Bruce K. Johnson, Dewaine H. Jackson, Rachel C. Cook, Darren A. Clark, Priscilla K. Coe, John G. Cook, Spencer N. Rearden, Scott L. Findholt, James H. Noyes
{"title":"Roles of maternal condition and predation in survival of juvenile Elk in Oregon","authors":"Bruce K. Johnson, Dewaine H. Jackson, Rachel C. Cook, Darren A. Clark, Priscilla K. Coe, John G. Cook, Spencer N. Rearden, Scott L. Findholt, James H. Noyes","doi":"10.1002/wmon.1039","DOIUrl":"https://doi.org/10.1002/wmon.1039","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Understanding bottom-up, top-down, and abiotic factors along with interactions that may influence additive or compensatory effects of predation on ungulate population growth has become increasingly important as carnivore assemblages, land management policies, and climate variability change across western North America. Recruitment and population trends of elk (<i>Cervus canadensis</i>) have been downward in the last 4 decades across the northern Rocky Mountains and Pacific Northwest, USA. In Oregon, changes in vegetation composition and land use practices occurred, cougar (<i>Puma concolor</i>) populations recovered from near-extirpation, and black bear (<i>Ursus americanus</i>) populations increased. Our goal was to provide managers with insight into the influence of annual climatic variation, and bottom-up and top-down factors affecting recruitment of elk in Oregon. We conducted our research in southwestern (SW; Toketee and Steamboat) and northeastern (NE; Wenaha and Sled Springs) Oregon, which had similar predator assemblages but differed in patterns of juvenile recruitment, climate, cougar densities, and vegetative characteristics.</p>\u0000 \u0000 <p>We obtained monthly temperature and precipitation measures from Parameter-elevation Regressions on Independent Slopes Model (PRISM) and estimates of normalized difference vegetation index (NDVI) for each study area to assess effects of climate and vegetation growth on elk vital rates. To evaluate the nutritional status of elk in each study area, we captured, aged, and radio-collared adult female elk in SW (<i>n </i>= 69) in 2002–2005 and NE (<i>n </i>= 113) in 2001–2007. We repeatedly captured these elk in autumn (<i>n </i>= 232) and spring (<i>n </i>= 404) and measured ingesta-free body fat (IFBF), mass, and pregnancy and lactation status. We fitted pregnant elk with vaginal implant transmitters (VITs) in spring and captured their neonates in SW (<i>n </i>= 46) and NE (<i>n </i>= 100). We placed expandable radio-collars on these plus an additional 110 neonates in SW and 360 neonates in NE captured by hand or net-gunning <i>via</i> helicopter and estimated their age at capture, birth mass from mass at capture, and sex. We monitored their fates and documented causes of mortality until 1 year of age. We estimated density of cougars by population reconstruction of captured (<i>n </i>= 96) and unmarked cougars killed (<i>n </i>= 27) and of black bears from DNA analysis of hair collected from snares.</p>\u0000 \u0000 <p>We found evidence in lactating females of nutritional limitations on all 4 study areas where IFBF<sub>autumn</sub> was below 12%, a threshold above which there are few nutritional limitations (9.8% [SE = 0.64%, <i>n</i> = 17] at Toketee, 7.9% [SE = 0.78%, <i>n</i> = 17] at Steamboat, 7.3% [SE = 0.33%, <i>n</i> = 46] at Sled Springs, and 8.9% [SE = 0.51%, <i>n</i>","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"201 1","pages":"3-60"},"PeriodicalIF":4.4,"publicationDate":"2019-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1039","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6120076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniel Gibson, Erik J. Blomberg, Michael T. Atamian, Shawn P. Espinosa, James S. Sedinger
{"title":"Effects of power lines on habitat use and demography of greater sage-grouse (Centrocercus urophasianus)","authors":"Daniel Gibson, Erik J. Blomberg, Michael T. Atamian, Shawn P. Espinosa, James S. Sedinger","doi":"10.1002/wmon.1034","DOIUrl":"https://doi.org/10.1002/wmon.1034","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Energy development and its associated infrastructure, including power lines, may influence wildlife population dynamics through effects on survival, reproduction, and movements of individuals. These infrastructure impacts may be direct or indirect, the former occurring when development acts directly as an agent of mortality (e.g., collision) and the latter when impacts occur as a by-product of other processes that are altered by infrastructure presence. Functional or numerical responses by predators to power-line corridors are indirect impacts that may suppress demographic rates for certain species, and perceived predation risk may affect animal behaviors such as habitat selection. Greater sage-grouse (<i>Centrocercus urophasianus</i>) are a species of conservation concern across western North America that may be affected by power lines. Previous studies, however, have not provided evidence for causal mechanisms influencing demographic rates. Our primary objective was to assess the influence of power lines on multiple sage-grouse vital rates, greater sage-grouse habitat selection, and ultimately greater sage-grouse population dynamics. We used demographic and behavioral data for greater sage-grouse collected from 2003 to 2012 in central Nevada, USA, accounting for sources of underlying environmental heterogeneity. We also concurrently monitored populations of common ravens (<i>Corvus corax</i>), a primary predator of sage-grouse nests and young. We focused primarily on a single 345 kV transmission line that was constructed at the beginning of our study; however, we also determined if similar patterns were associated with other nearby, preexisting power lines. We found that numerous behaviors (e.g., nest-site selection, brood-site selection) and demographic rates (e.g., nest survival, recruitment, and population growth) were affected by power lines, and that these negative effects were predominantly explained by temporal variation in the relative abundance of common ravens. Specifically, in years of high common raven abundance, avoidance of the transmission line was extended farther from the line, re-nesting propensity was reduced, and nest survival was lower near the transmission line relative to areas more distant from the transmission line. Additionally, we found that before and immediately after construction of the transmission line, habitats near the footprint of the transmission line were generally more productive (e.g., greater reproductive success and population growth) than areas farther from the transmission line. However, multiple demographic rates (i.e., pre-fledging chick survival, annual male survival, <i>per capita</i> recruitment, and population growth) for groups of individuals that used habitats near the transmission line declined to a greater extent than for individuals using habitats more distant in the years following construction of the transmission line","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"200 1","pages":"1-41"},"PeriodicalIF":4.4,"publicationDate":"2018-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5770259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mary M. Rowland, Michael J. Wisdom, Ryan M. Nielson, John G. Cook, Rachel C. Cook, Bruce K. Johnson, Priscilla K. Coe, Jennifer M. Hafer, Bridgett J. Naylor, David J. Vales, Robert G. Anthony, Eric K. Cole, Chris D. Danilson, Ronald W. Davis, Frank Geyer, Scott Harris, Larry L. Irwin, Robert McCoy, Michael D. Pope, Kim Sager-Fradkin, Martin Vavra
{"title":"Modeling Elk Nutrition and Habitat Use in Western Oregon and Washington","authors":"Mary M. Rowland, Michael J. Wisdom, Ryan M. Nielson, John G. Cook, Rachel C. Cook, Bruce K. Johnson, Priscilla K. Coe, Jennifer M. Hafer, Bridgett J. Naylor, David J. Vales, Robert G. Anthony, Eric K. Cole, Chris D. Danilson, Ronald W. Davis, Frank Geyer, Scott Harris, Larry L. Irwin, Robert McCoy, Michael D. Pope, Kim Sager-Fradkin, Martin Vavra","doi":"10.1002/wmon.1033","DOIUrl":"https://doi.org/10.1002/wmon.1033","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Studies of habitat selection and use by wildlife, especially large herbivores, are foundational for understanding their ecology and management, especially if predictors of use represent habitat requirements that can be related to demography or fitness. Many ungulate species serve societal needs as game animals or subsistence foods, and also can affect native vegetation and agricultural crops because of their large body size, diet choices, and widespread distributions. Understanding nutritional resources and habitat use of large herbivores like elk (<i>Cervus canadensis</i>) can benefit their management across different land ownerships and management regimes. Distributions of elk in much of the western United States have shifted from public to private lands, leading to reduced hunting and viewing opportunities on the former and increased crop damage and other undesired effects on the latter. These shifts may be caused by increasing human disturbance (e. g., roads and traffic) and declines of early-seral vegetation, which provides abundant forage for elk and other wildlife on public lands. Managers can benefit from tools that predict how nutritional resources, other environmental characteristics, elk productivity and performance, and elk distributions respond to management actions. We present a large-scale effort to develop regional elk nutrition and habitat-use models for summer ranges spanning 11 million ha in western Oregon and Washington, USA (hereafter Westside). We chose summer because nutritional limitations on elk condition (e. g., body fat levels) and reproduction in this season are evident across much of the western United States. Our overarching hypothesis was that elk habitat use during summer is driven by a suite of interacting covariates related to energy balance: acquisition (e g., nutritional resources, juxtaposition of cover and foraging areas), and loss (e g., proximity to open roads, topography). We predicted that female elk consistently select areas of higher summer nutrition, resulting in better animal performance in more nutritionally rich landscapes. We also predicted that factors of human disturbance, vegetation, and topography would affect elk use of landscapes and available nutrition during summer, and specifically predicted that elk would avoid open roads and areas far from cover-forage edges because of their preference for foraging sites with secure patches of cover nearby. Our work had 2 primary objectives: 1) to develop and evaluate a nutrition model that estimates regional nutritional conditions for elk on summer ranges, using predictors that reflect elk nutritional ecology; and 2) to develop a summer habitat-use model that integrates the nutrition model predictions with other covariates to estimate relative probability of use by elk, accounting for ecological processes that drive use. To meet our objectives, we used 25 previously ","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"199 1","pages":"1-69"},"PeriodicalIF":4.4,"publicationDate":"2018-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/wmon.1033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6010862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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