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California Polytechnic State University, San Luis Obispo

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Articles 121 - 147 of 147

Full-Text Articles in Ecology and Evolutionary Biology

The Spatial Games: Investigating The Spatial Distribution Of Anax And Select Prey As A Function Of Predator-Prey Interactions, Shane Elizabeth Johnson, Nene Kumashe Ugbah Jun 2012

The Spatial Games: Investigating The Spatial Distribution Of Anax And Select Prey As A Function Of Predator-Prey Interactions, Shane Elizabeth Johnson, Nene Kumashe Ugbah

Biological Sciences

Our study investigated the spatial distribution and movement behavior of predatory dragonfly larvae (Anax) and of two prey types: mosquito larvae and amphipods. Predator-prey interactions have important consequences for the population dynamics of both predator and prey groups and these interactions can shape community structure. We measured behavior of each prey type in the presence of the Anax predator and the behavior of the predator in the presence of these alternative prey types. Observations were made in five-gallon aquaria where a grid pattern allowed us to track the number of moves made by individuals. We compiled data from …


American Pika (Ochotona Princeps): Persistence And Activity Patterns In A Changing Climate, Cody P. Massing May 2012

American Pika (Ochotona Princeps): Persistence And Activity Patterns In A Changing Climate, Cody P. Massing

Master's Theses

An increasing amount of evidence suggests that as temperatures increase, montane animals are moving upward in elevation (IPCC 2007, Parmesan and Yohe 2003). As suitable habitats rise in elevation and then disappear altogether, these animals could be pushed to extinction. The American pika, Ochotona princeps, is a montane mammal that lives in western North America, usually at elevations above 1500 m (Smith and Weston 1990). Recent evidence suggests that pika population numbers are dropping in response to rising temperatures (Beever et al. 2010). The pika is a small herbivorous lagomorph, a relative of hares and rabbits. Its habitat is …


Camera Survey Of Wildlife Corridors Adjacent To Highway 101, Grace K. Mannell, Chelsea E. Rose Feb 2012

Camera Survey Of Wildlife Corridors Adjacent To Highway 101, Grace K. Mannell, Chelsea E. Rose

Natural Resources Management and Environmental Sciences

Driving poses a significant threat to safety for both humans and wildlife. Along highway 101 in San Luis Obispo, California, is a stretch of roadway that is exceptionally deadly to mammals such as deer and bears. Roadkill counts and motion-activated cameras have been utilized along this route in a previous study (Perrine and Snyder, 2011) to assist Caltrans in setting up wildlife barriers. We sought to continue this research using remote motion-sensing cameras to monitor wildlife during winter and spring of 2011. We set up cameras at five previously monitored locations that had already been determined to host heavy wildlife …


Brody-Bertalanffy Growth Curves From Tag And Recapture Studies On Cabezon (Scorpaenichthys Marmoratus) And Gopher Rockfish (Sebastes Carnatus) Of The Central Coast, Christie Yorke Dec 2011

Brody-Bertalanffy Growth Curves From Tag And Recapture Studies On Cabezon (Scorpaenichthys Marmoratus) And Gopher Rockfish (Sebastes Carnatus) Of The Central Coast, Christie Yorke

Biological Sciences

No abstract provided.


Classifying And Mapping Diversity In A Species-Poor System: The Mangrove Meta-Community Of Laguna Chacahua National Park, Oaxaca, Mexico, Elizabeth Kay Weisgerber Sep 2011

Classifying And Mapping Diversity In A Species-Poor System: The Mangrove Meta-Community Of Laguna Chacahua National Park, Oaxaca, Mexico, Elizabeth Kay Weisgerber

Master's Theses

ABSTRACT

Classifying and Mapping Diversity in a Species-Poor System: the mangrove meta-community of Laguna Chacahua National Park, Oaxaca, Mexico

by

Elizabeth Kay Weisgerber

Both field transects and imagery grid plots were analyzed with the goal of creating a community classification map for the mangrove forest of Parque Nacional Lagunas de Chacahua. In total, data was collected in 49 sites throughout the park, recording measures such as DBH, basal area, estimated dominance, frequency, cover and relative dominance. Field locations were marked and georeferenced with a GPS and grid plots overlaid on satellite imagery of the park were generated via a random …


Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley Aug 2011

Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley

STAR Program Research Presentations

Salmonids, such as Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss), are a staple economic, recreational, tribal, and environmental resource, yet many populations are unsustainable. This study was part of a broad scale effort to monitor the impact of downstream migration obstacles on juvenile salmonid health and survival, which is an essential step towards increasing Smolt-to-Adult Return ratios (SARs). The objective of this study was to determine if juvenile Chinook salmon and steelhead exhibit differing quantities of alphaII-Spectrin Breakdown Products (SBDPs) over two consecutive spring migration periods, indicative of neurogenesis rate and/or biological response to head …


Relationship Of Maternal Flow Environment To Offspring Size In Botrylloides Violaceus, Damion J. Delton, Sarah Cohen Aug 2011

Relationship Of Maternal Flow Environment To Offspring Size In Botrylloides Violaceus, Damion J. Delton, Sarah Cohen

STAR Program Research Presentations

Colonial botryllid tunicates, such as Botrylloides violaceus, brood large, non-feeding offspring with extremely limited larval life spans of minutes to perhaps one day. Despite the importance of this transitory life history stage, there is little information on how environmental factors such as ambient water flow affect larval size among invertebrates. Since adult tunicates feed by filtering particles from the water flowing around the siphons, we reasoned that colonies of B. violaceus in high water flow may produce larger offspring due to greater food availability. We tested to see whether there was a relationship between larval size and water motion in …


Informing Carbon In Arctic Reservoirs Vulnerability Experiment Flight Schedule Based Upon Soil And Vegetation Freeze And Thaw Event Variation Along The Alaska Ecological Transect, Jessica Potter, Kyle Mcdonald, Erika Podest Aug 2011

Informing Carbon In Arctic Reservoirs Vulnerability Experiment Flight Schedule Based Upon Soil And Vegetation Freeze And Thaw Event Variation Along The Alaska Ecological Transect, Jessica Potter, Kyle Mcdonald, Erika Podest

STAR Program Research Presentations

Established in the 1990s, the Alaska Ecological Transect (ALECTRA) is composed of a series of ground stations extending from the Franklin Bluff on Alaska’s North Slope to the Kenai Peninsula, south of Anchorage. At each station, sets of thermistors are deployed to monitor vegetation tissue temperature, air temperature, and soil profile temperatures. Also sensors are deployed for monitoring sap flow in individual trees. The stations are automated, with data loggers recording this data approximately every two hours. Dates marking the spring thaw and fall freeze transitions in soil and vegetation tissues from sites in Coldfoot, Dietrich Valley, and Bonanza Creek …


Influence Of Wave Action On Mytilus Californianus Mussel Beds, Jaclyn Mann Jun 2011

Influence Of Wave Action On Mytilus Californianus Mussel Beds, Jaclyn Mann

Biological Sciences

No abstract provided.


Harmful Algal Bloom (Hab) Communities And Co-Occurring Species In Relation To Near Shore Ocean Dynamics In San Luis Bay, California, Samuel Christopher Rankin Jun 2011

Harmful Algal Bloom (Hab) Communities And Co-Occurring Species In Relation To Near Shore Ocean Dynamics In San Luis Bay, California, Samuel Christopher Rankin

Master's Theses

The occurrence of phytoplankton taxa, with special focus on harmful algal bloom (HAB) taxa, was monitored for one year off the central coast of California to examine both their co-occurrence and physical and chemical variables influencing their temporal patterns. Bi-weekly samples were taken from October 6, 2008 to October 5, 2009 in San Luis Obispo Bay, CA. Canonical correspondence analysis (CCA) of weekly samples indicated that 46.1% of the variability in species abundance was explained by the variables in the model, higher than previous reports. Cluster analysis divided phytoplankton communities into HAB and non-HAB groups of species, while shared distribution …


Hydrologic Alteration And Sedimentation In The Upper Henry's Fork Watershed, Amelie Jeanne Charnaux Jun 2011

Hydrologic Alteration And Sedimentation In The Upper Henry's Fork Watershed, Amelie Jeanne Charnaux

Master's Theses

Abstract

Hydrologic Alteration and Sedimentation in the Upper Henry’s Fork Watershed

Amelie Jeanne Charnaux

The Henry’s Fork of the Snake River is venerated by the global recreational community as one of the finest trout fishing streams on the planet. Furthermore, this remarkable waterway flows within the bounds of one of the most important ecological corridors in the equally world-renowned Greater Yellowstone Ecosystem. While the recreational and biological features of this corner of Idaho may capture the interest of the broader public, the waterway is equally significant to the livelihoods of local interests, such as the ranching and farming communities. With …


The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach Mar 2011

The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach

Biological Sciences

The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997).  As far as we know, no previous data have been compiled regarding hormones and condition index of guppies.  In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River.  Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator.  The condition …


Trap Shyness And Avoidance Affects On Capture Proportions Of Dipodomys Heermanni Arenae, Natalie E. Folsom, Andrew R. Ruddock Mar 2011

Trap Shyness And Avoidance Affects On Capture Proportions Of Dipodomys Heermanni Arenae, Natalie E. Folsom, Andrew R. Ruddock

Biological Sciences

This is a study on trap shyness and trap avoidance in the kangaroo rat species Dipodomys heermanni arenae. This species is being studied as a surrogate for the critically endangered Dipodomys heermanni morroensis. This is an ongoing study that has been continuing for the past three years, with four three-day sessions per year. The study is a specific look at the effects of the use of Sherman traps on kangaroo rat behavior between individual session days. Capture proportions for each of the three days of each session were calculated and compared through a t-test. The current results of …


Songbird Diversity In Oak Woodland And Riparian Habitats In The Los Padres National Forest, San Luis Obispo County, California, Trevor Pell Feb 2011

Songbird Diversity In Oak Woodland And Riparian Habitats In The Los Padres National Forest, San Luis Obispo County, California, Trevor Pell

Biological Sciences

Diversity in songbirds (Passeriformes) between riparian and oak woodland habitats has not been studied before in the Los Padres National Forest around the Hi Mountain Lookout in San Luis Obispo County. Surveys of avian populations were conducted by point counts on fifty variable circular plots; surveys were performed between July and August of 2010. Diversity was calculated using the Shannon-Weiner method, and then squared for normality. No significant results were found when comparing the diversity values between riparian and oak woodland habitat (F = 0.52, p = 0.472). Although the results showed no significance, the data are still important, as …


Contrasting Effects Of Flow On Adult And Juvenile Ascidian Life History Stages, Including The Global Invasive Didemnum Vexillum, Tren C. Kauzer, C Sarah Cohen Jan 2011

Contrasting Effects Of Flow On Adult And Juvenile Ascidian Life History Stages, Including The Global Invasive Didemnum Vexillum, Tren C. Kauzer, C Sarah Cohen

STAR Program Research Presentations

Few studies have quantified a relationship between recruitment, growth, survival and flow with colonial filter feeders. In this study, the growth of D. vex and larval recruitment were evaluated under different local flow conditions in Half Moon Bay, California, USA. Tunicates were subjected to four different flow conditions, three of which included objects to differentially obstruct flow, and growth and recruitment were measured. A direct relationship was seen between increases in flow and adult growth, and an inverse relationship was seen between increases in flow and recruitment. These trends suggest that optimal flow conditions differ for juveniles and adults. The …


The Significance Of The Male Display During Male-Male Interactions In Guppies (Poecilia Reticulata), Rebecca Nuffer, Samantha M. Alburn Jun 2010

The Significance Of The Male Display During Male-Male Interactions In Guppies (Poecilia Reticulata), Rebecca Nuffer, Samantha M. Alburn

Biological Sciences

Guppies, Poecilia reticulata, are a model species for studies of female preference based on male courtship displays; however, males also display to each other in an aggressive context, and little attention has been paid to the role of male-male displays. The display involves a male positioning his body in front or to the side of another male, arching his body, and quivering with his dorsal fin splayed. To understand what behaviors elicit a male display, we assigned individual males a dominance status. We then examined the relationship between dominance status and the number of displays delivered and received. By …


Effects Of Nitrogen And Potassium Fertilizer On Willamette Spider Mite (Eotetranychus Willamettei) (Acari: Tetranychidae), Whitney Ann Geddes Jun 2010

Effects Of Nitrogen And Potassium Fertilizer On Willamette Spider Mite (Eotetranychus Willamettei) (Acari: Tetranychidae), Whitney Ann Geddes

Master's Theses

The spider mite family (Tetranychidae) is a well known pest group in agriculture. Within this family, Willamette spider mite (Eotetranychus willamettei) causes physical harm and potential damage to grapevines (Vitis vinifera) along the central and north coast of California as well as Washington and Oregon. Willamette spider mite prefers cooler climates and feeds by puncturing the plant leaf tissue; therefore removing plant nutrients in the early stages of plant growth. Amending soils with fertilizer is a common cultural practice used in commercial vineyards, but no study has documented the interaction between the effects fertilizer concentrations have on Willamette spider mite. …


Taxonomy, Biogeography And Pest Status Of Marmara Sp. In Northern Mexico And California Citrus Production, Paul Semet Jun 2010

Taxonomy, Biogeography And Pest Status Of Marmara Sp. In Northern Mexico And California Citrus Production, Paul Semet

Master's Theses

A novel lepidopteran sex pheromone lure which was thought to be species-specific to the citrus pest Marmara gulosa (Lepidoptera: Gracillariidae) Guillén (McElfresh et al. 2009) has attracted male moths exhibiting two distinct morphologies. The morphological features examined were the sclerotized parts that make up the male genitalia; which include the valvular lobes, costal lobes, cucullar lobes, and the aedeagus. The sclerotized parts were methodically dissected and mounted on microscope slides. Digital images captured of the slide-mounted specimens proved to be inconsistent with the illustrations provided in the original Marmara gulosa species description (Guillén et al. 2001).

The morphologies of all …


Fire: Ecology & Prevention, Justin R. Frey Jun 2010

Fire: Ecology & Prevention, Justin R. Frey

Social Sciences

No abstract provided.


Effect Of Sand Grain Size On Burrowing Behavior Of Juvenile Pacific Sand Crabs (Emerita Analoga), Natalie A. Lee, Laura M. Melroy Mar 2010

Effect Of Sand Grain Size On Burrowing Behavior Of Juvenile Pacific Sand Crabs (Emerita Analoga), Natalie A. Lee, Laura M. Melroy

Biological Sciences

Emerita analoga, Pacific coast sand crabs, are an important biological component of the swash zone ecosystem. They have evolved the ability to burrow into sand, and burrowing speed is commonly used as an indicator of performance relevant for fitness in this species. Sand grain size varies among beaches, and crabs may be better adapted to to burrow in some sand types. We performed a completely crossed 3-factor experiment to determine how the sand grain size associated with beach-of-origin and rearing conditions influence burrowing in coarse and fine sand. Crabs from a fine sand beach and a coarse sand beach were …


The Presence Of Micropterus Salmoides (Largemouth Bass) Influences The Populations Of Rana Draytonii (California Red-Legged Frog) And Pseudacris Regilla (Pacific Treefrog) In Two Ponds In Santa Barbara County, California, Kenneth Lee Gilliland Feb 2010

The Presence Of Micropterus Salmoides (Largemouth Bass) Influences The Populations Of Rana Draytonii (California Red-Legged Frog) And Pseudacris Regilla (Pacific Treefrog) In Two Ponds In Santa Barbara County, California, Kenneth Lee Gilliland

Master's Theses

Alien fish have been implicated in the decline of Rana draytonii (California red-legged frog) and Pseudacris regilla (Pacific treefrog) populations. Micropterus salmoides (largemouth bass) is a common sport fish that has been introduced into the sympatric range of these two anuran species; however, no studies have investigated the individual influence that this alien fish has on these two species. I conducted M. salmoides control or eradication experiments during a four year study in two ponds within the Transverse Mountain Range of Santa Barbara County, California. Changes in the densities of all life stages of R. draytonii and P. regilla were …


Arroyo Toad (Anaxyrus Californicus) Life History, Population Status, Population Threats, And Habitat Assessment Of Conditions At Fort Hunter Liggett, Monterey County, California, Jacquelyn Petrasich Hancock Dec 2009

Arroyo Toad (Anaxyrus Californicus) Life History, Population Status, Population Threats, And Habitat Assessment Of Conditions At Fort Hunter Liggett, Monterey County, California, Jacquelyn Petrasich Hancock

Master's Theses

The arroyo toad (Anaxyrus californicus) is a federally endangered species found on Fort Hunter Liggett, Monterey County, California. The species was discovered in 1996 and was determined to occupy 26.7 km of the San Antonio River from approximately 2.4 km northwest of the San Antonio Mission de Padua, to the river delta above the San Antonio Reservoir. The construction of the San Antonio Reservoir dam in 1963 isolated this northern population of arroyo toads. Through time, the Fort Hunter Liggett landscape has changed drastically. The land was heavily grazed by cattle until 1991, which considerably reduced vegetation in riparian areas. …


Attempted Cloning Of A Wnt Gene From Botrylloides Violaceus, Manasa Chandra, James Tumulak Dec 2009

Attempted Cloning Of A Wnt Gene From Botrylloides Violaceus, Manasa Chandra, James Tumulak

Biological Sciences

Botrylloides violaceus is a colonial ascidian with the ability to undergo sexual and asexual reproduction as well as regeneration. The canonical pathway starts with the extracellular protein Wnt and ends with β-catenin, a transcription factor, which also functions in cell adhesion. The Wnt signaling pathway is involved in embryogenesis and regeneration in a variety of other species. In our studies we attempt to isolate and sequence both a Wnt gene and from Botrylloides via degenerate primer design and PCR. Using bioinformatic methods we aligned sequences from other organisms, as the Botrylloides genome has not yet been sequenced. Using mouse, Ciona, …


Restoration Of A. Fasciculatum At Rocky Canyon Granite Quarry, San Luis Obispo, Ca, Catherine L. Roy Sep 2009

Restoration Of A. Fasciculatum At Rocky Canyon Granite Quarry, San Luis Obispo, Ca, Catherine L. Roy

Master's Theses

The objective of this study was to assess the above-ground factors affecting the establishment and recovery of the dominant chaparral shrub Adenostoma fasciculatum (chamise) on the Rocky Canyon granite mine.

Attempts to restore the California chaparral have been challenging and few successful efforts have been documented. However, the California chaparral can fully recover from fire in as little as 10-15 years. Factors affecting chamise seedling establishment were tested by planting chamise seed in forty eight 1square meter plots managed to test the effects of interspecific competition with native postfire vegetation, post-mining volunteer vegetation, and intraspecific only competition. Plots were managed …


Purple Martin, Progne Subis, In San Luis Obispo County Riparian Habitat: Presence, Persistence, Nesting, Brooding And Reproductive Success, Shannon Eileen Murphy Jun 2009

Purple Martin, Progne Subis, In San Luis Obispo County Riparian Habitat: Presence, Persistence, Nesting, Brooding And Reproductive Success, Shannon Eileen Murphy

Biological Sciences

The State of California, as of 2002, identified the Purple Martin as a bird species of Special Concern (Airola et al., 2003). These migrants were historically found in a unique habitat in Central California; nesting in natural cavities of Western Sycamores within Riparian Habitats. I am proposing that Purple Martins still successfully nest and brood young in this unique habitat in San Luis Obispo County. The primary study site is in Atascadero where Highway 41 meets San Gabriel Road and San Gabriel Road crosses Atascadero creek. The secondary site is Highway 58 in Santa Margarita where the highway crosses the …


The Relationship Between Plasma Steroid Hormone Concentrations And The Reproductive Cycle Of The Northern Pacific Rattlesnake, Crotalus Oreganus, Craig Michael Lind Jun 2009

The Relationship Between Plasma Steroid Hormone Concentrations And The Reproductive Cycle Of The Northern Pacific Rattlesnake, Crotalus Oreganus, Craig Michael Lind

Master's Theses

To gain a better understanding of the role of steroid hormones in vertebrate reproduction, we quantified steroid hormone concentrations in a free ranging population of the Northern Pacific rattlesnake, Crotalus oreganus. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (Mar-Oct). We measured testosterone (T), 5α-dihydrotestosterone (DHT), and corticosterone (B) concentrations in male and female snakes. 17β-estradiol (E2) and progesterone (P) were measured in females only. We also observed breeding behaviors (e.g. consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections. …


Spatial, Seasonal, And Size-Dependent Variation In The Diet Of Sacramento Pikeminnow In The Main Stem Of Chorro Creek, Central Coast California, Brian G. Dugas Jun 2009

Spatial, Seasonal, And Size-Dependent Variation In The Diet Of Sacramento Pikeminnow In The Main Stem Of Chorro Creek, Central Coast California, Brian G. Dugas

Master's Theses

This study examined the diet composition of ninety-nine Sacramento pikeminnow (150-410 mm [5.9-16 in] fork length [FL]) collected from the upper and lower main stem of Chorro Creek, Morro Bay Watershed, California in 2006. The goal of this study was to characterize the spatial and seasonal variability in the diet of Sacramento pikeminnow within Chorro Creek and to determine what proportion of the diet is represented by rainbow trout (Oncorhynchus mykiss) and their anadromous form (steelhead). Prey was identified in 88% of the samples collected in the early season and 84% of the samples collected in the late season. Fish …