Frank T van Manen, Ph.D.
Frank van Manen is an emeritus ecologist with the USGS who blends his research interest in large carnivores with landscape ecology. Frank was team lead of the Interagency Grizzly Bear Study Team from 2012-2025 and he is continuing to work with the team.
Research Interests
Frank's research focus is on 1) grizzly bear and black bear ecology and management, 2) demographic models to inform large carnivore management, 3) resource selection and energy landscapes, 4) wildlife genetics, and 5) international bear conservation.
Formerly, Frank spent 12 years with the USGS Leetown Science Center specializing in responses of mammals to landscape changes, management of large carnivores, and habitat models to support protection and restoration of plants and trees.
For available articles, click on the Publications tab.
Professional Experience
Frank was the Team Leader of the Interagency Grizzly Bear Study Team from 2012-2025, a cooperative research team that addresses monitoring and research needs for the Greater Yellowstone grizzly bear population.
His research focus for the past 35 years has been on bear ecology and management. Prior to his current research on Yellowstone grizzly bears, he conducted numerous studies on American black bears in the southeastern U.S. He has also collaborated on field studies with bear researchers in Ecuador (Andean bear), Sri Lanka (sloth bear), Malaysia, (sun bear), and China (giant panda).
Frank served as Treasurer and then President of the International Association for Bear Research and Management from 2001 through 2013 and is an Associate Editor for the scientific journal Ursus. He has adjunct appointments with Montana State University and the University of Tennessee.
Education and Certifications
Ph.D. 1994. Ecology and Statistics. University of Tennessee
B.S. and M.S. 1989. Biology. Wageningen Agricultural University, Netherlands
Science and Products
Filter Total Items: 84
Forty years of grizzly bear recovery in the Greater Yellowstone Ecosystem
No abstract available.
Authors
Frank T. van Manen, Cecily M. Costello, Kerry A. Gunther, Mark A. Haroldson
Density dependence, whitebark pine, and vital rates of grizzly bears
Understanding factors influencing changes in population trajectory is important for effective wildlife management, particularly for populations of conservation concern. Annual population growth of the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem, USA has slowed from 4.2–7.6% during 1983–2001 to 0.3–2.2% during 2002–2011. Substantial changes in availability...
Authors
Frank T. van Manen, Mark A. Haroldson, Daniel D. Bjornlie, Michael R. Ebinger, Daniel P. Thompson, Cecily M. Costello, Gary C. White
Multiple estimates of effective population size for monitoring a long-lived vertebrate: An application to Yellowstone grizzly bears
Effective population size (Ne) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well-studied population of...
Authors
Pauline L. Kamath, Mark A. Haroldson, Gordon Luikart, David Paetkau, Craig Whitman, Frank T. van Manen
Space use and habitat selection by resident and transient coyotes (Canis latrans)
Little information exists on coyote (Canis latrans) space use and habitat selection in the southeastern United States and most studies conducted in the Southeast have been carried out within small study areas (e.g., ≤1,000 km2). Therefore, studying the placement, size, and habitat composition of coyote home ranges over broad geographic areas could provide relevant insights regarding how...
Authors
Joseph W. Hinton, Frank T. van Manen, Michael J. Chamberlain
Book Reivew: A chance for lasting survival: Ecology and behavior of wild giant pandas
“If we watch species going extinct in front of us, how useful is that we publish 100 or even 1,000 papers by studying them?” (p. 330). This quote from senior author Pan Wenshi captures an important essence of this book. A translation of a 2001 monograph originally published in Chinese, this volume details the findings of a 15-year research program in the Qinling Mountains by Wenshi and...
Authors
Frank T. van Manen
Yellowstone grizzly bear investigations — Annual report of the Interagency Grizzly Bear Study Team 2014
This Annual Report summarizes results of grizzly bear (Ursus arctos) monitoring and research conducted in the Greater Yellowstone Ecosystem (GYE) by the Interagency Grizzly Bear Study Team (IGBST) during 2014. The report also contains a summary of grizzly bear management actions to address conflict situations.
Whitebark pine, population density, and home-range size of grizzly bears in the greater Yellowstone ecosystem
Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase...
Authors
Daniel D. Bjornlie, Frank T. van Manen, Michael R. Ebinger, Mark A. Haroldson, Daniel P. Thompson, Cecily M. Costello
Capture-recapture of white-tailed deer using DNA from fecal pellet-groups
Traditional methods for estimating white-tailed deer population size and density are affected by behavioral biases, poor detection in densely forested areas, and invalid techniques for estimating effective trapping area. We evaluated a noninvasive method of capture—recapture for white-tailed deer (Odocoileus virginianus) density estimation using DNA extracted from fecal pellets as an...
Authors
Matthew J Goode, Jared T Beaver, Lisa I. Muller, Joseph D. Clark, Frank T. van Manen, Craig T Harper, P Seth Basinger
Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment
Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work...
Authors
Charles C. Schwartz, Justin E. Teisberg, Jennifer K. Fortin, Mark A. Haroldson, Christopher Servheen, Charles T. Robbins, Frank T. van Manen
Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem
When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We...
Authors
Cecily M. Costello, Frank T. van Manen, Mark A. Haroldson, Michael R. Ebinger, Steven L. Cain, Kerry A. Gunther, Daniel D. Bjornlie
Re-evaluation of Yellowstone grizzly bear population dynamics not supported by empirical data: response to Doak & Cutler
Doak and Cutler critiqued methods used by the Interagency Grizzly Bear Study Team (IGBST) to estimate grizzly bear population size and trend in the Greater Yellowstone Ecosystem. Here, we focus on the premise, implementation, and interpretation of simulations they used to support their arguments. They argued that population increases documented by IGBST based on females with cubs-of-the...
Authors
Frank T. van Manen, Michael R. Ebinger, Mark A. Haroldson, Richard K. Harris, Megan D. Higgs, Steve Cherry, Gary C. White, Charles C. Schwartz
Yellowstone grizzly bear investigations—Annual report of the Interagency Grizzly Bear Study Team 2013
This Annual Report summarizes results of grizzly bear (Ursus arctos) monitoring and research conducted in the Greater Yellowstone Ecosystem (GYE) by the Interagency Grizzly Bear Study Team (IGBST) during 2013. The report also contains a summary of nuisance grizzly bear management actions.
Science and Products
Filter Total Items: 84
Forty years of grizzly bear recovery in the Greater Yellowstone Ecosystem
No abstract available.
Authors
Frank T. van Manen, Cecily M. Costello, Kerry A. Gunther, Mark A. Haroldson
Density dependence, whitebark pine, and vital rates of grizzly bears
Understanding factors influencing changes in population trajectory is important for effective wildlife management, particularly for populations of conservation concern. Annual population growth of the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem, USA has slowed from 4.2–7.6% during 1983–2001 to 0.3–2.2% during 2002–2011. Substantial changes in availability...
Authors
Frank T. van Manen, Mark A. Haroldson, Daniel D. Bjornlie, Michael R. Ebinger, Daniel P. Thompson, Cecily M. Costello, Gary C. White
Multiple estimates of effective population size for monitoring a long-lived vertebrate: An application to Yellowstone grizzly bears
Effective population size (Ne) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well-studied population of...
Authors
Pauline L. Kamath, Mark A. Haroldson, Gordon Luikart, David Paetkau, Craig Whitman, Frank T. van Manen
Space use and habitat selection by resident and transient coyotes (Canis latrans)
Little information exists on coyote (Canis latrans) space use and habitat selection in the southeastern United States and most studies conducted in the Southeast have been carried out within small study areas (e.g., ≤1,000 km2). Therefore, studying the placement, size, and habitat composition of coyote home ranges over broad geographic areas could provide relevant insights regarding how...
Authors
Joseph W. Hinton, Frank T. van Manen, Michael J. Chamberlain
Book Reivew: A chance for lasting survival: Ecology and behavior of wild giant pandas
“If we watch species going extinct in front of us, how useful is that we publish 100 or even 1,000 papers by studying them?” (p. 330). This quote from senior author Pan Wenshi captures an important essence of this book. A translation of a 2001 monograph originally published in Chinese, this volume details the findings of a 15-year research program in the Qinling Mountains by Wenshi and...
Authors
Frank T. van Manen
Yellowstone grizzly bear investigations — Annual report of the Interagency Grizzly Bear Study Team 2014
This Annual Report summarizes results of grizzly bear (Ursus arctos) monitoring and research conducted in the Greater Yellowstone Ecosystem (GYE) by the Interagency Grizzly Bear Study Team (IGBST) during 2014. The report also contains a summary of grizzly bear management actions to address conflict situations.
Whitebark pine, population density, and home-range size of grizzly bears in the greater Yellowstone ecosystem
Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase...
Authors
Daniel D. Bjornlie, Frank T. van Manen, Michael R. Ebinger, Mark A. Haroldson, Daniel P. Thompson, Cecily M. Costello
Capture-recapture of white-tailed deer using DNA from fecal pellet-groups
Traditional methods for estimating white-tailed deer population size and density are affected by behavioral biases, poor detection in densely forested areas, and invalid techniques for estimating effective trapping area. We evaluated a noninvasive method of capture—recapture for white-tailed deer (Odocoileus virginianus) density estimation using DNA extracted from fecal pellets as an...
Authors
Matthew J Goode, Jared T Beaver, Lisa I. Muller, Joseph D. Clark, Frank T. van Manen, Craig T Harper, P Seth Basinger
Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment
Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work...
Authors
Charles C. Schwartz, Justin E. Teisberg, Jennifer K. Fortin, Mark A. Haroldson, Christopher Servheen, Charles T. Robbins, Frank T. van Manen
Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem
When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We...
Authors
Cecily M. Costello, Frank T. van Manen, Mark A. Haroldson, Michael R. Ebinger, Steven L. Cain, Kerry A. Gunther, Daniel D. Bjornlie
Re-evaluation of Yellowstone grizzly bear population dynamics not supported by empirical data: response to Doak & Cutler
Doak and Cutler critiqued methods used by the Interagency Grizzly Bear Study Team (IGBST) to estimate grizzly bear population size and trend in the Greater Yellowstone Ecosystem. Here, we focus on the premise, implementation, and interpretation of simulations they used to support their arguments. They argued that population increases documented by IGBST based on females with cubs-of-the...
Authors
Frank T. van Manen, Michael R. Ebinger, Mark A. Haroldson, Richard K. Harris, Megan D. Higgs, Steve Cherry, Gary C. White, Charles C. Schwartz
Yellowstone grizzly bear investigations—Annual report of the Interagency Grizzly Bear Study Team 2013
This Annual Report summarizes results of grizzly bear (Ursus arctos) monitoring and research conducted in the Greater Yellowstone Ecosystem (GYE) by the Interagency Grizzly Bear Study Team (IGBST) during 2013. The report also contains a summary of nuisance grizzly bear management actions.