Open Access. Powered by Scholars. Published by Universities.®
Ecology and Evolutionary Biology Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Terrestrial and Aquatic Ecology (49)
- Population Biology (37)
- Animal Sciences (35)
- Other Ecology and Evolutionary Biology (34)
- Biology (31)
-
- Behavior and Ethology (23)
- Biodiversity (20)
- Physical Sciences and Mathematics (17)
- Environmental Sciences (15)
- Marine Biology (15)
- Natural Resources and Conservation (14)
- Zoology (14)
- Genetics and Genomics (13)
- Forest Sciences (11)
- Plant Sciences (11)
- Aquaculture and Fisheries (9)
- Forest Management (9)
- Ornithology (9)
- Evolution (8)
- Bioinformatics (7)
- Botany (7)
- Integrative Biology (7)
- Desert Ecology (6)
- Entomology (5)
- Oceanography and Atmospheric Sciences and Meteorology (5)
- Plant Biology (5)
- Social and Behavioral Sciences (5)
- Agriculture (4)
- Keyword
-
- Northern California (21)
- California (8)
- Habitat (8)
- Occupancy (8)
- Movement (7)
-
- Wildfire (7)
- Climate change (6)
- Community ecology (6)
- Behavior (5)
- Habitat selection (5)
- Humboldt Bay (5)
- Modeling (5)
- Restoration (5)
- Bats (4)
- Carnivore (4)
- Climate (4)
- Coyote (4)
- Drought (4)
- Ecosystem services (4)
- Eel River (4)
- Elk (4)
- Environmental DNA (4)
- Integrated pest management (4)
- Monitoring (4)
- Population (4)
- Redwood (4)
- Salmon (4)
- Abundance (3)
- Agriculture (3)
- Amphibian (3)
Articles 1 - 30 of 139
Full-Text Articles in Ecology and Evolutionary Biology
Symmetry In Affiliative Interactions Of North American River Otters (Lontra Canadensis) In A Northern California Estuary, Charlotte E. Norman
Symmetry In Affiliative Interactions Of North American River Otters (Lontra Canadensis) In A Northern California Estuary, Charlotte E. Norman
Cal Poly Humboldt theses and projects
Patterns of participation in affiliative behaviors may reflect underlying social dynamics. Two affiliative behaviors, allogrooming and social play, were assessed for their symmetry, or relative participation of participants, in a wild group of North American river otters. Behavioral observations were conducted over five months at the Little River estuary in northern California using video recordings and all-occurrence sampling. Observations included all-adult groups, a family group consisting of a breeding female and two pups, and an extended family group with one or two helpers, indicative of cooperative breeding. Individuals engaged in allogrooming and social play were classified by their group membership, …
Integrating Multi-Method Monitoring To Characterize Seasonal Habitat Use Of Green Sturgeon (Acipenser Medirostris) In Humboldt County, California, Olivia S. Boeberitz
Integrating Multi-Method Monitoring To Characterize Seasonal Habitat Use Of Green Sturgeon (Acipenser Medirostris) In Humboldt County, California, Olivia S. Boeberitz
Cal Poly Humboldt theses and projects
Green sturgeon (Acipenser medirostris) are a long-lived, anadromous, iteroparous species that spawns in large West Coast North American rivers but ranges widely in the coastal ocean. For coastal California Native American Tribes, green sturgeon are a vital part of their cultural heritage and traditions, and central to their food security. Two genetically distinct population segments (DPSs) of green sturgeon are recognized in the United States, Canada, and Mexico; the southern DPS is listed as “threatened” under the Endangered Species Act and the northern DPS is considered of “conservation concern.” Although green sturgeon are known to use large estuaries …
Aquatic Habitat Use By Western Toads And American Bullfrogs In California’S Central Valley: Effects Of Local Habitat Characteristics And Landscape Composition, Kaitlyn Breana Hernandez
Aquatic Habitat Use By Western Toads And American Bullfrogs In California’S Central Valley: Effects Of Local Habitat Characteristics And Landscape Composition, Kaitlyn Breana Hernandez
Cal Poly Humboldt theses and projects
Drastic losses of historic wetland habitat in the California Central Valley have caused widespread population declines and extirpations of aquatic breeding amphibians. Efforts to restore wetland habitat have included private land, which represents 70% of land tenure in the Central Valley. Management of these restored wetlands is focused on waterfowl with the assumption that they will provide habitat for native herpetofauna. This study used combined surveys to test the assumption that restored wetlands on private land provide habitat for native amphibians with the western toad (Anaxyrus boreas) as a case study. The objectives were to use environmental DNA …
From Theory To Ecosystems: Exploring Biodiversity And Ecosystem-Function In Pitcher Plant (Darlingtonia Californica) Microbial Communities, Gavin Sutter
Cal Poly Humboldt theses and projects
The relationship between biodiversity and ecosystem-function (BEF) has been a central focus of ecological research for the last three decades, yet the role of space in shaping BEF relationships remains relatively unknown. Research has shown that community diversity and composition can strongly influence productivity, nutrient cycling, and decomposition, but much of this work treats communities as spatially isolated, leaving open how dispersal and other spatial processes shape BEF at broader scales. To begin addressing this gap, I used microbial communities inhabiting Darlingtonia californica pitcher plant leaves to evaluate how spatial organization and successional change shape biodiversity and ecosystem-functioning. I quantified …
Geographic Variation In Proteomic Responses To Ocean Acidification In A Cold-Water Coral (Balanophyllia Elegans), Keana A. Richmond
Geographic Variation In Proteomic Responses To Ocean Acidification In A Cold-Water Coral (Balanophyllia Elegans), Keana A. Richmond
Cal Poly Humboldt theses and projects
In the face of a rapidly changing climate, assessing organismal responses to future stressors in the context of current, natural exposure to stress could provide key insights to understanding marine ecosystem resilience. I used Balanophyllia elegans, a cold-water, solitary, azooxanthellate coral as a model to better understand how varying oceanographic conditions across its geographic range have shaped its ability to tolerate and potentially adapt to current and future ocean acidification conditions. I collected B. elegans individuals from four sites across 2,500km of their range and subjected them to two pH treatments to investigate site-specific protein expression in response to …
Early Successional Response To Stream Daylighting In Redwood National And State Parks, Orick, California, Rylee Rawson
Early Successional Response To Stream Daylighting In Redwood National And State Parks, Orick, California, Rylee Rawson
Cal Poly Humboldt theses and projects
In-channel stream restoration projects can act as both disturbance and recovery mechanisms, disrupting existing conditions to reestablish the hydrologic and ecological processes that sustain stream ecosystems. These interventions initiate successional trajectories in which channel form and biological communities reorganize over time. In Redwood National and State Parks (California, USA), the Redwoods Rising initiative restores buried headwater channels by recontouring legacy logging roads and daylighting streams buried by Humboldt crossings. Using the National Park Service Klamath Network wadable stream monitoring protocol, I evaluated nine restored reaches spanning one to five years post-restoration, alongside old-growth reference reaches and available pre-treatment data. I …
Coho Salmon (Oncorhynchus Kisutch) Response To Habitat Restoration Through Space And Time: Monitoring Growth, Survival, And Movement In A Restored Habitat Network, Carter Perez Adamson
Coho Salmon (Oncorhynchus Kisutch) Response To Habitat Restoration Through Space And Time: Monitoring Growth, Survival, And Movement In A Restored Habitat Network, Carter Perez Adamson
Cal Poly Humboldt theses and projects
Despite the decline of coho salmon (Oncorhynchus kisutch), Prairie Creek, a tributary of Redwood Creek in northern California, remains a coho salmon stronghold. The restoration of juvenile coho rearing habitat was identified as a recovery objective in this watershed by the National Marine Fisheries Service. Among the restoration projects addressing this objective are an ongoing project on Prairie Creek and its tributary Skunk Cabbage Creek, and a prior effort on Strawberry Creek (a tributary of Redwood Creek’s estuary). Standard monitoring methods for assessing project success have limitations and may be improved by measuring salmon use of restored habitats …
Postfire Habitat Use And Density Of Pacific Martens (Martes Caurina) In Lassen National Forest, California, Deirdre L. Replinger
Postfire Habitat Use And Density Of Pacific Martens (Martes Caurina) In Lassen National Forest, California, Deirdre L. Replinger
Cal Poly Humboldt theses and projects
Increasing frequency, size, and severity of wildfires in western North America threatens forest-dependent wildlife species. The Pacific marten (Martes caurina) has historically been associated with mature, structurally complex forest throughout most of its range. Recently, martens have been detected in forests burned at high severity by the 2021 Dixie Fire—the largest recorded single fire in California state history. I used non-invasive remote camera traps and hair snares (n = 166 sites) to assess marten habitat use and density using spatial occupancy and spatial capture-recapture models. I detected martens across the burn severity gradient (unburned to high-severity) at …
Ectomycorrhizal Fungi Associated With Pinus Species Of California's Northwestern Coast, Monika Audrey Richardson
Ectomycorrhizal Fungi Associated With Pinus Species Of California's Northwestern Coast, Monika Audrey Richardson
Cal Poly Humboldt theses and projects
Ectomycorrhizal (ECM) fungi are vital for increasing host plant uptake of nutrients and stress tolerance within ECM forest ecosystems. The species assemblage of ECM fungi can vary locally in response to numerous biotic and abiotic environmental factors. In California’s northwestern coast the occurrence of three Pinus species, along with a disjunction between populations of Pinus muricata in Mendocino and Humboldt Counties, offer a unique opportunity to investigate the spatial and host effects on pine-associated ECM fungi. Ectomycorrhizal fungal community structure was quantified from host tree roots and sequenced sporocarps occurring at the same sites to create a project specific ITS …
Evidence Of Personality And Movement Syndromes In A Mobile Predator: How Individual Hunting Strategy Shapes Ecosystem Service Potential By Barn Owls (Tyto Furcata) In An Agroecosystem, Lauren M. Jackson
Cal Poly Humboldt theses and projects
Animal-mediated ecosystem services are delivered through the behavior of individuals, yet most studies evaluate service-providing species at the population level. We tested whether individual variation in plumage, behavior, and movement predicted hunting behavior and vineyard habitat use by adult male American barn owls (Tyto furcata) nesting in winegrape vineyards in Lodi, California, USA. We fitted GPS-accelerometer tags to 42 breeding males, quantified breast-plumage traits, measured neophobia using repeated novel object tests, and derived nightly movement metrics from GPS tracks and hidden Markov model-classified hunting locations. Several behavioral traits were repeatable, but movement traits showed the clearest repeatable individual …
Multiple Burn And Forest Characteristics Affect Gray Fox (Urocyon Cinereoargenteus) Occurrence Following A California Megafire, Amida Zohar Verhey
Multiple Burn And Forest Characteristics Affect Gray Fox (Urocyon Cinereoargenteus) Occurrence Following A California Megafire, Amida Zohar Verhey
Cal Poly Humboldt theses and projects
In western North American forests, predator communities are faced with changing fire regimes and increased fire severity and size, particularly with megafires (>10,000 ha). As some wildlife communities may restructure following the loss of apex consumers, understanding post-fire space use of mid-trophic carnivores may inform species composition in these forests. I compared gray fox (Urocyon cinereoargenteus) occupancy in and around the 2021 Dixie Fire, the largest single-ignition fire in California state history, to examine which spatially variable burn and forest characteristics affected the space use of a widespread generalist mesopredator. Using 210 camera traps placed in 2023, …
Jaguar (Panthera Onca) Population Status And Conservation Needs In Panama Revealed Using Spatial Density And Occupancy Models., Rebeca E. Becdach
Jaguar (Panthera Onca) Population Status And Conservation Needs In Panama Revealed Using Spatial Density And Occupancy Models., Rebeca E. Becdach
Cal Poly Humboldt theses and projects
Jaguars (Panthera onca) are key predators and the largest felid in the Americas. The species is listed as near threatened globally due to habitat loss, fragmentation, and human persecution. Their population decline can negatively affect the structure and functioning of the ecosystems they inhabit. Conservation efforts for jaguars and their habitat require understanding jaguar populations and how they are impacted by human presence across their range. This information is lacking in Panama, a critical portion of the Jaguar range. Panama forms a narrow land bridge connecting Central and South America, integral to wildlife movement, including jaguars, across both …
Associational Seaweed Defense Reduces Sea Urchin Grazing On Bull Kelp: Potential Use In Restoration, Brayden Tate Wiley
Associational Seaweed Defense Reduces Sea Urchin Grazing On Bull Kelp: Potential Use In Restoration, Brayden Tate Wiley
Cal Poly Humboldt theses and projects
Kelp forests are declining globally under warming seas, altered predator–prey dynamics, and intensified herbivory, with sea urchins often driving shifts from canopy-dominated forests to persistent urchin barrens. Management commonly relies on labor-intensive urchin removals, with variable success, underscoring the need for complementary, ecosystem-based tools that directly reduce urchin grazing pressure. Focusing on far northern California kelp forests, we combined subtidal surveys, field experiments, and laboratory feeding assays to assess whether the understory alga Desmarestia cf. herbacea can provide associational defense for bull kelp (Nereocystis luetkeana) by physically deterring purple sea urchin (Strongylocentrotus purpuratus) grazing and offering low …
Use Of Public Information For Prospecting And Nest Site Selection By Western Bluebirds (Sialia Mexicana), Fatime Wadad Jomaa
Use Of Public Information For Prospecting And Nest Site Selection By Western Bluebirds (Sialia Mexicana), Fatime Wadad Jomaa
Cal Poly Humboldt theses and projects
Public information that provides an estimate of reproductive success, in addition to information gained through direct environmental sampling, may provide an efficient way for individuals to assess future breeding site quality. I investigated the hypothesis that prospecting Western Bluebirds (Sialia mexicana) use post-breeding public information to select nest sites the following year across winegrape vineyards in Napa Valley. In late summer of 2023, I installed 200 nest boxes across 10 vineyards without prior box history. To simulate conspecific presence and successful breeding, boxes within 5 experimental vineyards were designated either full-treatment (boxes directly broadcasting adult song and nestling …
Using Environmental Dna Metabarcoding To Investigate Diversity And Seasonal Variation Of Fishes In Humboldt Bay, California, Johnathon M. Richardson
Using Environmental Dna Metabarcoding To Investigate Diversity And Seasonal Variation Of Fishes In Humboldt Bay, California, Johnathon M. Richardson
Cal Poly Humboldt theses and projects
This study applied environmental DNA (eDNA) metabarcoding to characterize fish diversity and temporal patterns in fish assemblage structure within Humboldt Bay, California. This work advances ecological understanding of Humboldt Bay’s ichthyofauna, regional natural history and ecosystem function. Over one year (February 2023–January 2024), triplicate surface-water samples were collected every two weeks from a fixed site in Humboldt Bay (n = 78). DNA was extracted from filters and amplified using MiFish 12S primers in six replicate PCRs per sample. Amplicon concentrations were normalized, pooled and sequenced on an Illumina MiSeq platform (2×150 bp). Sequences were processed using a custom bioinformatics pipeline, …
Community Assembly Across Environmental Gradients: Contrasting Patterns Of Funtional Convergence And Divergence In California Coastal Grasslands, Ernesto Chavez- Velasco
Community Assembly Across Environmental Gradients: Contrasting Patterns Of Funtional Convergence And Divergence In California Coastal Grasslands, Ernesto Chavez- Velasco
Cal Poly Humboldt theses and projects
Elucidating how plant community assembly processes interact across spatial scales to shape ecosystem function remains a central challenge in ecology. These processes are often hierarchical, with broad scale environmental filters constraining the composition of local communities. I investigated these hierarchical processes across three California coastal grassland sites spanning a ~1000 km gradient. At these sites, I measured community composition, standing biomass, four functional traits (plant height, specific leaf area, leaf dry matter content, and leaf lobedness), and estimated species’ environmental niches. To identify assembly mechanisms, I used null models to assess functional convergence or divergence and scaled these patterns with …
Patterns Of Kinship And Sociality In North American River Otters, Whitney E. Vickers
Patterns Of Kinship And Sociality In North American River Otters, Whitney E. Vickers
Cal Poly Humboldt theses and projects
Previous studies of river otters (Lontra canadensis) in coastal Humboldt County, California have documented varying social group compositions over the last four decades. It has been assumed that otters travel between coastal wetland sites, but the extent of movement has been unknown. Socially, river otters have been observed alone, in small family groups that consisted of an otter mom and pup(s), in larger helper groups that consisted of an otter mom, pup(s), and at least one additional adult or juvenile (helpers), and in all-adult social groups. Until now it was unknown whether the composition of social groups was …
Factors Influencing Elk Road Crossing Behavior, Brielle Christine Jaglowski
Factors Influencing Elk Road Crossing Behavior, Brielle Christine Jaglowski
Cal Poly Humboldt theses and projects
Highways fragment habitat and can impose barriers to wildlife. Installing wildlife crossing systems creates opportunities for safe animal movement, improved human safety, and reduced property damage. Research identifying key zones of connectivity can aid in providing recommendations for locations of these systems and other tools to improve highway safety. Although elk-vehicle collisions occur broadly across northwestern California, factors associated with these highway crossing zones have not been studied in this region. To address this gap in research, the objective of this study was to evaluate how environmental and structural factors influence the probability of elk (Cervus canadensis) crossing US-101 in …
Physiological Conditions Of Barn Owl (Tyto Furcata) Nestlings As Indicators Of Habitat Quality Within The Wine-Growing Region Of Napa Valley, Christian Cortez
Physiological Conditions Of Barn Owl (Tyto Furcata) Nestlings As Indicators Of Habitat Quality Within The Wine-Growing Region Of Napa Valley, Christian Cortez
Cal Poly Humboldt theses and projects
The global environmental impacts of increasing agricultural demand a transition to sustainable farming practices, including the use of integrated pest management to decrease reliance on harmful pesticides. Vineyard managers in Napa Valley, California, have implemented this strategy by establishing nest boxes that attract barn owls (Tyto furcata) which, in turn, provide an ecosystem service by removing rodent pests. Studies in this system have found uncultivated landcover to be positively associated with distributional and demographic measures of habitat quality for barn owls, but individual measures have not been thoroughly explored. I examined three physiological conditions of barn owl nestlings …
Roosting Habits Of Male Silver-Haired Bats In The Willard Creek Drainage Of Northeastern California, Alexander Christopher Lewis
Roosting Habits Of Male Silver-Haired Bats In The Willard Creek Drainage Of Northeastern California, Alexander Christopher Lewis
Cal Poly Humboldt theses and projects
Silver-haired bats (Lasionycteris noctivagans) are one of the most widely distributed forest bats in North America. Although wildfires have been increasing across their range, how they respond to wildfire is understudied. Previous studies on silver-haired bats and fire focused on roosting behavior in low-severity controlled burns or used acoustics to understand activity levels post-wildfire. Quantifying how silver-haired bats use the physical structures created by high-severity wildfires and the landscape features in which they occur is critical in the face of rapidly shifting fire regimes. During the summer of 2023 and 2024 I radio-tracked male silver-haired bats to 37 roosts …
Just Keep Swimming: Outmigration Survival Of Upper Klamath Basin Juvenile Chinook Salmon, James M. Whelan
Just Keep Swimming: Outmigration Survival Of Upper Klamath Basin Juvenile Chinook Salmon, James M. Whelan
Cal Poly Humboldt theses and projects
The removal of four impassable hydroelectric dams on the Klamath River provides salmonids with the opportunity to recolonize their historic range in the upper Klamath River watershed. However, successful reestablishment of salmon populations requires juvenile salmon born in Oregon's upper tributaries to safely migrate downstream through the river's upper reaches. This stretch of the Klamath River, immediately downstream of Upper Klamath Lake, presents multiple migration challenges, including two flow-control dams not scheduled for removal (Link River Dam and Keno Dam), significant water diversions, and water quality issues. To evaluate these challenges, I conducted experimental releases of radio-tagged juvenile Chinook salmon …
Investigating Fish Communities As Part Of The Food Web In Artificial Tidal Wetland Ponds Of Humboldt Bay, Ca, Lily M. Olmo
Investigating Fish Communities As Part Of The Food Web In Artificial Tidal Wetland Ponds Of Humboldt Bay, Ca, Lily M. Olmo
Cal Poly Humboldt theses and projects
In the face of global wetland loss, artificially created wetlands have the potential to restore ecosystem services for humans while also providing habitat for fish and wildlife. This study explored fish communities in three understudied artificial wetland ponds that are connected to Humboldt Bay in northern California and known to be important wildlife foraging areas. The objectives of this research were to 1) Characterize the environmental conditions of each pond, 2) Calculate the relative catch, richness, diversity, and biomass of fish in each pond, 3) Describe the movement of fish into and out of the ponds with the tides, and …
Bat Species Diversity In The Klamath Basin Prior To Dam Removals, Ryan Page Matilton
Bat Species Diversity In The Klamath Basin Prior To Dam Removals, Ryan Page Matilton
Cal Poly Humboldt theses and projects
River ecosystems make up a small percentage of the earth’s surface, but they support high levels of biodiversity and attract high levels of human use. Dams, for example, disrupt a river’s natural course and flow, alter water temperatures in the stream, redirect river channels, transform floodplains, and fragment river continuity, which affects ecological balance and food webs. The Klamath River in northern California, which has been dammed for the last century, experienced dramatic disruptions including a large fish die-off in 2002. With the negative impacts of the Klamath dams apparent, multiple entities negotiated to remove the dams and restore the …
Variation In The Timing And Duration Of Rough-Skinned Newt (Taricha Granulosa) Larval Period In The Center Of Their Geographic Range (Humboldt County, California), Emmery R. Parker
Variation In The Timing And Duration Of Rough-Skinned Newt (Taricha Granulosa) Larval Period In The Center Of Their Geographic Range (Humboldt County, California), Emmery R. Parker
Cal Poly Humboldt theses and projects
Rough-skinned newts (Taricha granulosa) occur along the Pacific coast of the U.S. from central California to southwestern Alaska at elevations from zero to 2,800 m. Across that range, the timing and duration of various life history events (i.e., hatching, metamorphosis, breeding, and oviposition) are largely unknown, although general trends have been observed in a few locales. Larval life stages are particularly important for determining amphibian population persistence, but there have been no formal studies describing the larval period of rough-skinned newts. Using minnow-trap and dip net surveys at nine lentic sites in northern Humboldt County, California (elevations 400 …
Examining The Effects Of Songbird Nest Boxes And Habitat On Avian And Arthropod Communities In A Vineyard Ecosystem, Eleanor Macdonald
Examining The Effects Of Songbird Nest Boxes And Habitat On Avian And Arthropod Communities In A Vineyard Ecosystem, Eleanor Macdonald
Cal Poly Humboldt theses and projects
Agricultural expansion threatens biodiversity, but integrating insectivorous birds into vineyard ecosystems may support both conservation and ecosystem services. We tested how nest boxes and habitat composition influence avian and arthropod communities in Napa Valley vineyards using a before-after, control-impact experiment across 20 sites. During the 2023-2024 breeding seasons we conducted avian point counts, sampled key pest and beneficial arthropods, and collected fecal samples from adult and nestling tree swallows (Tachycineta bicolor) and western bluebirds (Sialia mexicana) to detect vineyard pest DNA. Nest boxes significantly increased swallow and bluebird abundance within one year; swallow responses were strongest …
Microbes: Key Constituent Of Predator Risk Cues?, Jake R. Vargas
Microbes: Key Constituent Of Predator Risk Cues?, Jake R. Vargas
Cal Poly Humboldt theses and projects
Chemical cues emanating from predators can play a key role in aquatic predator-prey interactions and food webs. Understanding how prey respond to these risk cues is therefore critical for understanding the direct effects of predators on prey populations and their indirect effects on communities. To respond adaptively, prey must accurately assess the risk of predation associated with perceived chemical cues, an oft-documented phenomenon. However, little is known about how cues disperse, persist, and degrade, all of which could limit the adaptive responses of prey. Using laboratory-based observations of a well-studied predator cue-induced antipredator behavior by the marine gastropod Tegula funebralis …
Post-Fire Vegetation And Pyrodiversity Influence Breeding Abundances Of Lewis's Woodpeckers In The Eastern Cascades, Oregon, Brittany Welch
Post-Fire Vegetation And Pyrodiversity Influence Breeding Abundances Of Lewis's Woodpeckers In The Eastern Cascades, Oregon, Brittany Welch
Cal Poly Humboldt theses and projects
Lewis’s woodpeckers (Melanerpes lewis) are described as "burn specialists" due to their preference for breeding in recently burned pine forests in the western US. However, despite increasing fire activity, this species experienced a 48% range-wide decline between 1968 and 2019, which raises questions about their adaptability to altered fire regimes in the region. We partnered with the Oregon Department of Fish & Wildlife to investigate how Lewis’s woodpeckers in the eastern Cascades, Oregon were influenced by post-fire habitat characteristics such as snag size, snag density, and burn severity across five wildfires that varied in fire age, size, and …
Evaluating The Trojan Y Chromosome Strategy For The Removal Of Invasive Sacramento Pikeminnow From The Eel River, Ca, Alexander W. Juan
Evaluating The Trojan Y Chromosome Strategy For The Removal Of Invasive Sacramento Pikeminnow From The Eel River, Ca, Alexander W. Juan
Cal Poly Humboldt theses and projects
The recent introduction and spread of Sacramento Pikeminnow (Ptychocheilus grandis) in Northern California’s Eel River Basin represents a significant threat and impediment to the recovery of several threatened native fish species. This study was undertaken to evaluate the Trojan Y Chromosome Strategy (TYC) for the extirpation of pikeminnow from the basin. TYC is a genetic biocontrol method that relies on the production and stocking of fish with YY sex chromosomes, which may be phenotypically male (YY male) or female (YY female). These YY fish produce all-male offspring when mating with their wild conspecifics and TYC can lead to …
Pond Characteristics That Influence Oviposition Site Selection By Two Pond-Breeding Amphibians, Northern Red-Legged Frog (Rana Aurora) And Northwestern Salamander (Ambystoma Gracile), Jessica Jones
Cal Poly Humboldt theses and projects
Pond-breeding amphibians connect aquatic and terrestrial habitats through their biphasic life cycle, and understanding pond characteristics that support oviposition sites for multiple species is important for amphibian conservation. Two common amphibians in the Pacific Northwest, Northern red-legged frog (Rana aurora) and Northwestern salamander (Ambystoma gracile) often oviposit in the same pond; however, prior studies have focused on pond use by one species or the other, but not both together. I surveyed pond and oviposition site characteristics of 26 ponds in Humboldt County, CA, 10 of which were used only by R. aurora and 16 of which …
Characterizing New Plant Fossils With Woody Growth From The Battery Point Formation Of Quebec (Canada), Emma T. Casselman
Characterizing New Plant Fossils With Woody Growth From The Battery Point Formation Of Quebec (Canada), Emma T. Casselman
Cal Poly Humboldt theses and projects
The oldest woody growth has been recognized in several Early Devonian (ca. 410-395 Ma) euphyllophytes. Their taxonomic diversity is difficult to evaluate due to a lack of quantitative methods for comparing plants based on secondary xylem anatomy. In turn, this hinders understanding of their implications for the evolution of plant development. To develop metrics that quantify secondary xylem anatomy and allow for conclusive comparisons, I investigated extant taxa and Early Devonian fossil woody taxa. I developed multiple metrics for quantifying tracheid size as a function of position in the secondary xylem and tested them on a dataset of extant gymnosperms. …