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2017 Annual Report, Christopher C. Witt

Annual Reports

No abstract provided.

High Dispersal Ability Is Related To Fast Life-History Strategies, Noelle G. Beckman, James M. Bullock, Roberto Salguero-Gomez

Ecology Center Publications

1. Seed dispersal is an essential, yet often overlooked process in plant ecology and evolution, affecting adaptation capacity, population persistence and invasiveness. A species’ ability to disperse is expected to covary with other life-history traits to form dispersal syndromes. Dispersal might be linked to the rate of life history, fecundity or generation time, depending on the relative selection pressures of bethedging, kin competition or maintaining gene flow. However, the linkage between dispersal and plant life-history strategies remains unknown because it is difficult to observe, quantify and manipulate the influence of dispersal over large spatiotemporal scales.

2. We integrate datasets describing …

Patient Demographics And Reported Outcomes In Funded Versus Non-Funded Studies Assessing Thromboprophylaxis After Total Joint Arthroplasty: A Systematic Review, Hannah Groff, Ibrahim Azboy, Javad Parvizi

Research Day

Background: There are numerous studies discussing thromboprophylaxis after total joint arthroplasty (TJA), which have varying conclusions. The purpose of this study was to investigate if industry funding of the study impacted patient demographics and overall reported outcomes of studies evaluating venous thromboembolism (VTE) prophylaxis after TJA.

Methods: Electronic searches were completed for Ovid, PubMed, and Embase. Studies were included if: (1) published in the English language between 2000 and 2016 (2) including patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) (3) evaluating prevention and control of VTE with at least one thromboprophylactic agent.

Results: There were 57 …

Similarity Coefficients Influence The Delimitation Of Species In The Genus Aloe L. (Xanthorrhoeaceae), Halima Amir, Mkabwa Manoko

Tanzania Journal of Science

The present study was designed to establish the influence of coefficients indices in delimiting species using phenetic approach based on morphological data. Data were collected from thirty nine Aloe species described in Flora of Tropical East Africa. A total of forty two qualitative and quantitative characters were compiled from 83 specimens of aloes. Ten coefficient indices were tested. Data were analysed using UPMA approach of PAST software. The analyses confirmed that, truly coefficient of indices influenced the resulting classification. Of the 10 coefficients used only three produced 36-38 of the 39 species. Almost a third produced less than ten species-specific …

Variable Utilization Of Shelf Break-Associated Habitats By Chick-Brooding Rhinoceros Auklets In The California Current System, Bradley Wilkinson, Jaime Jahncke, Pete Warzybok, Russell Bradley, Scott A. Shaffer

Faculty Publications, Biological Sciences

Identifying frequently complex and dynamic spatial distributions of marine predators via the modeling of at-sea observations can be inherently challenging, especially when attempting to predict habitats of specific populations. Remotely-sensed tracking devices provide a viable alternative way to gather this information. We collected fine-scale spatiotemporal movement data for a small seabird, the rhinoceros auklet Cerorhinca monocerata, in the California Current System. Chick-brooding adults nesting on Southeast Farallon Island were outfitted with GPS loggers during the 2015 and 2016 breeding seasons (n = 15). Along with basic movement parameters, kernel density and residence time analyses were conducted to characterize at-sea distribution …

Demographic Hallmarks Of An Overbrowsed Population State In American Ginseng, James B. Mcgraw, Jennifer L. Chandler

Faculty & Staff Scholarship

Effects of high deer herbivory in North America on populations of favored plant browse species have been well-documented, however since less palatable plants now dominate the understory, we asked whether these species could be vulnerable as well, and if so, what symptoms might signal that this was occurring? Using American ginseng (Panax quinque- foliusL.) as our representative less palatable understory plant, we compared two sub- populations within a single natural population that were differentially exposed to browse; one isolated from deer by growing atop a large, flat-topped boulder, and a browse-exposed subpopulation in the surrounding low-lying area. We tested the …

Demography And Dendrochronology Of A Disjunct Population Of Eastern Hemlock In Southwestern Ohio, Marie Johnson

Browse all Theses and Dissertations

Edge and isolated plant populations provide information about the resilience and the most basic resource needs of a species. Plant demography examines changes in population size and structure over time. An isolated, disjunct eastern hemlock population in Clifton Gorge State Nature Preserve, Yellow Springs, Ohio consists of two distinct subpopulations each with different environmental characteristics, reproductive capacities, and health ratings. Both subpopulations at Clifton Gorge were found to exhibit significant decreases in average annual ring width through time. Linear regression modeling determined that average annual growing season precipitation and temperature were the strongest predictors of these growth trends. A comparative …

Time-Lagged Effects Of Weather On Plant Demography: Drought And Astragalus Scaphoides, Brigitte Tenhumberg, Elizabeth E. Crone, Satu Ramula, Andrew J. Tyre

School of Biological Sciences: Faculty Publications

Temperature and precipitation determine the conditions where plant species can occur. Despite their significance, to date, surprisingly few demographic field studies have considered the effects of abiotic drivers. This is problematic because anticipating the effect of global climate change on plant population viability requires understanding how weather variables affect population dynamics. One possible reason for omitting the effect of weather variables in demographic studies is the difficulty in detecting tight associations between vital rates and environmental drivers. In this paper, we applied Functional Linear Models (FLMs) to long-term demographic data of the perennial wildflower, Astragalus scaphoides, and explored sensitivity of …

Arthropod Diets In Chihuahuan Desert Snakes, Victor Manuel Parga

Open Access Theses & Dissertations

Over the past century, studies in herpetology regarding snake diets have been commonly focused on those species that feed or specialize in vertebrate prey items. For those that feed primarily on invertebrates however, little work has been done in determining diet specializations and comparing diets within a community of species. This Thesis focuses on small species of snakes that feed primarily on arthropods in a Chihuahuan Desert community, and will investigate if these are diet generalists or specialists. To this end, stomach contents were examined from preserved specimens of the following species: Rena humilis and Rena dissecta (Leptotyphlopidae), Gyalopion canum …

Grass Is Not Always Greener: Rodenticide Exposure Of A Threatened Species Near Marijuana Growing Operations, Alan B. Franklin, Peter C. Carlson, Angela Rex, Jeremy T. Rockwelt, David Garza, Emily Culhane, Steven F. Volker, Robert J. Dusek, Valerie I. Shearn-Bochsler, Mourad W. Gabriel, Katherine E. Horak

United States Department of Agriculture Wildlife Services: Staff Publications

Marijuana (Cannabis spp.) growing operations (MGO) in California have increased substantially since the mid-1990s. One environmental side-effect of MGOs is the extensive use of anticoagulant rodenticides (AR) to prevent damage to marijuana plants caused by wild rodents. In association with a long-term demographic study, we report on an observation of brodifacoum AR exposure in a threatened species, the northern spotted owl (Strix occidentalis caurina), found freshly dead within 669–1347 m of at least seven active MGOs.

Commentary: Research Recommendations For Understanding The Decline Of American Kestrels (Falco Sparverius) Across Much Of North America, Christopher J.W. Mcclure, Sarah E. Schulwitz, Richard Van Buskirk, Benjamin P. Pauli, Julie A. Heath

Biology Faculty Publications and Presentations

Across much of North America, populations of American Kestrels (Falco sparverius) have been in decline for decades (Farmer et al. 2008, Farmer and Smith 2009, Smallwood et al. 2009a, Paprocki et al. 2014, Sauer et al. 2014). Hypothesized causes of kestrel declines include predation by Cooper's Hawks (Accipiter cooperii; Farmer et al. 2008), pathogens (e.g., Nemeth et al. 2006), habitat loss (Sullivan and Wood 2005, Farmer et al. 2008, Bolgiano et al. 2015), pesticides (Smallwood et al. 2009a, Rattner et al. 2015), and climate change (Steenhof and Peterson 2009b), yet no hypothesized factor has been supported …

Landscape Genetics Of The California Tiger Salamander: Inferences From Multiple Methods, Samantha Gabrielle Thomas

Masters Theses & Specialist Projects

Landscape genetics is a rapidly growing field of study that compares patterns of gene flow among populations with habitat heterogeneity across a landscape to infer the interaction between dispersal of individuals and their physical environment. Empirical data generated from a landscape genetics study can inform conservation and management strategies, making the field increasing popular. However, concerns have arisen in the literature that the field is expanding faster than the analytic framework that supports it. Multiple methods for generating estimates of the association among habitat types and dispersal (i.e., least-cost paths and resistance surfaces) have been proposed, and there is a …

The Value Of Urban Parklands: A User Study Of The Baldwin Hills, Michele Romolini, Eric Strauss, Sarah Bruce-Eisen, Emily Simso

Center for Urban Resilience Scholarship

This report provides the results of a two-year research study by the Loyola Marymount University Center for Urban Resilience (CURes) to examine park visitation and user behavior and attitudes in the Baldwin Hills Parklands. Supported by the Baldwin Hill Conservancy through California Proposition 84 funding, the goal of this study was to better understand how individuals are using and interacting with the Baldwin Hills Parklands. It is the first large-scale, multi-year, field-based attendance survey and multifaceted analysis of visitors’ experiences in the Parklands, consisting of a pilot and four comprehensive field seasons.

Building on a pilot phase in 2014, 38 …

Fleas Of The American Pika: Diversity And Biogeography In North America’S Intermountain West, Niyomi Wijewardena

All NMU Master's Theses

American pikas (Ochotona princeps) are small mammals that are widely distributed across North America’s Intermountain West. Previous investigations revealed five geographically distinct mitochondrial lineages within O. princeps associated with different mountain systems of the Intermountain West. In contrast, diversity of endoparasitic helminths of pikas is not structured geographically in the same way. Instead, there are two primary parasite assemblages, one distributed across southwestern pika populations and one found across the northeastern part of the host range. These contrasting patterns suggest that the shared history of pikas and their parasites had different consequences for the evolutionary trajectories of these …

Plant-Microbial Interactions Are Strong Determinants Of Plant Population And Community Dynamics, Yan-Yi Anny Chung 9485698

Biology ETDs

Plant-microbial interactions are ubiquitous and yet the consequences of these interactions on plant population and community dynamics are relatively unknown. Here, we used two different classes of plant-microbial interactions to examine their effects on key plant population and community characteristics such as commonness and rarity, competition and coexistence, as well as community stability.

Vertically-transmitted endophytes had stage-dependent effects on the population growth of two grass species Poa sylvestris and Poa alsodes, and generally increased host population growth rates. However, it was the intrinsic demographic advantage of P. sylvestris that allowed its population to grow at a much faster rate …

Population Dynamics Of The Cotton Rat In Southeastern Virginia, Robert K. Rose, Heather Green Salamone

Virginia Journal of Science

We used monthly live trapping for 2.5 years to evaluate the life-history features of the most common small mammal, Sigmodon hispidus (hispid cotton rat), in an old field at its northern limit of distribution on the Atlantic Coast. Peak densities, achieved in late autumn or early winter, were among the highest recorded for the species and were more typical of geographically marginal populations rather than of central ones. Unlike some other marginal populations, hispid cotton rats in southeastern Virginia did not lose significant body mass over the winter (when few juveniles were present) and survival in winter was not significantly …

Climate Change, Managed Relocation, And The Risk Of Intra-Continental Plant Invasions: A Theoretical And Empirical Exploration Relative To The Flora Of New England, Jesse Bellemare, Bryan Connolly, Dov F. Sax

Biological Sciences: Faculty Publications

The high rate of anthropogenic climate change projected for coming decades and evidence of low migration ability for many species have led researchers to warn of a looming extinction crisis. This threat is expected to be most acute for small-ranged endemic species, which could see novel climatic conditions develop rapidly across the entirety of their limited geographic ranges. To avoid extinctions, some conservationists have proposed that climateimperiled species might be candidates for "assisted colonization" or "managed relocation" to new regions, outside their historical ranges. One major concern related to managed relocation is the possibility that some relocated species could later …

Rapid Increase In Genetic Diversity In An Endemic Patagonian Tuco-Tuco Following A Recent Volcanic Eruption, Jeremy L. Hsu, Sharon Kam, Mauro N. Tammone, Eileen A. Lacey, Elizabeth A. Hadly

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Catastrophic natural events can have profound impacts on patterns of genetic diversity. Due to the typically unpredictable nature of such phenomena, however, few studies have been able to directly compare patterns of diversity before and after natural catastrophic events. Here, we examine the impacts of a recent volcanic eruption in southern Chile on genetic variation in the colonial tuco-tuco (Ctenomys sociabilis), a subterranean species of rodent endemic to the area most affected by the June 2011 eruption of the Puyehue-Cordón Caulle volcanic complex. To provide a comparative context for interpreting changes in genetic variation in this species, we …

Will Seasonally Dry Tropical Forests Be Sensitive Or Resistant To Future Changes In Rainfall Regimes?, Kara Allen, Juan Manuel Dupuy, Maria G. Gei, Catherine Hulshof, David Medvigy, Camila Pizano, Christina M. Smith, Annette Trierweiler, Skip J. Van Bloem, Bonnie G. Waring, Xiangtao Xu, Jennifer S. Powers

Publications

Seasonally dry tropical forests (SDTF) are located in regions with alternating wet and dry seasons, with dry seasons that last several months or more. By the end of the 21st century, climate models predict substantial changes in rainfall regimes across these regions, but little is known about how individuals, species, and communities in SDTF will cope with the hotter, drier conditions predicted by climate models. In this review, we explore different rainfall scenarios that may result in ecological drought in SDTF through the lens of two alternative hypotheses: 1) these forests will be sensitive to drought because they are already …

Mitochondrial-Dna Phylogenetic Information And The Reconstruction Of Human Population History: The South American Case, María Bárbara Postillone, S. Ivan Perez

Human Biology Open Access Pre-Prints

Objectives: Mitochondrial DNA (mtDNA) sequences are becoming increasingly important in the study of human population history. Here, we explore the differences in the amount of information of different mtDNA regions and their utility for the reconstruction of South American population history.

Material and methods: We analyzed six datasets comprising 259 mtDNA sequences from South America: Complete mtDNA, Coding, Control, hypervariable region I (HVRI), cytochrome b (cytb) plus Control, and cytb plus 12S plus 16S. The amount of information in each dataset was estimated employing several site-by-site and haplotype based statistics, distances among sequences, Neighbor-joining trees, distances among the estimated trees, …

Enhancing Childrens Social-Emotional Learning Skills Through Mindfulness Practices, Shun Yi Wan, Stephanie Chang, Jordan Fenlon, Amrith Shettigar, Mckenzie Johnson, Sam Lealofi

Research Day

Background: The Kalamazoo Eastside neighborhood has been subject to a great deal of economic and functional instability, particularly impacting the youth. Local demographic studies indicate that 90% of children are eligible for free or reduced lunch due to low income, 58% of households are single-female households, and 29% of parents do not have a high school diploma. Eastside Youth Strong (EYS) is a local organization focused on improving the lives of these children. This study will be investigating the EYS afterschool program’s mindfulness initiative. Purpose: Social and emotional learning were chosen to be studied because these skills are critical for …

Reproductive Biology Of The Critically Endangered Endemic Planterodium Somanum In Turkey, Di̇lek Oskay

Turkish Journal of Botany

The reproductive characteristics of Erodium somanum (Geraniaceae), a critically endangered endemic species, were investigated in order to evaluate the main factors that affect its reproductive success and to evaluate their importance on its conservation. The estimated pollen/ovule ratio was calculated as 1187. Pollen viability and stigma receptivity experiments showed that stigma receptivity and pollen viability were high and synchronous throughout the anthesis. E. somanum is a strictly dioecious species and pollinated by insects. Flower visitors in the studied populations were mostly beetles and ants. The average percentage of fruit formation for each plant was determined as 46%. Capacity of seed …

Evolutionary Interactions Of Feather Molt In Birds, Ryan Scott Terrill

LSU Doctoral Dissertations

The evolution of feathers was a key innovation for birds. The many functions that feathers provide have allowed birds to diversify into myriad habitats and styles of life. However, feathers are lightweight and break down, and must be replaced regularly in a process known as molt. The patterns and timing with which birds molt varies within and between species, and these different strategies are likely a product of the different ways birds use their feathers and the uneven distribution of resources available for molt in time and space. So far, no studies have attempted to place these strategies into an …

An Evaluation Of The Use Of Pentosidine As A Biomarker For Ageing Turtles, John B. Iverson, Randal S. Stahl, Carol Furcolow, Fred Kraus

United States Department of Agriculture Wildlife Services: Staff Publications

Concentrations of the biomarker pentosidine have been shown to be useful measures of age for a number of avian and mammalian species. However, no study has examined its usefulness as an age marker in a long-lived ectotherm despite the fact that such a marker could prove useful in understanding age distributions of populations subject to conservation programmes. Therefore, we evaluated pentosidine concentrations in the interdigital webbing of 117 female yellow mud turtles (Kinosternon flavescens) at a 35 year study site in western Nebraska where nearly all turtles are of known age. Pentosidine concentrations were extraordinarily low and positively …

Differential Impacts Of Wildfire On The Population Dynamics Of An Old-Forest Species, Jeremy T. Rockweit, Alan B. Franklin, Peter C. Carlson

United States Department of Agriculture Wildlife Services: Staff Publications

Ecological disturbances shape and maintain natural communities, but climate change and human land use can alter disturbance regimes and affect population persistence and vital rates in unpredictable ways. Species inhabiting landscapes shaped by wildfire have evolved mechanisms allowing them to persist under this dynamic disturbance type, which creates habitats of varying quality for these species. We utilized data from a 26-yr demographic study of northern spotted owls to analyze the influence of wildfire on apparent survival and recruitment rates. Wildfires occurred across different years and affected different spotted owl territories, which allowed us to implement a retrospective Before-After-Control-Impact (BACI) analysis …

Quantile Regression Of Microgeographic Variation In Population Characteristics Of An Invasive Vertebrate Predator, Shane R. Siers, Julie A. Savidge, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Localized ecological conditions have the potential to induce variation in population characteristics such as size distributions and body conditions. The ability to generalize the influence of ecological characteristics on such population traits may be particularly meaningful when those traits influence prospects for successful management interventions. To characterize variability in invasive Brown Treesnake population attributes within and among habitat types, we conducted systematic and seasonally-balanced surveys, collecting 100 snakes from each of 18 sites: three replicates within each of six major habitat types comprising 95% of Guam's geographic expanse. Our study constitutes one of the most comprehensive and controlled samplings of …

Bayesian Model-Based Age Classification Using Small Mammal Body Mass And Capture Dates, Nathaneal Lichti, Kenneth F. Kellner, Timothy J. Smyser, Scott A. Johnson

United States Department of Agriculture Wildlife Services: Staff Publications

Accurate age determination is a fundamental prerequisite for demographic studies as well as population monitoring efforts that provide information for management and conservation. Yet, common age determination methods suffer from low accuracy rates, impose additional handling and time costs on animals and biologists, or rely on invasive techniques such as tooth extraction. We introduce an alternative, mixture modeling approach for age determination that exploits mammalian growth patterns to classify newly encountered animals as juveniles or adults, and present an example analysis that classifies Allegheny woodrats based solely on their capture dates and mass at capture, in combination with data from …

A Review Of Climate Change Induced Effects On Avian Prey Species And Their Consequences For Arctic Fox Populations Of Western Iceland, Mikala Jordan

Independent Study Project (ISP) Collection

Island arctic fox populations are considered to carry the future wellbeing of the global population. Iceland has an island population with two arctic fox eco-types: western/coastal and eastern/inland. The western fox population is protected by the Hornstrandir Nature Reserve; no such protection exists for the eastern fox population. Food sources in both regions differ from each other and vary from summer to winter, but reliable and ample winter time food sources are the most critical for fox population’s survival. A literature review on arctic foxes and their prey species in the face of climate change is important for understanding possible …

Field Estimates Of Parentage Reveal Sexually Antagonistic Selection On Body Size In A Population Of Anolis Lizards, Mary C. Duryea, Patrick Bergeron, Zachary Clare-Salzler, Ryan Calsbeek

Dartmouth Scholarship

Sexual dimorphism evolves when selection favors different phenotypic optima between the sexes. Such sexually antagonistic selection creates intralocus sexual conflict when traits are genetically correlated between the sexes and have sex‐specific optima. Brown anoles are highly sexually dimorphic: Males are on average 30% longer than females and 150% heavier in our study population. Viability selection on body size is known to be sexually antagonistic, and directional selection favors large male size whereas stabilizing selection constrains females to remain small. We build on previous studies of viability selection by measuring sexually antagonistic selection using reproductive components of fitness over three generations …

The Demography And Determinants Of Population Growth In Utah Moose (Alces Alces Shirasi), Joel S. Ruprecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Moose (Alces alces) occur widely in northern regions of the world. Across their distribution, the species is considered to be of high intrinsic, ecological and recreational value. Populations of moose along their southern range limit in North America have shown erratic population dynamics in recent decades including severe numeric declines in some areas. Moose in Utah belong to the Shiras subspecies, which is a relatively understudied population segment. Additionally, moose in Utah represent the southernmost naturally occurring moose populations worldwide. Concerns over possible declines and a paucity of baseline data on moose within the state prompted the Utah …