaul M. Cryan, Marcos Gorresen, Bethany Straw, Syhoune 'Simon' Thao, Elise DeGeorgeHistorical effective population size of North American hoary bat (Lasiurus cinereus) and challenges to estimating trends in contemporary effective breeding population size from archived samples
BackgroundHoary bats (Lasiurus cinereus) are among the bat species most commonly killed by wind turbine strikes in the midwestern United States. The impact of this mortality on species census size is not understood, due in part to the difficulty of estimating population size for this highly migratory and elusive species. Genetic effective population size (Ne) could provide an index of changing cenAuthorsRobert S. Cornman, Jennifer A. Fike, Sara J. Oyler-McCance, Paul M. CryanBehavioral patterns of bats at a wind turbine confirm seasonality of fatality risk
Bat fatalities at wind energy facilities in North America are predominantly comprised of migratory, tree-dependent species, but it is unclear why these bats are at higher risk. Factors influencing bat susceptibility to wind turbines might be revealed by temporal patterns in their behaviors around these dynamic landscape structures. In northern temperate zones, fatalities occur mostly from July thrAuthorsShifra Z Goldenberg, Paul M. Cryan, P. Marcos Gorresen, Lee J FingershPossibility for reverse zoonotic transmission of SARS-CoV-2 to free-ranging wildlife: A case study of bats
The COVID-19 pandemic highlights the substantial public health, economic, and societal consequences of virus spillover from a wildlife reservoir. Widespread human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also presents a new set of challenges when considering viral spillover from people to naïve wildlife and other animal populations. The establishment of new wildAuthorsKevin J. Olival, Paul M. Cryan, Brian R. Amman, Ralph S. Baric, David S. Blehert, Cara E. Brook, Charles H. Calisher, Kevin T. Castle, Jeremy T. H. Coleman, Peter Daszak, Jonathan H. Epstein, Hume Field, Winifred F. Frick, Amy T. Gilbert, David T. S. Hayman, Hon S. Ip, William B Karesh, Christine K. Johnson, Rebekah C. Kading, Tigga Kingston, Jeffrey M. Lorch, Ian H. Mendenhall, Alison J. Peel, Kendra L. Phelps, Raina K. Plowright, DeeAnn M. Reeder, Jonathan D. Reichard, Jonathan M. Sleeman, Daniel G. Streicker, Jonathan S. Towner, Lin-Fa WangAssessing the risks posed by SARS-CoV-2 in and via North American bats — Decision framing and rapid risk assessment
The novel β-coronavirus, SARS-CoV-2, may pose a threat to North American bat populations if bats are exposed to the virus through interaction with humans, if the virus can subsequently infect bats and be transmitted among them, and if the virus causes morbidity or mortality in bats. Further, if SARS-CoV-2 became established in bat populations, it could possibly serve as a source for new infectionAuthorsMichael C. Runge, Evan H. Campbell Grant, Jeremy T. H. Coleman, Jonathan D. Reichard, Samantha E. J. Gibbs, Paul M. Cryan, Kevin J. Olival, Daniel P. Walsh, David S. Blehert, M. Camille Hopkins, Jonathan M. SleemanHawaiian hoary bat (Lasiurus cinereus semotus) behavior at wind turbines on Maui
This study examined the activity of the endemic Hawaiian hoary bat (Lasiurus cinereus semotus) at wind turbines operated by Auwahi Wind Energy, LLC, on southern Maui Island, from August to November 2018. The research was conducted to assess the potential effect of wind speed and turbine operation on bat presence and behavior and compared information obtained from both acoustic monitoring and thermAuthorsP. Marcos Gorresen, Paul M. Cryan, Grace TredinnickUnited States bat species of concern: A synthesis
In 1994 the federal government designated 24 species or subspecies of bats in the United States (U.S.) and its territories as Category 2 candidates for listing as Endangered or Threatened under the U.S. Endangered Species Act. Category 2 was eliminated in 1996, but taxa previously receiving this designation were informally considered “species of concern”. Various state and federal agencies and coAuthorsThomas J. O'Shea, Paul M. Cryan, Michael A. BoganLandscape movements by two species of migratory nectar-feeding bats (Leptonycteris) in a northern area of seasonal sympatry
Animals often migrate to exploit seasonally ephemeral food. Three species of nectar-feeding phyllostomid bats migrate north from Mexico into deserts of the United States each spring and summer to feed on blooms of columnar cactus and century plants (Agave spp.). However, the habitat needs of these important desert pollinators are poorly understood. We followed the nighttime movements of 2 speciesAuthorsMichael A. Bogan, Paul M. Cryan, Christa D. Weise, Ernest W. ValdezDo you hear what I see? Vocalization relative to visual detection rates of Hawaiian hoary bats (Lasiurus cinereus semotus)
Bats vocalize during flight as part of the sensory modality called echolocation, but very little is known about whether flying bats consistently call. Occasional vocal silence during flight when bats approach prey or conspecifics has been documented for relatively few species and situations. Bats flying alone in clutter-free airspace are not known to forgo vocalization, yet prior observations suggAuthorsP. Marcos Gorresen, Paul M. Cryan, Kristina Montoya-Aiona, Frank BonaccorsoLong-term video surveillance and automated analyses reveal arousal patterns in groups of hibernating bats
Understanding natural behaviours is essential to determining how animals deal with new threats (e.g. emerging diseases). However, natural behaviours of animals with cryptic lifestyles, like hibernating bats, are often poorly characterized. White-nose syndrome (WNS) is an unprecedented disease threatening multiple species of hibernating bats, and pathogen-induced changes to host behaviour may contrAuthorsDavid T. S. Hayman, Paul M. Cryan, Paul D. Fricker, Nicholas G. DannemillerNon-USGS Publications**
Cryan, P.M. 1997. Distribution and roosting habits of bats in the southern Black Hills, South Dakota [M.S. Thesis]. Albuquerque, NM: University of New Mexico. 98 p.Perry, T.W., P.M. Cryan, S.R. Davenport, and M.A. Bogan. 1997. New locality for Euderma maculatum (Chiroptera: vespertilionidae) in New Mexico. Southwestern Naturalist. 42(1): 99-10.Bogan, M.A., T.J. O’Shea, P.M. Cryan, A.M. Ditto, W.H. Shaedla, and L. Ellison. 1996. Status and trends of bat populations at Los Alamos National Laboratory and Bandelier National Monument, Jemez Mountains, New Mexico. Annual report to Los Alamos National Laboratory and Bandelier National Monument. 1-18 p.Cryan, P.M. and M.A. Bogan. 1995. Ecology and distribution of bats in the southern Black Hills: Annual report to cooperators. Annual report prepared for Jewel Cave National Monument, National Park Service, Custer, SD. 23 p.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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