Research and Teaching Interests
My research focuses on species interactions and population dynamics, with an emphasis on northern environments at ecosystem transitions. I’m interested in how prey availability affects predators and their alternative prey, particularly within food webs that cross ecosystem boundaries (marine to terrestrial, and forest to tundra). I’m also interested in predators that engineer the Arctic ecosystem by concentrating nutrients, and the cascading impact on a diversity of species. As predators play an important role in regulating ecosystems and sustaining biodiversity, much of my research is significant not only academically, but also has important implications for conservation.
Members of my lab investigate direct and indirect interactions among species within food webs using a combination of field methods (e.g., mark-recapture, surveys, telemetry, trail cameras) and lab techniques (e.g., stable isotope analysis and other methods of diet reconstruction).
Research Interests
Biodiversity, Ecology and Environment, food web dynamics, predator-prey interactions, population cycles, spatial subsidies, indirect effects, ecosystem engineering, applications of stable isotope analysis.
Graduate Students
Audrey Moizan, PhD (in progress) Influence of fox reproduction on predator and scavenger activities in the low Arctic tundra.
Holly Gamblin, PhD (in progress) Scavenging and space use by red foxes and Arctic foxes near treeline. University of Manitoba.
Amanda Belanger, MSc (in progress) Seasonality of diet and movements in beluga whales. University of Manitoba (co-supervised with C Watt).
Rylie MacDonald, MSc (in progress) Evaluating ghost crab impacts on sea turtle reproduction. University of Manitoba (co-supervised with B Barton).
Alexandra Windsor, PhD (in progress) Limitations faced by red squirrels at the subarctic range boundary. University of Manitoba.
Sean Johnson-Bice, PhD (in progress) Influence of seasonal subsidies on Arctic foxes in northeastern Manitoba. University of Manitoba.
P Kasey Ryan, PhD (in progress) Space use of beluga whales. University of Manitoba (co-supervised with C Watt).
Chloe Warret Rodrigues, PhD (2022) Use of space and resources by red foxes and Arctic foxes in a coastal tundra transitional ecosystem. University of Manitoba.
Morgan Dobroski, MSc (2022) Interactions on the Arctic tundra between endemics, migrants, and northward expanding rodent populations. University of Manitoba.
Jillian St. George, MSc (2022) Food web interactions along a marine and freshwater gradient within a subarctic estuary. University of Manitoba (co-supervised with S Petersen).
Cody Carlyle, MSc (2022) Variation in ringed seal density, distribution, and diet across a latitudinal gradient of sea ice. University of Manitoba (co-supervised with S Ferguson).
Megan Dudenhoeffer, MSc (2020) Arctic fox winter diet variation during damped lemming cycles estimated using molecular methods and fecal DNA. University of Manitoba.
Jessica Lang, MSc (2019) Red foxes engineer the boreal forest: impacts of denning on vegetation near the Arctic treeline. University of Manitoba (co-supervised with J Markham).
Kyle Ritchie, MSc (2018) Ringed seal trends in abundance inferred from genetics. University of Manitoba (co-supervised with S Petersen).
Christa (Szumski) Burstahler, PhD (2018) Variation in facultative diet specialization of Canada lynx. University of Manitoba (co-supervised with D Murray).
Emily Choy, PhD (2017) The interconnectedness of diet, physiology, and physical condition in beluga whales as a sentinel species for environmental change in the Beaufort Sea ecosystem. University of Manitoba (co-supervised with L Loseto). Choy website
Jackie Verstege, MSc (2016) Fox and lemming responses to climate and snow conditions at the Arctic’s edge. University of Manitoba.
Michelle Ewacha, MSc (2016) Stress response of boreal woodland caribou, moose, and wolves to disturbance in eastern Manitoba. University of Manitoba.
Tazarve Gharajehdaghipoor, MSc (2015) Arctic foxes as ecosystem engineers: benefits to vegetation and collared lemmings through nutrient deposition. University of Manitoba.
Laura Murray, MSc (2015) Effect of nanosilver particles on metabolism and cortisol release in rainbow trout. University of Manitoba (co-supervised with M Rennie).
Danielle Mocker, MSc (2015) Diet reconstruction of wolves following a decline in Manitoba moose populations. University of Manitoba.
Andrew Coulson, MSc (2014) Agricultural subsidies affect isotopic niche size in elk and white-tailed deer. University of Manitoba.
Marci Trana, MSc (2014) Variation in blubber cortisol as a measure of stress in beluga whales of the Canadian Arctic. University of Manitoba. Trana website
Ryan McDonald, MSc (2013) Impact of prey availability and diet on stress in arctic foxes. University of Manitoba.
Olwyn Friesen, MSc (2013) Ecology of parasites in northern canids: impacts of age, sex, behavior, life history, and diet. University of Manitoba. Friesen website
Justin Brown, MS (2009) Factors affecting marine turtle egg predation by raccoons and ghost crabs on Canaveral National Seashore. University of Central Florida (co-advised with J Waterman).
Carlos Anderson, MS (2007) Individual identification of polar bears by whisker spot patterns. University of Central Florida (co-advised with J Waterman).
Brandon Barton, MS (2005) Cascading effects of predator removal on the ecology of sea turtle nesting beaches. University of Central Florida.
Laura Plog, MS (2004) Sea turtle nutrient input to dune vegetation: a stable isotope analysis. University of Central Florida (co-advised with J Weishampel).
Undergraduate Honours Students
Caila Kucheravy, BSc Honours (2020) Red foxes increase reproductive output of white spruce through ecosystem engineering (co-supervised with J Markham)
Dominik Simard, BEnvSc Honours (2018) Assessing body condition of moose killed by gray wolves in southern Manitoba (co-supervised with V Harriman)
Taylor Naaykens, BSc Honours (2016) Grey wolf selection for moose calves and factors influencing prey species consumption in southeastern Manitoba
Shu ting Zhao, BSc Honours (2016) Arctic foxes subsidize other wildlife through ecosystem engineering on the Canadian tundra
Alyssa Eby, BSc Honours (2015) Temporal variation of isotopic niche breadth and overlap between arctic foxes and red foxes at the edge of the Arctic
Paul Faford, BSc Honours (2015) Arctic foxes engineer the beach ridge plant community through nutrient deposition in the Canadian subarctic
Arielle Nagy, BSc Honours (2015) Effects of elk management on wolf diets in Riding Mountain National Park
Tera Edkins, BSc Honours (2014) The effects of a pulsed resource on the dietary niche of a seed predator and the consumption of alternative prey
Publications:
- *Warret Rodrigues C, Roth JD. 2023. Coexistence of two sympatric predators in a transitional ecosystem under constraining environmental conditions: a perspective from space and habitat use. Movement Ecology 11:60. https://doi.org/10.1186/s40462-023-00421-1
- *St. George JR, Petersen SD, Roth JD, Ferguson SD, Yurkowski DJ. 2023. Trophic structure and a temporal shift in trophic diversity of mobile consumers in a subarctic estuary. Estuaries and Coasts. https://doi.org/10.1007/s12237-023-01291-x
- *Johnson-Bice SM, Gable TD, Roth JD, Bump JK. 2023. Patchy indirect effects: how predators drive landscape heterogeneity and influence ecosystem dynamics via localized pathways. Oikos 2023:e10065. https://doi.org/10.1111/oik.10065
- *Szumski CM, Roth JD, Murray DL. 2023. Canada lynx foraging strategies: facultative specialists become obligate generalists towards the distribution edge. Ecosphere 14:e4629. https://doi.org/10.1002/ecs2.4629
- *Warret Rodrigues C, Armstrong D, Wang F, Roth JD. 2023. Tissue composition and storage duration affect the usefulness of generic wet-to-dry mass conversion factors in toxicology studies. Environmental Research 236:116727. https://doi.org/10.1016/j.envres.2023.116727
- *St. George JR, Petersen SD, Roth JD, Ferguson SD, Yurkowski DJ. 2023. Habitat coupling dynamics of mobile consumers along a freshwater and marine resource gradient in a sub-Arctic estuarine system. Estuarine, Coastal, and Shelf Science 292:108449. https://doi.org/10.1016/j.ecss.2023.108449
- *Verstege JS, Johnson-Bice SM, Roth JD. 2023. Arctic and red fox population responses to climate and cryosphere changes at the Arctic’s edge. Oecologia 202:589-599. https://doi.org/10.1007/s00442-023-05418-6
- *Johnson-Bice SM, Roth JD, Markham JH. 2023. A cosmic view of ‘tundra gardens’: satellite imagery provides a landscape-scale perspective of Arctic fox ecosystem engineering. Ecosystems. https://doi.org/10.1007/s10021-023-00857-x
- *Warret Rodrigues C, Roth JD. 2023. Feast to famine: sympatric predators respond differently to seasonal prey scarcity on the low-Arctic tundra. Ecology and Evolution 13:e9951. https://doi.org/10.1002/ece3.9951
- *Moizan A, *Warret Rodrigues C, Roth JD. 2023. Different selection criteria may relax competition for denning sites between expanding red foxes (Vulpes vulpes) and endemic Arctic foxes (Vulpes lagopus) on the low-Arctic tundra. Polar Biology 46:199-213. https://doi.org/10.1007/s00300-023-03116-w
- Elliott KH, Roth JD, Crook K, Yurkowski D. 2023. Lipid extraction and sample preservation techniques for stable isotope analysis and ecological assays. In Bhattacharya SK, ed. Lipidomics. Methods in Molecular Biology, vol 2625. Humana, New York, NY. https://doi.org/10.1007/978-1-0716-2966-6_21
- Gobin J, *Szumski CM, Roth JD, Murray DL. 2022. Patterns of dietary niche breadth and overlap are maintained for two closely related carnivores across broad geographic scales. Frontiers in Ecology and Evolution 10:1059155. https://doi.org/10.3389/fevo.2022.1059155
- *Kucheravy C, Roth JD, Waterman JM. 2022. Whisker spots on polar bears reveal increasing fluctuating asymmetry. Mammalian Biology 102:1537-1546. https://doi.org/10.1007/s42991-022-00294-8
- *Carlyle CG, Roth JD, Yurkowski DJ, Kohlbach D, Young BG, Brown T, Riget F, Dietz R, Ferguson SH. 2022. Spatial variation in carbon source use and trophic position of ringed seals across a latitudinal gradient of sea ice. Ecological Indicators 145:109746. https://doi.org/10.1016/j.ecolind.2022.109746
- *Zhao ST, *Johnson-Bice SM, Roth JD. 2022. Foxes engineer hotspots of wildlife activity on the nutrient-limited Arctic tundra. Global Ecology and Conservation e02310. https://doi.org/10.1016/j.gecco.2022.e02310
- *Kucheravy C, *Trana M, Watt CA, Roth JD, Tomy G, Anderson WG, Ferguson SH. 2022. Blubber cortisol in four Canadian beluga whale populations is unrelated to diet. Marine Ecology Progress Series 698:171-189. https://doi.org/10.3354/meps14147
- *Ewacha MVA, Roth JD, Waterman JM. 2022. Engineering effects of Cape ground squirrels on biodiversity in semi-arid grasslands. Journal of Arid Environments 207:104850. https://doi.org/10.1016/j.jaridenv.2022.104850
- *Lang JA, Roth JD, Tardif JC, Markham JH. 2022. Red foxes enhance long-term tree growth near the Arctic treeline. Ecosphere 13:e4236. https://doi.org/10.1002/ecs2.4236
- Brown T, Olek V, Roth JD, McKinnon L. 2022. Spatial variation in predator communities, predation risk, and shorebird daily nest survival near a sub-Arctic human settlement. Polar Biology 45:1175-1191. https://doi.org/10.1007/s00300-022-03061-0
- Lai S, *Warret Rodrigues C, Gallant D, Roth JD, Berteaux D. 2022. Red foxes at their northern edge: competition with the Arctic fox and winter movements. Journal of Mammalogy 103:586-597. https://doi.org/10.1093/jmammal/gyab164
- Bouchard É, Sharma R, Hernández-Ortiz A, Buhler K, Batol A, Su C, Fenton H, Gouin GG, Roth JD, Warret Rodrigues C, Pamak C, Simon A, Bachand N, Leighton P, Jenkins E (2022). Are foxes (Vulpes spp.) good sentinel species for Toxoplasma gondii in northern Canada? Parasites & Vectors 15:115. https://trebuchet.public.springernature.app/get_content/265fe784-b7c7-445f-ad12-dffa66875491
- Ryan KP, Ferguson SH, Koski WR, Young BG, Roth JD, Watt CA (2022). Use of drones for the creation and development of a photographic identification catalogue for an endangered whale population. Arctic Science 8:1191-1201. https://doi.org/10.1139/AS-2021-0047
- Clark D, Barnas AF, Brook RK, Ellis-Felege SN, Fishback LA, Higdon JW, Manning K, Rivet D, Roth JD, Trim V, Webb M, Rockwell R (2022). The state of knowledge about grizzly bears (Kakenokuskwe osow Muskwa (Cree), Ursus arctos L.) in northern Manitoba. Arctic 75:105-120. https://journalhosting.ucalgary.ca/index.php/arctic/article/view/74922
- Barrio et al. (2021). Developing common protocols to measure tundra herbivory across spatial scales. Arctic Science DOI: 10.1139/AS-2020-0020
- Dudenhoeffer M, Roth JD, Johnson LK, Petersen SD (2021). Arctic fox winter dietary response to damped lemming cycles estimated from fecal DNA. Journal of Mammalogy 102:1455-1465.
- Lang JA, Roth JD, Markham JH (2021). Foxes fertilize the subarctic forest and modify vegetation through denning. Scientific Reports 11:3031.
- Kucheravy C, Roth JD, Markham JH (2021). Red foxes increase reproductive output of white spruce in a non-mast year. Basic and Applied Ecology 51:11-19.
- Choy ES, Giraldo C, Rosenberg B, Roth JD, Ehrman AD, Majewski A, Swanson H, Power M, Reist JD, Loseto LL (2020). Variation in the diet of beluga whales in response to changes in prey availability: insights on changes in the Beaufort Sea ecosystem. Marine Ecology Progress Series 647:195-210.
- Fafard PM, Roth JD, Markham JH (2020). Nutrient deposition on Arctic fox dens creates atypical tundra plant assemblages at the edge of the Arctic. Journal of Vegetation Science 31, 173-179.
- Ehrich et al. (2020). Documenting lemming population change in the Arctic: Can we detect trends? Ambio 49, 786-800.
- Burstahler CM, Terwissen CV, Roth JD (2019). Latitudinal gradient in cortisol concentration in Canada lynx is not explained by diet. Canadian Journal of Zoology 97, 748-753.
- Choy ES, Campbell KL, Berenbrink M, Roth JD, Loseto LL (2019). Body condition impacts blood and muscle oxygen storage capacity of free-living beluga whales (Delphinapterus leucas). Journal of Experimental Biology 22, jeb191916.
- Choy ES, Haulena M, Rosenberg B, Roth JD, Loseto LL (2019). A comparison of diet estimates of captive beluga whales using fatty acid mixing models to their true diets. Journal of Experimental Marine Biology and Ecology 516, 132-139.
- Gharajehdaghipour T, Roth JD (2018). Predators attract prey through ecosystem engineering in the Arctic. Ecosphere 9, e02077.
- Li CH, Roth JD, Detwiler JT (2018). Isotopic turnover rates and diet-tissue discrimination depend on feeding habits of freshwater snails. PLoS One 13, e0199713.
- McDonald RS, Roth JD, Anderson WG (2018). Prey cortisol affects the usefulness of fecal glucocorticoid metabolite concentration to indicate stress in a carnivore. Canadian Journal of Zoology 96, 367-371.
- Berteaux et al. (2017). Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges, recommendations. Polar Research 36 (sup1), 2.
- Choy ES, Rosenberg B, Roth JD, Loseto LL (2017). Inter-annual variation in environmental conditions affect the prey and body condition of eastern Beaufort Sea beluga whale (Delphinapterus leucas) population. Marine Ecology Progress Series 579, 213-225.
- Elliott KH, Roth JD, Crook K (2017). Lipid extraction techniques for stable isotope analysis and ecological assays, Chapter 2, pp. 9-24. Springer New York.
- Ewacha MVA, Roth JD, Anderson WG, Brannen DC, Dupont DLJ (2017). Disturbance and chronic levels of cortisol in boreal woodland caribou. Journal of Wildlife Management 81, 1266-1275.
- McDonald RS, Roth JD, Baldwin FB (2017). Goose persistence in fall strongly influences Arctic fox diet, but not reproductive success, in the southern Arctic. Polar Research 36 (sup1), 5.
- Burstahler CM, Roth JD, Gau RJ, Murray DL (2016). Demographic differences in diet breadth of Canada lynx during a fluctuation in prey availability. Ecology & Evolution 6, 6366–6375.
- Choy ES, Roth JD, Loseto LL (2016). Lipid removal and acidification affect nitrogen and carbon stable isotope ratios of beluga whales and their potential prey species in the Beaufort Sea ecosystem. Marine Biology 163, 220.
- Ewacha MVA, Kaapehi C, Waterman JM, Roth JD (2016). Cape ground squirrels as ecosystem engineers: modifying habitat for plants, small mammals, and beetles in Namib Desert grasslands. African Journal of Ecology 54, 68-75.
- Freeth CE, Teillet MRE, Roth JD (2016). Variation in snowshoe hare density near Churchill, Manitoba estimated using pellet counts. Proceedings of Manitoba’s Undergraduate Science and Engineering Research 2, 1-6.
- Friesen OC, Roth JD (2016). Alternative prey use affects helminth parasite infections in gray wolves. Journal of Animal Ecology 85, 1265-1274.
- Gharajehdaghipour T, Roth JD, Fafard PM, Markham JH (2016). Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens. Scientific Reports 6, 24020.
- Maxner E, Halden NM, Roth JD, Davoren GK (2016). Intrinsic factors influence the timing of arrival of capelin (Mallotus villosus) to spawning grounds in coastal Newfoundland. Fisheries Research 179, 202-212.
- Naaykens T, Roth JD, Dupont D (2016). Grey wolf selection for moose calves and factors influencing prey species consumption in southeastern Manitoba. Proceedings of Manitoba’s Undergraduate Science and Engineering Research 2, 1-17.
- Trana MR, Roth JD, Tomy G, Anderson WG, Ferguson S (2016). Increased blubber cortisol in ice-entrapped beluga whales. Polar Biology 39, 1563-1569.
- Friesen OC, Roth JD, Graham LC (2015). Sex-biased parasitism in the monogamous arctic fox driven by diet. Journal of Mammalogy 96, 417-424.
- Trana MR, Roth JD, Tomy G, Anderson WG, Ferguson S (2015). Influence of sample degradation and tissue depth on blubber cortisol in beluga whales. Journal of Experimental Marine Biology and Ecology 462, 8-13.
- Ceriani SA, Roth JD, Ehrhart LM, Quintana-Ascencio PF, Weishampel JF (2014).Developing a common currency for stable isotope analyses of nesting marine turtles. Marine Biology 161, 2257-2268.
- Ceriani SA, Roth JD, Sasso CR, McClellan CM, James M, Haas HL, Smolowitz RJ, Evans DR, Addison DS, Bagley DA, Ehrhart LM, Weishampel JF (2014). Modeling and mapping isotopic patterns in the Northwest Atlantic derived from loggerhead sea turtles. Ecosphere 5, 122.
- Ewacha MVA, Roth JD, Brook RK (2014). Vegetation structure and composition determine snowshoe hare activity at arctic tree line. Canadian Journal of Zoology 92, 789-794.
- Makenbach SA, Waterman JM, Roth JD (2013). Predator detection and dilution as benefits of associations between yellow mongooses and Cape ground squirrels. Behavioral Ecology and Sociobiology 67, 1187-1194.
- Shura SK, Roth JD (2013). Impacts on declining moose populations in southeastern Manitoba. Proceedings of Manitoba’s Undergraduate Science and Engineering Research 1, 20-26.
- Thornton D, Wirsing AJ, Roth JD, Murray DM (2013). Habitat quality and population density drive occupancy dynamics of snowshoe hare in variegated landscapes. Ecography 36, 610-621.
- Ceriani SA, Roth JD, Evans D, Weishampel JF, Ehrhart LM (2012). Inferring foraging areas of nesting loggerhead turtles using satellite telemetry and stable isotopes. PLoS One 7 (9), e45335.
- Thornton D, Wirsing AJ, Roth JD, Murray DM (2012). Complex effects of site preparation and harvest on snowshoe hare abundance across a forest mosaic landscape. Forest Ecology and Management 280, 132–139.
- Anderson CJR, da Vitoria Lobo N, Roth JD, Waterman JM (2010). A computer aided photo identification system based on image pattern recognition with an application to polar bears using whisker spot patterns. Journal of Mammalogy 91, 1350–1359.
- Hillegass MA, Waterman JM, Roth JD (2010). Parasite removal increases reproductive success in a social African ground squirrel. Behavioral Ecology 21, 696-700.
- Witteven BH, Worthy GAJ, Roth JD (2009). Tracing migratory movements of breeding North Pacific humpback whales using stable isotope analysis. Marine Ecology Progress Series 393, 173-183.
- Witteven BH, Worthy GAJ, Wynne KA, Roth JD (2009). Population structure of North Pacific humpback whales on their feeding grounds as shown by stable carbon and nitrogen isotope ratios. Marine Ecology Progress Series 379, 299-310.
- Barton BT, Roth JD (2008). Implications of intraguild predation for sea turtle nest protection. Biological Conservation 141, 2139-2145.
- Roth JD, Murray DL, Steury TD (2008). Spatial dynamics of sympatric canids: modeling the impact of coyotes on red wolf recovery. Ecological Modelling 214, 391-403.
- Roth JD, Marshall JD, Murray DL, Nickerson DM, Steury TD (2007). Geographical gradients in diet affect population dynamics of Canada lynx. Ecology 88, 2736-2743.
Courses taught
BIOL 3318 Boreal Ecology (winter)
BIOL 3350 Data Analysis in Ecology (fall)
BIOL 4314 Arctic Field Ecology (summer)