The following publications largely reflect cooperative efforts between MS and PhD-level graduate students, their faculty advisors, and state and federal bear biologists.

Grizzly Bear Ecology Research

Field ecology studies

  • Rogers, S.A., C.T. Robbins, P. Mathewson, A.M. Carnahan, F. van Manen, M.A. Haroldson, W. Porter, T.R. Rogers, T. Soule, and R.A. Long. 2021. Thermal constraints on energy balance, behavior and spatial distribution of grizzly bears. Functional Ecology DOI:10.1111/1365-2435.13727.
  • Keay, J.A., C.T. Robbins, and S.D. Farley.  2018. Characteristics of a naturally regulated grizzly bear population.  Journal of Wildlife Management 82:789-801.
  • Robbins, C.T., and J.K. Fortin-Noreus. 2017. Nutritional ecology.  In Yellowstone Grizzly Bears: Ecology and Conservation of an Icon of Wildness, edited by P. J. White, K. A. Gunther, and F. T. van Manen.  Pp. 47-61. National Park Service and US Geological Survey, Washington D.C.
  • Mahalovich, M.F., M.J. Kimsey, J.K. Fortin-Noreus, and C.T. Robbins.  2016.  Isotopic heterogeneity in whitebark pine (Pinus albicaulis Engelm.) nuts across geographic, edaphic and climatic gradients in the Northern Rockies (USA).  Forest Ecology and Management 359:174-189.
  • Ripple, W.J., R.L. Beschta, J.K. Fortin, and C.T. Robbins.  2015.  Wolves trigger a trophic cascade to berries as alternative food for grizzly bears.  Journal of Animal Ecology 84:652-654.
  • Lopez-Alfaro, C., S.C.P. Coogan, C.T. Robbins, J.K. Fortin, and S.E. Nielsen.  2015. Assessing nutritional parameters of brown bear diets among ecosystems gives insight into differences among populations.  PLoS ONE 10(6): e0128088. doi:10.1371/journal. pone.0128088. 28 pp.
  • Ripple, W.J., R.L. Beschta, J.K. Fortin, and C.T. Robbins.  2014.  Trophic cascades from wolves to grizzly bears in Yellowstone.  Journal of Animal Ecology 83: 223-233.
  • Schwartz, C.C., J.K. Fortin, J.E. Teisberg, M. A. Haroldson, C. Servheen, C.T. Robbins, and F. Van Manen.  2014.  Body and diet composition of sympatric black and grizzly bears in the Greater Yellowstone Ecosystem.  Journal of Wildlife Management 78:68-78.
  • Erlenbach, J.A., K.D. Rode, D. Raubenheimer, and C.T. Robbins.  2014.  Macronutrient optimization and energy maximization determine diets of brown bears.  Journal of Mammalogy 95:160-168.
  • Teisberg, J.E., M.A. Haroldson, C.C. Schwartz, K.A. Gunther, J.K. Fortin, and C.T. Robbins.  2014.  Contrasting past and current numbers of bears visiting Yellowstone cutthroat trout streams.  Journal of Wildlife Management 78:369-378.
  • Schwartz, C.C., J.K. Fortin, J.E. Teisberg, M.A. Haroldson, C. Servhenn, C.T. Robbins, and F. Van Manen.  2014.  Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: A reassessment.  Wildlife Society Bulletin 38:664-670.
  • Fortin, J.K., C.C. Schwartz, K.A. Gunther, J.E. Teisberg, M.A. Haroldson, M.A. Evans, and C.T. Robbins.  2013.  Dietary adjustability of grizzly bears and American black bears in Yellowstone National Park.  Journal of Wildlife Management 77:270-281.
  • Robu, M., J.K. Fortin, M.P. Richards, C.C. Schwartz, J. Wynn, C.T. Robbins, and E. Trinkaus.  2013.  Isotopic evidence for dietary flexibility among European late Pleistocene cave bears (Ursus spelaeus).  Canadian Journal of Zoology 91:227-234.
  • Middleton, A.D., T.A. Morrison, J.K. Fortin, C.T. Robbins, K.M. Proffitt, P.J. White, D. E. McWhirter, T.M. Koel, D. Brimeyer, W.S. Fairbanks, and M.J. Kauffman.  2013.  Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone.  Proceedings of the Royal Society B 280: 1-8.
  • Lopez-Alfaro, C., C.T. Robbins, A. Zedrosser, and S.E. Nielsen.  2013.  Energetics of hibernation and reproductive trade-offs in brown bears.  Ecological Modeling 270:1-10.
  • Fortin, J., J.V. Ware, H.T. Jansen, C.C. Schwartz, and C.T. Robbins.  2013.  Temporal niche switching by grizzly bears but not American black bears in Yellowstone National Park.  Journal of Mammalogy 94:833-844.
  • Schwartz, C.C., M.A. Haroldson, K.A. Gunther, and C.T. Robbins.  2013.  Omnivory and the terrestrial food web: Yellowstone grizzly bear diets.  In Yellowstone’s Wildlife in Transition, Eds. P.J. White, R.A. Garrott, and G.E. Plumb.  Pp. 109-124.  Harvard University Press, Cambridge, MA.
  • Robbins, C.T., M. Ben-David, J.K. Fortin, and O.L. Nelson.  2012.  Maternal condition determines birth date and growth of newborn bear cubs.  Journal of Mammalogy 93:540-546.

Energetic Studies

  • Carnahan, A. M., A. M. Pagano, A. L. Christian, K. D. Rode and C. T. Robbins. 2024. Ursids evolved dietary diversity without major alterations in metabolic rates. Scientific Reports 14: 4751.
  • Carnahan, A. M., F. T. van Manen, M. A. Haroldson, G. B. Stenhouse, and C. T. Robbins. 2021. Quantifying energetic costs and defining energy landscapes experienced by grizzly bears. Journal of Experimental Biology 224:
  • Pagano, A.M., A.M. Carnahan, C.T. Robbins, M.A. Owen, T. Batson, N. Wagner, A. Cutting, N. Nicassio-Hiskey, A. Hash, and T.M. Williams. 2018. Energetic costs of locomotion in bears: Is plantigrade locomotion energetically economical? Journal of Experimental Biology 221:doi:10.1242/jeb.175372.
  • Shine, C.L., C.T. Robbins, O.L. Nelson, and C.P. McGowan.  2017. Grizzly bear (Ursus arctos horribilis) locomotion: forelimb joint mechanics across speed in the sagittal and frontal planes.  Journal of Experimental Biology 220:1322-1329.
  • Shine, C.L., S. Penberthy, C.T. Robbins, O.L. Nelson, and C.P. McGowan.  2015.  Grizzly bear (Ursus arctos horribilis) locomotion: gaits and ground reaction forces.  Journal of Experimental Biology 218: 3102-3109.

Salmon Studies

  • Deacy, W. W., J. A. Erlenbach, W. B. Leacock, J. A. Stanford, C. T. Robbins, and J. B. Armstrong. 2018. Phenological tracking associated with increased salmon consumption by brown bears. Scientific Reports 8:11008.
  • Deacy, W., J.B. Armstrong, W.B. Leacock, C.T. Robbins, D.D. Gustine, E.J. Ward, J.A. Erlenbach, and J.A. Stanford. 2017. Phenological synchronization disrupts trophic interactions between Kodiak brown bears and salmon.  Proceedings of the National Academy of Sciences 114:10432-10437.
  • Noel, M., J.R. Christensen, J. Spence, and C.T. Robbins.  2015.  Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to characterize copper, zinc and mercury along grizzly bear hair providing estimate of diet.  Science of the Total Environment 529:1-9.
  • Noel, M., J. Spence, K.A. Harris, C.T. Robbins, J.K. Fortin, P.S. Ross, and J.R. Christensen.  2014.  Grizzly bear hair reveals toxic exposure to mercury through salmon consumption.  Environmental Science and Technology 48:7560-7567.
  • Van Daele, M.B., C.T. Robbins, B.X. Semmens, E.J. Ward, L.J. Van Daele, and W.B. Leacock.  2013.  Salmon consumption by Kodiak brown bears (Ursus arctos middendorffi) with ecosystem management implications.  Canadian Journal of Zoology 91:164-174.

Grizzly Bear Genetic Research

  • Perry, B. W., A. L. Mcdonald, S. Trojahn, M. W. Saxton, E. P. Vincent, C. Lowry, B. D. E. Hutzenbiler, O. E. Cornejo, C. T. Robbins, H. T. Jansen, HT, and J. L. Kelley. 2023. Feeding during hibernation shifts gene expression toward active season levels in brown bears (Ursus arctos). Physiological Genomics 55:368-380.
  • Perry, B. W., M. W. Saxton, H. T. Jansen, C. R. Quackenbush, B. D. E. Hutzenbiler, C. T. Robbins, J. L. Kelley, and O. E. Cornejo. 2023. A multi-tissue gene expression dataset for hibernating brown bears. BMC Genomic Data 24: DOI 10.1186/s12863-023-01136-3
  • Saxton, M.W., B.W. Perry, B.D. Evans Hutzenbiler, S. Trojahn, A. Gee. A.P. Brown, G.E. Merrihey, J. Park, O.E. Cornejo, M.J. MacCoss, C.T. Robbins, H.T. Jansen, and J.L. Kelley. 2022. Serum plays an important role in reprogramming the seasonal transcriptional profile of brown bear adipocytes. iScience,
  • Armstrong, E.E., B.W. Perry, Y.Q. Huang, K.V. Garimella, H.T. Jansen, C.T. Robbins, N.R. Tucker, and J.L. Kelley. 2022. A beary good genome: Haplotype-resolved, chromosome-level assembly of the brown bear (Ursus arctos). Genome Biology and Evolution 14(9):DOI10.1093/gbe/evac125
  • Perry, B.W., E.E. Armstrong, C.T. Robbins, H.T. Jansen, and J.L. Kelley. 2022. Temporal analysis of gene expression and isoform switching in brown bears (Ursus arctos). Integrative and Comparative Biology: DOI10.1093/icb/icac093.
  • Tseng, E., J. Underwood, B.D. Evans Hutzenbiler, S. Trojahn, B. Kingham, O. Shevchenko, E. Bernberg, M. Vierra, C.T. Robbins, H.T. Jansen, and J. Kelley. 2022. Long-read isoform sequencing reveals tissue-specific isoform expression between active and hibernating brown bears (Ursus arctos). Genes, Genomes, Genetics 12:
  • Mugahid, D.A., T.G. Sengul, X. You, Y. Wang, L. Steil, N. Bergmann, M. H. Radke, A. Ofenbauer, M. Gesell-Salazar, A. Balogh, S. Kempa, B. Tursun, C. T. Robbins, U. Völker, W. Chen, O.L. Nelson, and M. Gotthardt. 2019.  Proteomic and transcriptomic changes in hibernating grizzly bears reveal metabolic and signaling pathways that protect against muscle atrophy. Scientific Reports 9: Article #19976, 16 pp.
  • Jansen, H.T., S. Trojahn, M. Saxton, C.R. Quackenbush, B.D. Evans Hutzenbiler, O.L. Nelson, O.E. Cornejo, C.T. Robbins, and J.L. Kelley. 2019. Hibernation induces widespread transcriptional remodeling in metabolic tissues of the grizzly bear. Communications Biology 2: article number 336, 10 pages. DOI: 10.1038/s42003-020-0978-1

Grizzly Bear Hibernation Physiology Studies

  • Vincent, E. P., B. W. Perry, J. L. Kelley, C. T. Robbins, and H. T. Jansen. 2023. Circadian gene transcription plays a role in cellular metabolism in hibernating brown bears, Ursus arctos. Journal of Comparative Physiology B 193: 699-713.
  • Hapner, H.R., B.D.E. Hutzenbiler, C.T. Robbins, and H.T. Jansen. 2022. Changing lanes: Seasonal differences in cellular metabolism of adipocytes in grizzly bears (Ursus arctos horribilis). Journal of Comparative Physiology B 192:397-410.
  • Jansen, H.T., B.D. Evans Hutzenbiler, H. R. Hapner, M. L. McPhee, A.M. Carnahan, J.L. Kelley, M. W. Saxton, and C.T. Robbins. 2021. Can offsetting the energetic cost of hibernation restore an active season phenotype in grizzly bears (Ursus arctos horribilis)? Journal of Experimental Biology 224: 10.1242/jeb.242560
  • Vella, C.A., O.L. Nelson, H.T. Jansen, C.T. Robbins, A.E. Jensen, S. Constantinescu, M.J. Abbott, and L.P. Turcotte. 2019. Regulation of metabolism during hibernation in brown bears (Ursus arctos): Involvement of cortisol, PGC-1α and AMPK in adipose tissue and skeletal muscle. Comparative Biochemistry and Physiology 240A: Article Number 110591, DOI: 10.1016/j.cbpa.2019.110591
  • Nelson, O.L., R.M. Wood, J. Häggström, C. Kvart, and C.T. Robbins. 2017. Myocardial adiponectin isoform shift iFn dogs with congestive heart failure—A comparison to hibernating brown bears (Ursus arctos horribilis). Veterinary Science 4(3):11 pp, doi:10.3390/vetsci4030035
  • Rigano, K.S., J.L. Gehring, B.D. Evans-Hutzenbiler, A.V. Chen, O.L. Nelson, C.A. Vella, C.T. Robbins, and H.T. Jansen.  2017.  Life in the fat lane: Seasonal regulation of insulin sensitivity, food intake, and adipose biology in brown bears.  Journal of Comparative Physiology 187:649-676.
  • Jansen, H., T. Leise, G. Stenhouse, K. Pigeon, W. Kasworm, J. Teisberg, T. Radant, R. Dallmann, S. Brown, and C.T. Robbins.  2016.  The bear circadian clock doesn’t sleep in hibernation.  Frontiers in Zoology 13: Article Number: 42, DOI: 10.1186/s12983-016-0173-x.
  • Gehring, J.L., K.S. Rigano, B.D. Evans-Hutzenbiler, O.L. Nelson, C.T. Robbins, and H.T. Jansen.  2016. A protocol for the isolation and cultivation of brown bear (Ursus arctos) adipocytes. Cytotechnology 68:2177-2191.
  • Nelson, O.L., and C.T. Robbins.  2015. Cardiovascular function in large to small hibernators: bears to ground squirrels.  Journal of Comparative Physiology B 185:265-279.
  • Ware, J.V., O.L. Nelson, C.T. Robbins, P. Carter, B. Sarver, and H.T. Jansen.  2013.   Endocrine rhythms in the brown bear (Ursus arctos):  Evidence supporting selection for decreased pineal gland size.   Physiological Reports 1:17pp.
  • Lin, D.C., J.D. Hershey, J.S. Mattoon, and C.T. Robbins.  2012.  Muscles of hibernating bears are unusually resistant to denervation.  Journal of Experimental Biology 215:2081-2087.
  • Ware, J.V., O.L. Nelson, C.T. Robbins, and H.T. Jansen.  2012.  Temporal organization of activity in the brown bear (Ursus arctos): Roles of circadian rhythms, light and food entrainment.  American Journal of Physiology – Regulatory, Integrative and Comparative Physiology 303:R890-R902.

Polar Bear Studies

  • Pagano, A. M., K. D. Rode, N. J. Lunn, D. McGeachy, S. N. Atkinson, S. D. Farley, J. A. Erlenbach, and C. T. Robbins. 2024. Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period. Nature Communications 15: Article number 947.
  • Robbins, C.T., T.N. Tollefson, K.D. Rode, and J.A. Erlenbach. 2022. New insights into dietary management of polar bears and brown bears. Zoo Biology 41:166-175. DOI: 10.1002/zoo.21658
  • Rode, K.D., C.T. Robbins, T.N.Tollefson, C. Stricker, and B. Taras. 2021. Energetic and health effects of protein overconsumption constrain dietary adaptation in an apex predator. Scientific Reports 11: 10.1038/s41598-021-94917-8
  • Ware, J.V., K.D. Rode, C.T. Robbins, T. Leise, C.R. Weil, and H.T. Jansen. 2020. The clock keeps ticking: Circadian rhythms of free-ranging polar bears. Journal of Biological Rhythms 35:180-194.DOI: 10.1177/0748730419900877
  • Ware, J.V., K.D. Rode, J.F. Bromaghin, D. Douglas, R.R. Wilson, E.V. Regehr, S.C. Amstrup, G. Durner, A. Pagano, J. Olson, C.T. Robbins, and H.T. Jansen. 2017.  Habitat degradation affects the summer activity of polar bears. Oecologia 184:87-99.
  • Pagano, A.M., K.D. Rode, A. Cutting, M.A. Owen, S. Jensen, J.V. Ware, C.T. Robbins, G.M. Durner, T.C. Atwood, M.E. Obbard, K.R. Middel, G.W. Thiemann, and T.M. Williams.  2017.  Using tri-axial accelerometers to identify wild polar bear behaviors.  Endangered Species Research 32:19-33.
  • Rode, K.D., C.A. Stricker, J. Erlenbach, C.T. Robbins, S.C. Cherry, S.D. Newsome, A. Cutting, S. Jensen, G. Stenhouse, M. Brooks, A. Hash, and N. Nicassio.  2016.  Isotopic incorporation and the effects of fasting and dietary lipid content on isotopic discrimination in large carnivorous mammals.  Physiological and Biochemical Zoology 89:182-197.
  • Ware, J.V., K.D. Rode, A.M. Pagano, J. Bromaghin, C.T. Robbins, J. Erlenbach, S. Jensen, A. Cutting, N. Nicassio-Hiskey, A. Nash, M. Owen, and H.T. Jansen.  2015.  Validation of mercury tip-switch and accelerometer activity sensors for identifying resting and active behavior in bears. Ursus 26:86-96.
  • Rode, K.D., C.T. Robbins, S.C. Amstrup, and O.L. Nelson.  2015.  Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities.  Frontiers in Ecology and the Environment 13:138-145.
  • Robbins, C.T., C. Lopez-Alfaro, K.D. Rode, Ø. Tøien, and O.L. Nelson.  2012.  Hibernation and seasonal fasting in bears: the energetic costs and consequences for polar bears.  Journal of Mammalogy 93:1493-1503.

Managing and Caring for Captive Bears

  • Robbins, C.T., A.L. Christian, T.G. Vineyard, D. Thompson, K.K. Knott, T.N. Tollefson, A.L. Fidgett, and T.A. Wickersham. 2022. Ursids evolved early and continuously to be low-protein macronutrient omnivores. Scientific Reports 12(1): DOI10.1038/s41598-022-19742-z
  • Rivet, D.R., O.L. Nelson, C.A. Vella, H.T. Jansen, and C.T. Robbins.  2017.  Systemic effects of a high saturated fat diet in grizzly bears (Ursus arctos horribilis). Canadian Journal of Zoology 95:797-807.
  • Waroff, A.J., L. Fanucchi, C.T. Robbins, and O.L. Nelson.  2017.  Tool use, problem-solving, and the display of stereotypic behaviors in the brown bear (Ursus arctos).  Journal of Veterinary Behavior 17:62-68.
  • Joyce-Zuniga, N., R.C. Newberry, J. Ware, H.T. Jansen, C.T. Robbins, and O.L. Nelson. 2016.  Positive reinforcement training for blood collection in grizzly bears (Ursus arctos horribilis) results in undetectable elevation in serum cortisol levels. Journal of Applied Animal Welfare Science 19:210-215.
  • Keen, H.A., O.L. Nelson, C.T. Robbins, M. Evans, D.J. Shepherdson, and R.C. Newberry.  2014.  Validation of a novel cognitive bias task based on difference in quantity of reinforcement for assessing environmental enrichment.   Animal Cognition 17:529-541.
  • Ware, J.V., O.L. Nelson, C.T. Robbins, and H.T. Jansen.  2012.  Split parturition observed in a captive North American brown bear (Ursus arctos).  Zoo Biology 31:255-259.

Disease Studies

  • Bando, M. K. H., O. L. Nelson, C. Kogan, R. Sellon, M. Wiest, H. J. Bacon, M. Hunter-Ishikawa, M. Leadbeater, K. Yamazaki, YP. Jin, T. Komatsu, and D. McGeachy. 2019. Metabolic derangements and reduced survival of bile-extracted Asiatic black bears (Ursus thibetanus). BMC Veterinary Research 15: 10.1186/s12917-019-2006-6.
  • Bando, M. K. H., O. L. Nelson, N. Webster, J. D. Ramsay, H. J. Bacon, and R. Sellon. 2018. Aortic aneurysm, dissection, and rupture in six bile-farmed bears. Journal of Zoo and Wildlife Medicine 49:738-747.
  • Robbins, C.T., Woodford, N.L., G.G. Clyde, C. Minor, O.L. Nelson, M.M. Brewer, P.H. Khalife, and J. R. Hawley. 2018. Salmon poisoning disease in grizzly bears with population recovery implications. Journal of Wildlife Management 82:1396-1402.

Other recent publications on various topics

  • Thiemann, G.W., K.D. Rode, J.A. Erlenbach, S.M. Budge, and C.T. Robbins 2022. Fatty acid profiles of feeding and fasting bears: Estimating calibration coefficients, the timeframe of diet estimates, and selective mobilization during hibernation. Journal of Comparative Physiology 192B:379-395. 
  • Cattet, M., D. M. Janz, L. Kapronczai, J.A. Erlenbach, H.T. Jansen, O.L. Nelson, C.T. Robbins, and G.B. Stenhouse. 2021. Cortisol levels in blood and hair of unanesthetized grizzly bears (Ursus arctos) following intravenous cosyntropin injection. Veterinary Medicine and Science 7:2032-2038.
  • Cattet, M., G.B. Stenhouse, D.M. Janz, L. Kapronczai, J.A. Erlenbach, H.T. Jansen, O.L. Nelson, C.T. Robbins, and J. Boulanger. 2017. The quantification of reproductive hormones in the hair of captive adult brown bears and their application as indicators of sex and reproductive state. Conservation Physiology 5: 1-21. doi: 10.1093/conphys/cox032
  • Teisberg, J.E., S.D. Farley, O.L. Nelson, G.V. Hilderbrand, M.J. Madel, P.A. Owen, J.A. Erlenbach, and C.T. Robbins.  2014.  Immobilization of grizzly bears (Ursus arctos) with Dexmedetomidine, Tiletamine, and Zolazepam.  Journal of Wildlife Diseases 50:74-83.