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Mark Haroldson

Mark Haroldson is a USGS Supervisory Wildlife Biologist for the Interagency Grizzly Bears Study Team and works out of the Northern Rocky Mountain Science Center, Bozeman, MT. 

Research Interest

Mark has had a passion for bears since he began studying them as an undergraduate in 1976.  He has worked in bear research and management in several western states ever since.  Since 1984 he has worked in various capacities for the Interagency Grizzly Bear Study Team in the Greater Yellowstone Ecosystem.   Current research is focused on mortality and population trend of grizzly bears in the Greater Yellowstone Ecosystem.

Education and Certifications

  • B.S. Wildlife Biology, 1979, University of Montana

  • Graduate level class work, 1982-88, University of Montana

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Female grizzly with cubs

Interagency Grizzly Bear Study Team

The Interagency Grizzly Bear Study Team (IGBST) is an interdisciplinary group of scientists and biologists responsible for long-term monitoring and research efforts on grizzly bears in the Greater Yellowstone Ecosystem (GYE). The team was formed by the Department of the Interior (DOI) in 1973 as a direct result of controversy surrounding the closure of open pit garbage dumps within Yellowstone...
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Ecosystems Mission Area, Species Management Research Program, Northern Rocky Mountain Science Center
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Interagency Grizzly Bear Study Team

The Interagency Grizzly Bear Study Team (IGBST) is an interdisciplinary group of scientists and biologists responsible for long-term monitoring and research efforts on grizzly bears in the Greater Yellowstone Ecosystem (GYE). The team was formed by the Department of the Interior (DOI) in 1973 as a direct result of controversy surrounding the closure of open pit garbage dumps within Yellowstone...
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Grizzly bear in the Greater Yellowstone Ecosystem

NOROCK Large Carnivore Research Program

NOROCK has substantial expertise in large carnivore research, primarily involving species listed as Threatened or Endangered. NOROCK’s Large Carnivore Research Program includes scientists from NOROCK’s Headquarters, West Glacier Field Station, and the Southern Appalachian Field Station. Studies are conducted in a wide variety of landscapes throughout the U.S., as well as international research...
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Ecosystems Mission Area, Northern Rocky Mountain Science Center
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NOROCK Large Carnivore Research Program

NOROCK has substantial expertise in large carnivore research, primarily involving species listed as Threatened or Endangered. NOROCK’s Large Carnivore Research Program includes scientists from NOROCK’s Headquarters, West Glacier Field Station, and the Southern Appalachian Field Station. Studies are conducted in a wide variety of landscapes throughout the U.S., as well as international research...
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Mortality, morphology, and water chemistry for 6PPD-quinone exposed coho embryos

Understanding evolutionary processes that drive population dynamics is critical in ecology. Measuring the performance-density relationship in long-lived mammalian species demands long-term data, limiting the ability to observe such mechanisms. We tested density-dependent (intrinsic) and density-independent (extrinsic) drivers of body composition of grizzly bears (Ursus arctos) in the Greater Yello
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Western Fisheries Research Center, Fish Health Program (FHP)

Body composition data of grizzly bears in the Greater Yellowstone Ecosystem 2000-2020

Understanding evolutionary processes that drive population dynamics is critical in ecology. Measuring the performance-density relationship in long-lived mammalian species demands long-term data, limiting the ability to observe such mechanisms. We tested density-dependent (intrinsic) and density-independent (extrinsic) drivers of body composition of grizzly bears (Ursus arctos) in the Greater Yello
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Northern Rocky Mountain Science Center

Documented known and probable grizzly bear mortalities in the Greater Yellowstone Ecosystem, 2015-2022 (ver. 2.0, April 2023)

We evaluate mortalities for population segments within the DMA by deriving estimates of total mortality for independent-age (equal to or less than 2 years old) females and independent-age males, including estimates of unknown/unreported mortalities based on Cherry et al. (2002). We then determine the total annual mortality rate for these segments as a percent of their respective population estimat
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Northern Rocky Mountain Science Center

Detection histories of grizzly bears in Grand Teton National Park, 2014-2015

This dataset contains detection histories of grizzly bears in areas of Grand Teton National Park that are open for elk harvest as part of the Elk Reduction Program. Sampling followed a robust design analysis with 6 primary sampling periods of 4 weekly secondary sampling periods each during 2014-2015. In both years, primary sampling periods were in July-August (no elk hunt), September-October (no e
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Northern Rocky Mountain Science Center

Canine distemper virus antibody titer results for grizzly bears and wolves in the Greater Yellowstone Ecosystem 1984-2014

We investigated the dynamics of canine distemper virus (CDV) in grizzly bears (Ursus arctos) and wolves (Canis lupus) of the Greater Yellowstone Ecosystem using serological data collected from 1984 to 2014. 565 sera samples were obtained from 425 unique grizzly bears (134 females and 291 males) from 1984 to 2014 and 319 sera samples were obtained from 285 unique wolves (130 females and 155 males)
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Northern Rocky Mountain Science Center

Potential movement paths for male grizzly bear (Ursus arctos) dispersal between the Northern Continental Divide and Greater Yellowstone Ecosystems, 2000-2015

For several decades, grizzly bear (Ursus arctos) populations in the Greater Yellowstone Ecosystem (GYE) and the Northern Continental Divide Ecosystem (NCDE) have increased in numbers and range extent. Whereas the NCDE population is contiguous with grizzly bear populations in the Canadian Rocky Mountains, genetic evidence suggests the GYE population remains isolated. Recent analyses indicate the ef
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Northern Rocky Mountain Science Center
Filter Total Items: 77

Evidence for density-dependent effects on body composition of a large omnivore in a changing Greater Yellowstone Ecosystem

Understanding the density-dependent processes that drive population demography in a changing world is critical in ecology, yet measuring performance–density relationships in long-lived mammalian species demands long-term data, limiting scientists' ability to observe such mechanisms. We tested performance–density relationships for an opportunistic omnivore, grizzly bears (Ursus arctos, Linnaeus, 17
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Andrea Corradini, Mark A. Haroldson, Francesca Cagnacci, Cecily M. Costello, Daniel D. Bjornlie, Daniel Thompson, Jeremy M. Nicholson, Kerry A. Gunther, Katharine R. Wilmot, Frank T. van Manen
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Grizzly bear movement models predict habitat use for nearby populations

Conservation planning and decision-making can be enhanced by ecological models that reliably transfer to times and places beyond those where models were developed. Transferrable models can be especially helpful for species of conservation concern, such as grizzly bears (Ursus arctos). Currently, only four grizzly bear populations remain in the contiguous United States. We evaluated transferability
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Sarah Nelson Sells, Cecily M. Costello, Paul Lukacs, Frank T. van Manen, Mark A. Haroldson, Wayne Kasworm, Justin Tesiberg, Milan Vinks, Daniel D. Bjornlie
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Enhancements to population monitoring of Yellowstone grizzly bears

In the Greater Yellowstone Ecosystem, counts of female grizzly bears (Ursus arctos) with cubs-of-the-year (females with cubs) from systematic aerial surveys and opportunistic ground sightings are combined with demographic data to derive annual population estimates. We addressed 2 limitations to the monitoring approach. As part of a rule set, a conservative distance of >30 km currently is used as a
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Frank T. van Manen, Michael Ebinger, Cecily M. Costello, Daniel D. Bjornlie, Justin Clapp, Daniel Thompson, Mark A. Haroldson, Kevin L. Frey, Curtis Hendricks, Jeremy M. Nicholson, Kerry A. Gunther, Katharine R. Wilmot, Hilary Cooley, Jennifer Fortin-Noreus, Pat Hnilicka, Daniel B. Tyers
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Genetic architecture and evolution of color variation in American black bears

Color variation is a frequent evolutionary substrate for camouflage in small mammals, but the underlying genetics and evolutionary forces that drive color variation in natural populations of large mammals are mostly unexplained. The American black bear, Ursus americanus (U. americanus), exhibits a range of colors including the cinnamon morph, which has a similar color to the brown bear, U. arctos,
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E. Puckett, I. S. Davis, D. C. Harper, K. Wakamatsu, G. Battu, J. L. Belant, D. E. Beyer, C. Carpenter, A. P. Crupi, M. Davidson, C. S. DePerno, N. Forman, N. L. Fowler, D. L. Garshelis, N. Gould, K. Gunther, Mark A. Haroldson, S. Ito, David. M Kocka, C. Lackey, R. Leahy, C. Lee-Roney, T. Lewis, A. Lutto, K. McGowan, C. Olfenbuttel, M. Orlando, A. Platt, M. D. Pollard, M. Ramaker, Heather Reich, Jaime L. Sajecki, S. K. Sell, J. Strules, S. Thompson, Frank T. van Manen, Craig Whitman, R. Williamson, F. Winslow, C. B. Kaelin, M. S. Marks, G. S. Barsh
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Yellowstone Grizzly Bear Investigations 2022: Annual Report of the Interagency Grizzly Bear Study Team

No abstract available.
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Agent-based models for collective animal movement: Proximity-induced state switching

Animal movement is a complex phenomenon where individual movement patterns can be influenced by a variety of factors including the animal’s current activity, available terrain and habitat, and locations of other animals. Motivated by modeling grizzly bear movement in the Greater Yellowstone Ecosystem, this article presents an agent-based model represented in a state-space framework for collective
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Andrew B. Hoegh, Frank T. van Manen, Mark A. Haroldson
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Physiological consequences of consuming low-energy foods: Herbivory coincides with a stress response in Yellowstone bears.

Meat, fruit, seeds and other high-energy bear foods are often highly localized and briefly available and understanding which factors influence bear consumption of these foods is a common focus of bear conservation and ecology. However, the most common bear foods, graminoids and forbs, are more widespread but of lower quality. We poorly understand how herbage consumption impacts bear physiology, su
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David A Christianson, Tyler H Coleman, Quint Doan, Mark A. Haroldson
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

A reassessment of Chao2 estimates for population monitoring of grizzly bears in the Greater Yellowstone Ecosystem

The Yellowstone Ecosystem Subcommittee (YES) asked the Interagency Grizzly Bear Study Team (IGBST) to re-assess a technique used in annual population estimation and trend monitoring of grizzly bears in the Greater Yellowstone Ecosystem (GYE). This technique is referred to as the Chao2 approach and estimates the number of females with cubs-of-the-year (hereafter, females with cubs) and, in associat
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Frank T. van Manen, Michael R. Ebinger, Mark A. Haroldson, Daniel D. Bjornlie, Justin Clapp, Daniel J. Thompson, Kevin L. Frey, Cecily M. Costello, Curtis Hendricks, Jeremy M. Nicholson, Kerry A. Gunther, Katharine R. Wilmot, Hilary Cooley, Jennifer Fortin-Noreus, Pat Hnilicka, Daniel B. Tyers
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Quantifying energetic costs and defining energy landscapes experienced by grizzly bears

Animal movements are major determinants of energy expenditure and ultimately the cost–benefit of landscape use. Thus, we sought to understand those costs and how grizzly bears (Ursus arctos) move in mountainous landscapes. We trained captive grizzly bears to walk on a horizontal treadmill and up and down 10% and 20% slopes. The cost of moving upslope increased linearly with speed and slope angle,
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Anthony M. Carnahan, Frank T. van Manen, Mark A. Haroldson, Gordon Stenhouse, Charles T. Robbins
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Thermal constraints on energy balance, behaviour and spatial distribution of grizzly bears

1. Heat dissipation limit theory posits that energy available for growth and reproduction in endotherms is limited by their ability to dissipate heat. In mammals, endogenous heat production increases markedly during gestation and lactation, and thus female mammals may be subject to greater thermal constraints on energy expenditure than males. Such constraints likely have important implications for
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Savannah A. Rogers, Charlie T. Robbins, Paul D. Mathewson, Anthony M. Carnahan, Frank T. van Manen, Mark A. Haroldson, Warren P. Porter, Taylor R. Rogers, Terrence Soule, Ryan A. Long
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Yellowstone grizzly bear investigations 2020 - Annual report of the Interagency Grizzly Bear Study Team

This Annual Report summarizes results of grizzly bear (Ursus arctos) research and monitoring conducted in the Greater Yellowstone Ecosystem (GYE) by the Interagency Grizzly Bear Study Team (IGBST) during 2020. The research and monitoring program is focused on population estimation and demographics, food monitoring, and habitat monitoring. This report also presents a summary of grizzly bear managem
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Ecosystems Mission Area, Northern Rocky Mountain Science Center

Brown Bear (Ursus arctos; North America)

This chapter comprises the following sections: names, taxonomy, subspecies and distribution, descriptive notes, habitat, movements and home range, activity patterns, feeding ecology, reproduction and growth, behavior, parasites and diseases, status in the wild, and status in captivity.
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Mark A. Haroldson, Melanie Clapham, Cecily M. Costello, Kerry A. Gunther, Kate Kendall, Sterling Miller, Karine Pigeon, Michael F. Proctor, Karyn D. Rode, Christopher Servheen, Gordon Stenhouse, Frank T. van Manen
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Ecosystems Mission Area, Northern Rocky Mountain Science Center
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In a changing ecosystem, Yellowstone grizzly bears are resilient

BOZEMAN, Mont. — Grizzly bears in the Greater Yellowstone Ecosystem have been able to gain the body fat they need for hibernation even as population...

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