Browsing by Author "Bailey, Larissa, committee member"
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Item Open Access Conserving tigers beyond protected area boundaries: the spatial ecology of tigers and their prey in farmlands in north India(Colorado State University. Libraries, 2019) Warrier, Rekha, author; Noon, Barry, advisor; Bailey, Larissa, committee member; Crooks, Kevin, committee member; Teel, Tara, committee memberTo view the abstract, please see the full text of the document.Item Open Access Effectiveness of light traps for detecting Razorback Sucker larvae(Colorado State University. Libraries, 2019) de Vlaming, Catherine M., author; Bestgen, Kevin, advisor; Bailey, Larissa, committee member; Wohl, Ellen, committee memberCurrent management strategies for improving the status of wild and endangered Razorback Sucker Xyrauchen texanus rely on adequate larval sampling of wetland and riverine backwater habitats to evaluate post-reproductive survival, spatial and temporal patterns of distribution and abundance, and entrainment into wetlands. One strategy uses the detection of Razorback Sucker larvae to prompt flow releases to inundate Green River floodplain wetlands, habitat which may increase survival of those early life stages. Light traps, a passive sampling gear which exploits the innate attraction of fish early life stages to light, are thought an effective gear type for sampling, but little is known of their efficacy to capture or retain larvae. Therefore, we assessed usefulness of light traps for sampling or retaining Razorback Sucker larvae under a variety of environmental conditions using laboratory and field experiments. In the laboratory, we investigated effects of light trap set time, release distance from trap, light presence, turbidity, light source, cover, and trap aperture on capture and retention probabilities of five early life stages of Razorback Sucker. Mean capture probability of protolarvae prior to the development of a swim bladder (7-9 mm total length [TL]) was 40% (28-55%) over the various treatments, but rose to 76% (73-80%) after protolarvae formed a swim bladder (9-10 mm TL). Mesolarvae (11-17 mm TL), the most commonly captured life stage in field sampling, had similar mean capture probabilities as later protolarvae at 86% (82-90%). Capture probability of metalarval (mean = 42%, range 21-63%; 15-24 mm TL) and juvenile (mean = 24%, range 20-28%; 22-37 mm TL) life stages were lower. Retention probabilities of larvae placed in traps were generally >75% and increased to 97% for juveniles, but some fish nearly always escaped. The relationship between set time and release distances of 1, 3, and 5 m on capture indicated longer set times positively influenced capture probabilities while distance had little effect. Light presence in traps greatly increased capture and retention of larvae compared to unlit traps, and indicated traps lit with light-emitting diodes (LED) increased capture of Razorback Sucker larvae due to increased light intensity when compared to chemical-light-stick-lit traps. Light trap aperture widths of 4 or 6 mm did not influence capture or retention. Overall, laboratory experiments provided valuable information on how specific variables affect capture and retention of Razorback Sucker larvae in light traps and provide a framework for interpreting and designing field studies, which we were able to subsequently carry out. Field experiments consisted of experimental releases of unmarked, single, and double-marked (immersion in oxytetracycline hydrochloride [OTC]) Razorback Sucker larvae over three nights in a managed wetland of the Green River, Utah at the Ouray National Wildlife Refuge. Batches of released larvae were paired with 1 of 12 light traps each night in various densities (10, 50, 250, 1,000 fish per trap), 3 and 10-m release distances from light traps, LED and chemical-light-stick light sources, and two release times to evaluate effects on larvae capture probabilities. In addition, batches of 25 single-marked larvae were placed in light traps and set on a fourth night in various environmental light conditions (night, sunrise, and sunlight) to evaluate effects on larvae retention. Light traps recaptured larvae each night, even with low density releases in the 53.5 ha wetland, and recapture probabilities ranged from 0 to 0.68. The LED trap capture probabilities were up to 2.5X greater than for chemical light stick traps, but capture probabilities were not influenced by release distance or larvae density. Inexplicably, retention was very low, a result inconsistent with the previous laboratory tests. Both laboratory and field experiments indicated light traps are a useful gear to monitor abundance of larvae, evaluate reproductive success of adults, and detect even low densities of larvae in large and open habitats. Additionally, light traps are suitable to detect presence of Razorback Sucker larvae in riverine backwaters each spring, the timing of which is used to begin high flow releases from Flaming Gorge Dam to inundate Green River, Utah, floodplain wetlands. Expanded ecological understanding of early life stages of Razorback Sucker will contribute to their conservation in the Colorado River basin.Item Open Access Effects of hydroperiods and predator communities on Pseudacris maculata: a model species for climate change impacts on amphibians(Colorado State University. Libraries, 2013) Amburgey, Staci Marie, author; Funk, W. Chris, advisor; Murphy, Melanie, committee member; Muths, Erin, committee member; Bailey, Larissa, committee member; Poff, LeRoy, committee memberTo view the abstract, please see the full text of the document.Item Open Access Effects of invasive species on native herpetofauna and pond communities in urban environments(Colorado State University. Libraries, 2022) Crone, Erin Renee, author; Preston, Daniel L., advisor; Angeloni, Lisa, committee member; Bailey, Larissa, committee member; Herrick, Bradley, committee memberUrban environments can provide high quality habitat for native species, yet these environments are also prone to species invasions via numerous introduction pathways. Invasive species may affect communities through multiple mechanisms including ecosystem engineering, predator-prey interactions, and resource competition, so isolating individual effects can be challenging. Further, urban environments commonly host multiple invasive species, which may interact with one another and amplify effects on native species. Despite their potential effects, however, the roles of invasive species in urban communities are often poorly understood. For example, the city of Madison, Wisconsin, USA is home to multiple invasive species, including jumping worms (Amynthas spp.), goldfish (Carassius auratus), and Chinese mystery snails (Cipangopaludina (=Bellamya) chinensis), but little is known about the community effects of these species. Jumping worms are non-native invasive earthworms that may act as ecosystem engineers in leaf litter habitat and potentially provide an abundant novel prey resource to native predators. Invasive goldfish and mystery snails have been widely introduced through aquarium trading and are known to co-occur in urban ponds. In the first study, we used a mesocosm experiment, laboratory feeding trials, and nonlethal stomach contents surveys to assess effects of invasive jumping worms on microhabitat and trophic interactions of native herpetofauna predators. We found that jumping worms reduced leaf litter biomass but did not influence soil conditions or survival of American toad (Anaxyrus americanus) metamorphs. Our results revealed that jumping worms are viable prey for native herpetofauna, especially common garter snakes (Thamnophis sirtalis), but may be challenging to capture due to defensive behaviors. In the second study, we used a mesocosm experiment to test for facilitative or antagonistic interactions between goldfish and mystery snails, and to examine individual and combined effects of goldfish and mystery snails in urban pond communities. We found evidence that goldfish facilitate invasive mystery snails, and that goldfish drive shifts in community composition and food web structure through trophic cascades. Comparatively, mystery snails had limited effects in the experimental community. Overall, our studies emphasize the diversity of roles invasive species can play in communities as ecosystem engineers, prey, predators, or competitors, and that their effects on native species are dependent on these roles. Broadly, our findings highlight the value of understanding invasive species effects in urban environments to direct management and support native species conservation.Item Open Access Guiding conservation of golden eagle populations in light of expanding renewable energy development: a demographic and habitat-based approach(Colorado State University. Libraries, 2015) Tack, Jason Duane, author; Noon, Barry, advisor; Fedy, Brad, advisor; Bailey, Larissa, committee member; Boone, Randall, committee member; Bowen, Zachary, committee memberGolden eagles (Aquila chrysaetoes) are an iconic wide-ranging predator distributed across the Northern Hemisphere. In western North America, populations are considered to be stable, though there is a mounting concern that an anticipated increase in renewable wind energy development will threaten populations. Wind turbines are a known source of mortality for many avian species including golden eagles, thus there is a pressing need to offer land managers conservation planning guidance in light of future development. Working with several collaborators, I aimed to develop applied research in support of golden eagle conservation, while thoroughly testing the analytical rigor of methods we employed to address such questions. In chapter 1, I developed a stochastic population model for golden eagles with coauthors Zack Bowen, Brad Fedy, and Barry Noon. We sought to develop a model that faithfully captured the population dynamics of a non-migratory golden eagle population in western North America, while accounting for the demographic and environmental (process) variation inherent in vital rates. Using data from multiple long-term studies, we parameterized a stage-based matrix projection model and evaluated the contribution of vital rates to asymptotic population growth rates within a life-stage simulation analysis (LSA) framework. With a life history that is characterized by long-lived individuals with relatively low reproductive output, breeding adult survival dominates population dynamics for golden eagles. Thus it is unfortunate that breeding adult survival is the least-represented vital rate estimated in published literature. Simulating reduced survival across stage-classes revealed that a relatively minor (4%) reduction in survival resulted in a growing population to decline. Furthermore, targeting management at bolstering reproductive output is unlikely to compensate for reduced survival. Productivity rates (young fledged per pair) necessary to produce stable asymptotic growth rates (λ=1), when survival is reduced below 4% often falls above the range observed in field studies. Our findings combine to suggest that mitigating for eagle "take" (mortalities) due to anthropogenic sources including wind development should focus disproportionately on strategies that improve survival among breeding adults. Chapter 2 provides a spatially explicit framework for conservation planning and mitigation for golden eagles with respect to wind development. Co-advisor Brad Fedy and I fit resource selection functions (RSF) to golden eagle nest site data across two major ecoregions across Wyoming. Terrain indices, spatial surrogates for prey density, and landcover explained variation in nest-site locations compared to the available landscape. Overlaying predictive models of golden eagle nesting habitat with wind energy resource maps allowed us to highlight areas of potential conflict among eagle nesting habitat and wind development. Our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated, revealing opportunities for conservation practitioners and industry to collaborate on energy siting and mitigation strategies. While these models are useful for conservation planning during a critical life stage in which many eagles are tied to breeding territories, Chapter 3 provides a critical examination of the transient nature of range dynamics during a non-breeding season. Using golden eagle survey data from annual flights across the western US, coauthors Zack Bowen, Brad Fedy, Barry Noon, and I investigate how climate, anthropogenic disturbance, and ecosystem processes converge to influence late summer space use by golden eagles. We found that spatially invariant processes of Gross Primary Productivity and drought severity drive occurrence patterns, while human footprint and terrain ruggedness are more permanent features that explain variation in space use. Our predictive models are helpful for prioritizing conservation efforts for golden eagles, but underscore the large landscapes necessary for conservation for this wide-ranging species. Lastly, in Chapter 4 I worked with colleague Travis Gallo using simulation via " “virtual ecologist" framework to evaluate the potential for misleading inference when applying occupancy analyses to point count data, an increasing common trend particularly in avian research. We found that arbitrary decisions about the scale of sites (e.g. sample units) can lead to highly biased estimates with poor coverage across methodological approaches, especially for species with low detectability. Furthermore, varying patterns of detectability can obfuscate community inference –a common among avian point counts. We applied findings to an empirical dataset of songbird response of habitat-treatments targeted for mule deer (Odocoileus hemionus) in pinyon-juniper landscapes in northwestern Colorado.Item Open Access Integrated statistical models in ecology(Colorado State University. Libraries, 2023) Van Ee, Justin, author; Hooten, Mevin, advisor; Koslovsky, Matthew, advisor; Keller, Kayleigh, committee member; Kaplan, Andee, committee member; Bailey, Larissa, committee memberThe number of endangered and vulnerable species continues to grow globally as a result of habitat destruction, overharvesting, invasive species, and climate change. Understanding the drivers of population decline is pivotal for informing species conservation. Many datasets collected are restricted to a limited portion of the species range, may not include observations of other organisms in the community, or lack temporal breadth. When analyzed independently, these datasets often overlook drivers of population decline, muddle community responses to ecological threats, and poorly predict population trajectories. Over the last decade, thanks to efforts like The Long Term Ecological Research Network and National Ecological Observatory Network, citizen science surveys, and technological advances, ecological datasets that provide insights about collections of organisms or multiple characteristics of the same organism have become prevalent. The conglomerate of datasets has the potential to provide novel insights, improve predictive performance, and disentangle the contributions of confounded factors, but specifying joint models that assimilate all the available data sources is both intellectually daunting and computationally prohibitive. I develop methodology for specifying computationally efficient integrated models. I discuss datasets frequently collected in ecology, objectives common to many analyses, and the methodological challenges associated with specifying joint models in these contexts. I introduce a suite of model building and computational techniques I used to facilitate inference in three applied analyses of ecological data. In a case study of the joint mammalian response to the bark beetle epidemic in Colorado, I describe a restricted regression approach to deconfounding the effects of environmental factors and community structure on species distributions. I highlight that fitting certain joint species distribution models in a restricted parameterization improves sampling efficiency. To improve abundance estimates for a federally protected species, I specify an integrated model for analyzing independent aerial and ground surveys. I use a Markov melding approach to facilitate posterior inference and construct the joint distribution implied by the prior information, assumptions, and data expressed across a chain of submodels. I extend the integrated model by assimilating additional demographic surveys of the species that allow abundance estimates to be linked to annual variability in population vital rates. To reduce computation time, both models are fit using a multi-stage Markov chain Monte Carlo algorithm with parallelization. In each applied analysis, I uncover associations that would have been overlooked had the datasets been analyzed independently and improve predictive performance relative to models fit to individual datasets.Item Open Access Introduction and management of Myxobolus cerebralis-resistant rainbow trout in Colorado(Colorado State University. Libraries, 2013) Fetherman, Eric R., author; Winkelman, Dana, advisor; Bailey, Larissa, committee member; Huyvaert, Kathryn, committee member; Angeloni, Lisa, committee memberTo view the abstract, please see the full text of the document.Item Open Access Occupancy dynamics of barred owls on a spotted owl landscape(Colorado State University. Libraries, 2024) McGee, Kaitlin R., author; Doherty, Paul, Jr., advisor; Franklin, Alan B., advisor; Bailey, Larissa, committee member; Hart, Sarah, committee memberInvasive barred owls (Strix varia) pose a significant threat to native northern spotted owls (Strix occidentalis caurina) in western North America. Barred owls compete with northern spotted owls for resources and habitat, leading to displacement and subsequent declines in northern spotted owl populations. This impact highlights the need for conservation efforts to mitigate the negative consequences of barred owl presence in spotted owl habitats. In my thesis, I explored barred owl habitat use in northern California using data on both lethal removals of barred owls and barred owl occupancy of non-removal areas from long-term studies. These studies provided a unique opportunity to study associations of barred owl land use both during initial colonization and over time. Barred owl land use was influenced by landscape factors such as topographic water accumulation, forest age, tree composition, and canopy cover as well as interspecific effects of northern spotted owls. I used these results to predict variation in barred owl use of landscapes, which can then focus barred owl management efforts in California.Item Open Access Spatial ecology and conservation of tigers and their prey in the Central Terai Landscape, India(Colorado State University. Libraries, 2016) Chanchani, Pranav, author; Noon, Barry, advisor; Bailey, Larissa, committee member; Crooks, Kevin, committee member; Hobbs, N. Thompson, committee memberRemnant populations of the world’s ~3800 wild tigers (Panthera tigris) are generally small (< 20 adult individuals), subject to high rates of poaching, and confined to fragmented habitats with high levels of human disturbance. The species persistence requires an in-depth understanding of the suite of exogenous and endogenous factors that drive spatial heterogeneity in its occurrence and abundance. We intensively sampled tiger habitats in the populous 4500 km2 Central Terai Landscape along the India-Nepal border and investigated the following questions: (a) what is the relative influence of protection designation (protected area or multiple use forests), prey availability, patch connectivity, human presence and habitat quality on landscape and local-scale tiger occurrence; (b) how do these and other factors drive spatial heterogeneity in tiger density at broad and fine spatial scales; and (c) what are the relationships between landscape fragmentation, adult sex ratios, and inter-specific interactions? We found that tiger occupancy and abundance were similar or higher in multiple use forests with high human use, than in several protected areas. Further, the distribution and abundance of prey and key habitats such as tall grasslands, –rather than protection designation, were the best predictors of spatial heterogeneity in tiger occupancy and density. The co-occurrence of tigers and humans in areas with high human use may be facilitated by refugia habitats such as tall grasslands and temporal partitioning of use. Habitat connectivity promoted high occupancy only when all habitats connected by corridors were effectively protected. Finally, we documented exacerbated potential for inter- and intra-sex competition and reduced population fitness in small, isolated tiger populations with male-biased adult sex ratios. Overall, our study reveals that the establishment of protected areas alone may be an inadequate strategy to secure the future of wild tigers. We identified key ecological and anthropogenic factors that cumulatively enable the species persistence in populous human dominated landscapes.Item Open Access The effects of urbanization on felid populations, interactions, and pathogen dynamics(Colorado State University. Libraries, 2014) Lewis, Jesse Scherer, author; Crooks, Kevin, advisor; VandeWoude, Sue, committee member; Bailey, Larissa, committee member; Theobald, David, committee member; Alldredge, Mat, committee memberUrbanization is one of the most ecologically impactful forms of landscape conversion with far-reaching effects on landscape pattern and process, particularly related to animal populations. We evaluated how urbanization affected population density, interspecific interactions, and pathogen exposure in wild felid populations. Specifically, we studied bobcats and pumas across wildland, exurban development, and wildland-urban interface (WUI) habitat to test hypotheses evaluating how urbanization impacts wild felids. Low-density residential development appeared to have a greater impact on felid population density compared to habitat adjacent to a major urban area; point estimates of population density were lower for bobcats and pumas in exurban development compared to wildland habitat, whereas population density for both felids appeared more similar between WUI and wildland habitat. For competitive interactions, occupancy modeling indicated that bobcats did not avoid pumas across broad spatial and temporal scales; however, at finer scales bobcats temporally avoided pumas in wildland areas, but did not appear to avoid pumas in urbanized habitat. Using telemetry data, contact networks revealed that space-use extent was an important predictor of possible social interactions, but that felids associated with urbanization did not appear to exhibit increased potential for interspecific interactions. Lastly, we provided a conceptual framework for evaluating the effects of multiple ecological mechanisms on patterns of pathogen exposure in animal populations; we demonstrated how demographic, social, and environmental characteristics affected the pathogen exposure in bobcat and puma populations across a gradient of urbanization.Item Open Access Understanding and mitigating coyote predation on black-footed ferrets(Colorado State University. Libraries, 2019) Windell, Rebecca Much, author; Breck, Stewart, advisor; Angeloni, Lisa, committee member; Bailey, Larissa, committee member; Eads, David, committee memberCoyotes (Canis latrans) kill more livestock than any other mammal in the U.S. and can be important predators of vulnerable native fauna. In prairie ecosystems, coyotes are the primary predator of endangered black-footed ferrets (Mustela nigripes; hereafter, ferret), where coyote predation can significantly hamper ferret recovery efforts. To better understand coyote predation on ferrets we used remote wildlife cameras, occupancy models, and overlap of circadian activity patterns to investigate multiple abiotic, biotic, and temporal factors hypothesized to influence coyote use of prairie dog colonies, and by proxy coyote-ferret interactions. We first assessed coyote preferences between prairie dog colonies and surrounding available grasslands and found coyotes used prairie dog colonies nearly twice as much as surrounding grasslands. Next, we investigated biotic and abiotic factors that may influence coyote use and frequency of use on prairie dog colonies. We found high coyote use across our study area, but frequency of use varied across prairie dog colonies and was higher in areas of high badger occurrence. Badgers and coyotes are known to form hunting associations and high overlap between coyote and badger activity patterns in our study further supported spatial use patterns revealed by our occupancy analysis. Strong interspecific competition and patterns of resource selection between badgers and ferrets have been documented in previous studies, and as a result, our study suggests that coyote attraction to badgers may be the principal influence on coyote-ferret interactions. To mitigate coyote predation on ferrets we excluded coyotes from ferret occupied areas with a new non- lethal tool, coyote fladry (hereafter; fladry), and rigorously assessed fladry's effectiveness for future use in both ecological and agricultural scenarios. Again using wildlife camera data, we evaluated coyote fladry with multi-season occupancy models, where we estimated probabilities of use (i.e., occupancy), avoidance (i.e., extinction), attraction (i.e., colonization), and activity (i.e., detection) in response to fladry. Our results indicate fladry reduced coyote use and activity within protected areas for at least 60 days; however, coyotes also increased activity around, and were attracted to, the periphery of fladry exclosures, suggesting fladry may function in a way that is counterintuitive to management expectations. Occupancy models permit robust evaluation of nonlethal tools beyond binary terms of success and failure and provide valuable additional information, such as the behavioral responses of carnivores to these tools. Coyote fladry does not deter badger use of protected areas, and given the importance of badgers in predicting coyote use of colonies, future efforts to reduce coyote predation on ferrets should compare the effectiveness of tools that exclude both badgers and coyotes to our study's results.Item Open Access Using population ecology to advance stream community assembly(Colorado State University. Libraries, 2019) Pregler, Kasey C., author; Kanno, Yoichiro, advisor; Bailey, Larissa, committee member; Koons, David, committee member; Poff, LeRoy, committee memberTo view the abstract, please see the full text of the document.