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Theses/Dissertations

2019

Conservation

Articles 1 - 11 of 11

Full-Text Articles in Ecology and Evolutionary Biology

Geographic Population Structure And Taxonomic Identity Of Rhinichthys Osculus, The Santa Ana Speckled Dace, As Elucidated By Nuclear Dna Intron Sequencing, Liane Raynette Greaver Sep 2019

Geographic Population Structure And Taxonomic Identity Of Rhinichthys Osculus, The Santa Ana Speckled Dace, As Elucidated By Nuclear Dna Intron Sequencing, Liane Raynette Greaver

Electronic Theses, Projects, and Dissertations

Rhinichthys osculus (Cyprinidae), the speckled dace, is the most widely distributed freshwater fish in the western United States. The southern California populations of R. osculus are identified as the Santa Ana speckled dace (SASD), though the SASD has not yet been formally recognized as a distinct taxon. Current mtDNA analysis performed in the Metcalf Lab has shown a reciprocally monophyletic relationship among three California regions; southern, central coast, and Owens Valley. Similarly, microsatellite genotyping has shown significant levels of geographic population structure. The purpose of this study was to provide nuclear DNA sequence data to determine the taxonomic status of …

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Mixing It Up: The Impact Of Episodic Introgression On The Evolution Of High-Latitude Mesocarnivores, Jocelyn P. Colella Jul 2019

Mixing It Up: The Impact Of Episodic Introgression On The Evolution Of High-Latitude Mesocarnivores, Jocelyn P. Colella

Biology ETDs

At high latitudes, climatic oscillations have triggered repeated episodes of organismal divergence by geographically isolating populations. For terrestrial species, extended isolation in glacial refugia – ice-free regions that enable terrestrial species persistence through glacial maxima – is hypothesized to stimulate allopatric divergence. Alternatively, upon glacial recession, divergent populations expanded from independent glacial refugia and often contacted other diverging populations. In the absence of reproductive isolating mechanisms, this biogeographic process may trigger hybridization and ultimately, gene flow between divergent taxa. My dissertation research aims to understand how these episodic periods of isolation and contact have impacted the evolution of high latitude …

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Factors Affecting Nest Success Of Colonial Nesting Waterbirds In Southwest Louisiana, Karis A. Ritenour Jul 2019

Factors Affecting Nest Success Of Colonial Nesting Waterbirds In Southwest Louisiana, Karis A. Ritenour

LSU Master's Theses

As the coastline of Louisiana shifts with global climate change, subsidence, and accelerated sea level rise, important breeding islands for colonial nesting waterbirds are disappearing. In many recent studies flooding has been a leading cause of nest failure for a variety of species, especially those that nest on the ground. I examined the nest success of four species of colonial nesting waterbirds with various nesting strategies on Rabbit Island in southwestern Louisiana during 2017 and2018 by determining nest and fledging success. I monitored 855 nests, including 457 Brown Pelicans nests with an estimated hatch probability of 70%, 270 Forster’s Terns …

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Assessing Populations Of Eastern Brook Trout (Salvelinus Fontinalis) Above And Below Waterfalls In Mountain Streams Of Virginia, Hannah Eisemann Macmillan May 2019

Assessing Populations Of Eastern Brook Trout (Salvelinus Fontinalis) Above And Below Waterfalls In Mountain Streams Of Virginia, Hannah Eisemann Macmillan

Masters Theses, 2010-2019

Anthropogenically driven factors, such as increasing temperature and sediment in valley streams, acidification of mountain streams, and the introduction of non-native trout, are restricting habitat suitable for healthy populations of eastern brook trout (Salvelinus fontinalis) throughout their native Appalachian range. Brook trout are important as predators of insects in mountain streams and as a favorite of anglers. It is crucial that remaining populations in sustainable habitats be identified and preserved. Waterfalls are geologic knickpoints preventing base-level lowering that create unique, stable landscapes above them, which may alleviate the temperature-productivity/acidity “habitat squeeze” for populations of brook trout and could …

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Herpetological Assemblages In Tropical Dry Forests Of The Azuero Peninsula, Panama: An Evaluation Of Reforestation, Tyler Kovacs May 2019

Herpetological Assemblages In Tropical Dry Forests Of The Azuero Peninsula, Panama: An Evaluation Of Reforestation, Tyler Kovacs

Masters Theses, 2010-2019

Tropical dry forests are considered one of the most endangered tropical ecosystems making reforestation increasingly necessary to restore Panama’s unique ecoregion. The isolated dry ecoregion surrounding the Bay of Parita in Panama has a long history of deforestation and cattle grazing. Successful reforestation of this land is important to restore ecosystem health and biodiversity. In Panama, reforestation ranges from monocultures of exotic teak (Tectona grandis) to passive regeneration. Faunal recovery within these reforestation systems may vary due to different habitat characteristics. In this study, amphibian and reptile communities were compared in two types of reforestation systems and protected riparian forests …

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Biogeography Of Endemic Dragonflies Of The Ozark-Ouachita Interior Highlands, Wade Alexander Boys May 2019

Biogeography Of Endemic Dragonflies Of The Ozark-Ouachita Interior Highlands, Wade Alexander Boys

Graduate Theses and Dissertations

A common pattern across many taxonomic groups is that relatively few species are widespread while the majority are restricted in their geographic ranges. Such species distributions are used to inform conservation status, which poses unique challenges for rare or cryptic species. Further, priority status is often designated within geopolitical boundaries, which may include only a portion of a species range. This, coupled with lack of distributional data, has resulted in species being designated as apparently rare throughout some portions of their range, which may not accurately reflect their overall conservation need. The Interior Highlands region of the central United States …

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Reassessment Of The Extinction Risk Of The Neotropical Freshwater Crabs Of The Family Pseudothelphusidae, Ada Acevedo Alonso May 2019

Reassessment Of The Extinction Risk Of The Neotropical Freshwater Crabs Of The Family Pseudothelphusidae, Ada Acevedo Alonso

All NMU Master's Theses

The Neotropical region is one of the world’s biodiversity hotspots, and its freshwater crabs are notably diverse, and are represented by two families, Pseudothelphusidae and Trichodactylidae. This study focuses on this region’s highly diverse Pseudothelphusidae which includes 48 genera and 289 species. The 2008 IUCN global conservation assessment found 15.5% of the Pseudothelphusidae to be threatened with extinction and projected that in the worst-case scenario (if all of the Data Deficient species turned out to be threatened), the number of threatened species would be significantly higher. In the last decade several new species of pseudothelphusids have been described, and more …

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Integrating The Effects Of Biotic Interactions Into Models Of Species Distributions, Jamie M. Kass Feb 2019

Integrating The Effects Of Biotic Interactions Into Models Of Species Distributions, Jamie M. Kass

Dissertations, Theses, and Capstone Projects

The study of species geographic distributions and their environmental drivers has developed at a fast pace in recent years, owing to improvements in technology and data availability, and is increasingly relevant in this era of advancing global change. Currently, the field focuses heavily on a variety of techniques to statistically estimate species’ ranges I refer to collectively as species distribution models (SDMs). These models are now used across a wide range of disciplines, but inadequacies remain in implementation, methodology, and theory that are in need of new insight. In this thesis I will address two key shortcomings that require improvement …

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Evaluation Of Range-Wide Occupancy And Survey Methods For The Giant Kangaroo Rat (Dipodomys Ingens), Alyssa E. Semerdjian Jan 2019

Evaluation Of Range-Wide Occupancy And Survey Methods For The Giant Kangaroo Rat (Dipodomys Ingens), Alyssa E. Semerdjian

Cal Poly Humboldt theses and projects

Though habitat suitability and occupancy are often correlated, they cannot always be inferred from each other. Therefore, a solid understanding of both is essential to effectively manage species. Recent studies have assessed range-wide habitat suitability for the giant kangaroo rat (Dipodomys ingens; GKR), but data regarding occupancy is lacking in parts of its distribution. Satellite and aerial imagery were used to identify GKR burrows across their known range, producing a range-wide occupancy map and non-invasive survey methods including track plates, manned flight, unmanned aerial vehicle, and sign surveys were conducted to determine effective methods for monitoring GKR occupancy. …

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Cisco Science: Using Omics To Answer A Range Of Key Questions, Hannah Lachance Jan 2019

Cisco Science: Using Omics To Answer A Range Of Key Questions, Hannah Lachance

Graduate College Dissertations and Theses

Coregonines, including cisco (Coregonus artedi), kiyi (Coregonus kiyi), and bloater (Coregonus hoyi), are a focus for prey fish conservation and restoration efforts throughout the Laurentian Great Lakes. However, fundamental questions about coregonine ecology and genetics remain. For example, we know little about how the early life stages of coregonines respond to environmental change at either the genotypic or phenotypic level. We also have limited knowledge about how to identify different species at the larval stage and the genetic relationships among species, which makes the different species difficult to study at the larval stage. To increase the probability for success in …

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Competition Or Facilitation: Examination Of Interactions Between Endangered Sida Hermaphrodita And Invasive Phragmites Australis, Samantha N. Mulholland Jan 2019

Competition Or Facilitation: Examination Of Interactions Between Endangered Sida Hermaphrodita And Invasive Phragmites Australis, Samantha N. Mulholland

Theses and Dissertations (Comprehensive)

Virginia Mallow (Sida hermaphrodita) is a perennial herb of the Malvaceae family that is native to riparian habitats in northeastern North America. Throughout most of its geographical distribution however, it is considered threatened and only two populations are known from Canada. The biology and ecology of S. hermaphrodita are still poorly understood and although few studies have been performed to determine the factors that contribute to the species rarity, it is considered threatened potentially due to the loss of habitat caused by exotic European Common reed (Phragmites australis subsp. australis) invasion. Allelopathic and phytotoxic conditioning of …

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