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
Professional Experience
Research Ecologist, USGS Northern Rocky Mountain Science Center: 2/10/14-present
David H. Smith Post-doctoral Conservation Research Fellow: 7/12 – 2/14
Education and Certifications
PhD. 2012. Northern Arizona University. Dissertation Title: Spatial ecology of grizzly bears in northwestern Montana and estimating resistance to gene flow
M.S. Wildlife Biology. 2002. University of Montana
Honors B.A. German Literature with distinction. 1995. University of Wisconsin-Madison
Science and Products
Bighorn Sheep in and near Glacier National Park
Ecology of Elk on Department of Interior Lands in Southwest Wyoming
Geocaching Natural Features - Applying Game Mechanics to Citizen Science Data Collection
Historical trend analysis of phenology dates across the Western US from 1982 to 2016
Projected peak instantaneous rate of green-up date and spring scale across Wyoming from 2000 to 2099
Remotely sensed elk locations on the National Elk Refuge, Wyoming, 2017-2019
Western bumble bee predicted occupancy and detection probability rasters for the western continental United States from 1998 to 2018
Ungulate Migrations of the Western United States, Volume 1
Bighorn sheep Ovine HD array genotypes from National Parks, 2004-2011
Bear capture recapture sampling in Glacier National Park, Montana, 2004
West Green River elk herd locations in southwestern Wyoming, 2005-2010
Northern Continental Divide Ecosystem grizzly bear (Ursus arctos) genetic profiles, 1998-2012
Human activities and weather drive contact rates of wintering elk
Systematics, evolution, and genetics of bears
Evaluating wildlife translocations using genomics: A bighorn sheep case study
Ungulate migrations of the western United States, Volume 1
Comparative performance and trend of remotely sensed phenology and productivity metrics across the Western United States
Western bumble bee: Declines in United States and range-wide information gaps
Connectivity in the Crown: Highway 2 wildlife crossings
To forage or flee: Lessons from an elk migration near a protected area
Mapping a keystone shrub species, huckleberry (Vaccinium membranaceum), using seasonal colour change in the Rocky Mountains
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report
Keeping the crown of the continent connected: An interagency US2 connectivity workshop report
Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks
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
Filter Total Items: 15
Bighorn Sheep in and near Glacier National Park
USGS collected GPS data as well as genetic and other samples on over 100 bighorn sheep east of the Continental Divide in Glacier National Park, Waterton National Park, and the Blackfeet Reservation. Bighorn sheep across the west are vulnerable to disease such as pneumonia. We are therefore working to improve our understanding of bighorn sheep movements, approaches for monitoring bighorns, and...Ecology of Elk on Department of Interior Lands in Southwest Wyoming
Between 2005 and 2010, we radio- collared 61 female elk (Cervus elaphus) on Fossil Butte National Monument and 12 female elk near Cokeville, Wyoming, slightly northwest of the Monument, all from the West Green River herd. We are using the 209,250 locations from these elk to identify seasonal distribution patterns, evaluate habitat use, and assess factors influencing the timing of migration...Geocaching Natural Features - Applying Game Mechanics to Citizen Science Data Collection
ScienceCache is a scientific geocaching mobile application framework that targets two user groups for citizen science data collection: youth and geocachers. By melding training and games into the hunt for place-based data collection sites and incorporating photo uploads as data and authentication, new volunteers can collaborate in robust data collection. Scientists build a project on the administr - Data
Filter Total Items: 21
Historical trend analysis of phenology dates across the Western US from 1982 to 2016
These data represent key phenology trends across the western United States from 1982-2016. Using two remote sensing datasets, CMGLSP and VIPPHEN-EVI2, trends were calculated for four phenology variables: Start of Season (SOS), Peak Instantaneous Rate of Green-Up Date (PIRGd), Peak of Season (POS), and End of Season (EOS). The Theil-Sen slope and standard deviation were applied to the phenology metProjected peak instantaneous rate of green-up date and spring scale across Wyoming from 2000 to 2099
These data represent projections of peak instantaneous rate of green-up date (PIRGd) and spring scale across Wyoming from 2000-2099. Annual data is provided in gridded time series at approximately 4 km spatial resolution. Projections were generated by applying linear mixed models to contemporary remote sensing data, and applying model parameters to future climate projection data from the MACA dataRemotely sensed elk locations on the National Elk Refuge, Wyoming, 2017-2019
Remotely sensed elk locations were derived from satellite and Unmanned Aerial Systems (UAS) imagery collected during the winter of 2018 and the winter and spring of 2019 at the National Elk Refuge in Jackson, Wyoming and compared to locations from Global Positioning System (GPS) collars from 2017 - 2019. This data release provides the source, date, time, latitude, and longitude of elk locations anWestern bumble bee predicted occupancy and detection probability rasters for the western continental United States from 1998 to 2018
These data represent occupancy estimates for western bumble bee across the western continental United States and the spatial variation in detection probabilities that occur during bumble bee surveys. This product contains five raster layers (appearing as separate bands in a multi-band raster). The first two bands represent the predicted occupancy of western bumble bee in 1998 and 2018. We modeledUngulate Migrations of the Western United States, Volume 1
This is the data archive for the publication Ungulate Migrations of the Western United States, Volume 1 (Kauffman et al. 2020) and includes the collection of GIS map files that are mapped and described in the report. These map files are meant to provide a common spatial representation of the mapped migrations. This data release provides the means for ungulate migrations to be mapped and planned foBighorn sheep Ovine HD array genotypes from National Parks, 2004-2011
Between 2004 and 2011 bighorn sheep were darted in Glacier National Park and in Dinosaur National Monument. Blood was drawn. These are the genotypes resulting from an Ovine HD array from the bighorns. The first 3 columns refers to bighorn sheep identifiers: 'Herd_Unit', 'IndID', and 'AgencyID'. IndID is the identifier assigned at Montana State University. Subsequent columns each represent a locus,Bear capture recapture sampling in Glacier National Park, Montana, 2004
Text files containing detection events from genetic sampling sites associated with the unique identifier of American black bears in Glacier National Park, Montana, USA, 2004. Data is formatted for spatial capture recapture data analysis.West Green River elk herd locations in southwestern Wyoming, 2005-2010
Between 2005 and 2010, 61 adult female elk were trapped using a baited corral trap on Fossil Butte National Monument during winter. An additional 12 female elk were darted from a helicopter during the winter of 2007 near Cokeville, WY, located approximately 20 km northwest of the Monument. We affixed all elk with GPS collars programmed to collect location data every 5 hours. In total we collectedNorthern Continental Divide Ecosystem grizzly bear (Ursus arctos) genetic profiles, 1998-2012
Two independent sampling methods were used to collect genetic samples from grizzly bears (Ursus arctos): (i) hair trapscorrals of barbed wire with lure in the center systematically distributed using an 8 x 8 km (1998, 2000) or 7 x 7 km (2004) grid and (ii) bear rubsnaturally occurring trees or other objects that bears rub on fitted with barbed wire (19982000, 2004, and 20092012). From 1998 to 2000 - Multimedia
- Publications
Filter Total Items: 32
Human activities and weather drive contact rates of wintering elk
Wildlife aggregation patterns can influence disease transmission. However, limited research evaluates the influence of anthropogenic and natural factors on aggregation. Many managers would like to reduce wildlife contact rates, driven by aggregation, to limit disease transmission. We develop a novel analytical framework to quantify how management activities such as supplemental feeding and huntingAuthorsWilliam Michael Janousek, Tabitha Graves, Ethan Berman, Geneva W. Chong, Eric K Cole, Sarah Dewey, Aaron N. Johnston, Paul C. CrossSystematics, evolution, and genetics of bears
Molecular genetics are key to understanding current and historical relationships between isolated populations, including species’ colonizations during glacial–interglacial cycles, to determine viability of local populations, needs for habitat corridors, and other aspects of population management, especially where bears are harvested for sport, etc. As natural habitats shrink, some bear species wilAuthorsAndrew C Kitchener, Eva Bellemain, Xiang Ding, Alexander Kopatz, Verena Kutschera, Valentina Salomashkina, Manuel Ruiz-Garcia, Tabitha Graves, Yiling Hou, Lars Werdelin, Axel JankeEvaluating wildlife translocations using genomics: A bighorn sheep case study
Wildlife restoration often involves translocation efforts to reintroduce species and supplement small, fragmented populations. We examined the genomic consequences of bighorn sheep (Ovis canadensis) translocations and population isolation to enhance understanding of evolutionary processes that affect population genetics and inform future restoration strategies. We conducted a population genomic anAuthorsElizabeth P Flesch, Tabitha Graves, Jennifer Thomson, Kelly Proffitt, P.J. White, Thomas R Stephenson, Robert A. GarrottUngulate migrations of the western United States, Volume 1
Across the western United States, many ungulate herds must migrate seasonally to access resources and avoid harsh winter conditions. Because these migration paths cover vast landscapes (in other words migration distances up to 150 miles [241 kilometers]), they are increasingly threatened by roads, fencing, subdivisions, and other development. Over the last decade, many new tracking studies have beAuthorsMatthew Kauffman, Holly Copeland, Jodi Berg, Scott Bergen, Eric Cole, Matthew Cuzzocreo, Sarah Dewey, Julien Fattebert, Jeff Gagnon, Emily Gelzer, Chris Geremia, Tabitha Graves, Kent Hersey, Mark Hurley, Rusty Kaiser, James Meacham, Jerod Merkle, Arthur Middleton, Tristan Nuñez, Brendan Oates, Daniel Olson, Lucas Olson, Hall Sawyer, Cody Schroeder, Scott Sprague, Alethea Steingisser, Mark ThonhoffComparative performance and trend of remotely sensed phenology and productivity metrics across the Western United States
Vegetation phenology and productivity play a crucial role in surface energy balance, plant and animal distribution, and animal movement and habitat use and can be measured with remote sensing metrics including start of season (SOS), peak instantaneous rate of green-up date (PIRGd), peak of season (POS), end of season (EOS), and integrated vegetation indices. However, for most metrics, we do not yeAuthorsTabitha Graves, Ethan Edward Berman, Nathaniel Mikle, Jerod Merkle, Aaron N. Johnston, Geneva W. ChongWestern bumble bee: Declines in United States and range-wide information gaps
In recent decades, many bumble bee species have declined due to changes in habitat, climate, and pressures from pathogens, pesticides, and introduced species. The western bumble bee (Bombus occidentalis ), once common throughout western North America, is a species of concern and will be considered for listing by the U.S. Fish and Wildlife Service (USFWS) under the Endangered Species Act (ESA). WeAuthorsTabitha Graves, William Michael Janousek, Sarah M. Gaulke, Amy Nicholas, Douglas Keinath, Christine M. Bell, Syd Cannings, Richard G. Hatfield, Jennifer M Heron, Jonathan B Koch, Helen L Loffland, Leif L Richardson, Ashley T. Rohde, Jessica Rykken, James P. Strange, Lusha Tronstead, Cory SheffieldConnectivity in the Crown: Highway 2 wildlife crossings
This report summarizes data collected to inform decisions on how to best mitigate the effects on wildlife migration from increasing traffic, development, and recreation along US highway 2. The highway, railway, and river split the Crown of the Continent Ecosystem. This data addresses SO 3362 by providing information on major wildlife trails, observed wildilfe crossings and road kills, and identiAuthorsJohn S. Waller, Tabitha Graves, Brad Anderson, Brandon Kittson, Sarah Mccrimmon GaulkeTo forage or flee: Lessons from an elk migration near a protected area
Alteration of wide-ranging wildlife migrations can drastically impact the structure and function of ecosystems, yet the causes and consequences of shifting migration patterns remain largely unknown. Management decisions made in one portion of a landscape may induce spatial and temporal shifts of wildlife use in another, creating tension among private, state, and federal lands with varying missionsAuthorsNathaniel Mikle, Tabitha A. Graves, Edward M. OlexaMapping a keystone shrub species, huckleberry (Vaccinium membranaceum), using seasonal colour change in the Rocky Mountains
Black huckleberries (Vaccinium membranaceum) provide a critical food resource to many wildlife species, including apex omnivores such as the grizzly bear (Ursus arctos), and play an important socioeconomic role for many communities in western North America, especially indigenous peoples. Remote sensing imagery offers the potential for accurate landscape-level mapping of huckleberries because the sAuthorsCarolyn R. Shores, Nathaniel Mikle, Tabitha A. GravesU.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report
The Wyoming Landscape Conservation Initiative (WLCI) was established in 2008 to address the scientific and conservation questions associated with land use changes because of energy development and other factors in southwest Wyoming. Over the past decade, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implemAuthorsLinda Zeigenfuss, Ellen Aikens, Cameron L. Aldridge, Patrick J. Anderson, Timothy J. Assal, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Cheryl A. Eddy-Miller, Stephen S. Germaine, Tabitha Graves, Collin G. Homer, Christopher Huber, Aaron N. Johnston, Matthew J. Kauffman, Daniel J. Manier, Ryan R. McShane, Kirk A. Miller, Adrian P. Monroe, Anna Ortega, Annika W. Walters, Teal B. WyckoffKeeping the crown of the continent connected: An interagency US2 connectivity workshop report
At over 2.5 million acres, Glacier National Park and the Bob Marshall Wilderness complex form one of the largest protected areas in the continental United States. Straddling the Continental Divide, these two areas form a vital linkage between vast areas of public land to the south towards Yellowstone, and contiguous protected areas north of the US-Canada border. However, US Highway 2 (US2) and theAuthorsJohn S. Waller, Tabitha GravesTrade-offs and efficiencies in optimal budget-constrained multispecies corridor networks
Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that desAuthorsBistra Dilkina, Rachel Houtman, Carla P. Gomes, Claire A. Montgomery, Kevin McKelvey, Katherine Kendall, Tabitha A. Graves, Richard Bernstein, Michael K. SchwartzNon-USGS Publications**
Graves, T.A., S. Farley, M. Goldstein, and C.Servheen. 2007. Identification of functional corridors with movement characteristics of brown bears on the Kenai Peninsula, Alaska. Landscape Ecology.Graves, T.A., S. Farley, and C.Servheen. 2006. Frequency and distribution of highway crossings by Kenai Peninsula brown bears. Wildlife Society Bulletin. 34: 800-808.Graves, T.A. and J. Waller. 2006. Identification of causes of missed fixes in GPS collar on animals. Journal of Wildlife Management. 70: 844-851.**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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