Paul Cryan, Ph.D.
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.
- Ph.D. Biology, University of New Mexico, 2003
- M.S. Biology, University of New Mexico, 1997
- B.A. Biology, The Evergreen State College, 1991
- 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
Science and Products
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.
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 WNS, and all four federally listed endangered species and subspecies of hibernating cave bats are in harm’s way.
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 kilometers (1,200 mi) away from the original site, and have infected bats in at least half or more of states and provinces in the U.S. and Canada. Most species of bats that hibernate in eastern North America are now known to be affected; little brown bats (Myotis lucifugus), northern long-eared bats (M. septentrionalis), and federally listed (endangered) Indiana bats (M. sodalis) have been hit particularly hard.
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 of bats provide free pest-suppression services across ecosystems and international borders.
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.
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 and come in the form of a GIS shape file.
Long-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.”
Landscape 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...Bogan, Michael A.; Cryan, Paul; Weise, Christa D.; Valdez, Ernest W.
Do 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...Gorresen, Paulo Marcos; Cryan, Paul; Montoya-Aiona, Kristina; Bonaccorso, Frank
Long-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...Hayman, David T.S.; Cryan, Paul; Fricker, Paul D.; Dannemiller, Nicholas G.
Long-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...Hayman, David T.S.; Cryan, Paul; Fricker, Paul D.; Dannemiller, Nicholas G.
Improving spatio-temporal benefit transfers for pest control by generalist predators in cotton in the southwestern U.S.
Given rapid changes in agricultural practice, it is critical to understand how alterations in ecological, technological, and economic conditions over time and space impact ecosystem services in agroecosystems. Here, we present a benefit transfer approach to quantify cotton pest-control services provided by a generalist predator, the Mexican free-...Wiederholt, Ruscena; Bagstad, Kenneth J.; McCracken, Gary F.; Diffendorfer, Jay E.; Loomis, John B.; Semmens, Darius J.; Russell, Amy L.; Sansone, Chris; LaSharr, Kelsie; Cryan, Paul; Reynoso, Claudia; Medellin, Rodrigo A.; Lopez-Hoffman, Laura
First direct evidence of long-distance seasonal movements and hibernation in a migratory bat
Understanding of migration in small bats has been constrained by limitations of techniques that were labor-intensive, provided coarse levels of resolution, or were limited to population-level inferences. Knowledge of movements and behaviors of individual bats have been unknowable because of limitations in size of tracking devices and methods to...Weller, Theodore J.; Castle, Kevin T.; Liechti, Felix; Hein, Cris D.; Schirmacher, Michael R.; Cryan, Paul M.
Evaluating the effectiveness of wildlife detection and observation technologies at a solar power tower facility
Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected...Diehl, Robert H.; Valdez, Ernest W.; Preston, Todd M.; Wellik, Mike J.; Cryan, Paul
Environment, host, and fungal traits predict continental-scale white-nose syndrome in bats
White-nose syndrome is a fungal disease killing bats in eastern North America, but disease is not seen in European bats and is less severe in some North American species. We show that how bats use energy during hibernation and fungal growth rates under different environmental conditions can explain how some bats are able to survive winter with...Hayman, David T.S.; Pulliam, Juliet R.C.; Marshall, Jonathan C.; Cryan, Paul M.; Webb, Colleen T.
Multiple mortality events in bats: a global review
Despite conservation concerns for many species of bats, factors causing mortality in bats have not been reviewed since 1970. Here, we review and qualitatively describe trends in the occurrence and apparent causes of multiple mortality events (MMEs) in bats around the world. We compiled a database of MMEs, defined as cases in which ≥...O'Shea, Thomas J.; Cryan, Paul; Hayman, David TH; Plowright, Raina K.; Streicker, Daniel G.
Book review: Bats: A world of science and mystery.
This book has something for everyone, from casual seekers of fascinating eye candy to professional scientists interested in the latest discoveries. Without losing sight of how mysterious bats remain despite decades of research, the authors deftly introduce readers to bats and the people who study them. The book is nice to look at, easy to...Cryan, Paul
Seasonally-dynamic presence-only species distribution models for a cryptic migratory bat impacted by wind energy development
Understanding seasonal distribution and movement patterns of animals that migrate long distances is an essential part of monitoring and conserving their populations. Compared to migratory birds and other more conspicuous migrants, we know very little about the movement patterns of many migratory bats. Hoary bats (Lasiurus cinereus), a cryptic,...Hayes, Mark A.; Cryan, Paul M.; Wunder, Michael B.
Not to put too fine a point on it - does increasing precision of geographic referencing improve species distribution models for a wide-ranging migratory bat?
Bat specimens held in natural history museum collections can provide insights into the distribution of species. However, there are several important sources of spatial error associated with natural history specimens that may influence the analysis and mapping of bat species distributions. We analyzed the importance of geographic referencing and...Hayes, Mark A.; Ozenberger, Katharine; Cryan, Paul M.; Wunder, Michael B.
Written by Marisa Lubeck and Ethan Alpern
Video surveillance is the most effective method for detecting animals flying around solar power towers, according to a study of various techniques by the U.S. Geological Survey and its partners at the Ivanpah Solar Electric Generating System facility in southeastern California.