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Full-Text Articles in Life Sciences

The Effect Of Shade Tree Species On Bird Communities In Central Kenyan Coffee Farms, Deven Kammerichs-Berke Jan 2020

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 …


Female Collegiate Student Athletes And The Perception, Attitudes And Experiences Of Psychological And Mental Health Services, Breonna Bejaran Jan 2020

Female Collegiate Student Athletes And The Perception, Attitudes And Experiences Of Psychological And Mental Health Services, Breonna Bejaran

Cal Poly Humboldt theses and projects

This study explored eighteen National Collegiate Athletic Association (NCAA) Division II female student athletes’ experiences and opinions of help seeking for mental health concerns. A mixed methodological design was used. Qualitative and quantitative data was collected to gain an understanding of help seeking barriers for the participant and their beliefs about help seeking barriers for their peers. Results from the qualitative data identified several themes that assisted in understanding help seeking behaviors. Data suggest that there was a lack of motivation when it came to seek mental health services as a whole by the female student athlete population. Time, lack …


The Independence Effects Of Gravitational And Inertial Forces On Gait Transitions In Humans, Nathan Frakes Jan 2020

The Independence Effects Of Gravitational And Inertial Forces On Gait Transitions In Humans, Nathan Frakes

Cal Poly Humboldt theses and projects

The Dynamic Similarity hypothesis suggests gravitational and inertial forces plays a role in determining preferred transition speed (PTS) for walk to run transitions (WRT) and run to walk transitions (RWT), and that humans prefer to transition gait when the ratio of inertial force (IF) to gravitational force (GF) (i.e. Froude #) is ~0.5. Purpose: To investigate the effect of gravitational and inertial forces on PTS, Froude # (Fr) and kinematics for both WRT and RWT. Methods: Twelve healthy adults (9 M, 3 F) performed WRT and RWT trials on a treadmill across seven combinations of altered body weight (BW) and …


Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel Jan 2020

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 …


Spatiotemporal Variability Of Rockfish Recruitment On California's North Coast In Relation To Habitat Availability, Carolyn Belak Jan 2020

Spatiotemporal Variability Of Rockfish Recruitment On California's North Coast In Relation To Habitat Availability, Carolyn Belak

Cal Poly Humboldt theses and projects

Characterizing primary drivers of temporal and spatial variability in recruitment is imperative to understanding the role of pre- and post-settlement processes influencing marine population dynamics. On benthic reefs, the quality and quantity of suitable settlement habitat can alter post-settlement density-dependent mortality rates and increase chances of survival. The north coast of California has experienced highly unusual oceanographic conditions in recent years, leading to severe loss of highly productive kelp forests and potentially deleterious ecosystem consequences. In the present thesis, I aimed to determine the effects of canopy-forming bull kelp (Nereocystis) and alternative complex habitats on the recruitment of …


Systematics Of Amanita (Amanitaceae, Agaricales, Basidiomycota) From The Guiana Shield And Central Africa, Kennan S. Mighell Jan 2020

Systematics Of Amanita (Amanitaceae, Agaricales, Basidiomycota) From The Guiana Shield And Central Africa, Kennan S. Mighell

Cal Poly Humboldt theses and projects

This study is a systematic assessment of ten species of ectomycorrhizal fungi of the genus Amanita (Amanitaceae, Agaricales, Basidiomycota) from the lowland tropical rainforests of the Guiana Shield and Central Africa. Fungi were collected in each of the above regions, analyzed morphologically, and compared to the literature on Amanita diversity worldwide. All species addressed herein are given full formal taxonomic descriptions including complete macro- and microscopic character profiles, habit, habitat, and distribution. Phylogenetic assessments using ribosomal DNA and protein coding genes are provided for Guiana Shield taxa, and sequence data for two non-protein coding regions, the …


Efficacy Of Forest Restoration Treatments Across A 40-Year Chronosequence At Redwood National Park, Kevin Soland Jan 2020

Efficacy Of Forest Restoration Treatments Across A 40-Year Chronosequence At Redwood National Park, Kevin Soland

Cal Poly Humboldt theses and projects

Following 20th century logging, much of the natural coast redwood (Sequoia sempervirens) range consists of dense second-growth stands with slow tree growth and low biodiversity. There is a landscape-scale effort in much of coastal northern California to increase tree growth rates and ecosystem biodiversity via thinning treatments, thereby hopefully accelerating the development of old-growth forest characteristics. Redwood National Park (RNP) has been experimenting with thinning in these forest types since the 1970s. Given the interesting history of logging and restoration in RNP and the future plans for widespread thinning in this region, my thesis examined the effects …


A Tale Of Two Cervids: Habitat Selection And Spatial Ecology Of Roosevelt And Tule Elk In California, Adam S. Mohr Jan 2020

A Tale Of Two Cervids: Habitat Selection And Spatial Ecology Of Roosevelt And Tule Elk In California, Adam S. Mohr

Cal Poly Humboldt theses and projects

California’s Roosevelt (Cervus canadensis rooseveltii) and tule elk (C. c. nannodes) populations have experienced a remarkable recovery after over-hunting and habitat loss nearly extirpated them from the state. Greater clarity of Roosevelt and tule elk habitat selection patterns would help managers continue to effectively support the recovery of these two iconic subspecies. As the manner in which elk populations balance their competing resource needs is unique to each population (Skovlin et al. 2002), I have examined Roosevelt and tule elk habitat selection patterns in separate analyses and present these results in independent chapters. In both cases, …


Multiple Criteria Decision-Making Approach To Support Timber Transportation Planning – Case Study In Brazil, Marinna Lopes Ferreira Gomes Jan 2020

Multiple Criteria Decision-Making Approach To Support Timber Transportation Planning – Case Study In Brazil, Marinna Lopes Ferreira Gomes

Cal Poly Humboldt theses and projects

Timber transportation is one of the costliest activities for a forest company in Brazil and in many other countries, and it is a determining factor for the success of the forest enterprise. Thus, decision support tools are commonly used as methods to reduce these costs. The purpose of this study was to develop and analyze mathematical models to define the weekly timber transport schedule based on the monthly demands of the customers. The goal is to minimize the operational costs of forest transportation related to distances, timber freshness and road qualities. The decision process was made in two steps; the …


Changes In Prey Mortality: The Efects Of Multiple Predators And Temperature On California Mussels, Wesley Hull Jan 2020

Changes In Prey Mortality: The Efects Of Multiple Predators And Temperature On California Mussels, Wesley Hull

Cal Poly Humboldt theses and projects

Organisms serve as prey to a variety of predators within natural systems, detecting threats through physical and chemical means. While predator feeding behavior is also affected by the presence of other predators, it is unclear whether differing modes of detection have similar effects on predator feeding behavior. In rocky intertidal zones in northern California, the California mussel (Mytilus californianus) is a competitively dominant foundation species consumed by a variety of predators. I quantified the individual and combined effects of ochre star (Pisaster ochraceus) and rock crab (Romaleon antennarium) predation on mussels by implementing mussel …


Effects Of Multiple Stressors: Hydroperiod, Introduced Bullfrogs, And Food Limitation On Northern Red-Legged Frogs (Rana Aurora), Lindsey L. Gordon Jan 2020

Effects Of Multiple Stressors: Hydroperiod, Introduced Bullfrogs, And Food Limitation On Northern Red-Legged Frogs (Rana Aurora), Lindsey L. Gordon

Cal Poly Humboldt theses and projects

As human activities reach every corner of the globe, climate change, invasive species, habitat destruction, and other stressors causing species’ declines no longer act alone. Climate change has the potential to exacerbate (or mitigate) other stressors (e.g. invasive species or pathogens) affecting amphibian populations. I assessed the combined effects of increased pond drying rates (potential impact of climate change), invasive bullfrogs (Lithobates catesbeianus) presence, and food availability on northern red-legged frog (Rana aurora) survival and body size after metamorphosis by rearing tadpoles under incrementally shortened hydroperiods with and without the presence of invasive bullfrog tadpoles in …


The Ability Of Fragmented Kelp Forests To Mitigate Ocean Acidification And The Effects Of Seasonal Upwelling On Kelp-Purple Sea Urchin Interactions, Kindall A. Murie Jan 2020

The Ability Of Fragmented Kelp Forests To Mitigate Ocean Acidification And The Effects Of Seasonal Upwelling On Kelp-Purple Sea Urchin Interactions, Kindall A. Murie

Cal Poly Humboldt theses and projects

Bull kelp (Nereocystis leutkeana) forests along the coast for northern California have decreased dramatically as a result of a ‘perfect storm’ of multiple environmental stressors. The disappearance of a predatory sea star and subsequent increase in purple sea urchins (Strongylocentrotus purpuratus) and the recurrence of marine heat waves have caused these once diverse ecosystems to be rapidly converted into relative species-depauperate urchin barrens. By examining the interactive effects of both a rapidly changing abiotic environment and the increase in urchin grazing pressure that is affecting this vital ecosystem, we can better understand its ultimate fate and …


Effects Of Gap Junction Blockage On Regenerating Body Segments Of Lumbriculus Variegatus, Monica K. Richmond Jan 2020

Effects Of Gap Junction Blockage On Regenerating Body Segments Of Lumbriculus Variegatus, Monica K. Richmond

Cal Poly Humboldt theses and projects

Lumbriculus variegatus is a freshwater annelid that is well known for its regenerative capacity. There are many different factors that affect regeneration in animals. Cell-to-cell communication is a key component of regeneration. Gap junctions are made up of proteins that create a channel that connects the cytoplasm of two cells. Many molecules and ions pass through the gap junctions that can affect regeneration. The purpose of this study was to determine if blocking gap junctions would have an impact on regenerating body segments of L. variegatus and what effects it would produce. L. variegatus was exposed to a known gap …


Apparent Survival Of Snowy Plovers Varies Across Years And Between Sexes In Coastal Northern California, Justin A. Windsor Jan 2020

Apparent Survival Of Snowy Plovers Varies Across Years And Between Sexes In Coastal Northern California, Justin A. Windsor

Cal Poly Humboldt theses and projects

Adult survival is one of the most influential vital rates affecting population growth of iteroparous organisms. Survival often varies annually due to environmental stochasticity. However, drastic variations in annual adult survival rates can have overwhelmingly negative impacts on population viability and growth. In many wild avian populations, adult survival varies between sexes and may owe to unequal risks associated with reproductive roles or predation; this is particularly true among shorebirds. I used mark-resight data from a 19-year study of Western Snowy Plovers (Charadrius nivosus nivosus) in coastal northern California to investigate sex-specific apparent survival of the adult population …


Impacts Of Ocean Acidification On Intertidal Macroalgae And Algivore Preference, Andrea Michelle Fieber Jan 2020

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, …


Phylogenetic And Population Genetic Analysis Of The Humboldt's Flying Squirrel Using High-Throughput Sequencing Data, Stella Chi Yuan Jan 2020

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 …


Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon Jan 2020

Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon

Cal Poly Humboldt theses and projects

Survival of juvenile ungulates is known to be highly variable, yet it is fundamental to understanding the dynamics and trends of wildlife populations. Factors influencing calf survival are poorly understood in northwestern California where Roosevelt elk (Cervus canadensis roosevelti) are known to exist. The objectives of this study were 1) to estimate summer and annual survival rates and determine recruitment rates for Roosevelt elk calves in the area, 2) to evaluate differences in calf survival by examining the effects of individual and population level covariates on summer and annual calf survival, 3) to identify factors influencing the timing …


Impacts Of Flow Releases On Invertebrate Drift And Juvenile Chinook Salmon (Oncorhynchus Tshawytscha) Diet On The Trinity River Below Lewiston Dam, Thomas R. Starkey-Owens Jan 2020

Impacts Of Flow Releases On Invertebrate Drift And Juvenile Chinook Salmon (Oncorhynchus Tshawytscha) Diet On The Trinity River Below Lewiston Dam, Thomas R. Starkey-Owens

Cal Poly Humboldt theses and projects

Benthic macroinvertebrate (BMI) drift, species composition and abundance are specific to local hydrologic and habitat conditions, which can restrict or enhance availability to salmonids as a food resource. Currently, a knowledge gap exists on the Trinity River (northern California) in how flow releases from Lewiston Dam potentially impact BMI drift and feeding opportunities for juvenile salmonids. Samples of BMIs from drift, benthos, and diets of juvenile Chinook salmon (Oncorhynchus tshawytscha) were collected from two sites in the upper Trinity River February-April 2018, during stable flow conditions (~8 ) and two increased flow conditions peaking at ~50 . Chironomidae …


Exploring The Origins Of Secondary Growth – Two Lower Devonian (Emsian) Euphyllophytes From Gaspé, Canada, And Their Implications For The Evolution Of Secondary Growth, Kelly C. Pfeiler Jan 2020

Exploring The Origins Of Secondary Growth – Two Lower Devonian (Emsian) Euphyllophytes From Gaspé, Canada, And Their Implications For The Evolution Of Secondary Growth, Kelly C. Pfeiler

Cal Poly Humboldt theses and projects

Secondary growth from a vascular cambium has a deep fossil record among euphyllophytes, with the earliest occurrence dated to 407 Ma. To date, Armoricaphyton and Franhueberia represent the only instances of secondary growth formally documented in the Early Devonian. Secondary growth diversified rapidly and was present in all major euphyllophyte lineages by the Middle Devonian. Here, I describe two new Early Devonian euphyllophytes exhibiting secondary growth, from the Emsian (c. 400-395 Ma) Battery Point Formation (Québec, Canada): Gmujij tetraxylopteroides gen. et sp. nov. and Perplexa praestigians gen et sp. nov. Both these plants possess mesarch actinosteles with Psilophyton-type …


Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong Jan 2020

Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong

Cal Poly Humboldt theses and projects

Distinct populations of steelhead in the wild are in decline. The propagation of steelhead in hatcheries has been used to boost population numbers for recreational fisheries and for use in conservation. However, hatchery breeding practices of steelhead can result in changes in genetic structure. I investigated the genetic structure of winter-run steelhead (Oncorhynchus mykiss) returning to the Mad River, California, where a hatchery has been used enhance production for recreational fisheries since 1971. Genetic variability in Mad River steelhead was evaluated using 96 single nucleotide polymorphisms (SNPs) among 4203 individuals, including the Mad River and nearby locations, and …


Comparing Environmental Dna And Traditional Monitoring Approaches To Assess The Abundance Of Outmigrating Coho Salmon (Oncorhynchus Kisutch) In California Coastal Streams, Emerson Alan Kanawi Jan 2020

Comparing Environmental Dna And Traditional Monitoring Approaches To Assess The Abundance Of Outmigrating Coho Salmon (Oncorhynchus Kisutch) In California Coastal Streams, Emerson Alan Kanawi

Cal Poly Humboldt theses and projects

Environmental DNA (eDNA) has the potential to dramatically increase the information available to managers regarding species distribution and abundance. Collection of reliable survey information on fish abundance is essential to monitor population trends and restoration efforts for endangered and threatened species. In Northern California, coho salmon are a federally listed species and a focus of ongoing monitoring programs and restoration projects. I examined the feasibility of using eDNA to supplement, or replace, traditional outmigrating juvenile coho salmon monitoring approaches currently used at two existing coho salmon life-cycle monitoring stations. Over the spring of 2018 and spring of 2019, I collected …


The Rattle Call: A Female-Specific Vocalization In Steller's Jays, Kachina L. Rowland Jan 2020

The Rattle Call: A Female-Specific Vocalization In Steller's Jays, Kachina L. Rowland

Cal Poly Humboldt theses and projects

While the elaborate songs of male passerines are well documented for their role in intrasexual resource competition and mate attraction, vocalizations used in female competition are poorly understood. Research has suggested that the female-specific rattle call of Steller’s jays (Cyanocitta stelleri) is used in competition for access to a territory and mate. I describe structural properties of the rattle call, and compare life history traits of individual females to rattle call occurrence. I used two rates to quantify rattle call occurrence from 20 females: rattles per observation period (RPO), and proportion of observations with a rattle call (POR) …


Anaerobic Capacity Measures In Healthy Active Adults Ages 18-29: Normative Reference Values And Differences Between Sex, Dylan E. Roberts Jan 2020

Anaerobic Capacity Measures In Healthy Active Adults Ages 18-29: Normative Reference Values And Differences Between Sex, Dylan E. Roberts

Cal Poly Humboldt theses and projects

The purpose of this study was to develop normative reference values for the modified Anaerobic Speed Test (mAST), an anaerobic capacity test that can be administered and completed on a commercial treadmill. The mAST of 15% grade has been created as one of the only protocols based on the original AST protocol of 20% grade. However, no percentile norms currently exist for this protocol, limiting its usefulness and interpretation of results. This paper presents normative values for active healthy adults ages 18-29, separated by sex. The sample consisted of 276 active healthy volunteers (161 men and 115 women). All mASTs …


Spatiotemporal Partitioning Of Mammalian Mesopredators In Response To Drought And Urbanization In California's Central Valley, Chad W. Moura Jan 2020

Spatiotemporal Partitioning Of Mammalian Mesopredators In Response To Drought And Urbanization In California's Central Valley, Chad W. Moura

Cal Poly Humboldt theses and projects

Mammalian mesopredators commonly associated with human dominated landscapes often exhibit generalist diets, behavioral plasticity, and relatively high reproductive rates. Because of this wide range of adaptive traits, ecologists have been speculative of what conditions may drive species to change their activity and behavior to avoid or mitigate against resource competition, intraguild predation, and human disturbance. I investigated a community of common mesopredators within the Sacramento Metropolitan Area of California’s Central Valley to address whether species are spatially and/or temporally partitioning due to a defacto apex predator, coyotes (Canis latrans), and humans alongside large landscape altering disturbances: urbanization and drought. I …


Growth Of Juvenile Red Abalone (Haliotis Rufescens) Fed Different Seaweed-Based Diets, Quinn C. Wulffson Jan 2020

Growth Of Juvenile Red Abalone (Haliotis Rufescens) Fed Different Seaweed-Based Diets, Quinn C. Wulffson

Cal Poly Humboldt theses and projects

The rise of abalone aquaculture has mitigated most of the global demand placed on wild stocks of abalone; however, the current production of abalone relies heavily on naturally harvested kelp. The continued reliance on wild kelp as a feed source further contributes to the disappearance of kelp forests throughout coastal ecosystems. This study aims to better understand how juvenile red abalone Haliotis rufescens grow and utilize nutrients from three diets: a control diet of naturally harvested bull kelp Nereocystis luetkeana, a formulated commercial diet (ABKelp®), and Pacific dulse Palmaria mollis produced using Integrated Multi-Trophic Aquaculture (IMTA). Juvenile …


Recolonization Potential For Coho Salmon (Oncorhynchus Kisutch) In Tributaries To The Klamath River After Dam Removal, Max M. Ramos Jan 2020

Recolonization Potential For Coho Salmon (Oncorhynchus Kisutch) In Tributaries To The Klamath River After Dam Removal, Max M. Ramos

Cal Poly Humboldt theses and projects

Removal of four major dams on the Klamath River is scheduled to begin in 2023, restoring access to greater than 50 km of historic mainstem habitat for coho salmon. However, mainstem habitat may not be suitable for juvenile coho salmon due to elevated water temperatures and high concentrations of infectious myxospores in the summer and fast water velocities in the winter. Small, cooler tributaries can provide essential habitat for escape from deleterious conditions in the mainstem Klamath River. I used temperature and other physical features of six tributaries to the Klamath River above Iron Gate Dam to assess their capacity …


Alternative Water Sources In Western Conifers Via Foliar Uptake And Hydraulic Redistribution, Ariel Sol Weisgrau Jan 2020

Alternative Water Sources In Western Conifers Via Foliar Uptake And Hydraulic Redistribution, Ariel Sol Weisgrau

Cal Poly Humboldt theses and projects

Water is often the most limiting resource in a plant’s environment. Plants that can maximize their ability to acquire water improve their chances of success. Outside of the traditional soil-plant-atmosphere continuum, plants can alternatively acquire water via foliar uptake of water and hydraulic redistribution (HR) of deep water. This study used greenhouse-based experiments to investigate water use and physiology in four conifer species native to the western U.S.: Picea sitchensis (Bong.) Carriére (PISI), Pseudotsuga menziesii (Mirb.) Franco (PSME), Sequoia sempervirens (D. Don) Endl. (SESE), and Thuja plicata Donn ex. D. Don (THPL). First, this work investigated the capacity for foliar …


The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler Jan 2020

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 …


Assessing Methods For Estimating Biological Sex From Subadult Skeletal Elements, Dorota Zabnicka Jan 2020

Assessing Methods For Estimating Biological Sex From Subadult Skeletal Elements, Dorota Zabnicka

Cal Poly Humboldt theses and projects

While methods for estimating the sex of adult skeletons are relatively accurate, these methods are often inconclusive when applied to subadults (non-adults), especially when many secondary sexual characteristics have not fully developed. Furthermore, existing methods for subadults are often tested on samples with relatively homogenous ancestries, calling into question their reliability in more diverse populations. This thesis reviewed techniques for estimating sex in subadult skeletal remains, and the most promising methods were retested on individuals of known sex between ages 3 and 17 years (n=39, 14 males, 25 females) from the Hamann-Todd Osteological Collection. Data collection included measurements of the …


Habitat Use And Prey Selection By Mountain Lions In An Altered Sagebrush Steppe Environment, Jonathan Ewanyk Jan 2020

Habitat Use And Prey Selection By Mountain Lions In An Altered Sagebrush Steppe Environment, Jonathan Ewanyk

Cal Poly Humboldt theses and projects

Throughout the American West there is an increasing trend of encroachment of woody vegetation on previously open sagebrush steppe habitat. The Modoc Plateau in northeastern California has not been excluded from this encroachment trend and has seen an increase in western juniper (Juniperus occidentalis) densities, likely as a result of long-term fire suppression. Mountain lions (Puma concolor) have not previously been studied on the Modoc Plateau, and there is potential for an increase in cover due to juniper encroachment to benefit the hunting behavior of lions. To better understand if the presence of cover is being …