Life Sciences Commons^™

Sex-Related Differences In Aging Rate Are Associated With Sex Chromosome System In Amphibians, Hugo Cayuela, Jean-François Lemaître, Jean-Paul Léna, Victor Ronget, Iñigo Martínez-Solano, Erin Muths, David S. Pilliod, Benedikt R. Schmidt, Gregorio Sánchez-Montes, Jorge Gutiérrez-Rodríguez, Graham Pyke, Kurt Grossenbacher, Omar Lenzi, Jaime Bosch, Karen H. Beard, Lawrence L. Woolbright, Brad A. Lambert, David M. Green, Nathalie Jreidini, Justin M. Garwood, Robert N. Fisher, Kathleen Matthews, David Dudgeon, Anthony Lau, Jeroen Speybroeck, Rebecca Homan, Robert Jehle, Eyup Başkale, Emiliano Mori, Jan W. Arntzen, Pierre Joly, Rochelle M. Stiles, Michael J. Lannoo, John C. Maerz, Winsor H. Lowe, Andrés Valenzuela-Sánchez, Ditte G. Christiansen, Claudio Angelini, Jean-Marc Thirion, Juha Merilä, Guarino R. Colli, Mariana M. Vasconcellos, Taissa C.V. Boas, Ísis Da C. Arantes, Pauline Levionnois, Beth A. Reinke, Cristina Vieira, Gabriel A.B. Marais, Jean-Michel Gaillard, David A.W. Miller

Wildland Resources Faculty Publications

Sex‐related differences in mortality are widespread in the animal kingdom. Although studies have shown that sex determination systems might drive lifespan evolution, sex chromosome influence on aging rates have not been investigated so far, likely due to an apparent lack of demographic data from clades including both XY (with heterogametic males) and ZW (heterogametic females) systems. Taking advantage of a unique collection of capture–recapture datasets in amphibians, a vertebrate group where XY and ZW systems have repeatedly evolved over the past 200 million years, we examined whether sex heterogamy can predict sex differences in aging rates and lifespans. We showed …

Nutrient Enrichment Increases Invertebrate Herbivory And Pathogen Damage In Grasslands, Anne Ebeling, Alex T. Strauss, Peter B. Adler, Carlos A. Arnillas, Isabel C. Barrio, Lori A. Biederman, Elizabeth T. Borer, Miguel N. Bugalho, Maria C. Caldeira, Marc W. Cadotte, Pedro Daleo, Nico Eisenhauer, Anu Eskelinen, Philip A. Fay, Jennifer Firn, Pamela Graff, Nicole Hagenah, Sylvia Haider, Kimberly J. Komatsu, Rebecca L. Mcculley, Charles E. Mitchell, Joslin L. Moore, Jesus Pascual, Pablo L. Peri, Sally A. Power, Suzanne M. Prober, Anita C. Risch, Christiane Roscher, Mahesh Sankaran, Eric W. Seabloom, Holger Schielzeth, Martin Schütz, Karina L. Speziale, Michelle Tedder, Risto Virtanen, Dana M. Blumenthal

Wildland Resources Faculty Publications

1. Plant damage by invertebrate herbivores and pathogens influences the dynamics of grassland ecosystems, but anthropogenic changes in nitrogen and phosphorus availability can modify these relationships.
2. Using a globally distributed experiment, we describe leaf damage on 153 plant taxa from 27 grasslands worldwide, under ambient conditions and with experimentally elevated nitrogen and phosphorus.
3. Invertebrate damage significantly increased with nitrogen addition, especially in grasses and non-leguminous forbs. Pathogen damage increased with nitrogen in grasses and legumes but not forbs. Effects of phosphorus were generally weaker. Damage was higher in grasslands with more precipitation, but climatic conditions did not change effects of nutrients …

General Destabilizing Effects Of Eutrophication On Grassland Productivity At Multiple Spatial Scales, Yann Hautier, Pengfei Zhang, Michel Loreau, Kevin R. Wilcox, Eric W. Seabloom, Elizabeth T. Borer, Jarrett E.K. Byrnes, Sally E. Koerner, Kimberly J. Komatsu, Jonathan S. Lefcheck, Andy Hector, Peter B. Adler, Juan Alberti, Carlos A. Arnillas, Jonathan D. Bakker, Lars A. Brudvig, Miguel N. Bugalho, Marc Cadotte, Maria C. Caldeira, Oliver Carroll, Mick Crawley, Scott L. Collins, Pedro Daleo, Laura E. Dee, Nico Eisenhauer, Anu Eskelinen, Philip A. Fay, Benjamin Gilbert, Amandine Hansar, Forest Isbell, Johannes M.H. Knops, Andrew S. Macdougall, Rebecca L. Mcculley, Joslin L. Moore, John W. Morgan, Akira S. Mori, Pablo L. Peri, Edwin T. Pos, Sally A. Power, Jodi N. Price, Peter B. Reich, Anita C. Risch, Christiane Roscher, Mahesh Sankaran, Martin Schütz, Melinda Smith, Carly Stevens, Pedro M. Tognetti, Risto Virtanen, Glenda M. Wardle, Peter A. Wilfahrt, Shaopeng Wang

Wildland Resources Faculty Publications

Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant diversity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species …

Investigating The Dynamics Of Elk Population Size And Body Mass In A Seasonal Environment Using A Mechanistic Integral Projection Model, Shelly Lachish, Ellen E. Brandell, Meggan E. Craft, Andrew P. Dobson, Peter J. Hudson, Daniel R. Macnulty, Tim Coulson

Wildland Resources Faculty Publications

Environmentally mediated changes in body size often underlie population responses to environmental change, yet this is not a universal phenomenon. Understanding when phenotypic change underlies population responses to environmental change is important for obtaining insights and robust predictions of population dynamics in a changing world. We develop a dynamic integral projection model that mechanistically links environmental conditions to demographic rates and phenotypic traits (body size) via changes in resource availability and individual energetics. We apply the model to the northern Yellowstone elk population and explore population responses to changing patterns of seasonality, incorporating the interdependence of growth, demography, and density-dependent …

Dna Persistence In Predator Saliva From Multiple Species And Methods For Optimal Recovery From Depredated Carcasses, Antoinette J. Piaggio, Susan A. Shriner, Julie K. Young, Doreen L. Griffin, Peggy Callahan, Darren J. Wostenberg, Eric M. Gese, Matthew W. Hopken

Wildland Resources Faculty Publications

Molecular forensics is an important component of wildlife research and management. Using DNA from noninvasive samples collected at predation sites, we can identify predator species and obtain individual genotypes, improving our understanding of predator–prey dynamics and impacts of predators on livestock and endangered species. To improve sample collection strategies, we tested two sample collection methods and estimated degradation rates of predator DNA on the carcasses of multiple prey species. We fed carcasses of calves (Bos taurus) and lambs (Ovis aires) to three captive predator species: wolves (Canis lupus), coyotes (C. latrans), and …

Space Use And Movement Of Urban Bobcats, Julie K. Young, Julie M. Golla, John P. Draper, Derek Broman, Terry Blankenship, Richard Heilbrun

Wildland Resources Faculty Publications

Global urbanization is rapidly changing the landscape for wildlife species that must learn to persist in declining wild spacing, adapt, or risk extinction. Many mesopredators have successfully exploited urban niches, and research on these species in an urban setting offers insights into the traits that facilitate their success. In this study, we examined space use and activity patterns from GPS-collared bobcats (Lynx rufus) in the Dallas–Fort Worth metroplex, Texas, USA. We found that bobcats select for natural/agricultural features, creeks, and water ways and there is greater home-range overlap in these habitats. They avoid roads and are less likely …

The Intrepid Urban Coyote: A Comparison Of Bold And Exploratory Behavior In Coyotes From Urban And Rural Environments, Stewart W. Breck, Sharon A. Poessel, Peter J. Mahoney, Julie K. Young

Wildland Resources Faculty Publications

Coyotes (Canis latrans) are highly adaptable, medium-sized carnivores that now inhabit nearly every large city in the United States and Canada. To help understand how coyotes have adapted to living in urban environments, we compared two ecologically and evolutionarily important behavioral traits (i.e., bold-shy and exploration-avoidance behavior) in two contrasting environments (i.e., rural and urban). Boldness is an individual’s reaction to a risky situation and exploration is an individual’s willingness to explore novel situations. Our results from both tests indicate that urban coyotes are bolder and more exploratory than rural coyotes and that within both populations there are …

Parental Habituation To Human Disturbance Over Time Reduces Fear Of Humans In Coyote Offspring, Christopher J. Schell, Julie K. Young, Elizabeth V. Lonsdorf, Rachel M. Santymire, Jill M. Mateo

Wildland Resources Faculty Publications

A fundamental tenet of maternal effects assumes that maternal variance over time should have discordant consequences for offspring traits across litters. Yet, seldom are parents observed across multiple reproductive bouts, with few studies consider‐ ing anthropogenic disturbances as an ecological driver of maternal effects. We ob‐ served captive coyote (Canis latrans) pairs over two successive litters to determine whether among‐litter differences in behavior (i.e., risk‐taking) and hormones (i.e., cortisol and testosterone) corresponded with parental plasticity in habituation. Thus, we explicitly test the hypothesis that accumulating experiences of anthropogenic disturbance reduces parental fear across reproductive bouts, which should have disparate phenotypic …

Hidden Cost Of Disease In A Free-Ranging Ungulate: Brucellosis Reduces Mid-Winter Pregnancy In Elk, Gavin C. Cotterill, Paul C. Cross, Arthur D. Middleton, Jared D. Rogerson, Brandon M. Scurlock, Johan T. Du Toit

Wildland Resources Faculty Publications

Demonstrating disease impacts on the vital rates of free‐ranging mammalian hosts typically requires intensive, long‐term study. Evidence for chronic pathogens affecting reproduction but not survival is rare, but has the potential for wide‐ranging effects. Accurately quantifying disease‐associated reductions in fecundity is important for advancing theory, generating accurate predictive models, and achieving effective management. We investigated the impacts of brucellosis (Brucella abortus) on elk (Cervus canadensis) productivity using serological data from over 6,000 captures since 1990 in the Greater Yellowstone Ecosystem, USA. Over 1,000 of these records included known age and pregnancy status. Using Bayesian multilevel models, …

A Landscape-Level Assessment Of Whitebark Pine Regeneration In The Rocky Mountains, Usa, Sara A. Goeking, Deborah K. Izlar, Thomas C. Edwards Jr.

Wildland Resources Faculty Publications

Whitebark pine (Pinus albicaulis Engelm.) has recently experienced high mortality due to multiple stressors, and future population viability may rely on natural regeneration. We assessed whitebark pine seedling densities throughout the US Rocky Mountains and identified stand, site, and climatic variables related to seedling presence based on data from 1,217 USDA Forest Service Forest Inventory and Analysis plots. Although mean densities were highest in the whitebark pine forest type, 83% of sites with seedlings present occurred in non-whitebark pine forest types, and the highest densities occurred in the lodgepole pine forest type. To identify factors related to whitebark pine …

It's Time To Listen: There Is Much To Be Learned From The Sounds Of Tropical Ecosystems, Jessica L. Deichmann, Orlando Acevedo-Charry, Leah Barclay, Zuzana Burivalova, Marconi Campos-Cerqueira, Fernando D'Horta, Edward T. Game, Benjamin L. Gottesman, Patrick J. Hart, Ammie K. Kalan, Simon Linke, Leandro Do Nascimento, Bryan Pijanowski, Erica Staaterman, T. Mitchell Aide

Wildland Resources Faculty Publications

Knowledge that can be gained from acoustic data collection in tropical ecosystems is low‐hanging fruit. There is every reason to record and with every day, there are fewer excuses not to do it. In recent years, the cost of acoustic recorders has decreased substantially (some can be purchased for under US$50, e.g., Hill et al. 2018) and the technology needed to store and analyze acoustic data is continuously improving (e.g., Corrada Bravo et al. 2017, Xie et al. 2017). Soundscape recordings provide a permanent record of a site at a given time and contain a wealth of …

Development Of On-Shore Behavior Among Polar Bears (Ursus Maritimus) In The Southern Beaufort Sea: Inherited Or Learned?, Kate M. Lillie, Eric M. Gese, Todd C. Atwood, Sarah A. Sonsthagen

Wildland Resources Faculty Publications

Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed on-shore during late summer and early fall has increased. Our objective was to investigate whether this on-shore behavior has developed through genetic inheritance, asocial learning, or through social learning. From 2010 to 2013, genetic data were collected from SB polar bears in the fall via hair snags …

The Role Of Small Ruminants On Global Climate Change, Alda Lúcia Gomes Monteiro, Amanda Moser Coelho Da Fonseca Faro, Mylena Taborda Piquera Peres, Rafael Batista, Cesar Henrique Espirito Candal Poli, Juan J. Villalba

Wildland Resources Faculty Publications

Global warming, as a consequence of excessive CO2 production mainly due to anthropogenic actions, is one of the main concerns of society due to the effects it can cause in the survival of humans, plants and animals. Several climatic consequences have already been reported, such as warming the oceans and changing biodiversity in various regions of the planet. One of the greenhouse gases responsible for global warming, which causes a lot of concern, is methane gas from digestion of food by ruminants. Besides that, emissions of greenhouse gases are represented also by waste management, rice cultivation, burning of residues from …

Improved Prediction Of Stream Flow Based On Updating Land Cover Maps With Remotely Sensed Forest Change Detection, Alexander J. Hernandez, Sean P. Healey, Hongsheng Huang, R. Douglas Ramsey

Wildland Resources Faculty Publications

The water balance in a watershed can be disrupted by forest disturbances such as harvests and fires. Techniques to accurately and efficiently map forest cover changes due to disturbance are evolving quickly, and it is of interest to ask how useful maps of different types of disturbances over time can be in the prediction of water yield. We assessed the benefits of using land cover maps produced at annual vs. five-year intervals in the prediction of monthly streamflows across 10 watersheds contained entirely within the US National Forest System. We found that annually updating land cover maps with forest disturbance …

Weak Interspecific Interactions In A Sagebrush Steppe? Conflicting Evidence From Observations And Experiments, Peter B. Adler, Andrew R. Kleinhesselink, Giles Hooker, Joshua B. Taylor, Brittany J. Teller, Stephen P. Ellner

Wildland Resources Faculty Publications

Stable coexistence requires intraspecific limitations to be stronger than interspecific limitations. The greater the difference between intra‐ and interspecific limitations, the more stable the coexistence, and the weaker the competitive release any species should experience following removal of competitors. We conducted a removal experiment to test whether a previously estimated model, showing surprisingly weak interspecific competition for four dominant species in a sagebrush steppe, accurately predicts competitive release. Our treatments were (1) removal of all perennial grasses and (2) removal of the dominant shrub, Artemisia tripartita. We regressed survival, growth, and recruitment on the locations, sizes, and species identities …

Use Of Unpalatable Forages By Ruminants: The Influence Of Experience With The Biophysical And Social Environment, Roberto A. Distel, Juan J. Villalba

Wildland Resources Faculty Publications

Unpalatable forage resources (low nutrient density, potentially toxic metabolites) are widespread and represent a challenge for ruminant nutrition, health, and welfare. Our objective was to synthesize the role of biophysical and social experience on the use of unpalatable forages by ruminants, and highlight derived behavioural solutions for the well-being of soils, plants, and animals. Environmental experiences early in life modulate gene expression and promote learning, which alters morpho-physiological and psychological mechanisms that modify behavioural responses and change food and habitat selection. In this process, ruminants can become better adapted to the habitat where they are reared. Moreover, experiential learning provides …

Ecosystem Functional Response Across Precipitation Extremes In A Sagebrush Steppe, Andrew T. Tredennick, Andrew R. Kleinhesselink, J. Bret Taylor, Peter B. Adler

Wildland Resources Faculty Publications

Background

Precipitation is predicted to become more variable in the western United States, meaning years of above and below average precipitation will become more common. Periods of extreme precipitation are major drivers of interannual variability in ecosystem functioning in water limited communities, but how ecosystems respond to these extremes over the long-term may shift with precipitation means and variances. Long-term changes in ecosystem functional response could reflect compensatory changes in species composition or species reaching physiological thresholds at extreme precipitation levels.

Methods

We conducted a five year precipitation manipulation experiment in a sagebrush steppe ecosystem in Idaho, United States. We …

Authors And Editors Assort On Gender And Geography In High-Rank Ecological Publications, Kezia R. Manlove, Rebecca M. Belou

Wildland Resources Faculty Publications

Peer-reviewed publication volume and caliber are widely-recognized proxies for academic merit, and a strong publication record is essential for academic success and advancement. However, recent work suggests that publication productivity for particular author groups may also be determined in part by implicit biases lurking in the publication pipeline. Here, we explore patterns of gender, geography, and institutional rank among authors, editorial board members, and handling editors in high-impact ecological publications during 2015 and 2016. A higher proportion of lead authors had female first names (33.9%) than editorial board members (28.9%), and the proportion of female first names among handling editors …

Iterative Near-Term Ecological Forecasting: Needs, Opportunities, And Challenges, Michael C. Dietze, Andrew Fox, Lindsay M. Beck-Johnson, Julio L. Betancourt, Melvin Hooten, Catherine S. Jarnevich, Timothy H. Keitt, Melissa A. Kenney, Christine M. Laney, Laurel G. Larsen, Henry W. Leoscher, Claire K. Lunch, Bryan C. Pijanowski, James T. Randerson, Emily K. Read, Andrew T. Tredennick, Rodrigo Vargas, Kathleen C. Weathers, Ethan P. White

Wildland Resources Faculty Publications

Two foundational questions about sustainability are “How are ecosystems and the services they provide going to change in the future?” and “How do human decisions affect these trajectories?” Answering these questions requires an ability to forecast ecological processes. Unfortunately, most ecological forecasts focus on centennial-scale climate responses, therefore neither meeting the needs of near-term (daily to decadal) environmental decision-making nor allowing comparison of specific, quantitative predictions to new observational data, one of the strongest tests of scientific theory. Near-term forecasts provide the opportunity to iteratively cycle between performing analyses and updating predictions in light of new evidence. This iterative process …

Evaluating The Impact Of An Exotic Plant Invasion On Rodent Community Richness And Abundance, Trinity N. Smith, Eric M. Gese, Bryan M. Kluever

Wildland Resources Faculty Publications

Cheatgrass (Bromus tectorum), Russian thistle (Salsola kali), and tall tumblemustard (Sisymbrium altissimum) are nonnative plants widely distributed throughout the desert and shrubsteppe communities of the western United States. The impact of these invaders on plant community structure, form, and function has been well documented, but investigations determining the impacts of this cumulative invasion on terrestrial vertebrates have not been undertaken. Our objective was to assess community-level rodent responses to changes in plant community features, with an emphasis on dominance of invasive plant species. We sampled rodent and plant communities in the Great Basin Desert …

Making Rewilding Fit For Policy, Nathalie Pettorelli, Jos Barlow, Philip A. Stephens, Sarah M. Durant, Ben Connor, Henrike Schulte To Bühne, Christopher J. Sandom, Jonathan Wentworth, Johan T. Du Toit

Wildland Resources Faculty Publications

1. Rewilding, here defined as “the reorganisation of biota and ecosystem processes to set an identified social–ecological system on a preferred trajectory, leading to the self‐sustaining provision of ecosystem services with minimal ongoing management,” is increasingly considered as an environmental management option, with potential for enhancing both biodiversity and ecosystem services.
2. Despite burgeoning interest in the concept, there are uncertainties and difficulties associated with the practical implementation of rewilding projects, while the evidence available for facilitating sound decision‐making for rewilding initiatives remains elusive.
3. We identify five key research areas to inform the implementation of future rewilding initiatives: increased understanding of the …

Effects Of Livestock Grazing On Rangeland Biodiversity: A Meta-Analysis Of Grouse Populations, Seth J. Dettenmaier, Terry A. Messmer, Torre J. Hovick, David K. Dahlgren

Wildland Resources Faculty Publications

Livestock grazing affects over 60% of the world’s agricultural lands and can influence rangeland ecosystem services and the quantity and quality of wildlife habitat, resulting in changes in biodiversity. Concomitantly, livestock grazing has the potential to be detrimental to some wildlife species while benefiting other rangeland organisms. Many imperiled grouse species require rangeland landscapes that exhibit diverse vegetation structure and composition to complete their life cycle. However, because of declining populations and reduced distributions, grouse are increasingly becoming a worldwide conservation concern. Grouse, as a suite of upland gamebirds, are often considered an umbrella species for other wildlife and thus …

Psychobiology Of Ingestive Behavior Of Herbivores, Juan J. Villalba

Wildland Resources Faculty Publications

This article describes the process of food selection and consumption in herbivores based on smell, taste, and touch.

Patterns In Greater Sage-Grouse Population Dynamics Correspond With Public Grazing Records At Broad Scales, Adrian P. Monroe, Cameron L. Aldridge, Timothy J. Assal, Kari E. Veblen, David A. Pyke, Michael L. Casazza

Wildland Resources Faculty Publications

Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) …

Herbivore Effects On Productivity Vary By Guild: Cattle Increase Mean Productivity While Wildlife Reduce Variability, Grace K. Charles, Lauren Mcgeoch Porensky, Corinna Riginos, Kari E. Veblen, Truman P. Young

Wildland Resources Faculty Publications

Wild herbivores and livestock share the majority of rangelands worldwide, yet few controlled experiments have addressed their individual, additive, and interactive impacts on ecosystem function. While ungulate herbivores generally reduce standing biomass, their effects on aboveground net primary production (ANPP) can vary by spatial and temporal context, intensity of herbivory, and herbivore identity and species richness. Some evidence indicates that moderate levels of herbivory can stimulate aboveground productivity, but few studies have explicitly tested the relationships among herbivore identity, grazing intensity, and ANPP. We used a long- term exclosure experiment to examine the effects of three groups of wild and …

Do We Need Demographic Data To Forecast Plant Population Dynamics?, Andrew T. Tredennick

Wildland Resources Faculty Publications

1. Rapid environmental change has generated growing interest in forecasts of future population trajectories. Traditional population models built with detailed demographic observations from one study site can address the impacts of environmental change at particular locations, but are difficult to scale up to the landscape and regional scales relevant to management decisions. An alternative is to build models using population-level data that are much easier to collect over broad spatial scales than individual-level data. However, it is unknown whether models built using population-level data adequately capture the effects of density-dependence and environmental forcing that are necessary to generate skillful forecasts.
2. Here, …

Evaluating Impacts Using A Baci Design, Ratios, And A Bayesian Approach With A Focus On Restoration, Mary M. Conner, W. Carl Saunders, Nicolaas Bouwes, Chris Jordan

Wildland Resources Faculty Publications

Before-after-control-impact (BACI) designs are an effective method to evaluate natural and human-induced perturbations on ecological variables when treatment sites cannot be randomly chosen. While effect sizes of interest can be tested with frequentist methods, using Bayesian Markov chain Monte Carlo (MCMC) sampling methods, probabilities of effect sizes, such as a ≥20 % increase in density after restoration, can be directly estimated. Although BACI and Bayesian methods are used widely for assessing natural and human-induced impacts for field experiments, the application of hierarchal Bayesian modeling with MCMC sampling to BACI designs is less common. Here, we combine these approaches and extend …

Disease Introduction Is Associated With A Phase Transition In Bighorn Sheep Demographics, Kezia R. Manlove, E. Frances Cassirer, Paul C. Cross, Raina K. Plowright, Peter J. Hudson

Wildland Resources Faculty Publications

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population‐level and 18 years of individual‐level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change …

A Life-History Perspective On The Demographic Drivers Of Structured Population Dynamics In Changing Environments, David N. Koons, David T. Iles, Michael Schaub, Hal Caswell

Wildland Resources Faculty Publications

Current understanding of life-history evolution and how demographic parameters contribute to population dynamics across species is largely based on assumptions of either constant environments or stationary environmental variation. Meanwhile, species are faced with non-stationary environmental conditions (changing mean, variance, or both) created by climate and landscape change. To close the gap between contemporary reality and demographic theory, we develop a set of transient life table response experiments (LTREs) for decomposing realised population growth rates into contributions from specific vital rates and components of population structure. Using transient LTREs in a theoretical framework, we reveal that established concepts in population biology …

Influence Of Free Water Availability On A Desert Carnivore And Herbivore, Bryan M. Kluever, Eric M. Gese, Stephen Dempsey

Wildland Resources Faculty Publications

Anthropogenic manipulation of finite resources on the landscape to benefit individual species or communities is commonly employed by conservation and management agencies. One such action in arid regions is the construction and maintenance of water developments (i.e., wildlife guzzlers) adding free water on the landscape to buttress local populations, influence animal movements, or affect distributions of certain species of interest. Despite their prevalence, the utility of wildlife guzzlers remains largely untested. We employed a before–after control-impact (BACI) design over a 4-year period on the US Army Dugway Proving Ground, Utah, USA, to determine whether water availability at wildlife guzzlers influenced …