Ecology and Evolutionary Biology Commons^™

Lizard Communities In A Shifting Landscape: The Current State Of Insectivorous Lizard Communities In The Jornada Basin Between Grassland, Mesquite Dune, And Creosote Bush Habitats In A Semi-Arid Landscape Undergoing Shrubification, Julie Marie Schlichte

Open Access Theses & Dissertations

Lizard communities in arid lands can act as model systems of how diversity and abundance are impacted in the face of ongoing climate variability and change, as they are sensitive to shifts in precipitation, temperature, and changing vegetation structure. The main research question we hope to answer is how the community composition of lizards varies between dominant vegetation types (Mesquite dunes, grasslands, and Creosote Bush flats). Nine sites (3 of each dominant vegetation type) with 16 pitfall traps each (n = 144) were surveyed from June 2016 -- June 2017. 12 lizard species were captured, consisting of 923 total captures …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

The Importance Of Soil Carbon In Large-Scale Shrub Removal Practices In The Chihuahuan Desert, Kathleen Schaeffer

Open Access Theses & Dissertations

Shrub encroachment is a worldwide phenomenon that affects multiple biomes at different ecological and anthropogenic levels. In dryland ecosystems, shrub encroachment is a noted concern amongst land managers, as it can lead to a loss of soil resources and biodiversity. To mitigate the negative effects of shrub encroachment in Drylands, land managers can implement large-scale shrub removal practices. These land restoration practices can shift landscapes to novel ecosystems, where resulting plant communities can vary following treatments. Grass recovery or increasing herbaceous cover is often a primary goal of these treatments, however predicting which sites may show higher grass responses to …

Linking Decomposition Reactions In Arctic Soils To Microbial Enzyme Production, Jane Karen Martinez

Open Access Theses & Dissertations

Microbial processes such as soil enzyme production are a major driver of decomposition and a current topic of interest in arctic soils due to the effects of climate warming. Despite the advances in understanding soil enzymes, there are still knowledge gaps regarding the role of enzymes in decomposition. In this dissertation, I addressed three of those gaps in the following chapters: (Ch.2) to explore the location of enzymes within the soil matrix, (Ch.3) to identify peptides matched to soil enzymes produced by microorganisms for organic matter decomposition, and (Ch.4) understand the longevity of enzymes in the soil after microbial production. …

Landscape Genomics Of The Tussock Cottongrass (Eriophorum Vaginatum) And The Dwarf Birch (Betula Nana) In North Central Alaska, Elizabeth Stunz

Open Access Theses & Dissertations

Global climate change has resulted in geographic range shifts of flora and fauna at a global scale. Extreme environments, like the Arctic, are seeing some of the most pronounced changes. This region covers 14% of the Earthâ??s land area, and while many arctic species are widespread, understanding ecotypic variation at the genomic level will be important for elucidating how range shifts will affect ecological processes. Increase in shrub cover is a major effect of ongoing climate change in arctic tundra ecosystems. The relative increases in abundance and cover of shrub species such as birch, willow, and alder (Betula, Salix, and …

Chihuahuan Desert Rock Pool Community Assemblages: Patterns Of Taxonomic Diversity, Joseph Lee Mcdaniel

Open Access Theses & Dissertations

As climate change continues to become more prevalent, increasing temperatures and altering precipitation patterns will disrupt the environmental balance of ecosystems and spark the imminent threat of a 6th mass extinction event. Many researchers believe this has already begun, as losses for numerous taxonomic clades have been well documented; however, the loss of invertebrates is still unknown and may be much more severe than those of other animal clades. A significant factor contributing to the shortfall of invertebrate biodiversity loss is rooted in the lack of understanding of the diversity and distribution of these animals. There is still much to …

Analyzing Genetic Variation Of The Tussock Cottongrass Among Ecotypes Along A Latitudinal Gradient Through Transcriptomics, Carmen Webster

Open Access Theses & Dissertations

The Arctic is seeing some of the most extreme effects of climate change that induce environmental pressures, including warmer temperatures and longer growing seasons. Due to this, taxa may need to adapt or migrate in order to survive. The long-lived tussock cottongrass, Eriophorum vaginatum, is a foundation species in the Arctic, and little is currently known about the genetic constraints that could be playing a role in how this species will respond to the changing climate. Specific gene families that play an important role in signaling genetic pathways related to plant phenology and response to environmental stress are likely to …

Strike-Induced Chemosensory Searching, Kleptoparasitism, And The Possibility Of Chemical Crypsis In Rattlesnakes, Mark Scott Teshera

Open Access Theses & Dissertations

Predator-prey interactions shape the natural histories of both species as each tries to adapt and counter-adapt to the tactics of the other. This important evolutionary dynamic is crucial for ecosystem formation and stability. Predation is a fundamental aspect of life for most organisms, and many venomous reptiles, particularly ambush-foraging viperids, have evolved a prey-acquisition strategy that is highly effective in immobilizing prey, while minimizing possible counterattacks. Best studied in rattlesnakes, this remarkable behavioral sequence is known as strike-induced chemosensory searching (SICS). Throughout decades of research, the body of SICS literature on venomous reptiles has become fairly robust, particularly in rattlesnakes. …

Behavioral Ecology Of A Desert Ambush Predator: Assessing Movement Patterns, Habitat And Microhabitat Use, And The Innate Feeding Response Of Eastern Black-Tailed Rattlesnakes (Crotalus Ornatus) In The Northern Chihuahuan Desert, James Emerson

Open Access Theses & Dissertations

Research on the ecology and evolution of rattlesnakes has been sporadic over the past 80 years, but has seen recent expansion into the diverse fields of physiology, physiological ecology, life history, behavioral ecology, ethology, reproductive biology, chemical ecology, venom biochemistry and medicine, conservation, and many other subdisciplines. The development of small, implantable VHF radiotransmitters in the 1980s revolutionized research in the field of behavioral ecology for rattlesnakes, which are uniquely suited for radiotelemetry studies because they possess several morphological, physiological, and behavioral characteristics that are unique among terrestrial vertebrates. The widespread application of radiotelemetry by the mid-1980s advanced the model …

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …

Movement Ecology Of A Cryptic Ambush Predator: Integrating Radio Telemetry And Tri-Axial Accelerometry To Evaluate Spatial Strategies And Activity Patterns By Western Diamond-Backed Rattlesnakes (Crotalus Atrox), Dominic L. Desantis

Open Access Theses & Dissertations

An animal's decision to move from one location to another within its environment is determined by a complex blend of internal and external factors. Teasing apart the relative roles of specific variables in this web of interacting mechanisms has been a long-standing challenge in animal movement ecology. Historically, this problem was viewed as a sort of black box for which a myriad of methodological limitations precluded rigorous study. Recently, a diversity of animal-borne transmitters and dataloggers (i.e., bio-loggers) have circumvented many of these traditional limitations and transformed field studies of animal movement, behavior, and physiology - in some cases, allowing …

Hidden Diversity In Aquatic Habitats: Lessons From Cryptic Species In Microscopic Invertebrates (Rotifera), Azar Kordbacheh

Open Access Theses & Dissertations

Speciation is a continuous and adaptive process by which lineages are diverged into multiple groups, and species are the product of this process. Taxonomy is the study of relationship between organisms, classifying and naming them, and one of the taxonomical challenges is delimiting species boundaries. Species delimitation can be controversial because biologists do not agree on species concepts and approaches for defining species boundaries. One of the well-known species concepts is the Biological Species Concept that requires studying reproductive barriers among populations. Investigating strength of reproductive isolation among populations is not always practical in the wild. Therefore, many biologists have …

Grasshopper (Orthoptera: Caelifera) And Plant Community Relationships On Indio Mountains Research Station, Hudspeth County, Texas, Sara Ebrahim Baqla

Open Access Theses & Dissertations

An ecogeographic analysis of a grasshopper survey was conducted at eight sites on Indio Mountains Research Station (IMRS) in the Chihuahuan Desert during September 2014 through December 2015. Five sites contained ephemeral water sources (earthen tanks), one had perennial water (spring system), and two were open desert. A total of 23 grasshopper species were identified, and six of those were new records for the property. The most species rich site was Echo Tank, with 14 grasshopper species. A UPGMA dendrogram showed Red Tank and Rattlesnake Tank, both wetland sites, to be the most similar (CBR = .84). A poisson model …

Ecological Features Of The Greater Earless Lizard, Cophosaurus Texanus, (Squamata: Phrynosomatidae) On Indio Mountains Research Station, Hudspeth County, Texas, Gabriela Franco

Open Access Theses & Dissertations

626 Cophosaurus texanus were captured on regular trips to Indio Mountains Research Station in Hudspeth County, Texas from August 2010 to November 2014. Mark-recapture methods using 81 pitfall traps and toe-clips for identification allowed for analyses of long-term trends. 291 adult females, 315 males, and 20 unsexed juveniles were recorded. A total of 180 independent recapture events were documented over the study period (44% females; 55% males). The greatest numbers of C. texanus were collected in 2011 (234), which was also the driest year of the four (6.77 cm), whereas 2014 was the wettest (34.95 cm), but had the second-most …

Systematics Of The African River Frog Genus Amietia (Anura: Pyxicephalidae) From Eastern Democratic Republic Of The Congo, Thornton Robert Larson

Open Access Theses & Dissertations

The African river frog genus Amietia is found near rivers and other lentic water sources throughout central, eastern and southern Africa. Because the genus includes multiple morphologically conservative species, taxonomic studies of river frogs have been limited. We sampled 49 individuals of Amietia from multiple localities in and near the Albertine Rift (AR) of Burundi, Democratic Republic of the Congo and Uganda. We utilized single-gene (16S) and concatenated (12S, 16S, cytochrome b and RAG1) gene-tree analyses and coalescent species-tree analyses to construct phylogenetic trees. Two divergence dating approaches were used in BEAST, including secondary calibration points with 12S, 16S and …

Phylogeny And Systematics Of Panaspis And Afroablepharus Skinks (Squamata: Scincidae) In The Savannas Of Sub-Saharan Africa, Maria Fernanda Medina

Open Access Theses & Dissertations

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. The allocation of these genera was frequently rearranged in the 20th century based on morphology, ecology and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species that have highly conserved morphology, which poses a challenge for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 91 Panaspis and Afroablepharus samples from various localities in eastern, central and southern Africa. Concatenated gene-tree and divergence dating analyses were conducted to infer phylogenies and …

Thermal Ecology Of Urosaurus Ornatus (Ornate Tree Lizard), In The Northern Chihuahuan Desert On Indio Mountains Research Station, Texas, Julia Sandoval Alva

Open Access Theses & Dissertations

The main goal of this study was to determine the thermal ecology of the small tree lizard Urosaurus ornatus in a Chihuahuan Desert landscape. The study site was located at Indio Mountains Research Station (IMRS), Hudspeth County, Texas. We obtained body temperature (Tb) data on 385 lizards collected from April 2007 to June 2014 during the active period using a cloacal thermometer. Additionally, we recorded air temperature (Ta) and substrate temperature (Ts) of lizard microhabitats at the time of capture, and the operative temperature of lizard models left in the sun and shade from May to September 2014. My results …

Revision Of The Ant Genus Bothroponera (Hymenoptera: Formicidae: Ponerinae) From The African Continent, Abdulmeneem Joma

Open Access Theses & Dissertations

Abstract (chapter 1)

The Afrotropical ants in the genus Bothroponera include the pumicosa, talpa, and sulcata species complexes. Species in the Bothroponera pumicosa species complex are mainly distributed in the southern part of Africa. This group of ants is characterized by having coarsely foveolate sculpture and by having either a raised a "v" or "u" shaped anterior medial area of the clypeus (anteclypeus), with or without a carina. The mandibles have 7 teeth in the majority of species and 8 teeth in the others. The eyes are relatively large. The scapes usually do not reach the posterior lateral corner of …

A Revision Of The New World Ants Of The Genus Platythyrea Roger 1863 (Hymenoptera: Formicidae), Mayra Janett Leyva

Open Access Theses & Dissertations

The genus Platythyrea consists of arboreal ants that are rarely collected. The genus was last partially revised in 1975 by Brown. Since that revision two additional species have been described. The New World genus Platythyrea now includes nine species: P. angusta Forel, P. exigua Kempf, P. lenca De Andrade, P. pilosula (Smith), P. prizo Kugler, P. punctata (Smith), P. sinuata (Roger), P. strenua Wheeler and P. zodion Brown. A new key, illustrations, diagnoses and distributions of the ants are provided.

International Polar Year (Ipy) Back To The Future (Btf): Changes In Arctic Ecosystem Structure Over Decadal Times Scales, Sandra Villarreal

Open Access Theses & Dissertations

Arctic vegetation communities are responding to climate warming through shifts in species composition and diversity but most observations have been made over relatively short time frames, and/or in association with experimental manipulations. Because vegetation plays a key role in regulating ecosystem productivity, nutrient cycling, surface energy budgets, and trophic interactions in the Arctic, there is a need to better understand shifts in tundra vegetation communities over decadal time scales. Understanding these shifts and their impact on ecosystem structure and function in the Arctic has important implications for predicting the future state of both the Arctic and the Earth System. Long …

Genetic Diversity In Populations Of Epiphanes Chihuahuaensis (Rotifera: Monogononta) In The Northern Chihuahuan Desert, Diego E. Reyes

Open Access Theses & Dissertations

1. Cryptic speciation in zooplankton is a phenomenon that has been recently gaining much attention. This is due in part to advances in molecular techniques which help in the identification of morphologically indistinct species. Organisms that have been traditionally believed to have cosmopolitan distributions are being found to be composed of cryptic species complexes with high levels of genetic divergence among lineages.

2. Epiphanes chihuahuaensis is a member in the Epiphanes senta species complex. In a previous study by Schröder & Walsh (2007), genetic data, along with morphological and reproductive isolation data were employed to help delineate four species within …

Comparison Of Ectoparasitic Mite Loads Between Gonochoristic (Aspidoscelis Marmorata) And Parthenogenic (A. Tesselata) Syntopic Whiptail Lizards (Teiidae) From The Northern Chihuahuan Desert Of Trans-Pecos, Texas, William Dawson Lukefahr

Open Access Theses & Dissertations

The objective of this study was to compare the ectoparasitic loads between two syntopic whiptail lizard species (Teiidae) that differ in their reproductive modes; Aspidoscelis marmorata (bisexual) and A. tesselata (unisexual). The study site was located on Indio Mountains Research Station (IMRS) in a Chihuahuan Desert Scrub landscape in Hudspeth County, Texas. Previous studies conducted at IMRS showed the two species having similar diets, morphology, and reproductive characteristics, but fluctuated in nematode loads. No comparative study of ecotoparasitic mites (Eutrombicula alfreddugesi) between the two species has ever been done.

Aspidoscelis marmorata (n = 141) and A. tesselata (n = 144) …

Spatial Ecology Of The Trans-Pecos Rat Snake (Bogertophis Subocularis) In The Chihuahuan Desert Of Trans-Pecos Texas, Arturo Rocha

Open Access Theses & Dissertations

The Trans-Pecos Rat Snake (Bogertophis subocularis) is a medium to large rat snake that occurs from south-central New Mexico, south-central Texas, down into the north-central and northeastern states of Mexico. There is paucity in the ecology of B. subocularis to date. Some North American colubrid snakes, such as Thamnophis sirtalis, are the most represented species in thermal ecology and life history studies in all reptiles. There is nothing known on the winter ecological aspects of this species, and very little information regarding its overall ecology. The goal of this study is to determine home range, movement patterns, habitats and utilization …

Systematics Of Leptopelis (Anura: Arthroleptidae) From The Itombwe Plateau, Eastern Democratic Republic Of The Congo, Francisco Portillo

Open Access Theses & Dissertations

Leptopelis, a genus of Central African treefrogs, includes 51 species that live in tropical forests and savannas. Currently, only two species of Leptopelis are known from the poorly explored Itombwe Plateau in eastern Democratic Republic of the Congo (DRC). Itombwe is renowned among conservationists for its rich and endemic amphibian fauna, including: Xenopus itombwensis, Chrysobatrachus cupreonitens, Laurentophryne parkeri, Hyperolius leleupi and at least three species of Arthroleptis. Evolutionary relationships of Itombwe Leptopelis were examined by sequencing two mitochondrial genes (16S: 557 bp [base pairs], cyt b: 620 bp) and one nuclear gene (RAG1: 761 bp). Results recovered strong support for …

Ecology Of The Rock Rattlesnake, Crotalus Lepidus, In The Northern Chihuahuan Desert, Vicente Mata Silva

Open Access Theses & Dissertations

The Rock Rattlesnake, Crotalus lepidus is a small species that is found from southern Arizona, southern New Mexico, and southern Texas, in the U.S., into northern Mexico. To date, little is known about the ecology of this species. Ecological information is becoming desperately needed for supporting the conservation and protection of species living in fragile environments such as the Chihuahuan Desert amid current local and global threats (e.g., habitat destruction and modification, urban development, and climate change). Although rattlesnakes spend a significant amount of time underground while overwintering, little is known about the physiology and behavior of these organisms during …

Phylogeography Of Northern Populations Of The Black-Tailed Rattlesnake (Crotalus Molossus Baird And Girard, 1853) With The Revalidation Of C. Ornatus Hallowell, 1854, Christopher Anderson

Open Access Theses & Dissertations

The black-tailed rattlesnake (Crotalus molossus Baird and Girard, 1853) is a wide-ranging species complex with representatives from the southwestern United States through the highlands of central and southern Mexico. The systematics of this group has received little attention and in the past six decades only two taxonomic revisions have been proposed (the transfer of C. basiliscus oaxacus to C. molossus and the elevation of C. m. estebanensis to full species). However, a recent revision of the Neotropical rattlesnakes (C. durissus and C. simus) recovered a polyphyletic C. molossus. Sequenced data were obtained from three mitochondrial genes …

Ecogeographical Distribution Of The Herpetofauna Of Indio Mountains Research Station, Hudspeth County, Texas, Ross Owen Couvillon

Open Access Theses & Dissertations

Indio Mountain Research Station (IMRS) in Trans-Pecos, Texas is dominated by Chihuahuan Desert scrub vegetation, but a complexity of plant communities exist relating to elevation, slope, and geologic formations. Surrounding the Indio Mountains are desert grasslands with various desert scrub associations. This mosaic of habitats forms a unique assemblage of amphibians and reptiles. The goal of this study was to determine if the current number of amphibians, turtles, lizards, and snakes (43 species) of IMRS was accurate and identify which biotic and abiotic factors define the distribution of these species. Records from the last approximately 25 years were used to …

Systematics Of The Genus Ptychadena Boulenger, 1917 (Anura: Ptychadenidae) From Democratic Republic Of The Congo, Katrina Marie Weber

Open Access Theses & Dissertations

This thesis increases the scope of previous phylogenetic analyses that revealed high levels of genetic differentiation within the anuran genus Ptychadena. Herein, I increase sampling of Central African populations of Ptychadena by over six times to examine their relationships to other African populations and to search for cryptic species. This study represents the most comprehensive molecular phylogeny of Ptychadena to date. A total of three mitochondrial (12S, 16S, and cyt b) and two nuclear (RAG1 and rhodopsin) genes were sequenced for 67 specimens of Ptychadena. Maximum parsimony, maximum likelihood, and Bayesian analyses were conducted. These analyses revealed …