Karyn Rode, Ph.D.
As a Research Wildlife Biologist, I conduct studies focused on the ecology, physiology, and behavior of large mammals to understand their response to environmental change, identify what environmental or ecological factors (e.g., prey availability, winter temperature, ice availability, etc.) most influence whether a population increases, decreases, or is stable, and to maintain positive wildlife-human interactions.
I work with international and bilateral groups, such as the Polar Bear Range States and US-Russia Polar Bear Commission, DOI partners, including U.S. Fish and Wildlife Service, the Bureau of Land Management, and the U.S. National Park Service, Alaska Native co-management groups, and local and state governments to identify and address research needs for polar bears and walruses. My research focuses primarily on identifying biological and ecological indicators for monitoring large mammal populations and ecosystem change and determining mechanisms of population regulation in response to environmental change. I also study wildlife interactions with humans in areas of industry, via tourism and recreation, and in local communities to help minimize or avoid negative effects on wildlife and ensure human safety. Much of my work is centered on nutritional and physiological ecology and its effects on wildlife body condition, reproduction, and survival. Often, I work to develop new methods needed to address information needs. Although all research questions pertain to wild populations, I also regularly conduct studies with animals in zoos and other captive settings where more detailed study of animal physiology and development of new research techniques are possible.
Professional Experience
Mar 2012 - Present Research Wildlife Biologist, USGS Alaska Science Center
Oct 2006 - Feb 2012 Wildlife Biologist, US Fish and Wildlife Service Polar Bear Program, Anchorage, Alaska
Jan 2006 - Oct 2006 Research Associate, Cornell University, Forest Elephant program
June 2002 - Dec 2005 Contract wildlife biologist - Alaska Department of Fish and Game/PhD candidate - Washington State University
Education and Certifications
Ph.D. Washington State University Zoology
M.S. Washington State University Zoology
B.S. Colorado State University Wildlife Biology
Affiliations and Memberships*
2020 - present Vice President- Americas, International Association of Bear Research and Management
2017 - present International Association of Bear Research and Management Grants Review Committee
2017 - present Member of the American Zoological Association’s Polar Bear Research Council
2015 - present Member of Science/TEK working group of the US Fish and Wildlife Service Polar Bear Recovery Team
2009 - 2010 Secretary/Treasurer of the Alaska chapter of the Wildlife Society
2008 - present Member of the International Union for the Conservation of Nature's (IUCN) Polar bear specialist group
2007 - present Member of the Scientific/TEK working group under the US-Russia polar bear commission
Science and Products
Integrated population modeling provides the first empirical estimates of vital rates and abundance for polar bears in the Chukchi Sea
Survey-based assessment of the frequency and potential impacts of recreation on polar bears
High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear
Den phenology and reproductive success of polar bears in a changing climate
Evaluating methods to assess the body condition of female polar bears
Polar bears, Ursus maritimus
Spring fasting behavior in a marine apex predator provides an index of ecosystem productivity
Harvesting wildlife affected by climate change: a modelling and management approach for polar bears
Simultaneous estimation of diet composition and calibration coefficients with fatty acid signature data
Habitat degradation affects the summer activity of polar bears
Using tri-axial accelerometers to identify wild polar bear behaviors
Collar temperature sensor data reveal long-term patterns in southern Beaufort Sea polar bear den distribution on pack ice and land
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
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- Publications
Filter Total Items: 58
Integrated population modeling provides the first empirical estimates of vital rates and abundance for polar bears in the Chukchi Sea
Large carnivores are imperiled globally, and characteristics making them vulnerable to extinction (e.g., low densities and expansive ranges) also make it difficult to estimate demographic parameters needed for management. Here we develop an integrated population model to analyze capture-recapture, radiotelemetry, and count data for the Chukchi Sea subpopulation of polar bears (Ursus maritimus), 20AuthorsEric V. Regehr, Nathan J. Hostetter, Ryan H. Wilson, Karyn D. Rode, Michelle St. Martin, Sarah J. ConverseSurvey-based assessment of the frequency and potential impacts of recreation on polar bears
Conservation plans for polar bears (Ursus maritimus) typically cannot prescribe management actions to address their primary threat: sea ice loss associated with climate warming. However, there may be other stressors that compound the negative effects of sea ice loss which can be mitigated. For example, Arctic tourism has increased concurrent with polar bears increasingly using terrestrial habitatsAuthorsKaryn D. Rode, Jennifer K. Fortin, Dave Garshelis, Markus Dyck, Vicki Sahanatien, Todd C. Atwood, Stanislav Belikov, Kristin L. Laidre, Susanne Miller, Martyn E. Obbard, Dag Vongraven, Jasmine V. Ware, James WilderHigh-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear
Regional declines in polar bear (Ursus maritimus) populations have been attributed to changing sea ice conditions, but with limited information on the causative mechanisms. By simultaneously measuring field metabolic rates, daily activity patterns, body condition, and foraging success of polar bears moving on the spring sea ice, we found that high metabolic rates (1.6 times greater than previouslyAuthorsAnthony M. Pagano, George M. Durner, Karyn D. Rode, Todd C. Atwood, Stephen N. Atkinson, Elizabeth Peacock, Daniel P. Costa, Megan A. Owen, Terrie M. WilliamsDen phenology and reproductive success of polar bears in a changing climate
Synchrony between reproduction and food availability is important in mammals due to the high energetic costs of gestation and lactation. Female polar bears (Ursus maritimus) must accumulate sufficient energy reserves during spring through autumn to produce and nurse cubs during the winter months in snow dens. Adequate time in a den is important to optimize cub development for withstanding harsh ArAuthorsKaryn D. Rode, Jay Olson, Dennis L. Eggett, David C. Douglas, George M. Durner, Todd C. Atwood, Eric V. Regehr, Ryan H. Wilson, Tom Smith, Michelle St. MartinEvaluating methods to assess the body condition of female polar bears
An animal's body condition provides insight into its health, foraging success, and overall fitness. Measures of body composition including proportional fat content are useful indicators of condition. Isotopic dilution is a reliable non-destructive method for estimating the body composition of live mammals, but can require prolonged handling times. Alternatively, bioelectrical impedance analysis (BAuthorsAnthony M. Pagano, Karyn D. Rode, Stephen N. AtkinsonPolar bears, Ursus maritimus
Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.AuthorsKaryn D. Rode, Ian StirlingSpring fasting behavior in a marine apex predator provides an index of ecosystem productivity
The effects of declining Arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter-specifically, spatially, and temporally. Because marine mammals occupy upper trophic levels in Arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. Polar bears (Ursus maritimus) are apex predators that primarily consumeAuthorsKaryn D. Rode, Ryan H. Wilson, David C. Douglas, Vanessa L Muhlenbruch, Todd C. Atwood, Eric V. Regehr, Evan Richardson, Nicholas Pilfold, Andrew E. Derocher, George M. Durner, Ian Stirling, Steven C. Amstrup, Michelle St. Martin, Anthony M. Pagano, Kristin S. SimacHarvesting wildlife affected by climate change: a modelling and management approach for polar bears
The conservation of many wildlife species requires understanding the demographic effects of climate change, including interactions between climate change and harvest, which can provide cultural, nutritional or economic value to humans.We present a demographic model that is based on the polar bear Ursus maritimus life cycle and includes density-dependent relationships linking vital rates to environAuthorsEric V. Regehr, Ryan H. Wilson, Karyn D. Rode, Michael C. Runge, Harry SternSimultaneous estimation of diet composition and calibration coefficients with fatty acid signature data
Knowledge of animal diets provides essential insights into their life history and ecology, although diet estimation is challenging and remains an active area of research. Quantitative fatty acid signature analysis (QFASA) has become a popular method of estimating diet composition, especially for marine species. A primary assumption of QFASA is that constants called calibration coefficients, whichAuthorsJeffrey F. Bromaghin, Suzanne M. Budge, Gregory W. Thiemann, Karyn D. RodeHabitat degradation affects the summer activity of polar bears
Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species’ distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of twoAuthorsJasmine V. Ware, Karyn D. Rode, Jeffrey F. Bromaghin, David C. Douglas, Ryan H. Wilson, Eric V. Regehr, Steven C. Amstrup, George M. Durner, Anthony M. Pagano, Jay Olson, Charles T. Robbins, Heiko T JansenUsing tri-axial accelerometers to identify wild polar bear behaviors
Tri-axial accelerometers have been used to remotely identify the behaviors of a wide range of taxa. Assigning behaviors to accelerometer data often involves the use of captive animals or surrogate species, as their accelerometer signatures are generally assumed to be similar to those of their wild counterparts. However, this has rarely been tested. Validated accelerometer data are needed for polarAuthorsAnthony M. Pagano, Karyn D. Rode, A. Cutting, M.A. Owen, S. Jensen, J.V. Ware, C.T. Robbins, George M. Durner, Todd C. Atwood, M.E. Obbard, K.R. Middel, G.W. Thiemann, T.M. WilliamsCollar temperature sensor data reveal long-term patterns in southern Beaufort Sea polar bear den distribution on pack ice and land
In response to a changing climate, many species alter habitat use. Polar bears Ursus maritimus in the southern Beaufort Sea have increasingly used land for maternal denning. To aid in detecting denning behavior, we developed an objective method to identify polar bear denning events using temperature sensor data collected by satellite-linked transmitters deployed on adult females between 1985 and 2AuthorsJay W Olson, Karyn D. Rode, Dennis L. Eggett, T. S. Smith, R. R. Wilson, George M. Durner, Anthony S. Fischbach, Todd C. Atwood, David C. DouglasNon-USGS Publications**
Voorhees, H., R. Sparks, H. P. Huntington, and K. D. Rode. 2014. Traditional knowledge of polar bears (Ursus maritimus) in Northwestern Alaska. Arctic 67(4):523-436. doi:10.14430/arctic4425.Erlenbach, J. A., K. D. Rode, D. Raubenheimer, and C. M. Robbins. 2014. Macronutrient optimization and energy maximization determine diets of brown bears. Journal of Mammalogy 95(1):160-168. doi:10.1644/13-MAMM-A-161.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(6):1493-1503. doi:10.1644/11-MAMM-A-406.1.Whiteman, J. P., K. A. Greller, H. J. Harlow, L. A. Felicetti, K. D. Rode, and M. Ben-David. 2012. Carbon isotopes in exhaled breath track metabolic substrates in brown bears (Ursus arctos). Journal of Mammalogy 93:413-421. doi:10.1644/11-MAMM-S-178.1.Gleason, J. S. and K. D. Rode. 2009. Polar bear distribution and habitat association reflect long-term changes in fall sea ice conditions in the Alaskan Beaufort Sea. Arctic 62(4):405-417.Schliebe, S. L., K. D. Rode, J. S. Gleason, J. Wilder, K. M. Proffitt, T. J. Evans, and S. Miller. 2008. Effects of sea ice extent and food availability on spatial and temporal distribution of polar bears during the fall open-water period in the Southern Beaufort Sea. Polar Biology 31(8):999-1010. doi:10.1007/s00300-008-0439-7.Stirling, I., A. E. Derocher, W. Gough, and K. D. Rode. 2008. Response to Dyck et al. (2007) on polar bears and climate change in western Hudson Bay. Ecological Complexity 5(3):193-201. doi:10.1016/j.ecocom.2008.01.004.Rode, K. D., S. C. Amstrup, and E. V. Regehr. 2007. Polar bears in the southern Beaufort Sea III: Stature, mass, and cub recruitment in relationship to time and sea ice extent between 1982 and 2006. USGS Administrative Report, 31 p.Robbins, C. T., J. K. Fortin, K. D. Rode, S. D. Farley, L. A. Shipley, and L. A. Felicetti. 2007. Optimizing protein intake as a foraging strategy to maximize mass gain in an omnivore. Oikos 116(10):1675-1682. doi:10.1111/j.0030-1299.2007.16140.x.Fortin, J. K., S. D. Farley, C. T. Robbins, and K. D. Rode. 2007. The role of salmon and berries in determining fall weight gains in brown bears. Ursus 18(1):19-29. doi:10.2192/1537-6176(2007)18[19:DASOBS]2.0.CO;2.Rode, K. D., S. D. Farley, and C. T. Robbins. 2006. Behavioral responses of brown bears mediate nutritional impacts of experimentally introduced tourism. Biological Conservation 133(1):70-80. doi:10.1016/j.biocon.2006.05.021.Rode, K. D., C. A. Chapman, L. D. McDowell, and C. A. Stricker. 2006. Nutritional mechanisms of population regulation across habitats and logging intensities in redtail monkeys (Cercopithecus ascanius). Biotropica 38:625-634. doi:10.1111/j.1744-7429.2006.00183.x.Rode, K. D., P. I. Chiyo, C. A. Chapman, and L. D. McDowell. 2006. Nutritional ecology of elephants in Kibale National Park, Uganda, and its relationship with crop raiding behaviour. Journal of Tropical Ecology 22(4):441-449. doi:10.1017/S0266467406003233. https://doi.org/10.1017/S0266467406003233
Rode, K. D., S. D. Farley, and C. T. Robbins. 2006. Sexual dimorphism, reproductive strategy, and human activities determine resource use by brown bears. Ecology 87(10):2636-2646. doi:10.1890/0012-9658(2006)87[2636:SDRSAH]2.0.CO;2.Danish, L., C. A. Chapman, C. O'Driscoll Worman, K. D. Rode, and M. B. Hall. 2006. The role of sugar content in diet selection in redtail and red colobus monkeys. In Feeding Ecology in apes and other primates. Cambridge University Press, UK.Chapman, C. A., L. J. Chapman, K. D. Rode, and L. D. McDowell. 2003. Variation in the nutritional value of primate foods: Among trees, time periods, and areas. International Journal of Primatology 24(2):317-337. doi:10.1023/A:1023049200150.Rode, K. D., C. A. Chapman, L. J. Chapman, and L. D. McDowell. 2003. Mineral resource availability and consumption by colobus monkeys in Kibale National Park, Uganda. International Journal of Primatology 24(3):541-573. doi:10.1023/A:1023788330155.Chapman, C. A., L. J. Chapman, M. Cords, M. Gauthua, A. Gautier-Hion, J. E. Lambert, K. D. Rode, C. E. G. Tutin, and L. J. T. White. 2002. Variation in the Diets of Cercopithecus Species: Differences Within Forests, Among Forests, and Across Species. In The Guenons: Diversity and Adaptation in African Monkeys. M. Glenn and M. Cords (eds.). Plenum Press New York City, NY, USA.Rode, K. D., C. T. Robbins, and L. A. Shipley. 2001. The constraints on herbivory by bears. Oecologia 128(1):62-71. doi:10.1007/s004420100637.Rode, K. D. and C. T. Robbins. 2000. Why bears consume mixed diets during fruit abundance. Canadian Journal of Zoology 78(9):1-6. doi:10.1139/z00-082.
**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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*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government