Other Ecology and Evolutionary Biology Commons^™

Using Environmental Dna To Detect Estuarine Crocodiles, A Cryptic-Ambush Predator Of Humans, Alea Rose, Yusuke Fukuda, Hamish A. Campbell

Human–Wildlife Interactions

Negative human–wildlife interactions can be better managed by early detection of the wildlife species involved. However, many animals that pose a threat to humans are highly cryptic, and detecting their presence before the interaction occurs can be challenging. We describe a method whereby the presence of the estuarine crocodile (Crocodylus porosus), a cryptic and potentially dangerous predator of humans, was detected using traces of DNA shed into the water, known as environmental DNA (eDNA). The estuarine crocodile is present in waterways throughout southeast Asia and Oceania and has been responsible for >1,000 attacks upon humans in the past …

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Human–Wildlife Interactions

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Predator-Based Selection And The Impact Of Edge Sympatry On Components Of Coralsnake Mimicry, Lauren E. Wilson

College of Graduate Studies: Theses & Dissertations

Studying warning coloration and mimicry is an effective way to understand predator-driven selection and phenotypic diversity. The presence (sympatry) or absence (allopatry) of a toxic model plays a role in shaping mimetic phenotypes. However, the impact of edge sympatry and allopatry on predation of mimetic phenotypes is not well understood. We studied coralsnake mimicry to test how edge sympatry and allopatry affect predation on mimetic phenotypes. Specifically, we tested 1) if overall attack rates varied with edge sympatry of coralsnakes 2) which color patterns conferred a fitness advantage 3) which specific mimetic signal components are important in driving predatory attacks …

Distribution And Reproduction By The Purple Gallinule (Porphyrio Martinica) In Arkansas, C. Renn Tumlison, Terry L. Tumlison, Tamzen T. Bryant

Journal of the Arkansas Academy of Science

The Purple Gallinule (Porphyrio martinica) is a rare bird in Arkansas, and its populations likely have declined due to loss of marshy areas with emergent vegetation. By use of online sources for citizen science combined with a field study, we elucidate the current distribution of this bird in Arkansas, and document characteristics of reproduction and development. Purple Gallinules arrive in Arkansas as early as April and remain to late October. Nesting occurs from early May into July, and nests may represent second broods. Ontogenetic changes in hatchlings are described.

Selection Of Forage And Avoidance Of Predation Risk By Partially Migratory Mule Deer, Collin Jeffrey Peterson

Graduate Student Theses, Dissertations, & Professional Papers

Migration by ungulates has traditionally been thought of as a strategy that increases access to forage quality or reduces exposure to risk of predation, but the benefits of migration may be waning globally. In partially migratory populations, the persistence of both migrant and resident strategies is an intriguing ecological phenomenon, because migrants and residents often face contrasting fitness consequences. Partial migration is common in mule deer (Odocoileus hemionus), a species that has experienced widespread declines across the western United States during recent decades. Mule deer seldom switch between migratory strategies throughout their lifetime, which may make them less resilient to …

Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan

Cal Poly Humboldt theses and projects

The intraspecific genetic variation and diversity within the Humboldt’s flying squirrel (Glaucomys oregonensis) has not yet been characterized despite its elevation to full species in 2017. The San Bernardino flying squirrel (G. o. californicus) is thought to be the southernmost population of G. oregonensis and is restricted to the San Bernardino and San Jacinto Mountains in California, but recent surveys indicate they have been extirpated from the latter locality. In order to provide baseline genetic data across the geographic range of G. oregonensis, I had the following objectives: 1) investigate the intraspecific molecular variation in …

The Effect Of Shade Tree Species On Bird Communities In Central Kenyan Coffee Farms, Deven Kammerichs-Berke

Cal Poly Humboldt theses and projects

Shade coffee has been recognized as a well-studied example of a land-sharing management strategy that both creates habitat for tropical birds while also maintaining agricultural yield. Despite the general consensus that shade coffee is more “bird-friendly” than a sun coffee monoculture, little work has been done to investigate the effects of specific shade tree species on bird diversity and their capacity to help deliver ecosystem services. Previous studies in temperate regions have demonstrated that due to shared evolutionary histories, native plant species are better at promoting native arthropod numbers, which in turn support a greater number of birds. This study …

The Chumash Heritage National Marine Sanctuary: An Exploration Of Changing The Discourse On Conservation, Arielle Ben-Hur

Pitzer Senior Theses

In 2015, the Northern Chumash Tribal Council submitted a National Marine Sanctuary Nomination to establish the Chumash Heritage National Marine Sanctuary– a means by which to ensure the protection of one of the most culturally and biologically diverse coastlines in the world. On October 5, 2015, John Armor of the National Oceanic and Atmospheric Administration (NOAA) responded to the nomination, adding it to the inventory of areas NOAA may consider in the future for national marine sanctuary designation.

In my thesis, I explore how the nomination of the Chumash Heritage National Marine Sanctuary acts as a platform from which Traditional …

Is Context Dependency Imperative To Understanding The Impacts Of Invasive Plants?, Brendan B. Haile

Masters Theses

Introduced exotic species have a tendency to become invasive and impact local biological communities. Invasions often impact community attributes such as cover and species richness, but these factors may also regulate patterns of invasion. In such cases, impacts may be dependent on the invasion context. We used data from the Buell-Small Succession Study, a long-term permanent plot study in the piedmont region of New Jersey, to document context dependency in invasion. To do this, we analyzed the factors that affected the colonization and growth of four invasive species, Alliaria petiolata, Lonicera japonica, Microstegium vimineum and Rosa multiflora, as well …

The Heat Is On: Comparison Of Thermoregulatory Behavior In Parasitised Versus Unparasitized Caterpillars Of The Tobacco Hornworm, Manduca Sexta (L.) [Lepidoptera: Sphingidae], Jessica M. Johnston

Theses and Dissertations

Insect thermoregulatory research has demonstrated evidence of variation occurring within and among species with respect to infection, pathogens, and parasitism, but few studies have examined differences in thermoregulatory behavior in a host-parasite system with a coevolved symbiotic virus. I investigated the role of parasitism by Cotesia congregata (Say) (Hymenoptera: Braconidae) on the thermoregulatory behavior of Manduca sexta (L.) (Lepidoptera: Sphingidae) using an experimental design in a thermal gradient chamber and a complementary observational field study on wild M. sexta collected from tobacco farms. Parasitism and larval age were not found to have a significant effect on the preferred body temperature …

Network Structure Of Vertebrate Scavenger Assemblages At The Global Scale: Drivers And Ecosystem Functioning Implications, Esther Sebastián-González, Zebensui Morales-Reyes, Francisco Botella, Lara Naves-Alegre, Juan M. Pérez-García, Patricia Mateo-Tomás, Pedro P. Olea, Marcos Moleón, Jomar M. Barbosa, Fernando Hiraldo, Eneko Arrondo, José A. Donázar, Ainara Cortés-Avizanda, Nuria Selva, Sergio A. Lambertucci, Aishwarya Bhattacharjee, Alexis L. Brewer, Erin F. Abernethy, Kelsey L. Turner, James C. Beasley, Travis L. Devault, Hannah C. Gerke, Olin E. Rhodes Jr, Andrés Ordiz, Camilla Wikenros, Barbara Zimmermann, Petter Wabakken, Christopher C. Wilmers, Justine A. Smith, Corinne Kendall, Darcy Ogada, Ethan Frehner, Maximilian L. Allen, Heiko U. Wittmer, James R. A. Butler, Johan T. Du Toit, Antoni Margalida, Pilar Oliva-Vidal, David Wilson, Klemen Jerina, Miha Krofel, Rich Kostecke, Richard Inger, Esra Per, Yunus Ayhan, Hasan Ulusoy, Doğanay Vural, Akino Inagaki, Shinsuke Koike, Arockianathan Samson, Paula L. Perrig, Emma Spencer, Thomas M. Newsome, Marco Heurich, José D. Anadón, Evan R. Buechley, José A. Sánchez-Zapata

Publications and Research

The organization of ecological assemblages has important implications for ecosystem functioning, but little is known about how scavenger communities organize at the global scale. Here, we test four hypotheses on the factors affecting the network structure of terrestrial vertebrate scavenger assemblages and its implications on ecosystem functioning. We expect scavenger assemblages to be more nested (i.e. structured): 1) in species-rich and productive regions, as nestedness has been linked to high competition for carrion resources, and 2) regions with low human impact, because the most efficient carrion consumers that promote nestedness are large vertebrate scavengers, which are especially sensitive to human …

Heat For The Masses: Thermal Ecology Of The Western Tent Caterpillar, Victoria Dahlhoff

Graduate Student Theses, Dissertations, & Professional Papers

A unique feature of some gregarious, colonial insects is their ability to create external structures that alter environmental conditions for the entire (often family) group. A combination of physical alteration of local microhabitats and behavioral thermoregulation allows many of these animals to actively control their body temperatures, which allows them to regulate energy use and metabolism in variable thermal environments. Here I describe mechanisms of microhabitat modification and thermal regulation in the western tent caterpillar, Malacosoma californicum pluviale. Tent caterpillars build communal silk tents, whose temperatures can rise substantially above ambient air temperature. I experimentally manipulated colony sizes and examined …

Impacts Of Rock Climbing On Lichen And Bryophyte Cliff Communities In The Arid West, Giovanna M. Bishop

2020 Symposium Posters

Lichens and bryophytes make up the majority of the diversity and cover in cliff systems around the world. Recently, with the rapid rise of rock climbing, there are concerns rock climbers are negatively impacting cliff communities. My study will compare climbed and unclimbed granite cliffs to better understand the impacts of rock climbing on lichen and bryophyte diversity and cover in eastern Washington. The objectives of this study are to assess the impacts of rock climbing on lichen and bryophyte cliff community diversity and cover and improve route development and cliff management practices for lichens and bryophytes. This study will …

Diet Of A Recently Reintroduced River Otter (Lontra Canadensis) Population In Taos County, New Mexico, Gabriela Alexandra Wolf-Gonzalez

Theses and Dissertations--Forestry and Natural Resources

North American river otters (Lontra canadensis), native to every U.S. state and Canada, experienced extensive population decreases and range reduction until the mid-20th century as a result of overexploitation and habitat loss during European colonization. The last known river otter in New Mexico was killed on the Gila River in 1953, although unverified reports continued thru 2008. After a nearly 60-year absence from New Mexico, 33 adult river otters were reintroduced to the Rio Pueblo de Taos in the northern part of the state between 2008-2010; however, they were not subsequently monitored or studied. I characterized diet of …

Species Conservation & Recovery Through Adequate Regulatory Mechanisms, Sandra B. Zellmer, Sam J. Panarella, Oliver Finn Wood

Faculty Journal Articles & Other Writings

The world is experiencing its sixth episode of mass extinction of life. In rhetoric typically used by bloggers rather than scientists, the National Academy of Sciences reports that this "biological annihilation" is more dire than previously believed,' and that the decimation of biodiversity and of the ecosystem services resulting from it is nothing less than a "frightening assault on the foundations of human civilization."2

Unlike previous episodes of mass extinction, this one is caused by human overpopulation, overconsumption, and anthropogenic climate change. The United States has been a world conservation leader for over a century, but its commitment to supporting …

Black Bear, Jimmy D. Taylor, James P. Phillips

Wildlife Damage Management Technical Series

The American black bear (Ursus americanus, Figure 1) is a challenging species for wildlife agencies to manage due to its size, intelligence, extensive range, food habits, and adaptability, as well as societal views. In North America alone, agencies receive more than 40,000 complaints about black bear annually. Black bears are known as ‘food-driven’ animals, meaning most conflicts result from a bear’s drive to meet its nutritional needs. Not surprisingly, an overwhelming proportion of conflicts are related to their use of anthropogenic (human) food sources, such as garbage, bird food, and crops. Understanding what drives human-bear conflict is the first part …

Using Unmanned Aircraft Systems To Identify Invasive Species, Tithe Ahmed

Mahurin Honors College Capstone Experience/Thesis Projects

Invasive species serve as a threat to native biodiversity and ecosystem sustainability. Combatting the spread of invasive species requires long-term physical and monetary commitments. In Balule Nature Reserve of Greater Kruger National Park, South Africa, Opuntia ficus-inidica (the common prickly pear) has been a relentless invader, displacing the local flora and fauna. The goal of this project is to battle invasive species such as prickly pear using efficient and inexpensive technology: unmanned aerial vehicles (UAVs or drones) and multispectral sensors.

Using a 4-bandwidth Parrot Sequoia multispectral sensor in tandem with the DJI Phantom Pro 3^TM UAV, images of land …

The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler

Cal Poly Humboldt theses and projects

Early successional wetland habitat is being lost in temperate regions worldwide as a result of changes in disturbance regimes that allow for the establishment and dominance of woody species. In particular, this phenomenon is pronounced in fens, which harbor high numbers of rare herbaceous species that require early successional habitat. I investigated the relationship between woody vegetation encroachment and herbaceous species diversity within a Northern California coastal fen that has been undergoing encroachment by woody vegetation for ca. 80 years by recording species richness and cover data from 338 permanent plots throughout the fen. I also investigated the effect of …

Impacts Of Ocean Acidification On Intertidal Macroalgae And Algivore Preference, Andrea Michelle Fieber

Cal Poly Humboldt theses and projects

Ocean acidification, a facet of global climate change, has the potential to induce changes in marine macroalgae that modify their existing interactions with algivorous invertebrates. In this study, I examined the effects of elevated carbon dioxide (pCO₂) on several species of intertidal macroalgae (Phaeophyta, Rhodophyta) and evaluated the present-day and predicted future preferences of algivores (Pugettia producta and Tegula funebralis) by assessing grazing rates on untreated algal tissue and on algae exposed to high-pCO₂ seawater. Both red and brown algae grew faster in elevated pCO₂ than in ambient seawater, …

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …