Animal Sciences Commons^™

Comparative Morphology And Ultrastructure Of Olfactory Epithelia In Plethodontid Salamanders: Effect Of Life History Variation, Emily Gremling

Cal Poly Humboldt theses and projects

Many amphibian species rely on olfaction for locating prey and for social interactions during different life stages. Despite the importance of the olfactory system, research on its structure has been taxonomically limited. The most diverse family of salamanders, the Plethodontidae, has been largely excluded from research efforts to describe olfactory morphology. Although several histological studies have been conducted, no studies have yet looked at morphology at the level of ultrastructure using electron microscopy. The primary goal of my research was to examine olfactory morphology and ultrastructure in plethodontid species with a range of life history strategies, to better understand the …

Characterizing The Habitat Use Of Pacific Coast Feeding Group Gray Whales (Eschrichtius Robustus) And The Spatial And Temporal Variability Of Their Benthic And Planktonic Invertebrate Prey In Northern California, Robyn E. Norman

Cal Poly Humboldt theses and projects

As opportunistic foragers, the Eastern North Pacific population (~20,000) of gray whales (Eschrichtius robustus) feed on diverse benthic and planktonic invertebrates in northern Alaska foraging grounds before they undertake one of the largest yearly migrations of any mammal to breed in Baja California, Mexico. While most of the population travels to the summer foraging grounds in Alaska, a sub-group of whales (~230) called the Pacific Coast Feeding Group (PCFG) summer between British Columbia, Canada, and northern California. The diet of PCFG whales typically includes high-density and/or high-caloric prey items like mysids and diverse species of amphipods, yet a …

Comparing Alternative Developmental Modes: Structure And Gene Expression In The Olfactory System Of Plethodontid Salamanders, Giuseppina S. Lanzilli

Cal Poly Humboldt theses and projects

The olfactory system of extant amphibians changes as the animal transitions from a fully aquatic to a terrestrial lifestyle at metamorphosis. Cellular morphology of the nose and expression patterns of olfactory genes in the nasal cavity have been examined for a variety of frogs and salamanders, but among plethodontid salamanders, molecular data are available only for Plethodon shermani. Using standard histology and micro-CT reconstruction, I investigated the structure of the olfactory organs of larvae, juveniles, and adults of six plethodontid species, with terrestrial, streamside, semiaquatic, and aquatic adults. The overall structure of the olfactory cavity was generally similar across …

Effects Of Habitat Selection And Individual Quality On The Reproductive Success Of Barn Owls (Tyto Furcata), Jaime E. Carlino

Cal Poly Humboldt theses and projects

The hypothesis of adaptive breeding habitat selection proposes congruence between the evolved selection of habitats and fitness components such as reproductive success. However, mismatches between habitat selection and observed fitness outcomes are not unusual and can arise for multiple reasons. Variation in individual qualities of animals has also been found to affect reproduction and survival. I examined associations between barn owl nest box selection, reproductive output, and plumage characteristics previously shown to correspond to individual quality. I found that barn owls selected tall nest boxes made of wood, mounted high off the ground, and with increased proportions of grassland around …

Evaluating The Utility Of Tracers To Characterize Environmental Dna Transport And Inform Detection Of Fishes In Small Streams, Gavin B. Bandy

Cal Poly Humboldt theses and projects

This study was motivated by the need to develop a noninvasive and highly sensitive monitoring tool for determining local occupancy of an endangered aquatic species To make inference into the occupancy of fishes within small stream sites, we developed a method to determine whether environmental DNA (eDNA) concentrations from a target species were elevated relative to a tracer, formulated to mimic eDNA and introduced at a single location. We examined patterns in the observed distribution of the tracer to account for the effects of site-specific transport processes and sampling on distributions of naturally occurring eDNA at small spatial scales (400 …

Temperature Driven Variability In Bull Kelp (Nereocystis Luetkeana) Early Life Stages: A Comparative Study Of California Populations, Marzia Fattori

Cal Poly Humboldt theses and projects

This study investigated the effects of elevated temperatures on the reproductive and developmental stages of Nereocystis luetkeana, a crucial brown macroalgae found along the western coast of North America. My objectives were to 1) evaluate the impact of increasing temperature on the abundance of gametophytes from various sites, 2) determine the length of gametophytes that were affected by temperature on day 10 of culture, 3) assess the presence or absence of oocytes, sporophytes (young vs. multicellular), and abnormal cells, to understand the reproductive and stress responses to higher temperatures, and 4) determine if there is variation among early developmental …

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 …

The Influence Of Hiking Trails On Salamanders, Emily M. Macdonald

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

Over half of the World’s salamanders are facing extinction. It is important to understand the impact Humans have on them in all parts of their ranges so we can better understand what they need and how we can prevent further extinctions. I conducted this study to try to determine if the human activity on the official hiking trails in the Arcata Community Forest in Arcata California; as designated by the official map of the Forest; is negatively impacting the salamanders that live in the Forest. I thought there would be an increase in the number of species and the overall …

Evaluating Benthic Macroinvertebrate Populations In Response To Scouring Events In The Trinity River, Ca, Liam Hay, Michael W. O'Neil, Chloe Pieper-Wasem

Environmental Science & Management Senior Capstones

River systems across California have been impacted by appurtenant structures such as dams and diversions. These structures have had an adverse impact on Benthic invertebrate (BMI) communities by regulating river systems and changing the natural hydraulic pulses that follow seasonal precipitation. Benthic invertebrates are a critical food resource for salmonids and serve as an indicator of ecosystem health. Our study was interested in seeing the effects of scouring events on BMI in the Trinity River of Trinity County, C.A. Following a large precipitation event that occurred in the region in December 2022, an influx of water entered the river through …

Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund

Cal Poly Humboldt theses and projects

Non-native species are increasing in prevalence around the world, resulting in negative economic and ecological impacts. However, the broad distributions of non-native species also offer a system for investigating the response of host-associated microbial communities to environmental factors across a range of ecological scales. At the broadest scale, I investigated the geography of microbial communities in the non-native estuarine anemone Diadumene lineata on the west coast of the United States of America. Across latitudes, microbial community composition was very similar and displayed a high percentage of Klebsiella spp. at all sites. However, the communities in California tended to exhibit higher …

Seasonal Growth, Movement, And Survival Of Juvenile Coho Salmon (Oncorhynchus Kisutch) Utilizing Restored Rearing Habitat, Monica S. Tonty

Cal Poly Humboldt theses and projects

The Scott River supports the most robust population of threatened Coho Salmon Oncorhynchus kisutch remaining in the Klamath River basin. Even in the Scott River, low quality and restricted extent of juvenile rearing habitat limits the Coho Salmon population to a small fraction of historic abundance. To support persistence and recovery of Scott River Coho Salmon, the Scott River Watershed Council (SRWC) has constructed a portfolio of restoration projects to improve juvenile rearing habitat, including beaver dam analogs (BDAs). The Scott River BDAs were the first implemented anywhere in California. This study compares juvenile Coho Salmon responses associated with production …

Effects Of Landscape Configuration Metrics On American Barn Owl Nest Box Occupancy And Hunting, Samantha D. Chavez

Cal Poly Humboldt theses and projects

Harnessing ecosystem services, broadly defined as the benefits nature gives to people, is one approach to minimize the widespread negative impacts of agriculture on wildlife and biodiversity conservation. Conservation biological control is one such service that aims to use natural enemies to reduce crops losses from pests without the use of harmful pesticides, including rodenticides. In Napa Valley, California, human-made nest boxes are deployed on wine grape vineyards to attract barn owls (Tyto furcata) that depredate and remove thousands of rodent pests throughout the nesting season. However, the provisioning of this ecosystem service depends on whether a box …

Carnivore And Ungulate Occurrence In A Fire-Prone Region, Sara J. Moriarty-Graves

Cal Poly Humboldt theses and projects

Increasing fire size and severity in the western United States causes changes to ecosystems, species’ habitat use, and interspecific interactions. Wide-ranging carnivore and ungulate mammalian species and their interactions may be influenced by an increase in fire activity in northern California. Depending on the fire characteristics, ungulates may benefit from burned habitat due to an increase in forage availability, while carnivore species may be differentially impacted, but ultimately driven by bottom-up processes from a shift in prey availability. I used a three-step approach to estimate the single-species occupancy of four large mammal species: mountain lion (Puma concolor), coyote …

Long-Line Culture Of Red Seaweed In The Pacific Northwest, Erika R. Thalman

Cal Poly Humboldt theses and projects

The goal of this study was to adapt open-water rope culture techniques to the native red seaweed Devaleraea mollis to support a new seaweed aquaculture industry in Humboldt Bay, California. The specific objectives for this study were to: 1) evaluate the growth of D. mollis cultivated at different depths and seasons (fall/winter, spring/summer), 2) estimate nutrients removed by D. mollis from the water, and 3) measure heavy metals and pesticides to determine potential health risk upon ingestion. Bundles of seaweed were inserted into 3 m long weighted vertical lines attached to two horizontal long-lines suspended by floats. Two four-month …

A Return To The Staging Grounds: Reassessment Of Aleutian Cackling Goose Spring Distribution In North Humboldt Bay, Shaun W. Thornton

Cal Poly Humboldt theses and projects

After a 15-year interval in research, spatial and temporal patterns of the Aleutian cackling goose during spring staging was assessed again in 2022. During my study, 3,389 goose flocks were recorded in Arcata Bottoms staging site, 1 January to 21 April 2022, amounting to an estimated total of 2,248,512 goosedays, which was 336.8% higher than 2007 estimates of 667,485 goosedays. Geese continued to use pastures with a wide range of landscape characteristics primarily represented by livestock grazing practices. Goose use was greater than availability on beef-cattle fields early in the season and dairy-cow fields later in the season. Human disturbances …

Effects Of Oyster Aquaculture On Elasmobranch Abundance And Habitat Use In Humboldt Bay, Ca, Rose Harman

Cal Poly Humboldt theses and projects

Habitat modification from aquaculture can have large effects on natural communities, with the habitat complexity provided by aquaculture structure positively influencing benthic invertebrates and small fish abundance. However, the effects of aquaculture on larger predatory fish like elasmobranchs (i.e., sharks and rays), which use nearshore habitat to forage and provide top-down control of these ecosystems, is largely unknown. Over two years, I deployed baited remote underwater video systems (BRUVS) to examine the effects of oyster aquaculture and environmental variables such as habitat (mudflat or eelgrass), salinity (ppt), turbidity (m), temperature (°C), pH (mV), dissolved oxygen (mg · L^-1), …

Comparing Fish Species Assemblage Between Impacted And Restored Estuarine Salt Marshes Within The Eel River Estuary, Humboldt Co. Ca, Adam Aguilar, Isaac Basham-Clair, Tristan F. Parkinson, Larkin C. Wells

Cal Poly Humboldt Capstone Honor Roll

This report details a study assessing the fish assemblages of a recently restored estuarine salt marsh site, and a similar unrestored and impacted site along the Eel River estuary. These two sites are located within the Eel River (Wiya’t) estuary, roughly 10 miles west of the city of Fortuna, CA. This study was conducted during the months of September through October 2023. Data collection was done through seine net dragging at randomly selected sample points across both sites. Seine net hauls were recorded by species and species count, which were later computed using a diversity index to provide values representative …

Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott

Cal Poly Humboldt theses and projects

Harmful algal blooms (HABs) result from outbreaks of any of several different species of toxin-producing phytoplankton and that can have major detrimental effects on marine ecosystems and pose severe health and economic threats to human communities. Of particular concern along the United States West Coast are HABs of pennate diatom genus Pseudo-nitzschia that produce the potent neurotoxin domoic acid (DA). The coastal ocean between Cape Mendocino, CA, and Cape Blanco, OR is a hotspot for Pseudo-nitzschia spp. HABs. Such blooms impact coastal fisheries and pose a potential threat to aquaculture operations in Humboldt Bay, California’s second largest estuary and largest …

Olfactory Organ Morphology And Ultrastructure Of The Larval Koh Tao Island Caecilian (Ichthyophis Kohtaoensis), Jaclyn M. Patmore

Cal Poly Humboldt theses and projects

The olfactory system of living amphibians (Lissamphibia) undergoes major changes as it transitions from an aquatic to a terrestrial system during metamorphosis. Patterns of change in the cellular morphology of the nose have been examined for frogs (Anura) and salamanders (Caudata). However, it remains unknown if caecilians (Gymnophiona) have similar patterns of change in their nasal ultrastructure. In particular, no data on larval caecilian olfactory cell types are available. Here, using light microscopy and transmission electron microscopy, I examined the olfactory organ of larvae of the caecilian Ichthyophis kohtaoensis, to establish the ultrastructure of the epithelium and compare it …

Survival And Growth Of Juvenile Coho Salmon (Oncorhynchus Kisutch) In Restored Wetlands Of Humboldt Bay, California, Josh D. Cahill

Cal Poly Humboldt theses and projects

Substantial investment in habitat restoration efforts have been made to promote coho salmon (Oncorhynchus kisutch) recovery, yet sampling efforts to document the response of coho salmon populations to wetland restoration are limited. I investigated two cohorts of juvenile coho salmon growth, movement, and survival within the Humboldt Bay drainage in California. My study sites included restoration features and other sample areas in upland creek habitat and in lowland estuarine wetlands that were located in the four largest watersheds within the Humboldt Bay drainage. The objectives of this study were to: (1) determine if coho salmon are using restored, …

Genetic Evaluation Of The Current Distribution And Possible Diffrentations Between Lasiurus Borealis And Lasiurus Frantzii In Southwestern North America, Zeinab M. Haidar

Cal Poly Humboldt theses and projects

Several recent accounts of overlap and historic misidentifications regarding two species of the genus Lasiurus, Western red bat (Lasiurus frantzii) and Eastern red bat (Lasiurus borealis), have cast doubt on our understanding of their distribution, assumed spatial allopatry, and interactions in the United States Southwest. With the use of morphometrics and genetic sequencing, utilizing tissue collected from specimens throughout California and adjoining states, we have reassessed the current distribution, best practices for field identification, and genetic differentiation between both species. Appropriate species classification by region was achieved utilizing mitochondrial DNA, targeting the cytochrome c oxidase …

North Coast Otters Public Arts Initiative: Commemorative Auction Catalog, J. M. Black

Archives & Reprint Series (imprint)

In 1999, a citizen science program for submitting river otter observations was created through the Humboldt State University Wildlife department. In 2017, Jeff and Gilly Black from the HSU Wildlife department were inspired by the public arts initiative by The Art of Fundraising project of England's Dartmoor National Park. In 2019, a special partnership with Ink People Center for the Arts, North Coast Open Studios, HSU’s Art Department, Crescent City Art, and the Trinity County Arts Council led to local North Coast artists decorating more than 100 3-foot-tall otter sculptures. The sculptures were displayed at shops, galleries, schools, and other …

List Of Fish Species Present In Galápagos, Ecuador, And California, U.S.A., With Notes On Their Commercial Importance And Conservation Status, Erin J. Hanson, Jose R. Marin Jarrin

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Winter Sandpiper Communities On Humboldt Bay: High-Tide Roost Use And Habitat Features That Influence Roost Site Selection, Chelsea Polevy

Cal Poly Humboldt theses and projects

Roosts, locations at which birds and other animals come together to rest and preen while remaining vigilant for predators, are a common facet of the nonbreeding biology of many shorebirds. Roosts fall on a continuum from traditional to ephemeral; traditional roosts are used consistently by the same individuals, whereas ephemeral roosts are used inconsistently and may be used only once or a few times. Studies show that roost habitat preference is the result of an individual shorebird’s attempt to optimize the costs and benefits associated with time constraints, energetic demands, and danger risks as they relate to overall fitness.

In …

Escherichia Coli And Salmonella Sp. In Domestic Cattle And Wild Roosevelt Elk: Fecal Pathogens At The Wildlife-Domestic Interface, Emily A. Buck

Cal Poly Humboldt theses and projects

Direct or indirect contact between domestic populations of animals and wildlife carries an inherent risk for transmission of pathogens that cause infectious disease. In Humboldt and Del Norte counties of northern California, ongoing conflict between ranchers and Roosevelt elk groups results from elk use of ranching pastures and pastures on private land. Fecal samples from elk in association with cattle, cattle, and from elk not in known association with cattle were assessed for the presence of bacteria Salmonella enterica and pathogenic Escherichia coli to assess whether association with cattle increases risk of infection for elk. Group identity (one of the …

Activity Patterns Of The Del Norte Salamander (Plethodon Elongatus): Monitoring Plethodontid Behavior Using Pit Tag Surveys, Sabrina Horrack

Cal Poly Humboldt theses and projects

Semi-fossorial plethodontid salamanders exhibit behavioral plasticity to avoid desiccation, retreating underground to shelter from adverse conditions such as low precipitation and high temperatures. In this study, I used passive integrated transponder (PIT) tag surveys to monitor this behavior in the Del Norte salamander (Plethodon elongatus), a small plethodontid native to northwestern California and southwestern Oregon. Within its range, a climatic gradient exists in which coastal areas experience milder temperatures and high precipitation, while inland areas tend to have colder winters, hotter summers, and lower precipitation. By monitoring the activity patterns of this species in inland and coastal areas, …

A Characterization Of The Sandy Beach Surf Zone Fish Community And Their Ecology In Northern California And The Effects Of Marine Protected Areas, Katie B. Terhaar

Cal Poly Humboldt theses and projects

Historically written off as dull and homogenous, the dynamics of the sandy beach surf zone remains under studied world-wide. Northern California has been no exception to this global standard, as the sandy beach surf zone ecosystem in this region has yet to be characterized, and the effect of Marine Protected Areas (MPAs) on the fish and macroinvertebrate community fully ascertained.

Considered data-poor by local wildlife officials, commercially, recreationally and culturally important Amphistichus rhodoterus (redtail surfperch) and common Hyperprosopon ellipticum (silver surfperch) utilize the sandy beach surf zone in Northern California. Little is known about the effect of various environmental factors, …

Geographic And Seasonal Variation Of Flying Squirrel Vocalizations In California, Travis A. Farwell

Cal Poly Humboldt theses and projects

Advancements in bioacoustics field studies have further elucidated spatial, temporal, and behavioral aspects of otherwise-cryptic species, as well as offering insights into species communication. The discovery of high-frequency vocalizations in North American flying squirrels in particular has allowed researchers to use ultrasonic acoustic recorders to detect these cryptic species in the wild. Investigations into vocalizations of northern flying squirrels (Glaucomys sabrinus) and southern flying squirrels (G. volans) have highlighted call type variation between species and the potential use of recorders as a tool to examine vocal activity patterns. However, high-frequency vocalizations had yet to be quantitatively …

Data Repository For "North American Porcupine Distribution In The Pacific Northwest And Evaluation Of A Non-Invasive Monitoring Technique", Cara L. Appel, Katie M. Moriarty, Sean M. Matthews, David S. Green, Stacy Anderson, Evan King, J Scott Yaeger, Jeremy Brown, Claire Bortot, Tim Bean

Research Data Sets

North American Porcupines (Erethizon dorsatum) have a broad geographic distribution across much of the continent, but recent evidence suggests that their populations may be declining in some areas, including the Pacific Northwest. Estimating baseline historical and contemporary distributions of Porcupines is necessary for initiating monitoring efforts and, if necessary, informing strategic conservation actions. We compiled 1905 occurrence records of Porcupines in Washington, Oregon, and northern California from 1908 to 2018. Using maximum entropy modeling (Maxent), we created historical and contemporary distribution models based on Porcupine records from 1981–2010 and 2012–2018, respectively, to match the temporal scale of available …

Data Repository For "Use Of Redwood Basal Hollows By Bats: A Focus On The Townsend’S Big-Eared Bat On The North Coast Of California", Amon J. Armstrong

Research Data Sets

Loss of roosting resources, either through disturbance or removal, negatively affects bats. Identifying sensitive species and determining roost requirements are critical components in conserving their habitat. Cavity roosting bats on the North Coast of California are known to use hollows in large redwood trees. In this study, we examined the factors determining the use of basal tree hollows by different bat species at eight redwood forest sites in Del Norte, Humboldt, and Mendocino Counties, California. Bat guano was collected from 179 basal hollow roosts from 2017 to 2018, and guano mass was used as an index of roosting activity. Nine …