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.
Tabitha Graves
Biography
Education
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
Research Interests
I answer applied research questions at the intersection of wildlife biology, landscape ecology, and statistics. 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.
Science and Products
Date published: July 21, 2019
Status: Active Western Bumblebee and Native Pollinator Research
The western bumblebee (Bombus occidentalis) occurs across western U.S. and Canada, and was one of the most common bumblebees in this region. However, research suggests it has been declining, and the U.S. Fish and Wildlife Service will consider it for listing under the Endangered Species Act. Data are needed to improve our understanding of the resilience, redundancy, and representation of the...
Contacts: Tabitha Graves
Attribution: Ecosystems, Northern Rocky Mountain Science Center (NOROCK)
Date published: September 19, 2017
Status: Active 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...
Date published: September 13, 2017
Status: Active 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 keystone species such as bighorn sheep and black bear. The mountain ecosystems of GNP that support these species are dynamic and influenced...
Date published: January 25, 2017
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...
Contacts: Tabitha Graves, Kate Kendall
Date published: April 12, 2016
Grizzly Bear Dispersal
This work has two components. First, we developed a method to use our family tree data to examine dispersal. Next, we would like to apply this method to our updated and more complete family tree to improve our understanding of how grizzly bears disperse.
Contacts: Tabitha Graves
Date published: April 12, 2016
Predicting changes in Bear Foods
Huckleberries are central to the diets of bears, grouse, and other animals, as well as being a cultural and food resource for humans. Approximately 15% of the diet of bears in the Whitefish range and Glacier National Park is huckleberries, and huckleberries help bears gain weight for hibernation. Changes in climate lead to changes in vegetation phenology, productivity, and quality that may...
Contacts: Tabitha Graves
Date published: April 12, 2016
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.
Contacts: Tabitha Graves
Date published: April 10, 2016
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...
Contacts: Tabitha Graves
Date published: April 9, 2016
Status: Active 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. ...
Date published: March 9, 2016
Status: Completed ScienceCache
If you like to geocache and you want to contribute to research, or you are a scientist looking to engage the public in repeat observations at a particular place, you should try ScienceCache.
ScienceCache is a scientific geocaching mobile application framework. By melding training and games into the hunt for place-based data...
Date published: April 7, 2015
Status: Active 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...
Attribution: Community for Data Integration (CDI)
Year Published: 2019
To 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...
Mikle, Nathaniel; Graves, Tabitha A.; Olexa, Edward M.Attribution: Northern Rocky Mountain Science Center (NOROCK), Ecosystems
Year Published: 2019
U.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,...
Zeigenfuss, Linda C.; Aikens, Ellen; Aldridge, Cameron L.; Anderson, Patrick J.; Assal, Timothy J.; Bowen, Zachary H.; Chalfoun, Anna D.; Chong, Geneva W.; Eddy-Miller, Cheryl A.; Germaine, Stephen S.; Graves, Tabitha; Homer, Collin G.; Huber, Christopher; Johnston, Aaron; Kauffman, Matthew J.; Manier, Daniel J.; McShane, Ryan R.; Miller, Kirk A.; Monroe, Adrian P.; Ortega, Anna; Walters, Annika W.; Wyckoff, Teal B.Attribution: Fort Collins Science Center, Ecosystems
View Citation
Zeigenfuss, L.C., Aikens, E., Aldridge, C.L., Anderson, P.J., Assal, T.J., Bowen, Z.H., Chalfoun, A.D., Chong, G.W., Eddy-Miller, C.A., Germaine, S.S., Graves, T., Homer, C.G., Huber, C.C., Johnston, A., Kauffman, M.J., Manier, D.J., McShane, R.R., Miller, K.A., Monroe, A.P., Ortega, A., Walters, A.W., and Wyckoff, T.B., 2019, U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report: U.S. Geological Survey Open-File Report 2018–1188, 57 p., https://doi.org/10.3133/ofr20181188.
Year Published: 2019
Keeping 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...
Waller, John S.; Graves, TabithaView Citation
Waller, J and TA Graves. 2018. Keeping the Crown of the Continent Connected: An interagency US2 connectivity workshop report. Unpublished report. National Park Service, Glacier National Park. 30 pp. https://irma.nps.gov/DataStore/Reference/Profile/2259314
Year Published: 2017
Trade-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...
Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P.; Montgomery, Claire A.; McKelvey, Kevin; Kendall, Katherine; Graves, Tabitha A.; Bernstein, Richard; Schwartz, Michael K.
Year Published: 2016
Nature vs. nurture: Evidence for social learning of conflict behaviour in grizzly bears
The propensity for a grizzly bear to develop conflict behaviours might be a result of social learning between mothers and cubs, genetic inheritance, or both learning and inheritance. Using non-invasive genetic sampling, we collected grizzly bear hair samples during 2011–2014 across southwestern Alberta, Canada. We targeted private agricultural...
Morehouse, Andrea T.; Graves, Tabitha A.; Mikle, Nathaniel; Boyce, Mark S.View Citation
Morehouse AT, Graves TA, Mikle N, Boyce MS. 2016. Nature vs. Nurture: Evidence for social learning of conflict behaviour in grizzly bears. PLoS ONE 11(11):e0165425. doi: 10.1371/journal.pone.0165425
Year Published: 2016
Community for Data Integration 2015 annual report
The Community for Data Integration (CDI) continued to experience success in fiscal year 2015. The CDI community members have been sharing, learning, and collaborating through monthly forums, workshops, working groups, and funded projects. In fiscal year 2015, CDI coordinated 10 monthly forums with 16 different speakers from the U.S. Geological...
Langseth, Madison L.; Chang, Michelle Y.; Carlino, Jennifer; Bellmore, J. Ryan; Birch, Daniella D.; Bradley, Joshua; Bristol, R. Sky; Buscombe, Daniel D.; Duda, Jeffrey J.; Everette, Anthony L.; Graves, Tabitha A.; Greenwood, Michelle M.; Govoni, David L.; Henkel, Heather S.; Hutchison, Vivian B.; Jones, Brenda K.; Kern, Tim; Lacey, Jennifer; Lamb, Rynn M.; Lightsom, Frances L.; Long, John L.; Saleh, Ra'ad A.; Smith, Stan W.; Soulard, Christopher E.; Viger, Roland J.; Warrick, Jonathan A.; Wesenberg, Katherine E.; Wieferich, Daniel J.; Winslow, Luke A.Attribution: Community for Data Integration (CDI), Earth Resources Observation and Science (EROS) Center, Earth Resources Observation and Science Center, Science Analytics and Synthesis (SAS), United States of America
View Citation
Langseth, M.L., Chang, M.Y., Carlino, Jennifer, Bellmore, J.R., Birch, D.D., Bradley, Joshua, Bristol, R.S., Buscombe, D.D., Duda, J.J., Everette, A.L., Graves, T.A., Greenwood, M.M., Govoni, H.S., Henkel, H.S., Hutchison, V.B., Jones, B.K., Kern, Tim, Lacey, Jennifer, Lamb, R.M., Lightsom, F.L., Long, J.L., Saleh, R.A., Smith, S.W., Soulard, C.E., Viger, R.J., Warrick, J.A., Wesenberg, K.E., Wieferich, D.J., and Winslow, L.A., 2016, Community for Data Integration 2015 annual report: U.S. Geological Survey Open-File Report 2016–1165, 57 p., http://dx.doi.org/10.3133/ofr20161165.
Year Published: 2016
Northern 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 traps—corrals 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 rubs—naturally occurring trees or other objects that bears rub on fitted with barbed...
Graves, Tabitha A.; Mikle, Nathaniel; Kendall, Katherine C.; Macleod, Amy C.Attribution: Northern Rocky Mountain Science Center (NOROCK)
View Citation
Graves, T.A., Mikle, N.L., Kendall, K.C., and Macleod, A.C., 2016, Northern Continental Divide Ecosystem grizzly bear (Ursus arctos) genetic profiles (1998-2012): U.S. Geological Survey data release, https://dx.doi.org/10.5066/F7Q81B63.
Year Published: 2016
Demographic mechanisms underpinning genetic assimilation of remnant groups of a large carnivore
Current range expansions of large terrestrial carnivores are occurring following human-induced range contraction. Contractions are often incomplete, leaving small remnant groups in refugia throughout the former range. Little is known about the underlying ecological and evolutionary processes that influence how remnant groups are affected during...
Mikle, Nathaniel; Graves, Tabitha A.; Kovach, Ryan P.; Kendall, Katherine C.; Macleod, Amy C.
Year Published: 2016
Density, distribution, and genetic structure of grizzly bears in the Cabinet-Yaak Ecosystem
The conservation status of the 2 threatened grizzly bear (Ursus arctos) populations in the Cabinet-Yaak Ecosystem (CYE) of northern Montana and Idaho had remained unchanged since designation in 1975; however, the current demographic status of these populations was uncertain. No rigorous data on population density and distribution or analysis of...
Macleod, Amy C.; Boyd, Kristina L.; Boulanger, John; Royle, J. Andrew; Kasworm, Wayne F.; Paetkau, David; Proctor, Michael F.; Annis, Kim; Graves, Tabitha A.
Year Published: 2014
Estimating landscape resistance to dispersal
Dispersal is an inherently spatial process that can be affected by habitat conditions in sites encountered by dispersers. Understanding landscape resistance to dispersal is important in connectivity studies and reserve design, but most existing methods use resistance functions with cost parameters that are subjectively chosen by the investigator....
Graves, Tabitha A.; Chandler, Richard B.; Royle, J. Andrew; Beier, Paul; Kendall, Katherine C.
Year Published: 2013
Spatial capture-recapture models for jointly estimating population density and landscape connectivity
Population size and landscape connectivity are key determinants of population viability, yet no methods exist for simultaneously estimating density and connectivity parameters. Recently developed spatial capture–recapture (SCR) models provide a framework for estimating density of animal populations but thus far have not been used to study...
Royle, J. Andrew; Chandler, Richard B.; Gazenski, Kimberly D.; Graves, Tabitha A.View Citation
Spatial capture-recapture models for jointly estimating population density and landscape connectivity; 2013; Article; Journal; Ecology; Royle, J. Andrew; Chandler, Richard B.; Gazenski, Kimberly D.; Graves, Tabitha A.
Year Published: 2012
Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?
Using multiple detection methods can increase the number, kind, and distribution of individuals sampled, which may increase accuracy and precision and reduce cost of population abundance estimates. However, when variables influencing abundance are of interest, if individuals detected via different methods are influenced by the landscape...
Graves, Tabitha A.; Royle, J. Andrew; Kendall, Katherine C.; Beier, Paul; Stetz, Jeffrey B.; Macleod, Amy C.View Citation
Balancing precision and risk: should multiple detection methods be analyzed separately in N-mixture models?; 2012; Article; Journal; PLoS ONE; Graves, Tabitha A.; Royle, J. Andrew; Kendall, Katherine C.; Beier, Paul ; Stetz, Jeffrey B.; Macleod, Amy C.
Pre-USGS Publications
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.
Date published: July 7, 2017
ScienceCache
ScienceCache is a scientific geocaching mobile application framework. By melding training and games into the hunt for place-based data collection sites, and incorporating photo uploads as data or for authentication, new volunteers can collaborate in robust data collection. As a volunteer, simply download the ScienceCache app, choose a route, and then follow the directions to collect data. ...
Date published: December 22, 2016
A Grand Slam for Students, Schools and Science
"It’s a grand slam for all involved,” said Dawn Childs, USGS Cooperative Fish and Wildlife Research Units. “Recent high school graduates with special needs get real-world experience while helping USGS scientists on projects ranging from grizzly bears and energy to historic documents and bird migration. And a school system gets to successfully train students to enter the workforce."
Date published: November 16, 2016
Nature vs. Nurture: Evidence for social learning of conflict behavior in grizzly bears
Offspring of grizzly bear mothers with a history of human-bear conflicts are more likely to be involved in human-bear conflicts than offspring of mothers without a history of human-bear conflicts, according to a new study.
Attribution: Northern Rocky Mountain Science Center (NOROCK)
Date published: September 21, 2016
Both gender and movement important for genetic diversity of grizzly bears.
Grizzly bears in the southern portion of the Northern Continental Divide Ecosystem experienced a rapid increase in genetic diversity, according to a new study led by the USGS.
Attribution: Northern Rocky Mountain Science Center (NOROCK)