Other Ecology and Evolutionary Biology Commons^™

Ecological Consequences Of Sea Star Wasting Disease: Non-Consumptive Effects And Trait-Mediated Indirect Interactions From Pisaster Ochraceus, Timothy Ian Mcclure

Cal Poly Humboldt theses and projects

Consumptive effects (CEs) of predators are an important factor in structuring biological communities, but further work is needed to understand how the interaction between spatial and temporal differences in predator density affects non-consumptive effects (NCEs) on prey. NCEs can cause indirect effects on food resources, known as trait-mediated indirect interactions (TMIIs), and thus can also affect community structure. However, few studies have considered the relationships between spatial and temporal predator density variation and the strength of NCEs and TMIIs in the natural environment. The ochre star Pisaster ochraceus is common predator of the herbivorous black turban snail Tegula funebralis, imposing …

Life History Of The Coastal Tailed Frog (Ascaphus Truei) Across An Elevational Gradient, Adrian Daniel Macedo

Cal Poly Humboldt theses and projects

The life history of a species is described in terms of its growth, longevity, and reproduction. Unsurprisingly, life history traits are known to vary in many taxa across environmental gradients. In the case of amphibians, species at high elevations and latitudes tend to have shorter breeding seasons, shorter activity periods, longer larval periods, reach sexual maturity at older ages, and produce fewer and larger clutches per year.

The Coastal Tailed Frog (Ascaphus truei) is an ideal species for the study of geographic variation in life history because it ranges across most of the Pacific Northwest from northern California …

Fire And Road Disturbance Impacts On Forest Plant Species And Seed Rain In Table Mountain Fire Arai, Kittitas County, Washington, Jonathan A. Betz

All Master's Theses

Forest communities are in a constant state of change. Disturbance events can alter the physical landscape and create conditions favorable to some species while negatively impacting others. Fire has been a natural, reoccurring source of disturbance in Pacific Northwest forests. Over the past centuries the fire paradigm has changed in favor of fire suppression. Forest roads permit access provide greater access but further fracture forest community’s continuity. The 2012 Table Mountain Fire and road influence have altered the plant community’s seed rain and vegetation. This study measured dispersed seeds and understory vegetation cover as functions of roads and fire intensity. …

Effects Of Fragmentation On Species Retention In National Parks, Liz Tanner

Master's Theses or Doctor of Nursing Practice

The North American landscape is becoming increasingly fragmented, resulting in habitat patches with decreased area and increased isolation. Often, these patches exist as protected areas, such as national parks. The Theory of Island Biogeography is frequently used as a model for these patches, where each park serves as an ‘island’ surrounded by a ‘sea’ of human-altered habitats. As such, species richness and extinctions in a park might be explained by its area. For this study, I used regression models to examine the relationship between richness and area, as well as extinctions and area, for mammals and birds in national parks. …

Efficacy Of An Online Native Snake Identification Search Engine For Public Use, Scott E. Henke, Samantha S. Kahl, David B. Wester, Gad Perry, David Britton

Human–Wildlife Interactions

Visual methods of species identification are used both in research and recreational contexts because they are inexpensive, non-invasive, and believed to be effective among uniquely identifiable individuals. We examined the ability of the general public to identify live snakes (Serpentes) that are native to the United States using an online snake identification search engine (SISE) produced by the North America Brown Tree Snake Control Team (NABTSCT) website, http://www.nabtsct.net. The SISE consisted of participants answering 7 descriptive questions concerning a snake and then reviewing photographs of snakes that matched that description. Using 3 species of snakes native to Texas, USA, 21% …

Modeling Genomes To Phenomes To Populations In A Changing Climate: The Need For Collaborative Networks, Nika Galic, Allyson G. Hindle, John P. Delong, Karen Watanabe, Valery Forbes, C. Loren Buck

School of Biological Sciences: Faculty Publications

Condensed Abstract

Climate is changing globally and its impacts can arise at different levels of biological organization; yet, cross-level consequences of climate change are still poorly understood. Designing effective environmental management and adaptation plans requires implementation of mechanistic models that span the biological hierarchy. Because biological systems are inherently complex and dynamic in nature, dealing with complexities efficiently necessitates simplification of systems or approximation of relevant processes, but there is little consensus on mathematical approaches to scale from genes to populations. Here we present an effort that aims to bring together groups that often do not interact, but that are …

Transgenerational Plasticity Is Sex-Dependent And Persistent In Yellow Moneyflower (Mimulus Guttatus), Kayla Akkerman

All Master's Theses

Transgenerational phenotypic plasticity, whereby environmental cues experienced by parents alter the phenotype of their progeny, has now been documented in diverse organisms. Transmission of environmentally determined responses is known to occur through both maternal and paternal gametes, but the underlying mechanisms have rarely been compared. In addition, the persistence of induction over multiple generations appears to vary widely but has been characterized for relatively few systems. Yellow monkeyflower (Mimulus guttatus) is known to exhibit transgenerational induction of increased glandular trichome production in response to simulated insect damage. Here we test for differences between maternal and paternal transmission of …

Shaping The Tools Of Battle : Sexual Selection, Contest Dynamics, And Weapon Divergence In The Asian Rhinoceros Beetle Trypoxylus Dichotomus, Jillian F. Del Sol

Graduate Student Theses, Dissertations, & Professional Papers

Exaggerated weapons of sexual selection often diverge more rapidly and dramatically than other body parts, suggesting that relevant agents of selection may be discernible in contemporary populations. I examined the ecology, reproductive behavior, and strength of sexual selection on horn length in five recently diverged beetle populations that differ in relative horn size. I show that mating system ecology differs between these locations and corresponds with the local strength of contemporary selection on horn length. Comparisons of ecological conditions and selection strength across populations offer a critical first step towards meaningfully linking mating system dynamics, selection patterns, and diversity in …

Estimating Space Sharing Between Seabird, Pinniped, And Human Use In The Northern California Coast, Claire Marie Nasr

Cal Poly Humboldt theses and projects

Rocky coastlines incur high impacts from human use, but these places are also essential habitat for marine wildlife including seabirds and pinnipeds (seals and sea lions). Marine wildlife use coastal rocks to breed, rest, and engage in social interaction and exhibit different habitat use during the breeding and non-breeding season. Peak timing of human use occurs in spring summer, coinciding with breeding seasons for colonial seabirds and gregarious pinnipeds. The high potential of spatial and temporal overlap between human and seabird use of rocky coastlines could lead to high risk of disturbance events. I investigated the relative risk of disturbance …

Eternal Enemies, Or Incidental Encounters? Structure And Patterns Of Interspecific Killing In Carnivora, Tor G. Bertin

Theses and Dissertations

Lethal interactions between carnivorans (interspecific killing) may influence their population dynamics, behavior, and other important aspects of their ecology. In this study, I expand upon previous research on the broad-scale patterns of interspecific killing in Carnivora (Palomares & Caro 1999, Donadio & Buskirk 2006) with a greatly expanded dataset (inclusion of scat and stomach data and more intensive sampling of the literature), and suggest avenues for future research. While like previous studies, I found a positive effect of relative body size between killer species and killed species on the likelihood of forming a killing interaction, I failed to find evidence …

Testing For Cryptic Diversity And Inference Of Population Structure In The Cosmopolitan Hoplonemertean Emplectonema Gracile (Nemertea), Paul L. Delaney Iv

Theses and Dissertations

Emplectonema gracile (Johnston 1837) is a hoplonemertean of marine intertidal hard-bottom communities and is distributed throughout the Northern Hemisphere. Although possessing a planktonic larval stage in its life history, the range of such cosmopolitan marine invertebrate species is often explained by cryptic speciation and anthropogenic transport. The purpose of this study is to test for possible cryptic species using mtDNA markers (COI and 16S rDNA) and to investigate population structure in E. gracile over a portion of its geographic range using mtDNA markers and ddRADseq nuclear SNP data. The results of both phylogenetic- and tree-based species delimitation revealed that E. …

Estimating Waterbird Abundance On Catfish Aquaculture Ponds Using An Unmanned Aerial System, Paul C. Burr, Sathishkumar Samiappan, Lee A. Hathcock, Robert J. Moorhead, Brian S. Dorr

Human–Wildlife Interactions

In this study, we examined the use of an unmanned aerial system (UAS) to monitor fish-eating birds on catfish (Ictalurus spp.) aquaculture facilities in Mississippi, USA. We tested 2 automated computer algorithms to identify bird species using mosaicked imagery taken from a UAS platform. One algorithm identified birds based on color alone (color segmentation), and the other algorithm used shape recognition (template matching), and the results of each algorithm were compared directly to manual counts of the same imagery. We captured digital imagery of great egrets (Ardea alba), great blue herons (A. herodias), …

Harnessing Population Genetics For Pest Management: Theory And Application For Urban Rats, Matthew Combs, Kaylee Byers, Chelsea Himsworth, Jason Munshi-South

Human–Wildlife Interactions

Effective management of rodent pests requires an ecological understanding of how they move through their environment and how those movements influence the invasion, persistence, or reinvasion of problematic colonies. Traditional methodologies used to describe rodent movement patterns, such as mark-recapture, are hindered by their time-consuming nature and limited geographic scope. As such, our understanding of how rodents interact with urban environments remains limited. Population genetic principles and tools have the capacity to greatly increase our understanding of rodent population dynamics, ecological relationships, and movements across space, but this field is often unapproachable to non-scientist pest management professionals (PMPs). In this …

Examining Aspen Expansion From Before And After Prescribed Burning In A Native Fescue Grassland Through Geospatial Techniques, Christopher Anderson

Dissertations, Master's Theses and Master's Reports

Native fescue (Fescue spp.) grasslands of the Intermountain West have become increasingly scarce due to the advent of modern agriculture, the loss of Indigenous people’s land management practices, modern wildfire management and the extirpation of bison (Bison bison bison). Native grassland is a biodiversity hot-spot, is significant for carbon sequestration, and essential to many species of flora and fauna that occur in the ecosystem. Our study site, on the Rocky Mountain Front in Waterton Lakes National Park, Alberta Canada, consists of 30 discrete aspen stands (Populous tremuloides) which are encroaching on this declining shortgrass fescue …

Competition Or Facilitation: Examination Of Interactions Between Endangered Sida Hermaphrodita And Invasive Phragmites Australis, Samantha N. Mulholland

Theses and Dissertations (Comprehensive)

Virginia Mallow (Sida hermaphrodita) is a perennial herb of the Malvaceae family that is native to riparian habitats in northeastern North America. Throughout most of its geographical distribution however, it is considered threatened and only two populations are known from Canada. The biology and ecology of S. hermaphrodita are still poorly understood and although few studies have been performed to determine the factors that contribute to the species rarity, it is considered threatened potentially due to the loss of habitat caused by exotic European Common reed (Phragmites australis subsp. australis) invasion. Allelopathic and phytotoxic conditioning of …

Evaluation Of Range-Wide Occupancy And Survey Methods For The Giant Kangaroo Rat (Dipodomys Ingens), Alyssa E. Semerdjian

Cal Poly Humboldt theses and projects

Though habitat suitability and occupancy are often correlated, they cannot always be inferred from each other. Therefore, a solid understanding of both is essential to effectively manage species. Recent studies have assessed range-wide habitat suitability for the giant kangaroo rat (Dipodomys ingens; GKR), but data regarding occupancy is lacking in parts of its distribution. Satellite and aerial imagery were used to identify GKR burrows across their known range, producing a range-wide occupancy map and non-invasive survey methods including track plates, manned flight, unmanned aerial vehicle, and sign surveys were conducted to determine effective methods for monitoring GKR occupancy. …

Intraguild Predation: Interactions Between Predators, Pathogens, And Their Shared Resources In Crop Pest Communities, Andrew Jason Flick

LSU Doctoral Dissertations

Crop pest management requires an understanding of the complex interactions among pest species that potentially damage crop yield and species that may be crucial for controlling pest species outbreaks. For example, predators, parasitoids, and pathogens are constantly interacting via their shared prey or hosts. Predators may prefer infected prey, which can be easier to catch; however, infected prey may be less nutritious or even lethal for predators. These interactions then dictate the short-term dynamics of host and pathogen as well as between prey and predator. "How these dynamics change as the species in the system change either empirically or theoretically?" …

A Change In Grain? Diet Induced Plasticity In The Generalist Grasshopper Melanoplus Differentialis, Austin M. Culotta

LSU New Orleans Theses and Dissertations

Phenotypic plasticity is favored in heterogeneous environments in which alternative phenotypes can exploit alternative resources. However, it’s not clear whether phenotypic plasticity is useful in environments that become more homogenous over an organism’s life cycle. I studied a population of grasshopper Melanoplus differentialis that experiences high resource diversity as nymphs but low resource diversity as adults to determine if individuals can undergo diet-induced morphological plasticity in head shape to increase biting ability and ingestion of hard diets. Insects on a soft diet were larger and had greater bite force than those on a hard diet. Head structures related to chewing …

Engineering Eden: The World's Attempt To Outsmart Water Scarcity, Kaitlin A. Sullivan

Capstones

Countries around the world are running out of fresh water, 43 already live with water scarcity, requiring more water than they have. In 2015 the global water crisis took first place in The World Economic Forum’s assessment of the risks that will have the most significant impact on economies, environments and people. Water beat out 27 other long-term risks including infectious diseases and weapons of mass destruction. What happened to Crowley County on the plains of Southeastern Colorado is a cautionary tale of borrowed water. It's been called the Detroit of Colorado, decimated by the reliance of a single industry. …

Safety, Stephen M. Vantassel, Brenda K. Osthus

Wildlife Damage Management Technical Series

Wildlife damage management (WDM) is an exciting field with many opportunities to provide solutions to the complex issues involved in human-wildlife interactions. In addition, WDM wildlife control operators (WCO) face a variety of threats to their physical well-being. Injuries can result from misused (Figure 1), faulty, or poorly maintained equipment, inexperience, mishandled wildlife, harsh weather, and dangerous situations, such as electrical lines. The goals of this publication are to: * Develop an awareness of safety issues and adopt a mindset of “Safety First”, * Review the major safety threats that WCOs face, * Provide basic information for WCOs to protect …