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• 21. [Article] Quantifying the Impacts of a Novel Predator: The Distinctive Case of the Oregon Spotted Frog (<i>Rana pretiosa</i>) and the Invasive American Bullfrog (<i>Rana (Aquarana) catesbeiana</i>)

  The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat ...

  Citation × Citation Citation Abstract Copy Title: Quantifying the Impacts of a Novel Predator: The Distinctive Case of the Oregon Spotted Frog (<i>Rana pretiosa</i>) and the Invasive American Bullfrog (<i>Rana (Aquarana) catesbeiana</i>) Author: Tidwell, Kyle Scott Year: 2017 The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat degradation and loss. The introduced American Bullfrog (Rana (Aquarana) catesbeiana) has been widely implicated in those declines, but the basis of that contention has been difficult to characterize. The bullfrog occurring at every site of recent Oregon Spotted Frog extirpation has focused concern about its impact. Here, I present a suite of interconnected studies that examine the behavioral ecology of both species to better understand the potential for bullfrog-mediated Oregon Spotted Frog extirpation. I quantified Oregon Spotted Frog anti-predator behavior from the only known population successfully co-occurring with bullfrogs (Conboy Lake) and a population devoid of bullfrog impact (Big Marsh), and compared these behaviors to the predatory traits of the bullfrog. The initial study revealed that captive-reared individuals from the Oregon Spotted Frog population that has successfully co-occurred with bullfrogs respond faster to a predatory stimulus (measured as latency to response) than Oregon Spotted Frogs from a population not to exposed to bullfrogs. Subsequent field investigations of the approach distance allowed by a predator stimulus before taking evasive action (termed the flight initiation distance: FID) conducted with the Oregon Spotted Frog population co-occurring with bullfrogs first demonstrated that FID of recently metamorphosed bullfrogs is consistently greater than that of recently metamorphosed Oregon Spotted Frogs. Further, examination of FID across all post-metamorphic age classes of Oregon Spotted Frogs revealed that older frogs do not allow as close approach as recently metamorphosed Oregon Spotted Frogs. This age class shift in FID did not occur in the Oregon Spotted Frog population not exposed to bullfrogs. In the latter population, FID did not differ among age classes. Since the bullfrog might be driving this age-based change in anti-predator behavior, I explored the variation in strike distance of bullfrogs from the site of co-occurrence in both the field and laboratory to determine the extent of overlap with Oregon Spotted Frog FID. I found that the bullfrog strike distance significantly overlaps the FID of all ages of Oregon Spotted Frogs from the bullfrog-free site but only that of youngest (recently metamorphosed) frogs at the site of co-occurrence. Older Oregon Spotted Frogs from the site of co-occurrence generally escaped at distances greater than the strike distance of bullfrogs. I also collected > 880 bullfrogs from the site of co-occurrence and analyzed the stomach contents to assess their dietary trends. I found that bullfrogs consume Oregon Spotted Frogs at the site, but do not eat the larger (older) frogs. Moreover, the body size ratio between Oregon Spotted Frogs as prey and bullfrogs as predators suggests that nearly all of the adult size distribution of bullfrogs at Conboy would be incapable of preying on adult Oregon Spotted Frogs. Collectively, these studies strongly suggest that bullfrogs have altered the escape behavior of Oregon Spotted Frogs at Conboy Lake and that most adult Oregon Spotted Frogs at Conboy may have a size-based release from predation by bullfrogs. Implicit in this finding is that bullfrogs may pose a real threat via predation to other Oregon Spotted Frog populations with which they might come into contact where the distribution of bullfrog body sizes differ substantially from that at Conboy Lake. Title: Quantifying the Impacts of a Novel Predator: The Distinctive Case of the Oregon Spotted Frog (<i>Rana pretiosa</i>) and the Invasive American Bullfrog (<i>Rana (Aquarana) catesbeiana</i>) Author: Tidwell, Kyle Scott Year: 2017 The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat degradation and loss. The introduced American Bullfrog (Rana (Aquarana) catesbeiana) has been widely implicated in those declines, but the basis of that contention has been difficult to characterize. The bullfrog occurring at every site of recent Oregon Spotted Frog extirpation has focused concern about its impact. Here, I present a suite of interconnected studies that examine the behavioral ecology of both species to better understand the potential for bullfrog-mediated Oregon Spotted Frog extirpation. I quantified Oregon Spotted Frog anti-predator behavior from the only known population successfully co-occurring with bullfrogs (Conboy Lake) and a population devoid of bullfrog impact (Big Marsh), and compared these behaviors to the predatory traits of the bullfrog. The initial study revealed that captive-reared individuals from the Oregon Spotted Frog population that has successfully co-occurred with bullfrogs respond faster to a predatory stimulus (measured as latency to response) than Oregon Spotted Frogs from a population not to exposed to bullfrogs. Subsequent field investigations of the approach distance allowed by a predator stimulus before taking evasive action (termed the flight initiation distance: FID) conducted with the Oregon Spotted Frog population co-occurring with bullfrogs first demonstrated that FID of recently metamorphosed bullfrogs is consistently greater than that of recently metamorphosed Oregon Spotted Frogs. Further, examination of FID across all post-metamorphic age classes of Oregon Spotted Frogs revealed that older frogs do not allow as close approach as recently metamorphosed Oregon Spotted Frogs. This age class shift in FID did not occur in the Oregon Spotted Frog population not exposed to bullfrogs. In the latter population, FID did not differ among age classes. Since the bullfrog might be driving this age-based change in anti-predator behavior, I explored the variation in strike distance of bullfrogs from the site of co-occurrence in both the field and laboratory to determine the extent of overlap with Oregon Spotted Frog FID. I found that the bullfrog strike distance significantly overlaps the FID of all ages of Oregon Spotted Frogs from the bullfrog-free site but only that of youngest (recently metamorphosed) frogs at the site of co-occurrence. Older Oregon Spotted Frogs from the site of co-occurrence generally escaped at distances greater than the strike distance of bullfrogs. I also collected > 880 bullfrogs from the site of co-occurrence and analyzed the stomach contents to assess their dietary trends. I found that bullfrogs consume Oregon Spotted Frogs at the site, but do not eat the larger (older) frogs. Moreover, the body size ratio between Oregon Spotted Frogs as prey and bullfrogs as predators suggests that nearly all of the adult size distribution of bullfrogs at Conboy would be incapable of preying on adult Oregon Spotted Frogs. Collectively, these studies strongly suggest that bullfrogs have altered the escape behavior of Oregon Spotted Frogs at Conboy Lake and that most adult Oregon Spotted Frogs at Conboy may have a size-based release from predation by bullfrogs. Implicit in this finding is that bullfrogs may pose a real threat via predation to other Oregon Spotted Frog populations with which they might come into contact where the distribution of bullfrog body sizes differ substantially from that at Conboy Lake. Close

• 22. [Article] Multimodel Simulations of Forest Harvesting Effects on Long-Term Productivity and CN Cycling in Aspen Forests

  The effects of forest management on soil carbon (C) and nitrogen (N) dynamics vary by harvest type and species. We simulated long-term effects of bole-only harvesting of aspen (Populus tremuloides) on ...

  Citation × Citation Citation Abstract Copy Title: Multimodel Simulations of Forest Harvesting Effects on Long-Term Productivity and CN Cycling in Aspen Forests Author: Wang, Fugui, Mladenoff, David J., Forrester, Jodi A., Blanco, Juan A., Scheller, Robert M., Peckham, Scott D., Keough, Cindy, Lucash, Melissa S. Year: 2014 The effects of forest management on soil carbon (C) and nitrogen (N) dynamics vary by harvest type and species. We simulated long-term effects of bole-only harvesting of aspen (Populus tremuloides) on stand productivity and interaction of CN cycles with a multiple model approach. Five models, Biome-BGC, CENTURY, FORECAST, LANDIS-II with Century-based soil dynamics, and PnET-CN, were run for 350 years with seven harvesting events on nutrient-poor, sandy soils representing northwestern Wisconsin, USA. Twenty CN state and flux variables were summarized from the models' outputs, and statistically analyzed using ordination and variance analysis methods. The multiple models' averages suggest that bole-only harvest would not significantly affect long-term site productivity of aspen, though declines in soil organic matter and soil N were significant. Along with direct N removal by harvesting, extensive leaching after harvesting before canopy closure was another major cause of N depletion. These five models were notably different in output values of the 20 variables examined, although there were some similarities for certain variables. PnET-CN produced unique results for every variable, and CENTURY showed fewer outliers and similar temporal patterns to the mean of all models. In general, this study demonstrated that when there are no site-specific data for fine-scale calibration and evaluation of a single model, the multiple model approach may be a more robust approach for long-term simulations. In addition, multi-modeling may also improve the calibration and evaluation of an individual model. Title: Multimodel Simulations of Forest Harvesting Effects on Long-Term Productivity and CN Cycling in Aspen Forests Author: Wang, Fugui, Mladenoff, David J., Forrester, Jodi A., Blanco, Juan A., Scheller, Robert M., Peckham, Scott D., Keough, Cindy, Lucash, Melissa S. Year: 2014 The effects of forest management on soil carbon (C) and nitrogen (N) dynamics vary by harvest type and species. We simulated long-term effects of bole-only harvesting of aspen (Populus tremuloides) on stand productivity and interaction of CN cycles with a multiple model approach. Five models, Biome-BGC, CENTURY, FORECAST, LANDIS-II with Century-based soil dynamics, and PnET-CN, were run for 350 years with seven harvesting events on nutrient-poor, sandy soils representing northwestern Wisconsin, USA. Twenty CN state and flux variables were summarized from the models' outputs, and statistically analyzed using ordination and variance analysis methods. The multiple models' averages suggest that bole-only harvest would not significantly affect long-term site productivity of aspen, though declines in soil organic matter and soil N were significant. Along with direct N removal by harvesting, extensive leaching after harvesting before canopy closure was another major cause of N depletion. These five models were notably different in output values of the 20 variables examined, although there were some similarities for certain variables. PnET-CN produced unique results for every variable, and CENTURY showed fewer outliers and similar temporal patterns to the mean of all models. In general, this study demonstrated that when there are no site-specific data for fine-scale calibration and evaluation of a single model, the multiple model approach may be a more robust approach for long-term simulations. In addition, multi-modeling may also improve the calibration and evaluation of an individual model. Close

• 23. [Article] Divergent trends in ecosystem services under different climate-management futures in a fire-prone forest landscape

  While ecosystem services and climate change are often examined independently, quantitative assessments integrating these fields are needed to inform future land management decisions. Using climate-informed ...

  Citation × Citation Citation Abstract Copy Title: Divergent trends in ecosystem services under different climate-management futures in a fire-prone forest landscape Author: Halofsky, Joshua S., Halofsky, Jessica E., Hemstrom, Miles A., Morzillo, Anita T., Zhou, Xiaoping, Donato, Daniel C. Year: 2017 While ecosystem services and climate change are often examined independently, quantitative assessments integrating these fields are needed to inform future land management decisions. Using climate-informed state-and-transition simulations, we examined projected trends and trade-offs for a suite of ecosystem services under four climate change scenarios and two management scenarios (active management emphasizing fuel treatments and no management other than fire suppression) in a fire-prone landscape of dry and moist mixed-conifer forests in central Oregon, USA. Focal ecosystem services included fire potential (regulating service), timber volume (provisioning service), and potential wildlife habitat (supporting service). Projections without climate change suggested active management in dry mixed-conifer forests would create more open forest structures, reduce crown fire potential, and maintain timber stocks, while in moist mixed-conifer forests, active management would reduce crown fire potential but at the expense of timber stocks. When climate change was considered, however, trends in most ecosystem services changed substantially, with large increases in wildfire area predominating broad-scale trends in outputs, regardless of management approach (e.g., strong declines in timber stocks and habitat for closed-forest wildlife species). Active management still had an influence under a changing climate, but as a moderator of the strong climate-driven trends rather than being a principal driver of ecosystem service outputs. These results suggest projections of future ecosystem services that do not consider climate change may result in unrealistic expectations of benefits. Title: Divergent trends in ecosystem services under different climate-management futures in a fire-prone forest landscape Author: Halofsky, Joshua S., Halofsky, Jessica E., Hemstrom, Miles A., Morzillo, Anita T., Zhou, Xiaoping, Donato, Daniel C. Year: 2017 While ecosystem services and climate change are often examined independently, quantitative assessments integrating these fields are needed to inform future land management decisions. Using climate-informed state-and-transition simulations, we examined projected trends and trade-offs for a suite of ecosystem services under four climate change scenarios and two management scenarios (active management emphasizing fuel treatments and no management other than fire suppression) in a fire-prone landscape of dry and moist mixed-conifer forests in central Oregon, USA. Focal ecosystem services included fire potential (regulating service), timber volume (provisioning service), and potential wildlife habitat (supporting service). Projections without climate change suggested active management in dry mixed-conifer forests would create more open forest structures, reduce crown fire potential, and maintain timber stocks, while in moist mixed-conifer forests, active management would reduce crown fire potential but at the expense of timber stocks. When climate change was considered, however, trends in most ecosystem services changed substantially, with large increases in wildfire area predominating broad-scale trends in outputs, regardless of management approach (e.g., strong declines in timber stocks and habitat for closed-forest wildlife species). Active management still had an influence under a changing climate, but as a moderator of the strong climate-driven trends rather than being a principal driver of ecosystem service outputs. These results suggest projections of future ecosystem services that do not consider climate change may result in unrealistic expectations of benefits. Close

• 24. [Article] Mitigating Marine Mammal Bycatch: Technological and Economic Efficiency

  Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, ...

  Citation × Citation Citation Abstract Copy Title: Mitigating Marine Mammal Bycatch: Technological and Economic Efficiency Author: Ballance, Lisa, Lent, Rebecca Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Title: Mitigating Marine Mammal Bycatch: Technological and Economic Efficiency Author: Ballance, Lisa, Lent, Rebecca Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Close

• 25. [Article] Balancing Carrots and Sticks for Fisheries Management: The Case of Hilsa Management in Bangladesh

  Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, ...

  Citation × Citation Citation Abstract Copy Title: Balancing Carrots and Sticks for Fisheries Management: The Case of Hilsa Management in Bangladesh Author: Mohammed, Essam Yassin Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Title: Balancing Carrots and Sticks for Fisheries Management: The Case of Hilsa Management in Bangladesh Author: Mohammed, Essam Yassin Year: 2016 Suggested Bibliographic Reference: Challenging New Frontiers in the Global Seafood Sector: Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, July 11-15, 2016. Compiled by Stefani J. Evers and Ann L. Shriver. International Institute of Fisheries Economics and Trade (IIFET), Corvallis, 2016. Close

• 26. [Article] Ecoroofs in Multnomah County: Oregon as habitat for the Oregon vesper sparrow and common nighthawk

  78 pages. Examining committee chair:David Hulse

  Citation × Citation Citation Abstract Copy Title: Ecoroofs in Multnomah County: Oregon as habitat for the Oregon vesper sparrow and common nighthawk Author: Lewis, Alison Year: 2016 78 pages. Examining committee chair:David Hulse Title: Ecoroofs in Multnomah County: Oregon as habitat for the Oregon vesper sparrow and common nighthawk Author: Lewis, Alison Year: 2016 78 pages. Examining committee chair:David Hulse Close

• 27. [Article] Intestinal Microbiota Diversity of Pre-Smolt Steelhead (Oncorhynchus mykiss) Across Six Oregon and Washington Hatcheries

  The Pacific Northwest is known for its once-abundant wild salmonid populations that have been in decline for more than 50 years due to habitat destruction and commercial overexploitation. To compensate, ...

  Citation × Citation Citation Abstract Copy Title: Intestinal Microbiota Diversity of Pre-Smolt Steelhead (Oncorhynchus mykiss) Across Six Oregon and Washington Hatcheries Author: Yildirimer, Christina Carrell Year: 2017 The Pacific Northwest is known for its once-abundant wild salmonid populations that have been in decline for more than 50 years due to habitat destruction and commercial overexploitation. To compensate, federal and state agencies annually release hundreds of thousands of hatchery-reared fish into the wild. However, accumulating data indicate that hatchery fish have lower fitness in natural environments, and that hatchery rearing negatively influences return rates of anadromous salmonids. Recently, mounting evidence revealed that the richness and diversity of intestinal microbial species influence host health. We examined the gut microbiota of pre-migratory hatchery-reared steelhead (Oncorhynchus mykiss) to assess microbial community diversity. The Cascade Mountains serve as an allopatric border between two distinct clades of steelhead that show significant differences in genomic and mitochondrial diversity. We identified differences in core microbiota of hatchery-reared fish that correlate with this divergent phylogeographic distribution. Steelhead sampled from hatcheries east of the Cascades had overall greater core gut microbiota diversity. These differences were found despite similarities in diet and rearing conditions. In addition to taxonomic variation across the geographic divide, we identified significant differences in metabolic pathways using PICRUSt gene prediction software. Our analysis revealed significant enrichment of genes associated with lipid metabolism in the gut microbiome of western fish. 8 of 19 individual lipid metabolism pathways were more prominent in western populations. Lipids are a vital nutritional component for teleost species involved in migration and subsequent return for spawning in natal environments. We hypothesize that the observed differences in lipid metabolism across this phylogenetic divide results from an increased ability of eastern Cascade (O. m. gairdneri) fish to utilize lipids taken in via the diet. This increased absorption and utilization would make lipids less available for the intestinal microbiota of the eastern fish, as evidenced by the lower abundance of lipid metabolism genes in the east. Our research utilizes information from the microbiome to understand the phenotypic implications occurring in segregated populations of hatchery-reared steelhead, further confirming elements of coevolution between an organism and its internal environment. Title: Intestinal Microbiota Diversity of Pre-Smolt Steelhead (Oncorhynchus mykiss) Across Six Oregon and Washington Hatcheries Author: Yildirimer, Christina Carrell Year: 2017 The Pacific Northwest is known for its once-abundant wild salmonid populations that have been in decline for more than 50 years due to habitat destruction and commercial overexploitation. To compensate, federal and state agencies annually release hundreds of thousands of hatchery-reared fish into the wild. However, accumulating data indicate that hatchery fish have lower fitness in natural environments, and that hatchery rearing negatively influences return rates of anadromous salmonids. Recently, mounting evidence revealed that the richness and diversity of intestinal microbial species influence host health. We examined the gut microbiota of pre-migratory hatchery-reared steelhead (Oncorhynchus mykiss) to assess microbial community diversity. The Cascade Mountains serve as an allopatric border between two distinct clades of steelhead that show significant differences in genomic and mitochondrial diversity. We identified differences in core microbiota of hatchery-reared fish that correlate with this divergent phylogeographic distribution. Steelhead sampled from hatcheries east of the Cascades had overall greater core gut microbiota diversity. These differences were found despite similarities in diet and rearing conditions. In addition to taxonomic variation across the geographic divide, we identified significant differences in metabolic pathways using PICRUSt gene prediction software. Our analysis revealed significant enrichment of genes associated with lipid metabolism in the gut microbiome of western fish. 8 of 19 individual lipid metabolism pathways were more prominent in western populations. Lipids are a vital nutritional component for teleost species involved in migration and subsequent return for spawning in natal environments. We hypothesize that the observed differences in lipid metabolism across this phylogenetic divide results from an increased ability of eastern Cascade (O. m. gairdneri) fish to utilize lipids taken in via the diet. This increased absorption and utilization would make lipids less available for the intestinal microbiota of the eastern fish, as evidenced by the lower abundance of lipid metabolism genes in the east. Our research utilizes information from the microbiome to understand the phenotypic implications occurring in segregated populations of hatchery-reared steelhead, further confirming elements of coevolution between an organism and its internal environment. Close

• 28. [Article] Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in Southeastern Oregon

  Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To ...

  Citation × Citation Citation Abstract Copy Title: Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in Southeastern Oregon Author: Creutzburg, Megan K., Henderson, Emilie B., Conklin, David R. Year: 2015 Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the potential impacts of climate change, disturbances, and management activities. We integrated information from a dynamic global vegetation model, a sage-grouse habitat climate envelope model, and a state-and-transition simulation model to project broad-scale vegetation dynamics and potential sage-grouse habitat across 23.5 million acres in southeastern Oregon. We evaluated four climate scenarios, including continuing current climate and three scenarios of global climate change, and three management scenarios, including no management, current management and a sage-grouse habitat restoration scenario. All climate change scenarios projected expansion of moist shrub steppe and contraction of dry shrub steppe, but climate scenarios varied widely in the projected extent of xeric shrub steppe, where hot, dry summer conditions are unfavorable for sage-grouse. Wildfire increased by 26% over the century under current climate due to exotic grass encroachment, and by two- to four-fold across all climate change scenarios as extreme fire years became more frequent. Exotic grasses rapidly expanded in all scenarios as large areas of the landscape initially in semi-degraded condition converted to exotic-dominated systems. Due to the combination of exotic grass invasion, juniper encroachment, and climatic unsuitability for sage-grouse, projected sage-grouse habitat declined in the first several decades, but increased in area under the three climate change scenarios later in the century, as moist shrub steppe increased and rangeland condition improved. Management activities in the model were generally unsuccessful in controlling exotic grass invasion but were effective in slowing woodland expansion. Current levels of restoration treatments were insufficient to prevent some juniper expansion, but increased treatment rates under the restoration scenario maintained juniper near initial levels in priority treatment areas. Our simulations indicate that climate change may have both positive and negative implications for maintaining sage-grouse habitat. Title: Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in Southeastern Oregon Author: Creutzburg, Megan K., Henderson, Emilie B., Conklin, David R. Year: 2015 Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the potential impacts of climate change, disturbances, and management activities. We integrated information from a dynamic global vegetation model, a sage-grouse habitat climate envelope model, and a state-and-transition simulation model to project broad-scale vegetation dynamics and potential sage-grouse habitat across 23.5 million acres in southeastern Oregon. We evaluated four climate scenarios, including continuing current climate and three scenarios of global climate change, and three management scenarios, including no management, current management and a sage-grouse habitat restoration scenario. All climate change scenarios projected expansion of moist shrub steppe and contraction of dry shrub steppe, but climate scenarios varied widely in the projected extent of xeric shrub steppe, where hot, dry summer conditions are unfavorable for sage-grouse. Wildfire increased by 26% over the century under current climate due to exotic grass encroachment, and by two- to four-fold across all climate change scenarios as extreme fire years became more frequent. Exotic grasses rapidly expanded in all scenarios as large areas of the landscape initially in semi-degraded condition converted to exotic-dominated systems. Due to the combination of exotic grass invasion, juniper encroachment, and climatic unsuitability for sage-grouse, projected sage-grouse habitat declined in the first several decades, but increased in area under the three climate change scenarios later in the century, as moist shrub steppe increased and rangeland condition improved. Management activities in the model were generally unsuccessful in controlling exotic grass invasion but were effective in slowing woodland expansion. Current levels of restoration treatments were insufficient to prevent some juniper expansion, but increased treatment rates under the restoration scenario maintained juniper near initial levels in priority treatment areas. Our simulations indicate that climate change may have both positive and negative implications for maintaining sage-grouse habitat. Close

• 29. [Article] Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos

  African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due ...

  Citation × Citation Citation Abstract Copy Title: Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos Author: Holdgate, Matthew Robert Year: 2015 African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate. Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS. In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved. Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence. Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so. This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management. Title: Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos Author: Holdgate, Matthew Robert Year: 2015 African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate. Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS. In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved. Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence. Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so. This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management. Close

• 30. [Article] Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream

  Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range ...

  Citation × Citation Citation Abstract Copy Title: Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream Author: Silver, Gregory Shell Year: 2015 Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range. We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat. Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances. Title: Investigations of Larval Pacific Lamprey Entosphenus tridentatus Osmotic Stress Tolerance and Occurrence in a Tidally-Influenced Estuarine Stream Author: Silver, Gregory Shell Year: 2015 Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing larval Pacific lamprey occupancy and distribution, habitat requirements, and the limiting factors of larval distribution in the freshwater ecosystem. As part of the effort to address these knowledge gaps, we investigated the potential for larval lampreys to occur in tidally-influenced estuarine environments. Research of this type may be valuable for future conservation, management or recovery efforts of Pacific lamprey throughout its range. We employed a two-phased approach, consisting of laboratory and field components to address our aims. We first conducted a series of controlled laboratory experiments to evaluate osmotic stress tolerance and osmoregulatory status of larval Pacific lamprey exposed to a range of (1) fixed salinity in various dilutions of saltwater and (2) oscillating salinity treatments designed to simulate tidal activity. Tolerance was assessed by monitoring and comparing survival of larvae in various treatments through 96 h. Osmoregulatory status was assessed by quantifying and comparing total body water content, plasma osmolality, and plasma cation (i.e., sodium) concentrations among larvae surviving various treatments. In fixed salinity experiments, 100% survival was observed in 0‰, 6‰, 8‰ and 10‰ through 96 h, while 0% survival was observed through 48 h in 12‰, 30 h in 15‰, and 12 h in 25‰ and 35‰. In oscillating salinity experiments, on the other hand, a significant increase in survival (100%) was observed through 96 h in treatments that oscillated between 12‰ and 0‰ (freshwater) at about 6 h intervals versus fixed 12‰ salinity experiments. A significant increase in survival also occurred in oscillating 15‰ treatments (60%) versus fixed 15‰ through 96 h. Linear regression analysis indicated higher environmental salinity in laboratory experiments was significantly related to increases in plasma osmolality and plasma sodium (the most abundant osmotically active plasma cation) concentrations, and concurrent decreases in total body water content among larvae that survived various treatments. Tidal oscillations in salinity appeared to temper the desiccating effects of salinity, as changes in body water content and sodium ion concentration were less abrupt than fixed salinity treatments. These results suggest larvae cannot osmoregulate in hyperosmotic environments, but are able to tolerate some fixed and oscillating hyperosmotic salinity exposure. Consequently, larvae may be able to occur in certain areas of estuaries, such as oligohaline habitats that are characterized by low levels of salinity. Experimental results were used, in part, to guide larval sampling in a tidally-influenced habitat. Occurrence of larval Pacific lamprey and Lampetra spp. (western brook and river lampreys) was subsequently investigated across a gradient of salinity in Ellsworth Creek (Pacific County, Washington) by electrofishing. Larval Pacific and Lampetra spp. were detected within an approximately 300 m long tidally-influenced segment of the study area. Salinity monitoring was conducted in six tidally-influenced reaches where larvae were detected for up to 14 d following electrofishing. Maximum tidal cycle salinity exceeded 15 ppt during 52% to 80% of tidal cycles within tidally-influenced reaches where larvae were detected. These results suggest potential for larval lamprey to occur in certain portions of tidal estuaries. However, long-term residence of larvae in tidally-influenced habitats and whether larvae are able to subsequently survive, grow, transform, and out-migrate is not known and requires further study. Given the potential for tidally-influenced habitats to be occupied by larvae, assessments of larval occurrence in other areas, such as the lower Columbia River, may be warranted. Knowledge of larval lamprey distribution in estuarine environments may be valuable for habitat restoration, and mitigating potential impacts from dredging and other human disturbances. Close