As a Principle Investigator and Research Statistician, I create science to support critical management decisions for hard to study species in a changing environment.
Such situations produce data that tend to be sparse, biased and/or imprecise, and have large knowledge gaps. Thus, I specialize in modifying state-of-the-art analytical and computational approaches for complex problems and intractable data, as well as creating new statistical theory and techniques when existing methods are inadequate. I routinely use Bayesian and frequentist paradigms.
Species Studied
My career-long species affiliations have varied across the plant and animal kingdoms, but my USGS research centers on marine mammals. I maintain a strong, decade-long collaboration with walrus researchers at USGS, USFWS and ADFG, and I have recently expanded my work to include collaborative sea otter and polar bear research.
Three-year goals
My highest priority goals include five different projects to estimate Pacific walrus abundance (while also refining estimates of their demographic rates and population trend). The Department of Interior needs population size and status information to manage this trust species which is an important resource for native subsistence hunters, is protected and managed under the Marine Mammal Protection Act, and was an endangered species candidate until the 2017 decision not to list—a decision which is being litigated by the Center for Biological Diversity. I also have ongoing demographic work using age-at-death distributions to estimate vital rates, in addition to mechanistic modeling for other species of concern.
Education and Certifications
Ph.D. 2009 Montana State University-Bozeman, MT Fish and Wildlife Biology
M.S. 2008 Montana State University-Bozeman, MT Statistics
M.S. 2001 Montana State University-Bozeman, MT Land Resources and Environmental Sciences
B.S. 1991 University of Wisconsin-Madison, WI Natural Science with majors in Wildlife Ecology and Zoology
Science and Products
Walrus Research
Ecosystems Analytics
Walrus Haulout and In-water Activity Levels Relative to Vessel Interactions in the Chukchi Sea, 2012-2015
Walrus used and available resource units for northeast Chukchi Sea, 2008-2012
Walrus Haulout and In-water Activity Levels Relative to Sea Ice Availability in the Chukchi Sea: 2008-2014
Exploring effects of vessels on walrus behaviors using telemetry, automatic identification system data and matching
Estimating reproductive and juvenile survival rates when offspring ages are uncertain: A novel multievent mark-resight model with beluga whale case study
Brown bear–sea otter interactions along the Katmai coast: Terrestrial and nearshore communities linked by predation
Barrier islands influence the assimilation of terrestrial energy in nearshore fishes
Estimating Pacific walrus abundance and survival with multievent mark-recapture models
Regional walrus abundance estimate in the United States Chukchi Sea in autumn
Abundance and distribution of sea otters (Enhydra lutris) in the southcentral Alaska stock, 2014, 2017, and 2019
Design considerations for estimating survival rates with standing age structures
Demography of the Pacific walrus (Odobenus rosmarus divergens) in a changing Arctic
Forecasting consequences of changing sea ice availability for Pacific walruses
Walrus haul-out and in water activity levels relative to sea ice availability in the Chukchi Sea
Space use of a dominant Arctic vertebrate: Effects of prey, sea ice, and land on Pacific walrus resource selection
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
Walrus Research
The USGS Alaska Science Center conducts long-term research on the Pacific walrus to provide scientific information to Department of Interior management agencies and Alaska Native co-management partners. In addition, the USGS Pacific walrus research program collaborates with the U.S. Fish and Wildlife Service (USFWS) and the State of Alaska’s Department of Fish and Game and Alaska Native co...Ecosystems Analytics
Ecosystems Analytics is a group of quantitative biologists and research statisticians with a diverse range of expertise and experience (summarized below). We collaborate with internal and external partners to answer challenging ecological questions that are a high priority of the U.S. Geological Survey Alaska Science Center, sister agencies within the Department of the Interior (DOI), and various... - Data
Walrus Haulout and In-water Activity Levels Relative to Vessel Interactions in the Chukchi Sea, 2012-2015
These data were used to evaluate effects of vessel exposure on Pacific walrus (Odobenus rosmarus divergens) behaviors. We obtained greater than 120,000 hours of location and behavior (foraging, in-water not foraging, hauled out) data from 218 satellite-tagged walruses and linked them to vessel locations from the marine Automated Information System. This yielded 206 vessel-exposed walrus telemetryWalrus used and available resource units for northeast Chukchi Sea, 2008-2012
Sea ice loss represents a stressor to the Pacific walrus, which feeds on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging walrus space use patterns. Thus, we examined walrus foraging resource selection as a function of proximity to resting substrates and prey biomass with a matched use-availability design. We quantifWalrus Haulout and In-water Activity Levels Relative to Sea Ice Availability in the Chukchi Sea: 2008-2014
An animal's energetic costs are dependent on the amount of time it allocates to various behavioral activities. For Arctic pinnipeds, the time allocated to active and resting behaviors could change with future reductions in sea ice cover and longer periods of open water. The Pacific walrus (Odobenus rosmarus divergens) is a large Arctic pinniped that rests on sea ice or land between foraging trip - Multimedia
- Publications
Filter Total Items: 15
Exploring effects of vessels on walrus behaviors using telemetry, automatic identification system data and matching
Arctic marine mammals have had little exposure to vessel traffic and potential associated disturbance, but sea ice loss has increased accessibility of Arctic waters to vessels. Vessel disturbance could influence marine mammal population dynamics by altering behavioral activity budgets that affect energy balance, which in turn can affect birth and death rates. As an initial step in studying these lAuthorsRebecca L. Taylor, Chadwick V. Jay, William S. Beatty, Anthony S. Fischbach, Lori T. Quakenbush, Justin A. CrawfordEstimating reproductive and juvenile survival rates when offspring ages are uncertain: A novel multievent mark-resight model with beluga whale case study
Understanding the survival and reproductive rates of a population is critical to determining its long-term dynamics and viability. Mark-resight models are often used to estimate these demographic rates, but estimation of survival and reproductive rates is challenging, especially for wide-ranging, patchily distributed, or cryptic species. In particular, existing mark-resight models cannot accommodaAuthorsGina K Himes Boor, Tamara L McGuire, Amanda J. Warlick, Rebecca L. Taylor, Sarah J. Converse, John R McClung, Amber D StephensBrown bear–sea otter interactions along the Katmai coast: Terrestrial and nearshore communities linked by predation
Sea otters were extirpated throughout much of their range by the maritime fur trade in the 18th and 19th centuries, including the coast of Katmai National Park and Preserve in southcentral Alaska. Brown bears are an important component of the Katmai ecosystem where they are the focus of a thriving ecotourism bear-viewing industry as they forage in sedge meadows and dig clams in the extensive tidalAuthorsDaniel Monson, Rebecca L. Taylor, Grant Hilderbrand, Joy Erlenbach, Heather Coletti, James L. BodkinBarrier islands influence the assimilation of terrestrial energy in nearshore fishes
We examined the relative importance of landscape features on estuarine fish trophic structure and dependence on terrestrial organic matter (OMterr) in four barrier island lagoon systems along the Alaskan Beaufort Sea coast. Our study compared two relatively large lagoon systems characterized by high river discharge and relatively free ocean water exchanges (central region near Prudhoe Bay, Alaska)AuthorsAshley E. Stanek, Vanessa R. von Biela, Sarah M. Laske, Rebecca L. Taylor, Kenneth H. DuntonEstimating Pacific walrus abundance and survival with multievent mark-recapture models
Arctic marine ecosystems are undergoing rapid physical and biological change associated with climate warming and loss of sea ice. Sea ice loss will impact many species through altered spatial and temporal availability of resources. In the Bering and Chukchi Seas, the Pacific walrus Odobenus rosmarus divergens is one species that could be impacted by rapid environmental change, and thus, populationAuthorsWilliam S. Beatty, Patrick R. Lemons, Jason P. Everett, Cara J. Lewis, Rebecca L. Taylor, Robert J. Lynn, Suresh A. Sethi, Lori T. Quakenbush, John J. Citta, Michelle Kissling, Natalia Kryukova, John K. WennburgRegional walrus abundance estimate in the United States Chukchi Sea in autumn
Human activities (e.g., shipping, tourism, oil, gas development) have increased in the Chukchi Sea because of declining sea ice. The declining sea ice itself and these activities may affect Pacific walrus (Odobenus rosmarus divergens) abundance; however, previous walrus abundance estimates have been notably imprecise. When sea ice is absent from the eastern Chukchi Sea, walruses in waters of the UAuthorsAnthony S. Fischbach, Rebecca L. Taylor, Chadwick V. JayAbundance and distribution of sea otters (Enhydra lutris) in the southcentral Alaska stock, 2014, 2017, and 2019
The Southcentral Alaska (SCAK) sea otter (Enhydra lutris) stock is the northernmost stock of sea otters, a keystone predator known for structuring nearshore marine ecosystems. We conducted aerial surveys within the range of the SCAK sea otter stock to provide recent estimates of sea otter abundance and distribution. We defined three survey regions: (1) Eastern Cook Inlet (2017), (2) Outer Kenai PeAuthorsGeorge G. Esslinger, Brian H. Robinson, Daniel H. Monson, Rebecca L. Taylor, Daniel Esler, Ben P. Weitzman, Joel Garlich-MillerDesign considerations for estimating survival rates with standing age structures
Survival rate estimates are critical to understanding the dynamics and status of a population, and they are often inferred from samples of the population’s age structure. A recently developed method uses time series of standing age-structure data with information about population growth rate or fecundity to provide explicit maximum likelihood estimators of age-specific survival rates, without assuAuthorsRebecca L. Taylor, Mark S. UdevitzDemography of the Pacific walrus (Odobenus rosmarus divergens) in a changing Arctic
The Pacific walrus (Odobenus rosmarus divergens) is a candidate to be listed as an endangered species under United States law, in part, because of climate change‐related concerns. While the population was known to be declining in the 1980s and 1990s, its recent status has not been determined. We developed Bayesian models of walrus population dynamics to assess the population by synthesizing informAuthorsRebecca L. Taylor, Mark S. Udevitz, Chadwick V. Jay, John J. Citta, Lori T. Quakenbush, Patrick R. Lemons, Jonathan A. SnyderForecasting consequences of changing sea ice availability for Pacific walruses
The accelerating rate of anthropogenic alteration and disturbance of environments has increased the need for forecasting effects of environmental change on fish and wildlife populations. Models linking projections of environmental change with behavioral responses and bioenergetic effects can provide a basis for these forecasts. There is particular interest in forecasting effects of projected reducAuthorsMark S. Udevitz, Chadwick V. Jay, Rebecca L. Taylor, Anthony S. Fischbach, William S. Beatty, Shawn R. NorenWalrus haul-out and in water activity levels relative to sea ice availability in the Chukchi Sea
An animal’s energetic costs are dependent on the amount of time it allocates to various behavioral activities. For Arctic pinnipeds, the time allocated to active and resting behaviors could change with future reductions in sea ice cover and longer periods of open water. The Pacific walrus (Odobenus rosmarus divergens) is a large Arctic pinniped that rests on sea ice or land between foraging tripsAuthorsChadwick V. Jay, Rebecca L. Taylor, Anthony S. Fischbach, Mark S. Udevitz, William S. BeattySpace use of a dominant Arctic vertebrate: Effects of prey, sea ice, and land on Pacific walrus resource selection
Sea ice dominates marine ecosystems in the Arctic, and recent reductions in sea ice may alter food webs throughout the region. Sea ice loss may also stress Pacific walruses (Odobenus rosmarus divergens), which feed on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging Pacific walrus space use patterns. We tested a seriesAuthorsWilliam S. Beatty, Chadwick V. Jay, Anthony S. Fischbach, Jacqueline M. Grebmeier, Rebecca L. Taylor, Arny L. Blanchard, Stephen C. JewettNon-USGS Publications**
Taylor, R. L., J. D. Tack, D. E. Naugle, and L. S. Mills. 2013. Combined effects of energy development and disease on Greater Sage-Grouse. PLoS One 8(8):e71256. doi:10.1371/journal.pone.0071256Taylor, R. L., B. L. Walker, D. E. Naugle, and L. S. Mills. 2012. Managing multiple vital rates to maximize Greater Sage-grouse population growth. Journal of Wildlife Management 76(2):336-347. doi:10.1002/jwmg.267Taylor, R. L. and G. K. Himes Boor. 2012. Beyond the robust design: Accounting for changing, uncertain states and sparse, biased detection in a multistate mark-recapture model. Ecological Modeling 243:73-80. doi:10.1016/j.ecolmodel.2012.06.013Taylor, R. L., B. D. Maxwell, and R. J. Boik. 2006. Indirect effects of herbicides on bird food resources and beneficial arthropods. Agriculture, Ecosystems, and Environment 116:157-164. doi:10.1016/j.agee.2006.01.012Maniscalco, J. M., R. L. Taylor, D. G. Calkins, and S. N. Atkinson. 2005. Reproductive Performance and Pup Mortality in Steller Sea Lions. Pages 290-301 in T. R. Loughlin, S. Atkinson and D. G. Calkins (eds). Synopsis of Research on Steller sea lions: 2001-2005. Alaska SeaLife Center, 344 p. Seward, AK, USA.Taylor, R. L., S. A. Temple, and D. M. Bird. 1991. Nutritional and energetic implications for raptors consuming starving prey. The Auk 108(3):716-719.Taylor, R. L. 1990. Avian indicators in the Chequamegon National Forest. The Passenger Pigeon 52(3):225-231.**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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