561 items found

CPW website species profile: ElkElk serve as one of Colorado’s most ecologically and economically important mammals. Therefore, it is critical that wildlife managers have the information and tools they need to properly manage elk populations. This involves understanding changes in habitat, climate, predator communities, and human development and how these changes impact elk population demography and behavior.

Elk Research Projects:

• Evaluating factors influencing elk recruitment in Colorado (ongoing)
• Response of elk to human recreation at multiple scales: demographic shifts and behaviorally mediated fluctuations in local abundance (ongoing)
• Evaluating Solutions to Reduce Elk and Mule Deer Damage to Agriculture (completed)
• Evaluating the Influence of Human Harvest, Carnivores, Climate, and Habitat on Female Elk Survival Across Western North America (completed)

1. Wildlife migrations provide important ecosystem services, but they are declining. Within the Greater Yellowstone Ecosystem (GYE), some elk Cervus canadensis herds are losing migratory tendencies, which may increase spatiotemporal overlap between elk and livestock (domestic bison Bison bison and cattle Bos taurus), potentially exacerbating pathogen transmission risk.
2. We combined disease, movement, demographic and environmental data from eight elk herds in the GYE to examine the differential risk of brucellosis transmission (through aborted foetuses) from migrant and resident elk to livestock.
3. For both migrants and residents, we found that transmission risk from elk to livestock occurred almost exclusively on private ranchlands as opposed to state or federal grazing allotments. Weather variability affected the estimated distribution of spillover risk from migrant elk to livestock, with a 7%–12% increase in migrant abortions on private ranchlands during years with heavier snowfall. In contrast, weather variability did not affect spillover risk from resident elk.
4. Migrant elk were responsible for the majority (68%) of disease spillover risk to livestock because they occurred in greater numbers than resident elk. On a per-capita basis, however, our analyses suggested that resident elk disproportionately contributed to spillover risk. In five of seven herds, we estimated that the per-capita spillover risk was greater from residents than from migrants. Averaged across herds, an individual resident elk was 23% more likely than an individual migrant elk to abort on private ranchlands.
5. Our results demonstrate links between migration behaviour, spillover risk and environmental variability, and highlight the utility of integrating models of pathogen transmission and host movement to generate new insights about the role of migration in disease spillover risk. Furthermore, they add to the accumulating body of evidence across taxa that suggests that migrants and residents should be considered separately during investigations of wildlife disease ecology. Finally, our findings have applied implications for elk and brucellosis in the GYE. They suggest that managers should prioritize actions that maintain spatial separation of elk and livestock on private ranchlands during years when snowpack persists into the risk period.

Current or Recent Research Projects

• Wolf ecology
  • Wolf habitat selection and movement during re establishment in Colorado
• Wildlife management
  • Statistical estimation of wolf abundance
  • Quantifying the effects of management practices and disease on wildlife harvest
• Wolf-livestock dynamics
  • Identifying and examining potential nonconsumptive effects of wolves on cattle
• Predator-prey dynamics
  • Examining wolf and hunter effects on elk movement, space use, and aggregation patterns
  • Quantifying conditions under which predators influence prey diseases​

Areas of Interest and Expertise​

My background is in terrestrial wildlife ecology with a focus on carnivores (primarily gray wolves) and infectious diseases. I am interested in many facets of wildlife ecology, especially social behaviors, predator-prey interactions, population dynamics, and disease dynamics. My work intersects wildlife ecology, wildlife management, statistics, and disease ecology.​

Select Publications

• Inzalaco, H. N. t., E. E. Brandell, S. P. Wilson, M. Hunsaker, D. R. Stahler, K. Woelfel, D. P. Walsh, T. Nordeen, D. J. Storm, and S. S. Lichtenberg. 2024. Detection of prions from spiked and free-ranging carnivore feces. Scientific Reports 14:3804. doi.org/10.1038/s41598-023-44167-7
• Cubaynes, S., E. E. Brandell, D. R. Stahler, D. W. Smith, E. S. Almberg, S. Schindler, R. K. Wayne, A. P. Dobson, B. M. vonHoldt, D. R. MacNulty, P. D. Cross, P. J. Hudson, and T. Coulson. 2022. Disease outbreaks select for mate choice and coat color in wolves. Science 378:300–303; DOI: 10.1126/science.abi8745
• Meyer, C. J., K. A. Cassidy, E. E. Stahler, E. E. Brandell, C. B. Anton, D. R. Stahler, and D. W. Smith 2022. Parasitic infection increases risk-taking in a social, intermediate host carnivore. Communications Biology 5:1–10; doi.org/10.1038/s42003-022-04122-0
• Brandell, E. E., M. K. Jackson, P. C. Cross, A. J. Piaggio, D. R. Taylor, D. W. Smith, B. Boufana, D. R. Stahler, and P. J. Hudson. 2022. Evaluating noninvasive methods for estimating cestode prevalence in a wild carnivore population. PLoS ONE 17(11): e0277420; doi.org/10.1371/journal.pone.0277420
• Brandell, E. E., D. J. Storm, T. R. Van Deelen, D. P. Walsh, and W. C. Turner. 2022. A call to action: standardizing white-tailed deer harvest data in the Midwestern United States and implicationsfor quantitative analysis and disease management. Frontiers in Ecology and Evolution; https://doi.org/10.3389/fevo.2022.943411
• Gilbertson, M. L., E. E. Brandell, M. E. Pinkerton, N. M. Meaux, M.  Hunsaker, D. Jarosinski, W. Ellarson, D. P. Walsh, D. J. Storm, and W. C. Turner. 2022. Cause of death, pathology, and chronic wasting disease status of white-tailed deer (Odocoileus virginianus) mortalities in Wisconsin, USA. Journal of Wildlife Diseases 54:803–815; DOI: 10.7589/JWD-D-21-00202​​
• ​Brandell, E. E., P. C. Cross, D. W. Smith, W. Rogers, N. L. Galloway, D. MacNulty, D. R. Stahler, J. Treanor, and P. J. Hudson. 2022. Examination of the interaction between age‐specific predation and chronic disease in the Greater Yellowstone Ecosystem​. Journal of Animal Ecology. 91:1373-1384, https://doi.org/10.1111/1365-2656.13661​
• Rogers, W., E. E. Brandell, and P. C. Cross. 2022. Epidemiological differences between sexes affect management efficacy in simulated chronic wasting disease systems. Journal of Applied Ecology 59:1122-1133. https://doi.org/10.1111/1365-2664.14125​
• Brandell, E.E., D. J. Becker, L. Sampson, and K. M. Forbes. 2021. Demography, education, and research trends in the interdisciplinary field of disease ecology. Ecology and evolution 11:17581-17592, https://doi.org/10.1002/ece3.8466​
• Brandell, E. E., A. P. Dobson, P. J. Hudson, P. C. Cross, and D. W. Smith. 2021. A metapopulation model of social group dynamics and disease applied to Yellowstone wolves. Proceedings of the National Academy of Sciences, 118(10), https://doi.org/10.1073/pnas.2020023118
• Brandell, E.E., P. C. Cross, M. E. Craft, D. W. Smith, E. J. Dubovi, M. L.  Gilbertson, T. Wheeldon, J. A. Stephenson, S. Barber-Meyer, B. L. Borg, and M. Sorum. 2021. Patterns and processes of pathogen exposure in gray wolves across North America​​. Scientific reports 11(1):1-14.​
• DeCandia, A. L., E. C. Schrom, E. E. Brandell, D. R. Stahler, and B. M. vonHoldt. 2021. Sarcoptic mange severity is associated with reduced genomic variation and evidence of selection in Yellowstone National Park wolves (Canis lupus). Evolutionary applications, 14(2):429-445, https://doi.org/10.1111/eva.13127
• Brandell, E. E., N. M. Fountain‐Jones, M. L. Gilbertson, P. C. Cross, P. J. Hudson, D. W. Smith, D. R. Stahler, C. Packer, and M. E. Craft. 2021. Group density, disease, and season shape territory size and overlap of social carnivores. Journal of Animal Ecology, 90(1):87-101.

Education

• Ph.D., Ecology – Pennsylvania State University, 2021
• B.S., Wildlife Biology –​ University of Montana, 2015 

Current or Recent Positions

• Wildlife Research Scientist – Colorado Parks and Wildlife, 2022-Present
• Postdoctoral Associate –​ Wisconsin Cooperative Wildlife Research Unit, Dept. of Forest and Wildlife Ecology, University of Wisconsin-Madison, 2020-2022

Contact Information

317 W. Prospect Rd.​Fort Collins, CO 80526

Email: ellen.brandell@stat​e.co.us​

Phone: ​970-698-0252

Aim

The space an animal uses over a given time period must provide the resources required for meeting energetic needs, reproducing and avoiding predation. Anthropogenic landscape change in concert with environmental dynamics can strongly structure space-use. Investigating these dynamics can provide critical insight into animal ecology, conservation and management.

Location

The Piceance Basin, Colorado, USA.

Methods

We applied a novel utilization distribution estimation technique based on a continuous-time correlated random walk model to characterize range dynamics of mule deer during winter and summer seasons across multiple years. This approach leverages second-order properties of movement to provide a probabilistic estimate of space-use. We assessed the influence of environmental (cover and forage), individual and anthropogenic factors on interannual variation in range use of individual deer using a hierarchical Bayesian regression framework.

Results

Mule deer demonstrated remarkable spatial philopatry, with a median of 50% overlap (range: 8–78%) in year-to-year utilization distributions. Environmental conditions were the primary driver of both philopatry and range size, with anthropogenic disturbance playing a secondary role.

Main conclusions

Philopatry in mule deer is suspected to reflect the importance of spatial familiarity (memory) to this species and, therefore, factors driving spatial displacement are of conservation concern. The interaction between range behaviour and dynamics in development disturbance and environmental conditions highlights mechanisms by which anthropogenic environmental change may displace deer from familiar areas and alter their foraging and survival strategies.

1. Sex-based differences in physiology, behaviour and demography commonly result in differences in disease prevalence. However, sex differences in prevalence may reflect exposure rather than transmission, which could affect disease control programmes. One potential example is chronic wasting disease (CWD), which has been observed at greater prevalence among male than female deer.
2. We used an age- and sex-structured simulation model to explore harvest-based management of CWD under three different transmission scenarios that all generate higher male prevalence: (1) increased male susceptibility, (2) high male-to-male transmission or (3) high female-to-male transmission.
3. Both female and male harvests were required to limit CWD epidemics across all transmission scenarios (approximated by R0), though invasion was more likely under high female-to-male transmission.
4. In simulations, heavily male-biased harvests controlled CWD epidemics and maintained large host populations under high male-to-male transmission and increased male susceptibility scenarios. However, male-biased harvests were ineffective under high female-to-male transmission. Instead, female-biased harvests were able to limit disease transmission under high female-to-male transmission but incurred a trade-off with smaller population sizes.
5. Synthesis and applications. Higher disease prevalence in a sex or age group may be due to higher exposure or susceptibility but does not necessarily indicate if that group is responsible for more disease transmission. We showed that multiple processes can result in the pattern of higher male prevalence, but that population-level management interventions must focus on the sex responsible for disease transmission, not just those that are most exposed.