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open access

Ultraviolet Radiation Tolerance in High Elevation Copepods from the Rocky Mountains of Colorado, USA

Copepods in high elevation lakes and ponds in Colorado are exposed to significant levels of ultraviolet radiation (UV), necessitating development of UV avoidance behavior and photoprotective physiological adaptations. The copepods are brightly pigmented due to accumulation of astaxanthin, a carotenoid which has photoprotective and antioxidant properties. Astaxanthin interacts with a crustacyanin-like protein, shifting its absorbance from 473 nm (hydrophobic free form, appears red) to 632 nm (pr… more

Date: December 2011

Creator: Hudelson, Karista

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Evaluating the Habitat Requirements of the Golden Orb Mussel (Quadrula Aurea) for Conservation Purposes

Many freshwater mussels are imperiled, due to a number of interrelated factors such as habitat alteration, degradation of water quality, and impoundments. The Golden Orb mussel (Quadrula aurea, I. Lea, 1859) is endemic to the state of Texas and is currently a candidate for the endangered species list, as the number of known populations has been declining in recent years. Little is currently known about Q. aurea aside from basic distribution data. This study is focused on evaluating a combinatio… more

Date: May 2013

Creator: Hammontree, Sarah

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Exploring the Evolutionary History of North American Prairie Grouse (Genus: Tympanuchus) Using Multi-locus Coalescent Analyses

Conservation biologists are increasingly using phylogenetics as a tool to understand evolutionary relationships and taxonomic classification. The taxonomy of North American prairie grouse (sharp-tailed grouse, T. phasianellus; lesser prairie-chicken, T. pallidicinctus; greater prairie-chicken, T. cupido; including multiple subspecies) has been designated based on physical characteristics, geography, and behavior. However, previous studies have been inconclusive in determining the evolutionary h… more

Date: May 2013

Creator: Galla, Stephanie J.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Cloacal Microbiota of Captive-bred and Wild Attwater’s Prairie-chicken, Tympanuchus Cupido Attwateri

The Attwater’s prairie-chicken (Tympanuchus cupido attwateri; APC) is a species of grouse native to Texas coastal prairies and is on the critically endangered species list as a result of habitat destruction and overhunting. All of the current populations were captively bred and released into the wild. Survivorship for released APCs is very low, and individuals seldom survive to reproduce in the wild. One factor contributing to this may be an alteration in the gut microbiota as a result of ca… more

Date: August 2014

Creator: Simon, Stephanie E.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

The Effects of Inbreeding on Fitness Traits in the Critically Endangered Attwater’s Prairie-chicken

The goals of captive breeding programs for endangered species include preserving genetic diversity and avoiding inbreeding. Typically this is accomplished by minimizing population mean kinship; however, this approach becomes less effective when errors in the pedigree exist and may result in inbreeding depression, or reduced survival. Here, both pedigree- and DNA-based methods were used to assess inbreeding depression in the critically endangered Attwater’s prairie-chicken (Tympanuchus cupido … more

Date: August 2014

Creator: Hammerly, Susan C.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Improving Processing Efficiency for Forensic DNA Samples

The goal of this project was to reduce processing time for forensic DNA testing without incurring significant added costs and/or the need for new instrumentation, while still generating high quality profiles. This was accomplished by: 1) extraction normalization using the ChargeSwitch® Forensic DNA Purification Kit such that a small range of DNA concentrations was consistently obtained, eliminating the need for sample quantification and dilution; 2) developing fast PCR protocols for STR primer … more

Date: May 2015

Creator: Connon, Catherine Cupples

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Dynamics of Stream Fish Metacommunities in Response to Drought and Re-connectivity

This dissertation investigates the spatio-temporal dynamics of intermittent stream fish metacommunities in response drought-induced fragmentation and re-connectivity using both field and experimental approaches. A detailed field study was conducted in two streams and included pre-drought, drought, and post-drought hydrological periods. Fish assemblages and metacommunity structure responded strongly to changes in hydrological conditions with dramatic declines in species richness and abundance du… more

Date: August 2015

Creator: Driver, Lucas J.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Thresholds and Legacy Effects of Tropical Floodplain Fish Assemblages in Response to Flood Attributes

Natural flow regimes are critical for sustaining biodiversity and river integrity. Floods and droughts form an important component of river systems and control population sizes and species diversity across space and time. Modification of flow regimes, including disruption of the timing, magnitude and duration of flooding, is a global problem, and many new impoundments are planned for large river-floodplain ecosystems in the tropics. Flow modifications may cause dramatic non-linear responses … more

Date: December 2015

Creator: Hoeinghaus, Ana Paula Ferrari

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Biodiversity and Genetic Structure of Benthic Macroinvertebrates Along an Altitudinal Gradient: A Comparison of the Windhond and Róbalo River Communities on Navarino Island, Chile

Altitudinal gradients in Sub-Antarctic freshwater systems present unique opportunities to study the effect of distinct environmental gradients on benthic macroinvertebrate community composition and dispersal. This study investigates patterns in biodiversity, dispersal and population genetic structure of benthic macroinvertebrate fauna across an altitudinal gradient between two watersheds on Navarino Island in southern Chile. Patterns in diversity, density, evenness and functional feeding grou… more

Date: May 2016

Creator: Pulliam, Lauren

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

The Effects of Neonicotinoid Exposure on Embryonic Development and Organ Mass in Northern Bobwhite Quail

Since their emergence in the early 1990s, neonicotinoid use has increased exponentially to make them the world's most prevalent insecticides. Although there is considerable research concerning the lethality of neonicotinoids, their sub-lethal and developmental effects are still being explored, especially with regards to non-mammalian species. The goal of this research was to investigate the effects of the neonicotinoid imidacloprid on the morphological and physiological development of northern … more

Date: May 2016

Creator: Gobeli, Amanda

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

The Influence of Urban Green Spaces on Declining Bumble Bees (Hymenoptera: Apidae)

Bumble bees (Bombus spp.) are adept pollinators of countless cultivated and wild flowering plants, but many species have experienced declines in recent decades. Though urban sprawl has been implicated as a driving force of such losses, urban green spaces hold the potential to serve as habitat islands for bumble bees. As human populations continue to grow and metropolitan areas become larger, the survival of many bumble bee species will hinge on the identification and implementation of appropria… more

Date: May 2016

Creator: Beckham, Jessica L.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Informing Conservation Management Using Genetic Approaches: Greater Sage-Grouse and Galápagos Short-Eared Owls as Case Studies

Small isolated populations are of particular conservation interest due to their increased extinction risk. This dissertation investigates two small wild bird populations using genetic approaches to inform their conservation. Specifically, one case study investigated a Greater Sage-grouse (Centrocercus urophasianus) population located in northwest Wyoming near Jackson Hole and Grand Teton National Park. Microsatellite data showed that the Jackson sage-grouse population possessed significantly re… more

Date: May 2016

Creator: Schulwitz, Sarah E.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Mass Spectrometry-Based Identification of Ceramic-Bound Archaeological Protein Residues: Method Validation, Residue Taphonomy, and Prospects

Despite the variety of successful reports of the preservation, recovery, and identification of archaeological proteins in general, there are few positive reports regarding mass spectrometry-based identification of ceramic-bound proteins. In large part, this shortage is due to the lack of consideration for the unique taphonomic histories of such residues and, in general, methods development. Further, because negative results are rarely published, there is no baseline to which results can be comp… more

Date: December 2018

Creator: Barker, Andrew Lewis

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

The Bobwhite Population Decline: Its History, Genetic Consequences, and Studies on Techniques for Locating and Assessing Current Populations

The northern bobwhite (Colinus virginianus) population decline is a severe, rangewide phenomenon beginning >150 years ago and continuing today. In this investigation, I: 1. document the timeline of bobwhite population decline and unintended genetic consequences of attempted remedies, 2) develop a model useful for predicting possible locations of potentially sustainable bobwhite populations in semiarid rangeland in Texas and Oklahoma, and 3) examine the relationship between population monitoring… more

Date: May 2019

Creator: Whitt, Jeffrey Glen

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Peregrine Falcon (Falco peregrinus) Subspecies Phylogenomics Using Whole Genome Re-Sequencing

Peregrine falcon subspecies taxonomy is widely debated due to uncertainty in their evolutionary history and unresolved phylogenetic reconstruction using both morphological and molecular data. Previous genetic work has shown limited support for subspecies taxonomy largely as a result of molecular markers used, potential contemporary gene flow, incomplete lineage sorting, and ancestral polymorphisms. With the advent of next-generation sequencing, the cost of generating large amounts of sequence d… more

Date: December 2020

Creator: Meeks, Garrett W.

Item Type: Thesis or Dissertation

Partner: UNT Libraries

A Genetic Assessment of the Mating System of a Suburban Red-Shouldered Hawk Population in Southwest Ohio

Considering the high reproductive investment of the social male and the cost to the female of losing this benefit by soliciting copulations outside the social pair bond, it is expected that most raptor populations would exhibit low to no occurrence of extra-pair paternity (EPP). This holds true for the majority of raptor species studied to date with only one exception of an urban Cooper's hawk (Accipiter cooperii) study which reported an unexpectedly high extra-pair young frequency of 19.29%. I… more

Date: May 2021

Creator: Wrona, Anna Maria

Item Type: Thesis or Dissertation

Partner: UNT Libraries

A Test of the Female Mimicry Hypothesis in Painted Buntings (Passerina ciris)

While female mimicry and lower status signaling hypotheses of delayed plumage maturation have received much discussion in the literature, the experimental tests of these hypotheses have been infrequent. Those experimental tests often use a simulated intruder method with artificial model intruders rather than using live conspecific birds as intruders. Subadult male painted buntings (Passerina ciris) possess delayed plumage maturation where they appear visually identical to adult females during t… more

Date: May 2021

Creator: Gurley, Christine E

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Particulate Matter Accumulation to Urban Rock Pigeon (Columba livia) Feathers

This research investigates particulate matter (PM) deposition to rock pigeons (Columba livia) in urban environments within Denton County, Texas. Pigeon habitat was characterized within a 2-km radius at eight locations using the 2016 National Land Cover Database (NLCD). In summer 2020, feathers were sampled from 10 rock pigeons at two locations (n = 20) differing in degree of urban development. Birds were captured using walk-in funnel traps baited with bird seed. Based on molt pattern and app… more

Date: August 2021

Creator: Ellis, Jennifer Lee

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Sociality in Harris's Hawks Revisited: Patterns of Reproductive Output and Delayed Dispersal

In the lower Rio Grande Valley of south Texas, more than half the nesting groups of Harris's hawks (Parabuteo unicinctus) include at least one auxiliary group member in addition to a breeding pair. To provide further insight into cooperatively breeding raptors, I evaluated sociality in Harris's hawks through the dual benefits framework. I explored the formation, structure, and stability of cooperative group formation across a spatially variable study area, which includes high levels of urbaniza… more

Date: August 2021

Creator: Gibbons, Andrea L

Item Type: Thesis or Dissertation

Partner: UNT Libraries

Multiple Dimensions of Fish Functional Traits, Trait Relationships, and Associations with Community Structure and Dynamics

Trait-based approaches are useful in ecological research because of their potential ability to predict species responses from patterns present in the community and to infer mechanisms driving community assembly. Current approaches for fishes are lacking traits across all five fundamental niche dimensions (i.e. habitat, life history, trophic, metabolic and defense). This study quantified a broad range of fish functional traits across all five niche dimensions (commonly used traits and novel trai… more

Date: December 2021

Creator: Harried, Brittany Lee

Item Type: Thesis or Dissertation

Partner: UNT Libraries

open access

Space Use, Microhabitat and Macrohabitat Use of the Three-Toed Box Turtle (Terrapene carolina) in North Texas

Box turtle (Terrapene carolina) populations are steadily declining due their unique natural history, effects of climate change, and anthropogenic land use change. There is a need for updated information on box turtle space and micro and macro-habitat use to inform conservation efforts. This study used VHF radiotelemetry and GPS data loggers to examine box turtle space and habitat use in North Texas. Box turtle home range sizes averaged 6.6ha (range = 0.79 - 18.08, n = 23), and males (n = 9) had… more

Date: December 2022

Creator: Joseph, Sara A.

Item Type: Thesis or Dissertation

Partner: UNT Libraries