Browsing by Subject "Bats"
Now showing 1 - 20 of 26
Results Per Page
Sort Options
Item A PRELIMINARY INVESTIGATION INTO THE EXTENDED LIFESPAN OF BAT SPECIES: THE RELATIONSHIP BETWEEN THE EXTRACELLULAR MATRIX PROTEIN HAS2 AND LONGEVITY(2015-06-05) Denham, Aimee N.; Eoff, Shirley M; Ammerman, Loren K; Wilke, RussellInvestigation into physiological and molecular factors influencing the extended lifespan of long-lived species significantly contributes to clinical research aimed at improving the lives of humans. Bats have a significantly longer lifespan than other mammals of similar size and have not been recorded to develop cancer. The longevity and anti-cancer properties displayed by bats are features shared by another well-studied mammal, the naked mole rat. The naked mole rat is currently the longest living rodent with a maximum lifespan of over 30 years, and the species exhibits a novel anti-cancer mechanism involving the rapid production of hyaluronan. The naked mole rat has a unique sequence of hyaluronan synthase 2 (HAS2) which rapidly produces high molecular mass hyaluronan and contributes to reduced activity of hyaluronan degrading enzymes. Known genomic sequences of several species of bats were analyzed to determine differences in amino acid sequence for the HAS2 gene. Furthermore, RNA extracted from captured bats was subjected to real-time polymerase chain reaction to measure the expression level of HAS2 in various tissues. Genomic sequence analysis revealed that the bat species examined did not have the same amino acid substitutions in HAS2 as the naked mole rat. Real-time PCR trials using multiple primers designed to be specific for the HAS2 region resulted in inconclusive data. Therefore, gene expression analysis conclusions cannot be made until successful HAS2 primers are generated to amplify the HAS2 region. Further research needs to be directed towards determining alternative methods to study the longevity and anti-cancer mechanisms bats possess.Item Aspects and evolutionary implications of the brain anatomy of American leaf-nosed bats (Chiroptera, phyllostomatidae)(Texas Tech University, 1973-12) McDaniel, V. RickNot availableItem BASELINE ASSESSMENT OF THE BATS OF DEVILS RIVER STATE NATURAL AREA, DAN A. HUGHES UNIT, VAL VERDE COUNTY, TEXASAllred, Fredric Grayson; Dowler, Robert C; Ammerman, Loren K; Dixon, Michael T; Baker, Gary AA survey of bats was conducted from July 2013 to December 2014 to determine the species diversity and community composition at Devils River State Natural Area, Dan A. Hughes Unit, (DRSNA-DHU). Traditional and acoustic techniques for sampling bat species were used to detect species at six stationary sites and along a 12.9-km transect route across DRSNA-DHU. There were a total of 24 transects driven, 14 nights of stationary recording, and 10 nights of mist netting during the course of the study. Using information from acoustic recordings (analyzed manually and via software analysis) and mist net captures, 13 species were documented at DRSNA-DHU: Antrozous pallidus, Corynorhinus townsendii, Lasiurus borealis, Lasiurus cinereus, Lasionycteris noctivagans, Mormoops megalophylla Myotis velifer, Myotis yumanensis, Nycticeius humeralis, Nyctinomops macrotis, Parastrellus hesperus, Perimyotis subflavus, Tadarida brasiliensis.Item Chromosomal banding and phylogenetic relationships of vespertilionid bats(Texas Tech University, 1976-05) Bickham, John WNot availableItem Distribution of mammals in the davis mountains, texas and surrounding areas(Texas Tech University, 2008-08) DeBaca, Robert S.; Zak, John; Bravo, Jorge S.; Phillips, Carleton J.; Mulligan, Kevin; Bradley, Robert D.This project focused on the dispersal and distribution patterns of mammals in or near the Davis Mountains, Texas. Data were obtained from existing museum and literature records and from extensive field sampling of the region, which resulted in the acquisition of more than 2,000 museum specimens and related data (Appendix A). The purpose of this research was to investigate regional and local patterns of mammalian biodiversity as these relate to dispersal and distribution in montane ecosystems at a regional scale in the Trans-Pecos and at a local scale in and near the Davis Mountains. In the first chapter, paleontological data suggested that now isolated mountain ranges in the Trans-Pecos were once connected in a north-south network. Research in that chapter examined modern patterns of biodiversity in the mountains that could have resulted from patterns inherited from Pleistocene distributions and dispersal routes of species in mixed-conifer forests or piñon-juniper-oak woodlands. Evidence presented in chapter one indicated that connectivity to source areas could have improved dispersal opportunities through highland corridors and montane areas. The second research chapter evaluated an observed pattern of greater species richness at a middle elevation study site in the Davis Mountains that was about 15 percent the size of a larger study site in the highlands of this mountain range. Rodents were the focus of research to find a partial explanation for this pattern, in which a dispersal filter may have allowed dispersal of some species but hindered others along an elevational gradient from lowlands to highlands. This pattern suggested a decrease in the body size of a lowland group of species along this gradient in response to a substrate that becomes more unavailable to larger burrowing rodents. That pattern was not statistically significant, but an alternative investigation showed that the smaller mid-elevation site likely had greater habitat variety in comparison to the high elevation one, which could have provided more microhabitats for more species to coexist at the smaller, more diverse site. In the final research chapter, biodiversity patterns were investigated for bats in relation to broad-scaled ecological patterns and site-specific resource partitioning that could account for the observed spatial and temporal distribution patterns. Along an elevational gradient, five species were specific to a smaller series of elevations and habitat types; whereas, twelve species were either too rare to analyze or were widespread throughout the sampled array of environmental conditions. Five species also showed elevational segregation by sex, with females occupying a lower range of elevations than males, which was a surrogate measure of warmer macrohabitat utilization by females. Lastly the most prolific sampling site, a semi-perennial pool, was analyzed for temporal differences in its use by month and by time of night. The results showed that vespertilionid bats dominated use of this resource during mid-summer and during the first two hours of the night and that molossid bats dominated its use after the first two hours and during the latter part of the summer. This partitioning could result from the thermoregulation constraints of the main vespertilionid species that concentrated activity early in the evening and during the warmer months of the sampling period. In response to vespertilionid use and to prevent collisions, the fast-flying, less maneuverable molossid bats may avoid the area until use by other bats dwindles both during the night and warmer months of the season.Item Diversification of Old World Bats in Malaysia: an evolutionary and phylogeography hypothesis tested through the Genetic Species Concept(2008-05) Anwarali Khan, Faisal Ali; Baker, Robert J.; Wilson, Don E.; Kingston, TiggaObjectives of this study are to use a multifaceted approach to understand biodiversity and systematic implications through the interpretation of genetics and morphological datasets. Extensions to this approach use phylogenetic datasets to infer biogeographic scenarios of diversification, distribution and establishment of monophyletic evolutionary lineage. In Chapter II, I have first assessed the genetic variation within Malaysian bats collected during the TTU-UNIMAS Sowell Expedition in 2006 that are distributed in both Peninsular Malaysia and Borneo. Out of 16 species studied in this study, nine were identified with 5% or more genetic divergences indicating these phylogroups have been evolving independently for sufficient time to speciate by the Bateson-Dobzhansky-Mueller (BDM) model and therefore deserve further study to determine if specific status is merited. Further study on the taxonomy of these species within their geographic range indicates that some of these species merit a specific status. In some cases, they have been recognized previously as subspecies. Using this as the preliminary data, in Chapter III, I have further applied the genetic species concept to the genus: Kerivoula which was found to exhibit more than 10% genetic divergence within morphologically identified species. Based on the field keys available to us we concluded there were at least three species present in our field collection: K. pellucida, K. intermedia, and K. papillosa. However, based on subsequent morphometric and genetic analyses we identified six species within our collection: K. hardwickii, K. intermedia, K. lenis, K. minuta, K. papillosa, and K. pellucida. The utility of multiple data sets to assess poorly studied genera that show morphological similarities is explained.Item Early embryology of Macrotus waterhousii californicus, the California leaf-nosed bat(Texas Tech University, 1971-08) Bleier, William JosephNot availableItem Ecological characterization of bat species distributions in Michoacan, Mexico using a geographic information system(Texas Tech University, 2001-05) Wang, Hu GeorgeNot availableItem Ecomorphological structure of an Amozonian phyllostomid bat assemblage(2008-05) Arias, Lily Carola; Willig, Michael R.; Strauss, Richard E.; Salazar, JorgeMorphologically similar species likely consume similar resources and thus engage in competitive interactions. Competitive exclusion arises if a superior species causes on the inferior species to become locally extinct. Alternatively, the populations may diverge in morphology and resource use, thus reducing competition and allowing coexistence. If competition is not intense enough to produce such patterns, it may nonetheless, have an effect on the population sizes of competitors by a mechanism known as density compensation. This deterministic mechanism should be expressed as a positive association between abundance and ecomorphological dissimilarity. Bats are ideal organisms with which to test hypotheses related to coexistence, especially in the Neotropics, where they reach their highest levels of taxonomic and functional diversity. In terms of species richness and abundance, the ensemble of frugivorous species is most dominant in those Neotropical assemblages. Herein, I use simulation models to evaluate the presence of interspecific competition, expressed as density compensation, in structuring the frugivore ensemble of the Iquitos bat assemblage in three habitats that differ in degree of modification. In each habitat, analyses were conducted with respect to four different scenarios based on proximity of morphological neighbors. In each scenario, parametric and non-parametric analyses were conducted, using multivariate and univariate metrics. Evidence of density compensation was weak in primary and mixed forest, and nonexistent in secondary forest. As such, interspecific competition may not be the main factor structuring the ensemble of frugivorous bats in Iquitos. A state of non-equilibrium produced by deforestation, a combination of mechanisms that operate at local and regional scales such as source-sink dynamics, or particular characteristics of the natural history of the bat species are possible factors that might account for the absence of evidence for strong deterministic mechanisms.Item Ecomorphological structure of bat communities: alternative models and environmental gradients(Texas Tech University, 1996-05) Stevens, Richard DNot availableItem Effect of drought conditions on the diet of insectivorous bat species: a molecular diet studyKuzdak, Kaitlin Frances; Ammerman, Loren K; Dowler, Robert; Negovetich, Nicholas; Singg, SangeetaThe effect of drought on the diets of four insectivorous bat species (Antrozous pallidus, Myotis thysanodes, M. yumanensis, and Parastrellus hesperus) was assessed using cytochrome oxidase-I mini-barcodes organized into molecular operational taxonomic units. I hypothesized that there would be a significant difference between diet diversity in the drought and non-drought years, the species would feed more opportunistically during the drought year, per optimal foraging theory, and there would be low dietary overlap between years. Fecal samples were collected in Big Bend National Park (Brewster Co., TX). Diet diversity differed between years for all species, excluding A. pallidus. Diet diversity was greater during the drought year for A. pallidus and P. hesperus. Antrozous pallidus exhibited high dietary overlap (0.608) between the years and overlap values for the other three species was low (0.027 - 0.149). Overall, no two bat species in this analysis changed their diet similarly in response to drought conditions.Item Electrophoretic studies of relationships within the genus Artibeus (Chiroptera: Phyllostomidae)(Texas Tech University, 1982-08) Koop, Benjamin FNot availableItem Environmental Effects on the Habits of Myotis Velifer Incautus(Texas Tech University, 1961-08) Patterson, Irvin GaynelNot Available.Item Evolution in the family Pteropodidae (Chiroptera: Megachiroptera) as indicated by chromosomal and immunoelectrophoretic analyses(Texas Tech University, 1983-08) Haiduk, Michael WayneNot availableItem Evolutionary Implications of the G-Banded and C-Banded Karyotypes of Phyllostomatoid Bats(Texas Tech University, 1976-08) Patton, John CNot Available.Item Fine structure of implantation and the corpus luteum in the California leaf-nosed bat, Macrotus californicus(Texas Tech University, 1975-08) Bleier, William JosephNot availableItem The iconography of Moche winged figures(2010-08) Earle, Wendy Rose; Bourget, Steve, 1956-; Guernsey, JuliaThe Moche fineline painting corpus contains hundreds of representations of winged figures, but these have never been analyzed as a group. This thesis is an investigation of these winged figures, focusing on iconographic methodology. I have identified and categorized representations of birds (ducks, the Falconidae family, owls,hummingbirds, vultures and condors, etc.), mammals (bats) and insects (dragonflies) in the fineline paintings. Special attention has been paid to genus and family, including the attributes and behaviors of these animals. This has yielded several important observations about how the Moche represented and linked winged figures. In the second part of this thesis I use semiotic analysis to consider winged figures as symbols rather than naturalistic representations. I also examine anthropomorphic winged figures, and analyze the interpretive possibilities and the implications of these interpretations.Item Morphometric analysis of three subfamilies of the phyllostomatidae (Chiroptera): an evaluation of the M-statistic(Texas Tech University, 1980-05) McBee, KarenNot availableItem Morphometrics, cytotaxonomy, and evolution of mainland bats of the genus Macrotus (Gray)(Texas Tech University, 1973-08) Davis, Brent LeeNot availableItem Repetitive DNA in genome organization of phyllostomoid bats: test of a molecular model for chromosomal evolution(Texas Tech University, 1997-05) Maltbie, MaryMy study involves pairwise comparisons of species representing various higher taxa. The main comparison will be between Rhinophylla pumilio that has undergone karyotypic megaevolution (Baker and Bickham 1980, Baker and Bickham 1984), and Rhinophylla fischerae with very little karyotypic change. To make the test more robust, there are certain criteria that should be met. First, the comparisons should be between taxa where all other proposed variables casually related to chromosomal evolution are equivalent. For example, the two taxa should have equivalent effective population size, breeding structure, generation time and life history characteristics. The second criterion is that the taxon being compared should share a recent common ancestor. Finally, and critical to the comparison, is an appropriate cladistic analysis that will document primitive versus derived karyotypes (Baker et al. 1987) as well as where chromosomal evolution has occurred within each lineage.