Browsing by Author "Brigham, Mark"

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Open Access
Celebration Of Authorship Program 2019-2020
(University of Regina Library, 2020) Afolabi, Taiwo; Belisle, Donica; Beveridge, Daniel M.; Brigham, Mark; Duggleby, Jim; Fox, Bevann; Grimard, Céleste; Hillabold, Jean R. (pen name: Jean Roberta); Hu, Shuchen; Koops, Sheena; Lewis, Patrick; Lockhart, Daniel; Marsh, Charity; Oehler, Alex; Petry, Yvonne; Powell, Marie; Pridmore, Helen; Reul, Barbara; Robertson, Lloyd Hawkeye; Ruddell, Rick; Schultz, Christie; Stonechild, A. Blair
While our physical circumstances may have changed this year, the commitment of the Dr. John Archer Library and Archives to celebrate the many and varied accomplishments of University of Regina’s authors has not. While we cannot gather together to celebrate in person, this booklet highlights the impressive and wide-ranging scholarship of our faculty, staff, alumni, and students. One of the things that we have learned in this unprecedented time is that even when we are apart, the written word creates community. I want to recognize and congratulate all of our 2020 authors, and thank them for their contributions to building our local, provincial, national, and international communities.
Open Access
Celebration Of Authorship Program 2020-2021
(University of Regina Library, 2021) Afolabi, Taiwo; Bates-Hardy, Courtney; Battis, Jes; Bradley, Crista; Brigham, Mark; Carter, Claire; Clausson, Nils; Cote, L. Lynn; Cote, Margaret R.; Coupal, Chelsea; French, Lindsey; Gacek, James; Hanson, Cindy; Hu, Shuchen; Juschka, Darlene; Khan, Tanisha; Macdonald, Iain; Marsh, Charity; Melançon, Jérôme; Morgan, R. Grace; Okimasis, Jean L.; Piercey, Robert; Plummer, David William; Powell, Mary; Purdham, Medrie; Ratt, Solomon; Trussler, Michael; Wolvengrey, Arok
The past year has disrupted many things in both our academic and personal lives, but something that has not changed is the commitment of the University of Regina community to advancing research and sharing knowledge and stories with a world-wide audience. The Dr. John Archer Library and Archives is again proud to unveil our new Celebration of Authorship booklet, highlighting books and other creative works published in-print or electronically over the past year by faculty, staff, students, retirees, and alumni of the University of Regina and its federated colleges.
Open Access
Celebration Of Authorship Program 2021-2022
(University of Regina Library, 2022) Abbott, Sarah; Afolabi, Taiwo; Ashton, Emily; Bliss, Stacey; Bonner, William; Bradley, Crista; Brigham, Mark; Campbell, Ian; Campbell, Lori; Carter, Heather; Chadwick, Sydney; Chiefcalf, April; Clarke, Paul; Cliveti, Monica; Clune, Laurie; Demers, Jason; Donovan, Darcy; Eisler, Dale; Eaton, Emily; Elliott, Patricia; Enoch, Simon; French, Lindsey; Gacek, James; Gardiner, Christopher Campbell; Berard-Gardiner, Shannon; Gebhard, Amanda; Grahame, Ann; Han, Yu (Jade); Hanson, Cindy; Hart, Mel; Hu, Shuchen; Hurlbert, Margot; Isiaka, Abiodun; Jaffe, Joann; King, Alex; Koops, Sheena; Kossick, Don; Long, Timothy; Maeers, Esther; Mair, Leslea; Mathes, Carmen Faye; Munro, Emelia; Naytowhow, Joseph; Phillips, Kaetlyn; Polster, Claire; Quark, Amy; Ramsay, Christine; Ricketts, Kathryn; Rasmussen, Ken; Reul, Barbara; Rennie, Morina; Rolli (Charles Anderson); Ruddy, Evie Johnny; Russell, Gale; Sardarli, Arzu; Saul, Gerald; Sawatzky, Katie Doke; Sellers, Cora; Snider, Amy; Stadnichuk, Cheryl; Stevens, Andrew; Stratton, Florence; Swan, Ida; Tomesh, Trevor; Trussler, Michael; Vélez, Maria; Wilson, Ken
For the first time in three years, we are thrilled to be again gathering in person to celebrate the published scholarly and creative work of our University of Regina community. Archer Library is proud to unveil the 2021-22 University of Regina Celebration of Authorship Program booklet. This downloadable publication highlights University of Regina authors/creators of books, edited proceedings, sound recordings, musical scores and film or video recordings published over the last year in any format (print or electronic). We encourage you to take a moment to view the program booklet and extend your congratulations to all of the University of Regina students, faculty, staff, and alumni who are being celebrated this year.
Open Access
Census methodology and habitat use of long-billed curlews ( Numenius americanus) in Saskatchewan.
(Faculty of Graduate Studies and Research, University of Regina, 2003) Foster-Willfong, Janna M.; Brigham, Mark; James, Paul
Open Access
Community ecology of migratory bats in a northern sky island
(Faculty of Graduate Studies and Research, University of Regina, 2024-06) Green, Dana Maureen; Brigham, Mark; Baerwald, Erin; Somers, Chris; Buttigieg, Josef; Hurlbert, Margot; Fraser, Erin
Animal migrations are often motivated by the opportunity to exploit seasonal abundances of resources, a phenomenon particularly pronounced for species migrating to higher latitudes where seasonality is more extreme. Bats are the only mammalian order to have evolved flight, and three North American migratory bats are the long-distance migrating hoary (Lasiurus cinereus) and silver-haired bats (Lasionycteris noctivagans), and the regionally migrating little-brown Myotis bats (Myotis lucifugus). I describe a highly seasonal community of migratory bats in a northern “sky island” within the Cypress Hills of southern Saskatchewan, Canada, focusing on abundance trends, foraging behavior, niche ecology, and ecophysiology. By collecting data spanning 20 years, my first chapter describes that while long-distance migrating bats are experiencing population declines, the Cypress Hills currently has locally increasing abundances of hoary and silver-haired bats, likely driven by increased roosting habitat. Further in my second chapter, I found that three species of bat separate their ecological niches, allowing for current co-existence, but that silver-haired bats may experience competition with either the hoary or little-brown myotis. My final chapter describes the inter- and intra-specific differences of fur cortisol, a regulatory hormone often associated with stress. Notably, silver-haired bats exhibit elevated fur cortisol levels, but only in juveniles, suggesting it was transferred through their mothers milk while pups grew fur. Thus, female silver-haired bats likely have interactions within their environment causing increased cortisol circulation. Collectively based on my results, I postulate that long-distance migratory bats are disproportionally attracted to the Cypress Hills, and the local population of silver-haired bats may be experiencing increased inter- and intra- competition, resulting in heightened cortisol levels. Although each of the three bat species are seasonally abundant within the Cypress Hills, they are all currently experiencing population declines across their ranges. The environmental conditions hoary, silver-haired, and little-brown myotis bats face consist of highly seasonal resources in a relatively small area of land, while also experiencing habitat loss and increased risk during their annual migrations. My work highlights the importance of both long-term studies and datasets, and lays the foundation to continue to study the summer ecology of at risk species.
Open Access
Comparative Ecology of Three Sympatric Snake Species in Southwestern Saskatchewan
(Faculty of Graduate Studies and Research, University of Regina, 2012-07) Gardiner, Laura Elaine; Somers, Christopher; Poulin, Ray; Brigham, Mark; Pruss, Shelley D.
My research focused on the comparative ecology of three sympatric snake species which are of conservation concern in southwestern Saskatchewan: eastern yellow-bellied racers (Coluber constrictor flaviventris), a Threatened species in Canada; bullsnakes (Pituophis catenifer sayi), Data Deficient, and; prairie rattlesnakes (Crotalus viridis), yet to be assessed, but considered a high priority candidate. Few studies on snake ecology have collected data for multiple species at the same site, a factor potentially important for understanding resource partitioning and competition between sympatric species. Furthermore, identifying which resources elicit competition may be critical for the conservation and management of endangered species. I used radio-telemetry, GIS, and multivariate modeling to identify and compare habitat use by racers (n = 33), bullsnakes (n = 16), and rattlesnakes (n = 23) in and around Grasslands National Park, Saskatchewan, Canada. Used and available macrohabitat sites were compared to quantify habitat use by these species. I found that although all species hibernate in communal den sites, during the active season they disperse into different macrohabitats across the landscape. As a result, home ranges were dumbbell-shaped with activity centers near hibernacula and in well-defined areas used in summer, and these centers of activity were connected by narrow corridors. Bullsnakes had the smallest home range (4.6 ± 0.7 ha), while racers (14.2 ± 0.9 ha) and rattlesnakes (13.9 ± 1.5 ha) were similar. Racers strongly selected for riparian areas, bullsnakes tended to inhabit valley grassland habitats, and rattlesnakes tended to be associated with prairie dog colonies. Some rattlesnakes travelled great distances (over 11 km) from the dens compared to the other species (bullsnake maximum = 4 km; racer maximum = 5 km), which may be a result of the macrohabitat selected being more patchily distributed in the landscape. In addition, I identified microhabitat selection by rattlesnakes which selected for sites with cover (e.g. shrubs and burrows) along the edges of prairie dog colonies. The habitat use by the three species I studied is consistent with habitat partitioning during the active season, though overlap does occur at the overwintering sites and in movement between selected macrohabitats. In addition to the general ecological value of my findings, the results of this study will be useful in aiding designation of critical habitat for the eastern yellow-bellied racer and contribute to assessment of bullsnakes and prairie rattlesnakes in Canada.
Open Access
Developing Grassland Songbird Management Targets for Multi-Species Conservation on Native Mixed-Grass Prairie
(Faculty of Graduate Studies and Research, University of Regina, 2018-07) Rose, Phillip Kelsey; Brigham, Mark; Davis, Stephen; Vetter, Mary; Sutter, Glenn
Grassland birds are declining at steeper rates than birds from nearly every other habitat type, and the primary reasons for these declines are loss and degradation of native grasslands. Moisture, along with other environmental conditions such as soil type, topography, fire, and grazing, play important roles in determining the extent of habitat features important to grassland songbirds. I examined the associations between the abundance/occurrence of 14 grassland songbird species and vegetation characteristics along a moisture gradient in southwest Saskatchewan. Associations with at least one vegetation characteristic changed along the moisture gradient for 12 of the 14 species. Songbird abundance/occurrence was typically greater in areas with dense cover at drier sites along the moisture gradient when overall cover was sparse and greater in areas with sparser cover at wetter sites when overall cover was dense; however, absolute values for vegetation characteristics associated with peak abundance/occurrence often remained similar along the moisture gradient. The umbrella species concept is based on the premise that the conservation of a single species can also aid in conservation of a wide range of other co-occurring species with overlapping habitat requirements. I examined how the vegetation attributes of greater sage-grouse (Centrocercus urophasianus) critical habitat influenced grassland songbirds, and whether sage-grouse could potentially serve as an umbrella species for the grassland songbird community at the northern extent of the sage-grouse range. I found that abundance of Sprague’s pipit (Anthus spragueii) and Baird’s sparrow (Ammodramus bairdii) was lower and abundance of lark bunting (Calamospiza melanocorys) was higher within greater sage-grouse critical habitat in comparison to a 1.6 km buffer surrounding critical habitat. The abundance of all endemic grassland songbirds, except lark bunting, was negatively associated with vegetation attributes that characterized sage-grouse critical habitat (i.e., shrub and sagebrush cover). The vegetation characteristics associated with shrub-steppe songbirds and several grassland generalists overlapped with vegetation characteristics that defined greater sage-grouse critical habitat. Greater sage-grouse conservation is likely to have a positive influence on shrub-tolerant species, such as lark bunting, and a neutral or positive effect on generalist grassland species, but will provide few benefits to other grassland species at risk.
Open Access
Dietary Niche and Foraging Ecology of a Generalist Predator, Double-Crested Cormorant (Phalacrocorax Auritus): Insight Using Stable Isotopes
(Faculty of Graduate Studies and Research, University of Regina, 2012-04) Doucette, Jennifer Lee; Somers, Christopher; Brigham, Mark; Wissel, Bjoern; Fallat, Shaun; Hobson, Keith
The ability of predator populations to expand their ranges and adapt to new environments is often attributed to having a generalist dietary strategy, which is thought to be represented both at the population and individual level. Cormorants (Phalacrocorax spp.) are considered to be opportunistic generalists capable of using a wide variety of aquatic prey. This reputation is partially responsible for the global conflict between piscivorous cormorants and fish harvesters, which is one of the most widespread wildlife management issues in history. Despite the persistent belief that cormorants adversely affect economically important fish populations, relatively little is known about their trophic ecology and habitat use. Stable nitrogen and carbon isotopes are popular tools for studying food webs, and offer a comprehensive assessment of diet, trophic position, and ecological niche when combined with traditional diet analyses. However, the interpretation of isotope data may be confounded by variation in the lipid content of sample tissues. No validated lipid-normalization procedures are currently available for any cormorant species, or any fish-eating birds. As such, I first determined the effect of lipids on the stable carbon and nitrogen isotopes (δ13C and δ15N) values in cormorant tissues, and tested three published lipid-normalization models on stable isotope signatures in double-crested cormorant (P. auritus) muscle and liver tissues. The presence of lipids in cormorant muscle and liver altered the stable isotopes values, indicating corrections were required. However, the effects of lipids in cormorants were unpredictable and thus violated a major assumption of published lipid-normalization models. As a result, lipids must be chemically removed from cormorant muscle and liver tissue. I then examined the diet and trophic position of breeding populations of double-crested cormorants from three different lakes. The results revealed that cormorants generally occupied top-predator positions and relied heavily on pelagic prey in all food webs examined. The isotopic values of cormorants and pelagic predatory fish were sometimes similar, suggesting that dietary overlap is possible. To determine whether cormorants are true dietary generalists I studied double-crested cormorants from breeding colonies spanning three major ecoregions. Analyses of stomach contents revealed that at the population level cormorant diet varied widely by location, likely reflecting local food-web structure. However, within populations individuals were much more specialized than expected. Temporal shifts in δ13C and δ15N values in cormorant tissues with different turnover rates (muscle vs. liver) indicated that foraging varied among populations. The dietary niche occupied by cormorants will affect their interactions with fish, highlighting the importance of understanding their impacts to fish populations both at the population and individual level. Ultimately, my research has shown that cormorants do not consume prey indiscriminately, and instead may have more specific and uniform dietary niche requirements than previously considered. From a management perspective, cormorants should not be assumed to have negative effects on fish in all situations; however, further attention is required to determine the impacts of dietary overlap with sport fish. Ecologically, I have shown that generalist species can be much more consistent and specialized than previously considered. Further, individuals within generalist species may be highly specialized, which will change the overall effects of the population on other species in the food web.
Open Access
Ecological aspects of torpor use and inactivity during winter by common poorwills.
(Faculty of Graduate Studies and Research, University of Regina, 2003) Woods, Christopher P.; Brigham, Mark
Open Access
Effects of Oil Development on Grassland Songbirds and Their Avian Predators in Southeastern Saskatchewan
(Faculty of Graduate Studies and Research, University of Regina, 2015-10) Unruh, Jason Howard; Brigham, Mark; Davis, Stephen; Somers, Christopher; Mahony, Nancy
The quantity and quality of Saskatchewan’s remaining grassland may be threatened by energy development such as oil extraction. Grassland songbird populations are declining and increased oil development may be contributing to their declines through habitat loss and degradation. More quantitative research is needed to inform our understanding of how grassland songbirds are affected by oil development. I examined grassland songbird abundance, vegetation structure, habitat type (native and planted grasslands), and avian predator occurrence across a gradient of oil disturbance to determine the extent to which oil well proximity, density, and cumulative habitat disturbance influences the abundance of grassland songbirds and the occurrence of avian predators. I conducted 486 point counts in 243 sample sites (259 ha) at varying distances from oil wells, and in areas with varying well densities (0-48 wells/259 ha). The abundance of seven songbird species was reduced near oil wells or in areas with higher well densities, the abundance of two species was not influenced by oil wells, and the abundance of two species increased in the presence of oil wells or with greater well density. Three species also exhibited reduced abundance with greater cumulative disturbance, while two species exhibited reduced abundance when the area covered by well pads or oil access roads increased. I also found evidence that the abundance of four species was lowest in planted grassland compared to native grassland in the presence of oil development. My results indicate that oil development influenced vegetation structure, which likely influenced grassland songbird abundance to some degree. However, structural changes in vegetation did not account for all observed variation in songbird abundance. Finally, my results provide evidence that Northern Harrier occurrence is negatively influenced by oil development but that buteos and corvids are not affected. Northern Harrier occurrence is possibly influenced by habitat fragmentation caused by oil development since they are known to be area sensitive. As oil development increases in grassland habitat, its negative impacts on grassland songbirds will likely become more pronounced. Efforts should be made to limit well density and the cumulative area of disturbance on the landscape.
Open Access
Environmental Factors Affecting the Distribution and Abundance of Richardson’s Ground Squirrels
(Faculty of Graduate Studies and Research, University of Regina, 2013-10) Fortney, Ashley Nicole; Somers, Christopher; Poulin, Ray; Brigham, Mark; Hare, James
Richardson's ground squirrels (RGS) (Urocitellus richardsonii) are an important species for the grassland ecosystem on the Northern Great Plains of North America. They are a main source of prey and burrows for many prairie species including several Species at Risk (SAR) of extinction. RGS are also maligned as agricultural pests and managed extensively via poisoning. Control programs have negative consequences for RGS and non-target species, including some SAR. Despite their ecological importance and agricultural pest status, little is actually known about their distribution on the landscape and habitat variables that influence their distribution and abundance. This lack of knowledge is a major impediment to development of conservation strategies for SAR that are significantly impacted by the management of RGS, and a key limitation for forecasting conflicts with agricultural producers. The objective of my research was to provide information on the distribution of RGS and determine how habitat variables influence their presence and abundance. I surveyed for the presence (detected at a site) and abundance (number of individuals) across a large area (130,000 km2) of RGS range on the Canadian prairies during 2011 and 2012 using an alarm call-playback method. I found that RGS were not distributed evenly on the landscape. RGS were only detected at 157 (8%) of 1,900 systematic survey points across Saskatchewan, with an average of 3.3 ± 0.4 individuals per used location. In 2012, additional searches to locate larger colonies in the high-conflict (between RGS and agricultural producers) area of southwestern Saskatchewan resulted in 31 colony locations with an average of 10.1 ± 1 RGS per colony. The systematic broad-scale surveys and more random colony searches revealed fewer and more patchily distributed RGS than expected given their pest status. I used multivariate Resource Selection Function (RSF) modeling to examine RGS habitat selection. Habitat variables included in the analysis were vegetation height, land cover types, land use, and proximity to water, shrubs, trees, and buildings/structures. Vegetation height was the top predictor of RGS presence and abundance; vegetation height above 15-30 cm was associated with a drastic decrease in the probability of habitat use. RGS presence was positively influenced by the percentage cover of grass in an area and bare ground when greater than 10% of the land cover. The proximity to trees within 400 m had a negative effect on RGS presence, as did proximity to shrubs and water on RSG abundance. Lastly, RGS abundance was positively influenced by finely textured soils and tilled crops, while negatively affected by increasing percent shrub cover. My data on RGS distribution and habitat selection can be used to implement integrated pest management strategies, such as through the inclusion of habitat modification, and will also provide valuable information to aid conservation planning for SAR that rely on RGS.
Open Access
An exploratory consideration of cognition and physiology in athletes following concussion
(Faculty of Graduate Studies and Research, University of Regina, 2023-03) Lillie, Garrett Richard; Dorsch, Kim; Neary, Patrick; Mang, Cameron; Brigham, Mark
A mild traumatic brain injury (mTBI), colloquially known as a concussion, is an injury of the brain that often results in significant functional impairment for days, weeks, or even months. While the most common symptoms of concussion have been well documented and studies frequently note a deficit in either higher-level cognitive functioning and autonomic physiological control, there is a lack of research describing the effect of concussion on executive functioning and heart rate variability (HRV). The aim of this study was to address gaps in literature by describing changes in an individual’s executive functioning and physiology simultaneously following a concussion using two investigative approaches, using the theory of neurovisceral integration as a guiding framework. Secondary data from University of Regina athletes was used to examine baseline executive functioning (measured by Neurotracker®) and athlete HRV transformed from ECG. These results were subsequently compared to the same measures postinjury. Prior to review of data from the 2019-2020 academic year, there was an expectation that occurrence of a concussion would be associated with a decrease in Neurotracker® performance, Mean R-R intervals (Mean R-R), and Root-Mean-Square-Difference of successive R-R intervals (RMSSD) while also being associated with increases in Low-Frequency/High-Frequency (LF/HF) ratio and Standard Deviation 2/Standard Deviation 1 (SD2/SD1) ratios. Across a sample of eight participants, only one participant experienced the expected change in variable while the two participants that experienced symptoms the longest, featured smaller deviations from their baselines. My study was exploratory in nature and suggests directions for future research.
Open Access
From gee to haw (and everything in between): Deconstructing the transspecies pidgin of mushing in northern Saskatchewan
(Faculty of Graduate Studies and Research, University of Regina, 2024-07) Doley Barman, Pradeep Ranjan; Oehler, Alex; Abbott, Sarah; Brigham, Mark
This multispecies ethnography deconstructs the Gee Haw transspecies pidgin of settler origin mushing in Northern Saskatchewan, Canada. Through a focus on multisensory methodological inquiry, I describe interspecies communication and human perceptions around nonhuman knowledge in the context of sled dog racing. This pidgin is a product of biconstructivism which includes motherese (verbal) words rooted in the English language, vocalisation, short phrases for reinforcement, the use of material devices, and training methodologies to shape a multisensory experience of interspecies collaboration. Dogs are considered nonhuman athletes in this hybrid community. They are bred, cared and trained for their “drive”, speed, endurance and the ability to understand commands. The sled dog exchange is explored through the lens of team sports and perceptions around nonhuman “occupation” are explained. This study aims to contribute towards an academic space given to more than human communication by detailing its findings from Gee (right) to Haw (left) and everything in between. Keywords: mushing, pidgin, dog-human communication, nonhuman athletes, haptic sociality
Open Access
Furry and Feathered Bats: Myths, Mysteries, and Mushrooms
(University of Regina Library, 2012-10-31) Brigham, Mark
When: Wednesday, October 31 1:00pm – 2:00pm Where: University of Regina Main Campus Classroom Building Lecture Theatre 128 (CL 128)
Open Access
Habitat selection and demography of mixed -grass prairie songbirds in a fragmented landscape.
(Faculty of Graduate Studies and Research, University of Regina, 2003) Davis, Stephen K.; Brigham, Mark; James, Paul
Open Access
Habitat selection and nesting ecology of translocated Greater Sage-grouse
(Faculty of Graduate Studies and Research, University of Regina, 2017-02) Balderson, Kayla Lane; Brigham, Mark; Davis, Stephen; Somers, Christopher; Moehrenschlager, Axel
Sagebrush ecosystems are one of the most imperiled ecosystems in North America. The cumulative effects of habitat loss, fragmentation and degradation of the sagebrush ecosystem threaten the persistence of the Greater Sage-grouse. Sage-grouse depend on healthy, intact areas of sagebrush habitat throughout the year. In Alberta, the sage-grouse population is estimated to be only 5% of what it was in 1968. During the spring of 2011 and 2012, 41 sage-grouse were fitted with GPS transmitters and translocated from stable populations in Montana to active lek sites in southeast Alberta. I conducted research to improve our understanding of translocation as a management tool, and how translocated sage-grouse are affected by anthropogenic features. I examined nesting ecology including the differences in post-release movements between nesting and non-nesting hens and the extent to which nest success is affected by anthropogenic features. I also identified habitat that translocated sage-grouse select in relation to anthropogenic and natural features. My research documented some of the largest post-release movement distances, rates and areas ever recorded for grouse after being translocated. Average weekly linear distance travelled was 56 km and average area traversed was 1944 km2. Non-nesting hens had significantly higher movement rates than nesting hens. Movement rates of nesting hens decreased during the nest initiation period, whereas movement rates of non-nesting hens did not decrease until 6 weeks later. Apparent annual hen survival ranged between 31-72% across the study period. Nest initiation (53%) and nest success (29%) were low compared to other sage-grouse populations across their range. Nest success decreased with increasing distance from trees, power lines and settlements, suggesting that translocated hens are naïve to the release area and do not recognize the risks that are typically associated with certain anthropogenic features. Translocated sage-grouse were more likely to be observed, with increasing distance from all of the anthropogenic features included in the movement models: as far as 3 km from trees and gas wells, 10 km from buildings and 15 km from settlements, at least 23 km from power lines and 2.5 km from roads. Interaction models suggest that sage-grouse are avoiding anthropogenic features because of the disturbance of the features themselves, and not because the features occur in poor sagebrush habitat. My results indicate that the effects of power lines, buildings, trees and oil wells (up to 5 km) on the occurrence of sage-grouse were largest, suggesting that these features should be prioritized for removal. However, it is likely that cumulative effects of some or all anthropogenic features cause sage-grouse to select habitat further away from these features. The predicted intensity map I generated could be used to help strategically guide habitat enhancement efforts in the study area. Habitat enhancements would best be focused in areas where predicted intensity was high and suitable habitat was present yet no sage-grouse were observed, with the goal of increasing the likelihood of sage-grouse use within those areas. Future assessments of proposed developments should consider the construction of all new anthropogenic features as a potential detriment to habitat quality.
Open Access
The heat shock response in embryonic and young of the year juvenile round whitefish (prosopium cylindraceum)
(Faculty of Graduate Studies and Research, University of Regina, 2017-03) Murillo, Andrea Michelle; Manzon, Richard; Brigham, Mark; Somers, Christopher
I investigated the effects of acute, increased temperatures on round whitefish embryos at the protruding mouth stage and young-of-the-year (YOY) juveniles at 3.5 months post hatch by characterizing the kinetics of the heat shock response (HSR). The HSR provides protection from a variety of stressors (i.e., thermal stress) at the cellular level and is characterized by the upregulation of a suite of proteins called heat shock proteins (Hsps). Round whitefish embryos were exposed to two heat shock (HS) temperatures (6 or 9 °C above control temperature) for 4 different lengths of time (1, 2, 3, or 4 h) followed by a 2 h recovery period at the control temperature of 4 °C, a typical incubation temperature for round whitefish embryos. Post-HS recovery was also examined by exposing embryos to a 2 h HS at 9 °C above control temperature followed by a recovery period of 0, 2, 4, 12, 24, or 48 h at the control temperature of 4 °C. YOY juveniles acclimated to an ecologically relevant 10 °C were exposed to three different HS temperatures (6, 9, or 12 °C above control temperature) for 4 different lengths of time (1, 2, 3, or 4 h) and not given a recovery period. Post HS recovery was examined by exposing YOY juveniles to a 2 h HS at 6, 9, or 12 °C above control temperature followed by a 0, 1, 4, or 8 h recovery period at the control temperature of 10 °C prior to sampling. In embryos, hsp70 mRNA levels were the only consistently upregulated heat shock protein (Hsp), whereas in YOY juveniles hsp70 and hsp47 mRNA levels were consistently upregulated. Furthermore, in comparison to juveniles, embryos took a longer time to initiate a HSR but once upregulated the HSR was long lasting in both life history stages. These data indicate that embryos and juveniles are able to trigger a protective HSR which presumably aids them in surviving a 3 h HS of +9 °C and a 4 h of HS +12 °C, respectively. This suggests HSR is one of the mechanisms available to round whitefish when experiencing thermal stress in fluctuating environments.
Open Access
The influence of embryo incubation temperature on later life aerobic performance of Lake Whitefish (Coregonus clupeaformis) and Yellow Perch (Perca flavescens)
(Faculty of Graduate Studies and Research, University of Regina, 2023-03) Dorsey, Spencer William; Manzon; Brigham, Mark; Somers, Christopher; Tierney, Keith
Temperature represents one of the most influential abiotic factors affecting all living organisms. Ectotherms, including fish, can be affected by temperature at the cellular, individual, population, and community levels. In modern times, climate change and thermal pollution pose major threats as they threaten to elevate water temperatures, therefore limiting optimal thermal habitats and exposing species to suboptimal environmental conditions. While adult fish of many species have the capacity to avoid these thermally impacted areas, early life stages (i.e., embryonic, larval, and juvenile) are typically limited in mobility and lack the ability to avoid these areas. These early life stages are especially vulnerable, as this is a time of rapid growth and development. While numerous studies have evaluated the effects of temperature during development on hatching success, developmental rates, and phenotypic plasticity, few have assessed its effects on later life whole-animal performance. I used intermittent swim respirometry to evaluate the effects of embryo incubation temperature on two measurements of whole-animal aerobic performance: aerobic scope and critical swimming speed. I chose to use two species of fish that use distinct reproductive characteristics, the fall spawning Lake Whitefish and the spring spawning Yellow Perch. I hypothesized that whole-animal aerobic performance of both species would be reduced when embryos were incubated at temperatures 3 °C above optimal. I also hypothesized that Lake Whitefish would be impacted more drastically than Yellow Perch due to their narrower thermal tolerance. Finally, I predicted that whole-animal aerobic performance would be maximized at temperatures near the thermal preference of the species, respectively. To test my hypotheses, I first incubated Lake Whitefish and Yellow Perch embryos at 2 and 5 °C, and 15 and 18 °C, respectively. I then reared Lake Whitefish at common-garden temperatures of 12 °C for 14 to 16 months and Yellow Perch at 18 °C for and 9 to 12 months. Following the rearing periods, Lake Whitefish and Yellow Perch were split into experimental temperature groups and acclimated to 15 and 19 °C, and 20, 24, and 28 °C respectively, for 2-4 weeks before swim respirometry trials began. I found that embryo incubation temperature influences the whole-animal aerobic performance of Lake Whitefish but does not affect Yellow Perch. Lake Whitefish incubated as embryos at 5 °C demonstrated a reduction in critical swimming when acclimated to 15 °C as juveniles. An interaction between the embryo incubation temperature and the response to juvenile acclimation temperature was also detected in Lake Whitefish, where the routine metabolic rate of fish incubated as embryos at 5 °C did not increase when acclimated as juveniles to 19 °C compared to 15 °C. No influence of embryo incubation temperature was observed in the whole-animal aerobic performance of Yellow Perch. My results imply that Lake Whitefish and potentially other species that demonstrate similar developmental characteristics are likely to be impacted by increases in global water temperatures. Decreases in whole-animal aerobic performance could have negative impacts on survival and recruitment. Yellow Perch and other species that share developmental characteristics will be impacted to a lesser extent. Although the mechanisms responsible for the effects of embryo incubation temperature on later life whole-animal aerobic performance are not well understood, this study gives a baseline for further research to build upon. By understanding the potential for embryo incubation temperature to influence later life whole-animal aerobic performance, future studies can be conducted to isolate the mechanisms associated.
Open Access
The Influence of Weather, Time of Season, and Time of Day on Bullsnake (Pituophis atenifer sayi) Thermoregulation and Habitat Selection
(Faculty of Graduate Studies and Research, University of Regina, 2021-04) Johnson, Noah Brian; Somers, Christopher; Poulin, Ray; Brigham, Mark; McAlpine, Donald
The grasslands of Western Canada are exposed to one of the most variable terrestrial climates on Earth. Ectothermic reptiles such as the bullsnake (Pituophis catenifer sayi) must respond to this variation by altering their behaviour over daily and seasonal scales. In Chapter 2, I addressed questions regarding the extent to which bullsnakes thermoregulate. I examined how body temperatures (Tb) varied with available operative temperatures (Te) over an active season at a site in southwestern Saskatchewan, Canada. Bare ground Te was variable (x̄ min = 9.3, x̄ max = 31.4°C) and was outside voluntary limits (15 – 35°C) 45 % of the time. However, burrows created by mammals provided stable thermal conditions that remained within voluntary ranges for 93 % of the active season. Bullsnakes should not need to move far to thermoregulate because of thermal gradients (up to 27.2°C in less than 1 m) formed between burrows and patches of sun-exposed bare ground. Time of day, day of year, and bare ground Te (R2 = 0.578) were useful predictors of Tb (x̄ min = 20.1, x̄ max = 29.1°C). Bullsnakes thermoregulated by conforming to Te near their preferred range (21 to 27°C), selecting locations that enabled heating up below this range, and avoiding warmth above this range. My results support the hypothesis that predicts reptiles will thermoregulate more when environmental temperatures deviate from preferred ranges, and when energetic costs of movement are lower due to high thermal heterogeneity. Despite the extreme surface temperatures of high-latitude grasslands, thermoregulation may be easier for snakes than in high-latitude forests due to the thermal gradients available because of burrows in areas exposed to sun. In Chapter 3, I examined the influence of time (time of day, day of year) and weather (temperature, humidity, and precipitation) on a suite of behaviours in 4 bullsnake populations in Saskatchewan. I studied variation in 4th order use and selection for burrows, concealment probability, relocation probability, and movement distances. Bullsnakes altered behaviours in response to time and weather. The greatest variation was explained for concealment (R2 = 0.244) and 4th order habitat selection (R2 = 0.144 – 0.169). However, 4th order habitat use (R2 = 0.0366), relocation (R2 = 0.0419), and movements (R2 = 0.025 – 0.071) were relatively unpredictable based on time and weather variables. Movement distances were particularly variable among individuals. Overall bullsnake activity was highest in spring and during afternoons. Poor weather and unfavourable temperatures were avoided. Humidity was more important than expected. Humidity (or precipitation) was negatively associated with activity in spring or at cool temperatures, but positively associated with activity in summer or at hot temperatures. I suggest that current management recommendations for bullsnakes are valid. However, sample biases could create the false appearance of different habitat requirements among populations if weather conditions, time of day, or season were to differ among studies. Time and weather were useful for predicting the probability of finding bullsnakes on the surface (AUC = 0.8015) and should be used to forecast optimal conditions for surveys. Snake behaviour is often considered to be unpredictable, but the results of Chapter 2 and 3 suggest that weather variables and time are important for predicting bullsnake behaviour, and particularly general surface activity. Behaviours varied widely over the active season, and the effects of time and weather variables were context dependent. My thesis highlights the importance of long study periods under a wide range of conditions to understand the ecology of reptiles in highly seasonal environments.
Open Access
Long-Term Effects of Forest Harvesting on Habitat Use By Insectivorous Bats
(Faculty of Graduate Studies and Research, University of Regina, 2019-04-09) Lauzon, Audrey; Brigham, Mark; Sleep, Darren; Somers, Christopher; Fraser, Erin
The short-term effects of forest harvesting on forest-dwelling bats have received considerable attention. However, knowledge about the long-term effects are also essential to better conserve forest-dwelling bat populations in North America. As vegetation regenerates over time post-harvest, changes created by harvesting (e.g., cutblocks and forest edges) will blur and eventually disappear with natural forest regrowth. Long-term effects of forest harvesting could thus differ from short-term effects on forest-dwelling bat species. To evaluate changes in habitat use by an insectivorous bat community in response to forest harvesting over time, I repeated a study (Grindal and Brigham 1999) conducted near Nelson, British Columbia, Canada. Grindal and Brigham’s principal objective was to evaluate bats’ use of habitats created by or left after clear-cut logging using acoustic detectors. I revisited the same exact locations 20+ years later to determine how bats use the forest regrowth of these habitats. As was done in 1993-94, I assessed bat community activity and insect community composition (bat prey) in three habitats types (i.e. cutblocks, forest edges, unlogged forests) in combination with different habitat features at landscape and local scales. I found that insect community composition within regenerating cutblocks and along forest edges, when compared to adjacent old-growth forests, showed signs of recovery suggesting the movement of the community towards a new equilibrium. I found that the bat community had modified its use of the same disturbed areas since 1993. My results suggest that clutter and openadapted bats mostly foraged and commuted above the canopy of dense and cluttered forest regrowth of regenerating cutblocks and along the remaining vertical forest edges. I also found that clutter-adapted bats flying within vegetation mainly used old-growth forests to forage and commute. By using a different approach than previous studies my research proposes a time and cost-effective way to enhance our knowledge about changes of bat habitat use over time in a dynamic environment.