Michigan Research: Projects, Research Publications, Presentations, Thesis and Dissertations, Technical Publications

Michigan Research Activities

Coyotes are important predators along an urban to rural gradient

The Michigan Unit studies a number of different topics including wildlife response to forest management, the impacts of human development on wildlife communities, and the effects of wetlands management on reptile and mammal populations.

Projects

Project	Completion Date
Evaluating outcomes of oak forest management on Southern Michigan State Game Areas.	December 2028	Upland oak ecosystems in the Eastern United States are critically important habitats for a wide diversity of game and nongame wildlife species. However, these ecosystems are threatened by "mesophication", a process in which mesic-adapted tree species such as maples invade and displace oak. Oak displacement can cause a regime shift which can only be reversed with extremely intensive management intervention. In order to protect intact upland oak ecosystems, it is imperative that we understand the efficacy of oak habitat management techniques (prescribed fire, mechanical disturbance, herbicide application). Working with partners from the Michigan Department of Natural Resources, Michigan State University, and Michigan Natural Features Inventory, we are evaluating the outcomes of oak management at a large number of oak stands (~75 units) and implementing a Before-After Control-Impact study. Results from this study will assist our partners at DNR in understanding which tools and the frequency of implementation required to combat mesophication and ensure the long-term persistence of valuable oak woodlands.	Upland oak ecosystems in the eastern United States are generally characterized by open understories with a range of canopy cover, ranging from nearly closed-canopy forests to savannas of scattered open-grown trees. However, without frequent and proper management, mesic forest communities dominated by maples can cause a state shift in oak ecosystems. Reversing these state changes can be extremely difficult and costly. Here, we are working with cooperators at Michigan DNR to evaluate the outcomes of oak woodland management under a range of scenarios to evaluate management success and the wildlife community response to different management tactics. Our results should inform future habitat management for upload oak ecosystems.
Beaver response to non-lethal water control structures	December 2026	American beavers <i>(Castor canadensis) </i>are broadly distributed throughout the Great Lakes region, and their tendency to alter water flow through dam building has positive and negative consequences (Taylor and Singleton 2014). Lethal control is often used to regulate beaver activity in areas experiencing negative impacts (e.g., to private property, infrastructure; Parker and Rosell 2003) but public interests in non-lethal approaches is growing. Recent literature suggests that water control structures, if installed and managed correctly, can reduce damage while keeping beavers resident. In areas heavily populated by humans, controlling water flow while keeping beavers resident (as opposed to exporting the flooding problem to another locale) is a desirable management outcome. In collaboration with partners from USDA Wildlife Services, we are radio-tracking beavers at locations where water-control structures are being installed to evaluate how to most effectively install and maintain flow structures while keeping beavers resident.	American beavers <i>(Castor canadensis) </i>are broadly distributed throughout the Great Lakes region, and their tendency to alter water flow through dam building has positive and negative consequences (Taylor and Singleton 2014). Lethal control is often used to regulate beaver activity in areas experiencing negative impacts (e.g., to private property, infrastructure; Parker and Rosell 2003) but public interests in non-lethal approaches is growing. Recent literature suggests that water control structures, if installed and managed correctly, can reduce damage while keeping beavers resident. In areas heavily populated by humans, controlling water flow while keeping beavers resident (as opposed to exporting the flooding problem to another locale) is a desirable management outcome. In collaboration with partners from USDA Wildlife Services, we are radio-tracking beavers at locations where water-control structures are being installed to evaluate how to most effectively install and maintain flow structures while keeping beavers resident.
WildSNaP: Biodiversity in Solar through Native Planting	July 2026	Renewable energy production is exponentially increasing worldwide to reduce greenhouse gas emissions and meet the goals of the Paris Agreement. Solar energy has rapidly expanded across the US landscape to meet the population’s growing energy needs, with a projected increase of solar energy contribution from 3% of total electricity generation in 2020 to 20% in 2050. Solar production in the US is estimated to have increased by 33.2% just in the last year. Production of small-scale residential and commercial solar arrays has increased, but the largest contribution of solar energy growth now comes from utility-scale solar arrays. These arrays are frequently built in agricultural fields or croplands, because the flat open landscape maximizes efficiency of solar power generation and minimizes site preparation activities. There has been a recent movement to plant low-growing native plant communities under solar arrays to reduce the costs associated with turf grass mowing. We are evaluating how the bird, amphibian, pollinator, bat, and mammal communities use solar arrays with an understory of native grasses and forbs compared to sites with turf grass as well as reference sites.	Renewable energy production is exponentially increasing worldwide to reduce greenhouse gas emissions and meet the goals of the Paris Agreement. Solar energy has rapidly expanded across the US landscape to meet the population’s growing energy needs, with a projected increase of solar energy contribution from 3% of total electricity generation in 2020 to 20% in 2050. Solar production in the US is estimated to have increased by 33.2% just in the last year. Production of small-scale residential and commercial solar arrays has increased, but the largest contribution of solar energy growth now comes from utility-scale solar arrays. These arrays are frequently built in agricultural fields or croplands, because the flat open landscape maximizes efficiency of solar power generation and minimizes site preparation activities. There has been a recent movement to plant low-growing native plant communities under solar arrays to reduce the costs associated with turf grass mowing. We are evaluating how the bird, amphibian, pollinator, bat, and mammal communities use solar arrays with an understory of native grasses and forbs compared to sites with turf grass as well as reference sites.
Project Snapshot: USA	December 2025	As the country undergoes rapid development and alteration to accommodate our growing human population, it becomes ever more important to have baseline data regarding wildlife populations and distribution so we can identify how our actions affect wildlife. Snapshot USA is a coordinated, nationwide camera trapping study aimed at collecting rigorous, long-term baseline data regarding mammalian communities across the country and in different environments. Contributors from all 50 states collect and share data in a standardized fashion. This growing body of publicly-available data will form the foundation for numerous high-impact investigations on the impacts of humans on wildlife and mammal community assembly rules. CRU scientists, Brett DeGregorio and Robert Lonsinger, have contributed to Snapshot:USA since its 2019 inception. They have contributed data from Oklahoma, Arkansas, and Michigan. They join co-collaborators from state, federal, and tribal entities as well as universities and NGOs. The publicly-available data set generated by Snapshot USA has already proven extremely valuable to practitioners looking to track population declines, changes in distribution, changes in behavior, and changes in community assembly in relation to landscape or anthropogenic factors.	As the country undergoes rapid development and alteration to accommodate our growing human population, it becomes ever more important to have baseline data regarding wildlife populations and distribution so we can identify how our actions affect wildlife. Snapshot USA's goal is to facilitate the collaboration of cooperators to contribute to a national database of public wildlife data. This nationwide data is being used to examine nationwide trends in mammal community assembly rules associated with natural environmental and anthropogenic filters. Collaborators from all 50 states have and continue to contribute camera trap data from a standardized camera trap array at the same time from each site and the Smithsonian Institute compiles and makes available these data. Brett DeGregorio has been contributing data to this coordinated effort since 2019, first in Arkansas and now in Michigan. To date, Brett and his students have provided data from 6 study sites in Arkansas and will shortly be contributing from 3 in Michigan. Data provided should provide information regarding the occupancy of mesopredators, activity patterns of animals across the country and between habitats, and relatively density of several common species of mammals. This effort continues to expand each year to include more contributors and even additional countries. This database is being established as one of the largest camera trap image repositories in existence and provides the raw material for numerous large-scale ecological examinations of mammal populations.

Research Publications

Research Publications	Publication Date
Veon, J.T., E. Lassiter, E. Johansson, M. Shaw, L. McTgue, R. Gibson, A. Massey, and B.A. DeGregorio. 2023. Influence of Human Development and Predator Abundance on Virginia Opossum Occupancy, Abundance, and Activity Patterns. Journal of Zoology. doi:10.1111/jzo.13111 \| Abstract \| Download	August 2023	As human development increases across the globe, wildlife are either pushed out of developed areas or adapt to survive in these novel, human-dominated landscapes. Many mammalian mesopredators, such as the Virginia opossum (<i>Didelphis virginiana</i>), have adapted to living alongside human development in order to take advantage of human-subsidized food, water, and shelter and may also benefit from being “shielded” by humans from their natural predators if those predator species are less able to coexist with humans or if they alter their behavior when living in proximity to humans (the human shield hypothesis). The human shield hypothesis has been used to explain the co-existence of dominant and subordinate mesopredators in some of North America’s largest cities. Our objective was to evaluate if patterns of Virginia opossum occupancy, abundance, and activity conformed to patterns consistent with the presence of a human shield. We used data from a coordinated continent-wide camera trapping study, Snapshot USA to estimate Virginia opossum occupancy, abundance, and activity and relate these measures to surrounding landscape and urbanization variables. We found that opossum occupancy was positively associated with an index of human activity (anthropogenic sound), although at very high levels of sound, opossum occurrence decreased. Furthermore, opossum in heavily forest areas were more likely to be detected in areas with nearby anthropogenic sound indicating a preference towards settling near humans. In areas with a high density of human housing, opossum relative abundance and predator abundance both increased suggesting that opossum were shielded from predators, whereas at low or moderate levels of housing density, opossum abundance did not increase although predator abundance did. We found that opossum were strictly nocturnal (99% of detections) and that they shifted their activity to being active earlier in the evening in the presence of high predator abundance. We found evidence that Virginia opossum are likely shielded by humans from their predators and this was most apparent when examining abundance and to some extent occupancy. These results help to explain why the Virginia opossum is such a successful urban-exploiter.
Veon, J.T., D.G. Krementz, L.W. Naylor, B.A. DeGregorio. 2023. Effects of landscape composition on winter mallard (Anas platyrhnchos) body condition in Eastern Arkansas. Journal of Wildlife Management \| Abstract \| Download	November 2023	Overwintering waterfowl with a higher body condition index are thought to be more likely to survive the winter and have increased productivity during the following breeding season. Body condition index in waterfowl should reflect the resources available to them locally. Here, we analyze the relationship of landscape composition on mallard (<i>Anas platyrhynchos</i>)<i> </i>body condition using a mass by wing length index (BCI) within the Lower Mississippi Alluvial Valley of Arkansas. We measured hunter-harvested mallards during the 2019-2020 and 2020-2021 duck hunting seasons. We found that mallards collected from areas with high proportions of water cover, woody wetlands, and open water within a 30-km radius had higher BCI. Conversely, we found that mallards collected from areas with higher proportions of herbaceous wetlands or human disturbance had lower BCI. Management actions focused on maintaining water levels for waterfowl to access food resources, while providing ample habitat that allows for resting, loafing, and other life cycle events free of human disturbance, will most likely increase BCI in mallards wintering in the Lower Mississippi Alluvial Valley.
McTigue, L.E., E.V. Lassiter, M. Shaw, E. Johansson, K. Wilson, and B.A. DeGregorio. 2023. Does daily activity overlap of mesocarnivores vary with human development? PLoS One. https://doi.org/10.1371/journal.pone.0288477 \| Abstract \| Download	January 2024	Predation and competition can influence the behavior and activity patterns of co-occurring species. Often subordinate species will alter their activity patterns to avoid being active at the same time as larger, dominant species. Human development can complicate interspecies interactions, as not all wildlife responds to human activity in the same manner. While some species may alter their activity to avoid being active when humans are, others may be unaffected or may benefit from being active at the same time as humans to reduce predation risk or competition. To further explore this phenomenon, we used data from a coordinated national camera-trapping program (Snapshot USA) to explore the temporal activity overlap of a large, dominant mesocarnivore, the coyote (<i>Canis latrans</i>) with two subordinate species, Virginia opossum (<i>Didelphis virginiana</i>) and Northern raccoon (<i>Procyon lotor</i>) along a gradient of human development. We found all three species to be predominantly nocturnal and while the subordinate species showed modest changes to their activity patterns in response to increasing human development, the dominant coyote did not alter activity patterns in response to surrounding development. As a result, temporal activity overlap was generally high between all species regardless of development. It appears that competitive and predatory pressures between these three generalist species were insufficient to cause any of them to strongly alter their activity patterns.
McTigue, L. and B.A. DeGregorio. 2023. Effects of Landcover on Mesocarnivore Density Along an Urban to Rural Gradient. Global Ecology and Conservation. \| Abstract \| Download	November 2023	Human development has major implications for wildlife populations with urban-exploiters benefiting from human subsidized resources whereas urban-avoiders can vanish from the wildlife communities in highly developed areas. Therefore, understanding how the density of different species varies in response to landcover associated with human development can provide important insight into how wildlife communities are likely to change and provide a starting point for predicting the consequences of those changes. Here, we use estimated the population density of five common mesocarnivore species (coyote (<i>Canis latrans</i>), bobcat (<i>Lynx rufus</i>), red fox (<i>Vulpes vulpes</i>), raccoon (<i>Procyon lotor</i>), and Virginia opossum (<i>Didelphis virginiana)</i>) along an urban to rural gradient in a rapidly developing area of the United States. At each study site, we applied the random encounter model to data from motion-triggered cameras to calculate the density of our five focal species. We then evaluated variation in density for each species based on natural and anthropogenic landcover variables. Coyotes and raccoons occurred in the greatest densities in areas with high estimated anthropogenic noise, suggesting that both species are synanthropic and able to co-exist in areas of high human activity. High densities of these species in proximity to human activity has potential repercussions for wildlife-human conflict. Alternatively, Virginia opossum and red fox attained the greatest densities in open, developed areas (lawns, golf courses, cemeteries, and parks) and were absent (red fox) or rare (opossum) in natural areas. Opossum and red fox were capable of living alongside humans but did so by an association with these novel, human-created and maintained environments. We found no evidence that bobcat density varied along the urban to rural gradient studied but suggest that this may have been confounded by the small spatial scale of many of our sites in relation to this wide-ranging species. The density estimates we report here based on game camera data of unmarked animals were consistent with reports from the literature for these same species. Furthermore, our results show that several mesopredators attain very high densities in close proximity to humans which certainly has implications for increased conflict with humans and our pets, their role as predators in human-dominated environments, and the risk of disease transmission in and around people. Finally, our results show that the novel environments that spread with the human footprint support large numbers of mesopredators that may be absent or occur in low densities in undeveloped areas.
Johansson, E.P., and B.A. DeGregorio. 2023. The Effects of Landscape and Yard Features on Mammal Diversity in Residential Yards. Urban Ecosystems. \| Abstract \| Download	October 2023	The human footprint is rapidly expanding, and wildlife habitat is continuously being converted to human residential properties. Most wildlife residing in developing areas are displaced to nearby undeveloped areas. However, some animals can co-exist with humans and acquire the necessary resources (food, water, shelter) within the human environment. This may be particularly true when development is low intensity, as in residential suburban yards. Yards are individually managed “greenspaces” that can provide a range of food (e.g., bird feeders, compost, gardens), water (bird baths and garden ponds), and shelter (e.g., brush-piles, outbuildings) resources and are surrounded by varying landscape cover. To evaluate which landscape and yard features influence the richness and diversity of the herbivores and mesopredators within residential yards in a rapidly developing region; we deployed wildlife game cameras in 46 residential yards in summer 2021 and 96 yards in summer 2022. We found that mesopredator diversity was negatively impacted by fences and positively influenced by the number of bird feeders present in a yard. Mesopredator richness increased with the amount of forest within 400m of the camera. Herbivore diversity and richness were positively influenced by the area of forest within 400m of the yard and by the area of garden space within the yard, respectively. Our results suggest that while landscape does play a role in the presence of wildlife in a residential area, homeowners also have agency over the richness and diversity of mammals using their yards based on the features they create or maintain on their properties.
DeGregorio, B.A., M. McElroy, and E.P. Johansson. 2023. Occupancy and Activity Patterns of Nine-Banded Armadillos (Dasypus novemcinctus) in a Suburban Environment. Diversity 15: https://doi.org/10.3390/d15080907. \| Download	July 2023

Presentations

Presentations	Presentation Date
Wolff, P., J. Sperry, P. Hart, H. Klinck, J. Mortensen, and B. DeGregorio. 2023. Evaluating an Automated, Real-time Acoustic Monitoring System for Detecting Vocalizations of DoD Mission-Sensitive Species. SERDP-ESTCP Annual Symposium.	November 2023	This project evaluates near-real time acoustic monitoring technology to immediately inform Dept of Defense partners when threatened and endangered species are present on the property to inform training activities.
Wilson, K., C. Roberts, and B.A. DeGregorio. Effects of relative hog abundance on the occupancy and community composition of breeding birds. The Wildlife Society Annual Conference.	November 2023	Feral hogs are an economic and ecologically destructive invasive species. Because they alter the vegetation community via their foraging behavior and through consumption of acorns to suppress oak regeneration, they almost certainly affect the bird community although this is has not yet been assessed.
Wilson K, DeGregorio BA, Roberts CP, Chiavacci S. 2024. Effects of relative hog abundance on the occupancy and community composition of birds. Arkansas Chapter of The Wildlife Society. Mount Magazine State Park, Arkansas.	March 2024	Quantifying feral hog impacts on native biodiversity is critical for calibrating management priorities. Here, we discuss feral hog impacts on ground nesting birds in bottomland hardwoods.<br><br>
Vertebrates in Trade that Pose High Invasion Risk to the United States. Brett DeGregorio, Wesley Daniel, Helen Sofaer, Catherine Jarnevich, Richard Erickson, Peder Engelstad, Jonathan Freedman, and Deah Lieurance. Michigan Chapter of the Wildlife Society.	April 2024	Invasive species are ecologically and economically costly. If potentially invasive species are identified before they can be established, great harm can be averted. Here, we have reviewed over 19,000 wildlife species in the legal trade to evaluate which are potential invaders.
Shaw, M., B.A. DeGregorio, and C.R. Roberts. Plains Spotted Skunk Distribution and Habitat Associations in the Great Plains. Oral Presentation.	November 2023	The plains spotted skunk is declining and is a candidate for federal protection. Little is known about its distribution or habitat associations outside of several mountainous areas.
L.E. McTigue and B.A. DeGregorio. Does daily activity overlap of three mesocarnivores vary based on human development? Animal Behavioral Society Annual Conference.	July 2023	Examination of behavioral patterns of 3 co-occurring mesopredators that often live near people. Understanding these patterns can allow us to better understand how these species can persist in human-dominated landscapes, the fitness consequences of their adaptations, and potentially human-wildlife conflict.
Donahue, E.R., A.J. Worm, B.A. DeGregorio, L.A. Neuman-Lee, and T.J. Boves. Investigating the prevalence and effects of agricultural toxins in Loggerhead Shrikes in Arkansas, USA. American Ornithological Society Annual Conference.	August 2023	The loggerhead shrike is declining rapidly across its range and we do not know the causes. Here, we investigate the potential role of agricultural chemicals in reducing the fitness of the enigmatic species.
Donahue, E.R., A.J. Worm, B.A. DeGregorio, L.A. Neuman-Lee, and T.J. Boves. 2024. Investigating the prevalence and effects of neonicotinoid pesticides in a songbird, the Loggerhead Shrike in Arkansas. Oral Presentation. Association of Southeastern Biologists.	March 2024	Agricultural toxins are known to cause a variety of effects, either detrimental or adaptive, in off-target species. Here, we investigate the potential sublethal effects of widespread neonicotinoids on the ecology and behavior of a declining songbird, the Loggerhead Shrike.
DeGregorio, B.A. 2024. Armadillos are coming: Why we should care. Michigan Department of Natural Resources Annual Meeting.	March 2024	Armadillos are rapidly expanding their geographic range in the United States. Due to their habitat altering burrowing behavior, they are sure to have both positive and negative effects on native wildlife.
Comparative analyses of the gut microbiome in agricultural and non-agricultural Loggerhead Shrikes (Lanius ludovicianus). Emily R. Donahue, Brian K. Trevelline, Alexander J. Worm, Alix E. Matthews, Brett A. DeGregorio, Than J. Boves, and Lorin A. Neuman-Lee	October 2024	Pesticides can have profound effects of food webs due to their indiscriminate killing of invertebrates. However, less attention has been focused on the indirect effects of non-target vertebrates living in agricultural settings. Here, we explore how pesticides may be altering the gut microbiome of the Loggerhead Shrike.
Berry LL, DeGregorio BA, Uden DR, Roberts CP. 2024. Grassland bird occupancy responses to two new spatial early warning signals of state transitions: testing spatial variance and spatial covariance. Arkansas Chapter of The Wildlife Society. Mount Magazine State Park, Arkansas.	March 2024	Grassland birds are the fastest-declining bird guild in North America. Here, we show results from an analysis testing the ability of a novel landscape metric--spatial covariance--for identifying grassland core habitat to target conservation.

Theses and Dissertations

Theses and Dissertations	Publication Date
Shaw, M. 2023. Habitat Associations of the Plains Spotted Skunk. University of Arkansas. MS Thesis	December 2023

Data or Software Releases

Type	Citation	Publication Date
Data Release	McTigue, L. and B.A. DeGregorio. Nine Banded Armadillo (Dasypus novemcinctus) Occupancy and Density Along an Urban to Rural Gradient.	November 2023
Data Release	McTigue, L. and B.A. DeGregorio. Density of five mesocarnivores along an urban to rural gradient in northwest Arkansas. Dryad. DOI: https://doi.org/10.5061/dryad.47d7wm3kc	June 2023
Data Release	Johansson, E.P. and B.A. DeGregorio. Mammalian Camera Trap Data: Northwest Arkansas. Dryad. https://doi.org/10.5061/dryad.kd51c5bb6	August 2023

Cooperative Fish and Wildlife Research Units Program: Michigan Education, Research and Technical Assistance for Managing Our Natural Resources

Michigan Research Activities

Cooperative Fish and Wildlife Research Units Program: Michigan
Education, Research and Technical Assistance for Managing Our Natural Resources