USGS field technician photographing bumble bees captured during monitoring surveys at Logan Pass, Glacier National Park, Montana.
Tabitha Graves, Ph.D.
I answer applied research questions at the intersection of wildlife biology, landscape ecology, and statistics.
Research Interests
My work falls under three broad themes: (1) understand the influence of humans and associated land use impacts on wildlife distributions, densities, and related processes at local and landscape scales, (2) develop new analytical tools that address the influence of landscape features on animals at the sub-population and population scales, and (3) improve efficiency of research and monitoring through optimal study design. I have >15 years experience studying grizzly bears, bighorn sheep, elk, and the development of novel and integrated analyses of habitat use, connectivity, migration, and genetics, all very applied work. I have also assisted with projects studying black bears, wolverines, mountain goats, wolves, lynx, kinkajou, loons, hawks, owls, riparian vegetation, pika, and sugar pine.
Current projects
- Chronic wasting disease- evaluating changes in density and contacts across multiple cervid populations
- Assessing current and changing forage for elk and mule deer with climate change
- Assessing connectivity and migration in and around Glacier National Park (GNP)
- Optimal monitoring of wildlife with occupancy models
- Pollinator communities and Western bumble bee assessment on BLM lands in Montana and the Dakotas, in GNP, and across the west
- Mountain goat and bighorn sheep abundance, trend, population structure, and habitat
- Spatial capture recapture approaches
- Water to Wildlife: Connecting changes in water to vegetation to wildlife across 3 northwest parks
- Evaluating potential impacts of climate change on berry plant abundance and production
Science and Products
Filter Total Items: 17
USGS Chronic Wasting Disease Research at NOROCK
Chronic wasting disease (CWD) is a growing management issue in the U.S. and has been detected in 36 states as of April 2025, including many western states. There is no cure or vaccine for CWD, and the disease threatens economically important animals like elk and deer. NOROCK scientists have taken a multi-pronged approach to develop actionable science including 1) evaluating CWD management options...
USGS Chronic Wasting Disease Research at the National Elk Refuge
Over the past 20 years, chronic wasting disease (CWD) in Wyoming has been spreading slowly outward from the southeastern corner of the state into the Greater Yellowstone Area and Wyoming's elk feed grounds. CWD detections have been getting closer to the National Elk Refuge, which provides supplemental feeding to approximately 8,000 elk and 500 bison each winter. NOROCK scientists have been...
Developing Tools to Evaluate Chronic Wasting Disease Transmission Risk
Chronic Wasting Disease (CWD) infects and kills ungulates (deer, elk, moose), and has been spreading across North America for the past 20 years. Some ungulate populations have declined because of CWD and there are no viable vaccines or treatments for this disease. Therefore, tools that assist wildlife managers in preventing and mitigating CWD can be powerful assets in protecting our nation’s big...
Bighorn Sheep and Mountain Goat Research in Western National Park Units
Mountain goat and bighorn sheep are iconic symbols of many national lands in the West. Both species have limited distributions that can be difficult to observe and face multiple stressors including disease, increasing recreation in remote areas, and shifting weather regimes that influence their forage and thermoregulation. As species with relatively small population sizes, understanding...
Using Pollinator Environmental DNA to Assess the Ecological Resilience of America’s Grasslands
Scientists from six USGS science centers are collaborating with USDA, university, and Tribal partners, and Department of the Interior land managers, to assess the status of pollinator communities and the distribution of species of conservation concern using environmental DNA. These methods will be used to improve assessments of habitat quality and pollinator responses to restoration, including...
By
Species Management Research Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Great Lakes Science Center, Northern Prairie Wildlife Research Center, Northern Rocky Mountain Science Center, Upper Midwest Environmental Sciences Center, Pacific Northwest Environmental DNA Laboratory
From Water to Wildlife: Linking Water Timing and Availability to Meadows and Wildlife in a Changing Climate
Mountain meadows in the western United States provide key habitats for many plant and wildlife species, many of which rely exclusively on these areas. Mountain meadows are also treasured by the public and provide beautiful areas to view wildflowers and wildlife on public lands such as national parks. However, mountain ecosystems are expected to be disproportionately affected by climate...
Western Bumble Bee and Native Pollinator Research
The western bumble bee was historically one of the most common bumble bees across the western U.S. and Canada. However, our research and others found it has declined substantially across its range and the U.S. Fish and Wildlife Service is considering it for listing under the Endangered Species Act. Bureau of Land Management, National Park Service, and other land managers need information to inform...
Predicting Future Forage Conditions for Elk and Mule Deer in Montana and Wyoming
Improving the quality of habitat for western big-game species, such as elk and mule deer, was identified as a priority by the Department of the Interior in 2018. Maintaining healthy herds not only supports the ecosystems where these species are found, but also the hunting and wildlife watching communities. For example, in Wyoming, big game hunting contributed over $300 million to the...
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...
Science in Glacier National Park
Glacier National Park (GNP) is considered a stronghold for a large diversity of plant and animal species and harbors some of the last remaining populations of threatened and endangered species such as grizzly bear and bull trout, as well as non threatened, yet ecologically important species such as bighorn sheep and black bear. The mountain ecosystems of GNP that support these species are dynamic...
Long Term Research in northwest Montana
The Northern Continental Divide Ecosystem (NCDE) in northwest Montana is one of the last strongholds of the grizzly bear in the lower 48 states. Of the six established grizzly bear recovery zones, the NCDE is the third largest in area, potentially harboring the greatest number of grizzly bears, and is the only zone contiguous to a strong Canadian population. However, little information exists...
Grizzly Bear Family Tree
Building a family tree of grizzly bears can both satisfy our natural curiosity about bear society and answer many ecologically important questions about the ways bears interact with each other and the landscape.
Photographing bumble bees
USGS field technician photographing bumble bees captured during monitoring surveys at Logan Pass, Glacier National Park, Montana.
Western Bumble Bee
Many bumble bee species have declined in recent decades due to changes in habitat, climate, and pressures from pathogens, pesticides and introduced species. The western bumble bee, once common throughout western North America, is a species of concern and is being considered for listing by the U.S. Fish and Wildlife Service under the Endangered Species Act.
Many bumble bee species have declined in recent decades due to changes in habitat, climate, and pressures from pathogens, pesticides and introduced species. The western bumble bee, once common throughout western North America, is a species of concern and is being considered for listing by the U.S. Fish and Wildlife Service under the Endangered Species Act.
Bighorn Sheep Ram
The USGS studies bighorn sheep movements, population structures, and habitat use in and near Glacier National Park.
The USGS studies bighorn sheep movements, population structures, and habitat use in and near Glacier National Park.
Science and Products
Filter Total Items: 17
USGS Chronic Wasting Disease Research at NOROCK
Chronic wasting disease (CWD) is a growing management issue in the U.S. and has been detected in 36 states as of April 2025, including many western states. There is no cure or vaccine for CWD, and the disease threatens economically important animals like elk and deer. NOROCK scientists have taken a multi-pronged approach to develop actionable science including 1) evaluating CWD management options...
USGS Chronic Wasting Disease Research at the National Elk Refuge
Over the past 20 years, chronic wasting disease (CWD) in Wyoming has been spreading slowly outward from the southeastern corner of the state into the Greater Yellowstone Area and Wyoming's elk feed grounds. CWD detections have been getting closer to the National Elk Refuge, which provides supplemental feeding to approximately 8,000 elk and 500 bison each winter. NOROCK scientists have been...
Developing Tools to Evaluate Chronic Wasting Disease Transmission Risk
Chronic Wasting Disease (CWD) infects and kills ungulates (deer, elk, moose), and has been spreading across North America for the past 20 years. Some ungulate populations have declined because of CWD and there are no viable vaccines or treatments for this disease. Therefore, tools that assist wildlife managers in preventing and mitigating CWD can be powerful assets in protecting our nation’s big...
Bighorn Sheep and Mountain Goat Research in Western National Park Units
Mountain goat and bighorn sheep are iconic symbols of many national lands in the West. Both species have limited distributions that can be difficult to observe and face multiple stressors including disease, increasing recreation in remote areas, and shifting weather regimes that influence their forage and thermoregulation. As species with relatively small population sizes, understanding...
Using Pollinator Environmental DNA to Assess the Ecological Resilience of America’s Grasslands
Scientists from six USGS science centers are collaborating with USDA, university, and Tribal partners, and Department of the Interior land managers, to assess the status of pollinator communities and the distribution of species of conservation concern using environmental DNA. These methods will be used to improve assessments of habitat quality and pollinator responses to restoration, including...
By
Species Management Research Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Great Lakes Science Center, Northern Prairie Wildlife Research Center, Northern Rocky Mountain Science Center, Upper Midwest Environmental Sciences Center, Pacific Northwest Environmental DNA Laboratory
From Water to Wildlife: Linking Water Timing and Availability to Meadows and Wildlife in a Changing Climate
Mountain meadows in the western United States provide key habitats for many plant and wildlife species, many of which rely exclusively on these areas. Mountain meadows are also treasured by the public and provide beautiful areas to view wildflowers and wildlife on public lands such as national parks. However, mountain ecosystems are expected to be disproportionately affected by climate...
Western Bumble Bee and Native Pollinator Research
The western bumble bee was historically one of the most common bumble bees across the western U.S. and Canada. However, our research and others found it has declined substantially across its range and the U.S. Fish and Wildlife Service is considering it for listing under the Endangered Species Act. Bureau of Land Management, National Park Service, and other land managers need information to inform...
Predicting Future Forage Conditions for Elk and Mule Deer in Montana and Wyoming
Improving the quality of habitat for western big-game species, such as elk and mule deer, was identified as a priority by the Department of the Interior in 2018. Maintaining healthy herds not only supports the ecosystems where these species are found, but also the hunting and wildlife watching communities. For example, in Wyoming, big game hunting contributed over $300 million to the...
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...
Science in Glacier National Park
Glacier National Park (GNP) is considered a stronghold for a large diversity of plant and animal species and harbors some of the last remaining populations of threatened and endangered species such as grizzly bear and bull trout, as well as non threatened, yet ecologically important species such as bighorn sheep and black bear. The mountain ecosystems of GNP that support these species are dynamic...
Long Term Research in northwest Montana
The Northern Continental Divide Ecosystem (NCDE) in northwest Montana is one of the last strongholds of the grizzly bear in the lower 48 states. Of the six established grizzly bear recovery zones, the NCDE is the third largest in area, potentially harboring the greatest number of grizzly bears, and is the only zone contiguous to a strong Canadian population. However, little information exists...
Grizzly Bear Family Tree
Building a family tree of grizzly bears can both satisfy our natural curiosity about bear society and answer many ecologically important questions about the ways bears interact with each other and the landscape.
Photographing bumble bees
USGS field technician photographing bumble bees captured during monitoring surveys at Logan Pass, Glacier National Park, Montana.
USGS field technician photographing bumble bees captured during monitoring surveys at Logan Pass, Glacier National Park, Montana.
Western Bumble Bee
Many bumble bee species have declined in recent decades due to changes in habitat, climate, and pressures from pathogens, pesticides and introduced species. The western bumble bee, once common throughout western North America, is a species of concern and is being considered for listing by the U.S. Fish and Wildlife Service under the Endangered Species Act.
Many bumble bee species have declined in recent decades due to changes in habitat, climate, and pressures from pathogens, pesticides and introduced species. The western bumble bee, once common throughout western North America, is a species of concern and is being considered for listing by the U.S. Fish and Wildlife Service under the Endangered Species Act.
Bighorn Sheep Ram
The USGS studies bighorn sheep movements, population structures, and habitat use in and near Glacier National Park.
The USGS studies bighorn sheep movements, population structures, and habitat use in and near Glacier National Park.