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Assessing The Trophic Positions Of Lake Michigan Fishes Using Stable Carbon And Nitrogen Isotopes, Benjamin Alan Turschak Aug 2021

Assessing The Trophic Positions Of Lake Michigan Fishes Using Stable Carbon And Nitrogen Isotopes, Benjamin Alan Turschak

Theses and Dissertations

Lake Michigan is the second largest Laurentian Great Lake and is characterized by broad spatiotemporal variation in ecosystem processes such as nutrient cycling and energy flow. Variation in ecosystem processes—such as those induced by invasive dreissenid mussels—and subsequent changes in the spatiotemporal distribution of resources (i.e. prey or habitat) has resulted in major changes in Lake Michigan’s fish community. The ability of fish species to cope with spatiotemporal resource dynamics is at least partially dependent on their ability to shift apparent trophic position along various resource gradients. The objectives of this research were to quantify trophic positions of Lake Michigan …


Survival Of Off-Host Rhipicephalus (Boophilus) Annulatus (Acari: Ixodidae) Larvae In Study Arenas In Relation To Climatic Factors And Habitats In South Texas, Usa, Emily Jesselle Zamora May 2020

Survival Of Off-Host Rhipicephalus (Boophilus) Annulatus (Acari: Ixodidae) Larvae In Study Arenas In Relation To Climatic Factors And Habitats In South Texas, Usa, Emily Jesselle Zamora

Theses and Dissertations

The cattle fever tick, Rhipicephalus (Boophilus) annulatus (Say), is an economically destructive arthropod because of its ability to vector bovine babesiosis. Cattle fever ticks can spend more than 90% of their life cycle as questing larvae, but the effect of climatic factors on their off-host behavior and survival is unclear. The goal of this study was to measure the effects of specific ecological factors on off-host larvae in nature. The study was conducted in a south Texas pasture over a 20-mo period, during which time larval populations were surveyed and ambient weather variables - relative humidity and temperatures – were …


Questing Activity Of Cattle Fever Tick Larvae, Rhipicephalus (Boophilus) Microplus (Acari: Ixodidae): Environmental Influences And Implications For Control In South Texas, Brenda Leal Aug 2018

Questing Activity Of Cattle Fever Tick Larvae, Rhipicephalus (Boophilus) Microplus (Acari: Ixodidae): Environmental Influences And Implications For Control In South Texas, Brenda Leal

Theses and Dissertations

Questing ticks ascend stems, leaves, or rocks, extend their front legs, and wait poised for attachment to a passing host. Ixodid ticks have four developmental stages. Because ticks detach and molt between stages most ticks require three separate hosts to complete their lifecycle. Three-host ticks quest for a new host between each stage, whereas a few specialist tick species remain on and thus require only a single host. These one-host ticks only quest for hosts as larvae. As much as 90% of the life cycle may consist of questing when hosts are scarce. Most of the literature on questing relates …


A Survey Of Invasive Exotic Ants Found On Hawaiian Islands: Spatial Distributions And Patterns Of Association, Camie Frandsen Martin Dec 2012

A Survey Of Invasive Exotic Ants Found On Hawaiian Islands: Spatial Distributions And Patterns Of Association, Camie Frandsen Martin

Theses and Dissertations

An intensive sampling of all ant species encountered on 6 Hawaiian Islands: Big Island, Maui, Oahu, Kauai, Molokai, and Lanai took place between 1988 and 1996. Species presence and absence was recorded at each site. Using remote sensing, variables were added insitu and used throughout my analysis. Species accumulation curves suggest that sampling was comprehensive. There is a significant trend between island area and species richness which validates the Theory of Island Biogeography for invasive species. Islands were found to be significantly nested by area, order, and tourism. Cluster analysis shows a link between elevation, land-use and island, and species …


Stable Isotope Diet Reconstruction Of Feral Horses (Equus Caballas) On The Sheldon National Wildlife Refuge, Nevada, Usa, Megan Kathleen Nordquist Dec 2011

Stable Isotope Diet Reconstruction Of Feral Horses (Equus Caballas) On The Sheldon National Wildlife Refuge, Nevada, Usa, Megan Kathleen Nordquist

Theses and Dissertations

Feral horse management has become a subject of significant controversy in the United States. This is because of differing opinions and minimal recent empirical data on feral horses. In recent years, numbers of feral horses have increased due to governmental horse removal restrictions (specifically the Wild Horse and Burro act of 1971). With increasing numbers of feral horses on rangelands, land managers are challenged with identifying the appropriate course of action for satisfying groups with differing opinions. The purpose of this study is to characterize diet consumption through the use of stable isotope dietary analysis (δ15N and δ13C). We did …


Usage And Development Of Molecular Markers For Investigation Of The Population And Ecological Genetics Of Bromus Tectorum L., Keith R. Merrill Mar 2011

Usage And Development Of Molecular Markers For Investigation Of The Population And Ecological Genetics Of Bromus Tectorum L., Keith R. Merrill

Theses and Dissertations

This thesis includes two studies: The first examined patterns of neutral genetic diversity within Bromus tectorum L. across the IMW region, and uses patterns of microsatellite (SSR) genotype distribution to make inferences about the respective roles of adaptively significant genetic variation, adaptive phenotypic plasticity, and facultative outcrossing in the ongoing invasion and recent range expansion of B. tectorum. It has been previously demonstrated that, due to extremely low outcrossing rates, it is possible to characterize individual genotypes of this species using four SSR loci. We sampled 20 individuals from each of 96 B. tectorum populations (classified by region and …


Multidisciplinary Assessment And Documentation Of Past And Present Human Impacts On The Neotropical Forests Of Petén, Guatemala, Christopher Stephen Balzotti Jul 2010

Multidisciplinary Assessment And Documentation Of Past And Present Human Impacts On The Neotropical Forests Of Petén, Guatemala, Christopher Stephen Balzotti

Theses and Dissertations

Tropical forests provide important habitat for a tremendous diversity of plant and animal species. However, limitations in measuring and monitoring the structure and function of tropical forests has caused these systems to remain poorly understood. Remote-sensing technology has provided a powerful tool for quantification of structural patterns and associating these with resource use. Satellite and aerial platforms can be used to collect remotely sensed images of tropical forests that can be applied to ecological research and management. Chapter 1 of this article highlights the resources available for tropical forest remote sensing and presents a case-study that demonstrates its application to …


Diversity And Abundance Of The Dark Kangaroo Mouse, Microdipodops Megacephalus, In Communities Of Nocturnal Granivorous Rodents In Western North America, Ashley Sagers Haug Mar 2010

Diversity And Abundance Of The Dark Kangaroo Mouse, Microdipodops Megacephalus, In Communities Of Nocturnal Granivorous Rodents In Western North America, Ashley Sagers Haug

Theses and Dissertations

The dark kangaroo mouse, Microdipodops megacephalus, is a sensitive species in the Great Basin Desert. This thesis explores the structure of desert rodent communities of the Great Basin to better understand M. megacephalus' place in the community and the conditions that promote large and stable populations. To determine community structure, I used nestedness analysis to evaluate 99 communities of nocturnal granivorous rodents. I found that the community structure was non-random, indicating the existence of assembly rules and ecological constraints. I also found that M. megacephalus was the second most vulnerable species in the community. To explore the correlation …


Arthropod And Plant Communities As Indicators Of Land Rehabilitation Effectiveness In A Semi-Arid Shrub-Steppe, Eric T. Gardner Jul 2008

Arthropod And Plant Communities As Indicators Of Land Rehabilitation Effectiveness In A Semi-Arid Shrub-Steppe, Eric T. Gardner

Theses and Dissertations

We describe a case study evaluating the ecological impact of Bromus tectorum L. (cheatgrass) invasion following fire disturbance and the effectiveness of revegetation in improving ecological integrity in a degraded semi-arid shrub steppe system. The effectiveness of rehabilitation efforts was assessed from measurements of arthropod richness, vegetation and arthropod community composition, and ground cover characteristics in three habitats: undisturbed, burned and weed-infested (B. tectorum), and burned and rehabilitated with native and non-native vegetation. Arthropods were collected in each habitat using pitfall traps. Differences in arthropod richness were compared using rarefaction curves. Non-metric multidimensional scaling, and non-parametric multivariate statistical procedures including …


The Mammals Of Zion National Park With Emphasis On Ecology And Distribution Of Twelve Species Of Rodents, Paul A. Gardner Jul 1977

The Mammals Of Zion National Park With Emphasis On Ecology And Distribution Of Twelve Species Of Rodents, Paul A. Gardner

Theses and Dissertations

Information concerning the mammals of Zion National Park was needed for management purposes and general information. During the summers of 1975 and 1976, mammals observed throughout the park were recorded and habitat structure was measured for each animal at the immediate observation site. Ordinations based on stepwise discriminant analyses of the data on 12 rodent species were constructed and substantiated by Bray-Curtis analyses. The results showed that amounts of cover and boulders contrasted the habitats of Peromyscus eremicus, P. maniculatus, P. crinitus, P. boylii and P. truei. A second group of species--Eutamias minimus, E. umbrinus, Spermophilus variegatus, Tamiasciurus hudsonicus, Dipodomys …


The Spatial Distribution Of The Nests Of The Black-Crowned Night Heron (Nycticorax Nycticorax) And The Snowy Egret (Leucophoyx Thula) In Central Utah, Randall S. Isham Aug 1974

The Spatial Distribution Of The Nests Of The Black-Crowned Night Heron (Nycticorax Nycticorax) And The Snowy Egret (Leucophoyx Thula) In Central Utah, Randall S. Isham

Theses and Dissertations

Nests of the Black-crowned Night Heron and the Snowy Egret were examined in five central Utah colonies in 1973 to determine the spatial distribution within the colony. Nest locations of the 1085 nests of the two species were plotted to the nearest foot with an alidade and plane table. Tests of randomness, clump size, association, segregation, and T distribution were utilized. No differences between species were noted for the distance to the nearest and the next nearest nest. The Night Heron nested closer to other Night Herons and more often than did the Snowy Egret which non-significantly selected either species …


Habitat And Time Utilization Of A Pair Of Nesting Sharp-Shinned Hawks (Accipiter Striatus Velox) : A Telemetry Study, Joseph Belnap Platt Jul 1973

Habitat And Time Utilization Of A Pair Of Nesting Sharp-Shinned Hawks (Accipiter Striatus Velox) : A Telemetry Study, Joseph Belnap Platt

Theses and Dissertations

Telemetric observations were conducted on a pair of Sharp-Shinned Hawks (Accipiter striatus velox) nesting in Spanish Fork Canyon, Utah in 1972. The movements of both adults were monitored from the time their eggs hatched in late June until they left the study area in early August, fourty-two days later. A transmitter was also attached to one of the young at the time of fledging. The adult's main hunting area was a single plant community located 1600 meters from the nest. The male performed the majority of the foraging while the female spent the greatest part of her time at the …


Growth And Development Of The Western Harvest Mouse, Reithrodontomys Megalotis Megalotis, Gary H. Richins Apr 1973

Growth And Development Of The Western Harvest Mouse, Reithrodontomys Megalotis Megalotis, Gary H. Richins

Theses and Dissertations

Growth rates, gestation period, litter size, reproductive age, sex ratios, and development were studied on 198 litters of Reithrodontomys megalotis megalotis. Growth was characterized by several standard skull and body measurements, and was partitioned into four phases of 1-3, 4-12, 13-22, and 23-70 days. Growth was best described by measurements of tail length, ear length, and dried eye lens weight. Reproductive activity began as early as 38 days for females and 59 days for males. Gestation period was 22 days and mean litter size was 3.83 (range 1-7). Sex ratio was 53.49% males to 46.51% females. Reproductive efficiency was 53.53%. …


Environmental Factors That Influence The Timing Of A Cyclic En Masse Foraging Migration Of Ligia Occidentalis Dana (Crustacea: Isopoda) On The Northern Gulf Of California, J. Wanless Southwick Aug 1971

Environmental Factors That Influence The Timing Of A Cyclic En Masse Foraging Migration Of Ligia Occidentalis Dana (Crustacea: Isopoda) On The Northern Gulf Of California, J. Wanless Southwick

Theses and Dissertations

En masse foraging migrations of Ligia occidentalis Dana were conspicuous events on rocky beaches near Puerto Peñasco, Sonora, Mexico. Experiments were conducted to determine which factors of the environment contained the regulating rhythm for the migration, if indeed the event were cyclic. Experiments were conducted in the laboratory using a tide-simulation aquarium and in the field using mark and release techniques. A time-lapse photography system was used in the field to quantify isopod activity for comparison with environmental factors. A regular cycle for the foraging migration was found. It was in tune with both insolation and tidal cycles so that …


Overwintering Sites And Winter Mortality Rates Of Certain Predaceous Mites In Central Utah Orchards (Phytoseiidae: Typhlodromus), John Wayne Leetham Aug 1968

Overwintering Sites And Winter Mortality Rates Of Certain Predaceous Mites In Central Utah Orchards (Phytoseiidae: Typhlodromus), John Wayne Leetham

Theses and Dissertations

The overwintering habitats and winter mortality rates of predaceous mites (Phytoseiidae: Typhlodromus) were investigated during three successive winters, 1965-66, 1966-67, and 1967-68. Three species were predominant in derelict apple orchards, Typhlodromus mcgregori Chant on twigs and spurs and rough bark of scaffold limbs and trunk, Typhlodromus occidentalis Nesbitt on rough bark of scaffold limbs and trunk, and Amblyseius cucumeris Oudemans in ground cover. Other species (Typhlodromus columbiensis Chant, Typhlodromus caudiglans Schuster, Amblyseius fallacis (Garman), Amblyseius ovatus (Garman), Amblyseius floridanus (Muma), and Amblyseius rosellus Chant) were collected only incidentally. Substantial numbers of T. mcgregori and T. occidentalis were found to fall …


Nesting Ecology Of The Ferruginous Hawk (Buteo Regalis) In West-Central Utah, John Bradford Weston Aug 1968

Nesting Ecology Of The Ferruginous Hawk (Buteo Regalis) In West-Central Utah, John Bradford Weston

Theses and Dissertations

During the spring seasons of 1967 and 1968 ecological studies were made of nesting Ferruginou.s Hawks (Buteo regalis) in a 325 square mile area in west-central Utah. In the springs of 1967 and 1968 a systematic search was conducted throughout the study area for Ferruginous Hawk nests. When active nests were located they were kept under observation throughout the study. The density of nesting pairs in 1967 and 1968 ranged from 7 to 15.4 square miles per pair. An annual seasonal displacement was exhibited, with Ferruginous Hawks being present in the study area only during the nesting season, which lasted …


Life History And Ecology Of The Colorado Chipmunk (Eutamias Quadrivittatus Hopiensis), Carl Eugene Wadsworth May 1967

Life History And Ecology Of The Colorado Chipmunk (Eutamias Quadrivittatus Hopiensis), Carl Eugene Wadsworth

Theses and Dissertations

Observations of reproductive behavior, growth and development of the young, food habits, habitat preference, and daily and seasonal activity patterns of the Colorado chipmunk are presented for the first time. The breeding cycle is as follows: mating occurs in late February or early March; the young are born in early to mid-April and first appear above ground in May, but do not reach breeding age until the following spring. There is only one litter of young per year. The mean number per litter was 5.7 for three litters born in captivity. The sex ratio of the animals born in captivity …


Investigations Into The Spawning Ecology Of The White Bass Roccus Chrysops, (Rafinesque) In Utah Lake, Utah, Frédérick Vinvent May 1967

Investigations Into The Spawning Ecology Of The White Bass Roccus Chrysops, (Rafinesque) In Utah Lake, Utah, Frédérick Vinvent

Theses and Dissertations

Utah Lake, located in Utah County, north-central Utah, is one of the most important natural fishing lakes in the state. The spawning ecology of the white bass (Roccus chrysops) was studied in Utah Lake between 1964 and 1966. Gill nets and seining were the primary means of sampling. The spawning location was sampled every other day throughout the spring and early summer of 1966. Three major winter schooling areas were found: Provo Bay - Creer Access south to the mouth of Spanish Fork River, Lincoln Beach, and off Ludlow Barn. There appears to be extensive winter feeding and movement among …


Mammals Of The Lynndyl, Utah, Sand Dune Area : A Population Problem, Hugh J. Phillips Aug 1955

Mammals Of The Lynndyl, Utah, Sand Dune Area : A Population Problem, Hugh J. Phillips

Theses and Dissertations

The purpose of this study was to determine the kinds, population, distribution, and general habits of the mammals of the Lynndyl sand dune area. Only one article concerning the dunes was found, but several have been written on other dunes; however, none was found concerning mammals. Two quantitative studies, plot and transect trappings, were made and general observations were taken within the study area. Three types of plots; Russian thistle, juniper, and baren moving dunes; were trapped and revealed the following species: Dipodomys ordii, Peromyscus maniculatus, Reithrodontomys megalotis, Onychomys leucogaster, and Neotoma lepida. The most numerous animal in all plots …


Ecology Of Passerine Birds Wintering At Utah Lake, Joseph R. Murphy Jun 1951

Ecology Of Passerine Birds Wintering At Utah Lake, Joseph R. Murphy

Theses and Dissertations

During the period of October to April of the winter of 1950-51, an ecological study was undertaken of a population or passerine birds wintering in a segment of the Utah Lake Shore. Available winter weather data indicated that although such factors as precipitation, temperature, and wind may often be severe, they are not critical enough to prevent a fairly large population of passerine birds from spending the winter months in the study locale. Five fairly distinct plant communities can be recognized in the area. There is evidence which indicates that certain passerine bird species are especially dependent on a particular …