Population Biology Commons^™

The Population Dynamics Of Two Rodents In Two Coastal Marshes In Virginia, Robert K. Rose, John A. March

Virginia Journal of Science

The communities of small mammals were evaluated for 13 months with capture-mark-recapture methods in two Spartina-Juncus marshes of the Atlantic coast in Northampton County, Virginia. Small mammals were trapped for three days each month using live traps placed on floats on two study grids. Two rodents were numerically dominant (~90% of small mammals) there: marsh rice rat, Oryzomys palustris, and meadow vole, Microtus pennsylvanicus. Monthly estimates of population density were greater for rice rats (peak: 45/ha) than for those of meadow voles (peak: 30/ha). Survival rates were generally low, especially for rice rats, indicating highly vagile populations. Both …

Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang

Scripps Senior Theses

Inbreeding involves the mating of closely related individuals at a higher frequency than at random; this can decrease the average fitness of populations and individuals by reducing the presence of heterozygotes and augmenting the expression of deleterious genes. Since marine invertebrates exhibit widespread dispersal, their potential for inbreeding is often disregarded. The adult sessile state of barnacles creates the potential for inbreeding as a result of necessary copulation between neighboring individuals. Depending on the degree of mixing that occurs during dispersal, closely related individuals or siblings may settle in close proximity, generating the possibility of kin aggregation and consequent inbreeding. …

A Study Of The Spatial Dynamics Of Some Introduced Avian Species In The Southwest Region Of Western Australia, Desiree L. Moon

Theses: Doctorates and Masters

The Southwest region of Western Australia is a recognised ‘biodiversity hotspot’, as it possesses high levels of biodiversity and endemism; it also holds a number of species threatened by habitat loss. The arrival of Europeans in the region wrought major changes on the natural landscape. Extensive tracts of bushland were cleared for housing, infrastructure, forestry, farming, and mining. Another challenge to regional biodiversity was the spread of exotic plants and animals (including birds); the latter provide the focus for the present study. The research examines four bird species that colonised the Southwest region following European settlement: Australian White Ibis (Threskiornis …

Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan

School of Biological Sciences: Faculty Publications

Soil microbial diversity is vast, and we lack even basic understanding of how this diversity is distributed ecologically. Using pyrosequencing and microarray methods, we quantified the structure of bacterial communities in two contrasting soils underlying Bornean rain forest (clay and sandy loam) that differ markedly in soil properties, aboveground tree flora, and leaf litter decomposition rates. We found significant soil-related taxonomic and phylogenetic differences between communities that, due to their proximity, are independent of climate. Bacterial communities showed distinct compositional and taxon-abundance distributions that were significantly correlated with the structure of the overlying tree community. Richness of bacteria was greater …

Climate And Vegetation Change In The Newberry Mountains, Southern Clark County, Nevada, Ross Joseph Guida

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ecological studies have shown worldwide that vegetation is being affected by climate change. Species are shifting to new elevations and physiographic positions to adapt to changes in their environment. More specifically, paleoecology studies in the Mojave Desert have shown shifting vegetation patterns in response to past warming and precipitation changes. Recent studies have shown mortality among desert plants related to extended drought and warming. However, few studies have shown how the geographic distribution of Mojave Desert species has changed during this most recent period of warming. This study addresses this gap in the literature by focusing on several plant species …

The Distribution And Life Cycle Of Alliaria Petiolate In Lincoln, Nebraska, Caleb Pharris

Department of Environmental Studies: Undergraduate Student Theses

Alliaria petiolata (Garlic Mustard) is a biennial alien invasive plant species of the Brassicacea family. It is responsible for displacing native plant species throughout North America and its management has proven to be extremely difficult. Recently several populations of Alliaria petiolata have been discovered in southwestern Lincoln, Nebraska. The spread of Alliaria petiolata is a concern for natural resource managers and the general public. Due to the difficulty of its control, Alliaria petiolata is capable of creating monocultures which diminish the aesthetic value of an ecosystem. While most commonly found in the understory of hardwood forests, it is capable of …

Time, Temperature And Species Interactions In A Duckweed–Herbivore Mesocosm, Ian Waterman

School of Biological Sciences: Dissertations, Theses, and Student Research

Species interactions within a community are impacted by a variety of abiotic factors. Temperature is known to alter population dynamics such that direct and indirect interactions between populations within a community are affected. Here I investigate the effect of temperature change on species interactions within a duckweed-herbivore mesocosm. Multiple communities were constructed, from a single population of duckweed, to two populations of duckweed consumed by aphids. In the one-predator two-prey web we predicted mutually positive indirect effects between duckweed populations during the first generation of growth. As aphid populations respond numerically to more abundant prey, mutually negative and asymmetric indirect …

Osteology, Natural History Notes, And Phylogenetic Relationships Of The Poorly Known Caribbean Frog Leptodactylus Nesiotus (Anura, Leptodactylidae), María Laura Ponssa, Michael J. Jowers, Rafael O. De Sá

Biology Faculty Publications

The Leptodactylus melanonotus group consists of 15 species, but references to skeletal characters are available for only three species: L. leptodactyloides, L. melanonotus, and L. diedrus. Leptodactylus nesiotus is a member of the melanonotus group known only from the type locality, Bonasse swamp, on the Southwestern peninsula of Trinidad, Trinidad and Tobago. This species has been categorized as vulnerable given its restricted distribution. Herein, we report the adult osteology of L. nesiotus, the skeletal characters are compared with the available data from other Leptodactylus species. A phylogenetic analysis recovers a paraphyletic L. melanonotus group relative to the L. …

Environmental And Endogenous Factors Influencing Emigration In Juvenile Anadromous Alewives, Benjamin I. Gahagan, Eric T. Schultz, Katie E. Gherard

EEB Articles

We analyzed juvenile anadromous alewife migration at Bride Lake, a coastal lake in Connecticut, during summer 2006 and found that migration on 24-hour and seasonal timescales was influenced by conditions of the environment and characteristics of the individual. To identify environmental cues of juvenile migration, we continuously video recorded fish at the lake outflow and employed information-theoretic model selection to identify the best predictors of daily migration rate. More than 80% of the approximately 320,000 juveniles that migrated from mid-June to mid-August departed in three pulses lasting one or two days. Pulses of migration were associated with precipitation events, transient …

Determination Of Dispersal Patterns Of The Small-Mouthed Salamander (Ambystoma Texanum) In Eagle Creek Park (Indianapolis, In), Stacey Diane Summitt

Undergraduate Honors Thesis Collection

Urbanization and the increasing threat of habitat fragmentation are contributing to the significant declines in amphibian populations world-wide. Ambystomatid species are particularly susceptible to habitat fragmentation because they migrate yearly across upland forests to their breeding sites. Habitat changes could be altering the genetic structure in these species; however few studies have focused on this topic and more generally, examined the dispersal patterns of Ambystomatids. In 2003, Clark, Cripe, and Stachniw conducted a study on “Metapopulation Structure of Ambystoma texanum in Eagle Creek Park (Indianapolis, IN) and the Potential for Gene Flow.” They hypothesized that distance limits the dispersal of …

Ecology And Morphological Comparison Between Rough Greensnakes (Opheodrys A. Aestivus) And Eastern Smooth Greensnakes (Opheodrys V. Vernalis) In West Virginia, Timothy Earl Baldwin

Theses, Dissertations and Capstones

Since 1971, documented Rough Greensnake (Opheodrys aestivus) occurrences in West Virginia have declined from approximately 100 to less than 20 occurrences in the last 10 years. In contrast to the decline of Rough Greensnakes in WV, Smooth Greensnake (O. vernalis) populations appear to be stable over the same period of time. Historic sites from the West Virginia Biological Survey were cross referenced with habitat descriptions in published literature to establish research locations. One hundred nineteen Rough and Smooth Greensnakes were measured for snout-vent length and total body length, and of these, 78 were measured in detail for external head morphology …

Das Arteninventar Der Avifauna Der Mongolei Während Einer Nord-Süd-Durchquerung 1997, Tobias Stenzel, Michael Stubbe, R. Samjaa, Annegret Stubbe, C. Dulamsuren

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Here we present a detailed report on bird biodiversity of ecosystems along a North-South transect through Mongolia in 1997whic h serves as a guideline for further research projects and training for students in all Mongolian vegetation zones from northern steppes to southern deserts.

Two hundred fifty-five bird species were observed between 21st of July and 10th of August 1997. The main study sites were located in the North the Selenge-Orchon-basin with meadows and dune woodlands 15 km southern from Suchbaatar, the Middle Gobi-Aimag with desert steppes and sajrs (covered with Ulmus pumila) and in the Bordzongijn-gobi in the South …

First Results Of Wild Ass Research In The South Gobi Aymag/Mongolia In 2003 And 2004, Annegret Stubbe, Michael Stubbe, N. Batsajchan, R. Samjaa, S. Doržderem

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The population of the Mongolian wild ass belongs to the nominate form Equus hemionus hemionus described by Pallas in 1775. This species is adapted to semidesert habitats in the Gobi region and is listed in the Red Book of Mongolia as well as on appendix I of the Washington Convention (CITES). Mapping of the northern border of the distributional range showed a remarkable decrease in size in comparison to the maps of Murzaev (1954) or Bannikov (1954). The pressure of civilization, settlements, motorization, and increasing numbers of domestic livestock in connection with the occupation of water resources and illegal hunting …

Beiträge Zur Ökologie Und Verbreitung Der Steppenwühlmaus Microtus Brandti Radde, 1861 In Der Mongolei = Ecology And Distribution Of The Steppe Vole Microtus Brandti Radde, 1861 In Mongolia, N. Dawaa, Michael Stubbe, Annegret Stubbe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Microtus brandti is one of the most important pest species of Mongolian rodents. Since the publication of Bannikov (1954) the area of expansion is increased, in the Archangaj-Aimag 200 km westward, in the Central Aimag 70 km to the North and in the north-eastern part of Dornogov’- Aimag about 110 km to the South. In years of gradation the plant cover was exterminated up to 100%. We can distinguish a zone of exposed harmfulness with a damage of 70-100%. In this region 16 great centers of infestation were listed. Between 1925 and 1985 six important calamities were noticed, in intervals …

The Distribution Of Macroinvertebrates In The Schoolcraft/Mississippi River-Lake System, Sarah Roley

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Apparent Interactions In Community Models: A Challenge For Theoretical Ecology, Peter J. Taylor

Working Papers on Science in a Changing World

The primary aim of this working paper is to challenge theoretical ecologists to clarify the intended status of any simple model that they use. If we restrict our attention to a subcommunity and treat it as if it were the full community, we need to invoke apparent interactions that incorporate the effects of unspecified or hidden variables as well as direct interactions. This position resembles that of previous discussions of apparent competition (Holt 1977), indirect effects (Lawlor 1979), and ecological abstraction (Schaffer 1981), but my definition of apparent interactions differs from those stated or implied by these authors. I advance …

The Relationship Between Mathematical Expression And Biological Insight: Some Issues In Community Ecology Modeling, Exemplified By The Logistic Equation, Peter J. Taylor

Working Papers on Science in a Changing World

The relationship between mathematical expression and biological insight is a central problem for modelers in community ecology. In this paper I distinguish three interpretations of this relationship: models as redescriptions as observations; models as capturing fundamental or generative biological relations; and models as an aid in exploring how to formulate the inquiries we put to nature. I aim to show that we can reduce ambiguities and confusion and ecological theory if we hold the different interpretations clearly in mind. I conclude by advancing an overall strategy of model building—de/composition—in which each of the interpretations plays a role. The logistic equation, …

Introduced Species And The Issue Of Animal Welfare, Michael Hutchins, Victoria Stevens, Natasha Atkins

Ecology Collection

Recently, considerable debate has been heard about the control or elimination of introduced or "exotic" animals on publicly held U.S. lands. Species introductions, whether intentional or unintentional, seem to be an inevitable result of human activities, but they may result in both economic and ecological problems: It has been estimated that over 90 percent of all such introductions have been harmful in some respect. Control of exotics can be accomplished through containment, shooting, poisoning, reintroduction of native predators, introduction of disease organisms, live capture and removal, and reproductive inhibition.

Those who must make decisions about the fate of introduced species …

The Microclimate, Ion And Water Balance Of Larval And Adult Ascaphus Truei Stejneger, Terry L. Mullen

All Master's Theses

The purpose of this paper is first to describe the microclimate occupied by larval and adult Ascaphus. This microclimate presents certain osmo- and iono- regulatory problems. The second purpose of this paper is to show how Ascaphus meets these osmo- and iono- regulatory problems.

An Annotated Check List Of The Land Mammals Of Curry County, Oregon, Paul Emerson Sherrell

All Master's Theses

Curry County merits study for several reasons. Very little work has been done on its mammalian fauna resulting in a limited number of specimens. In turn there is a sparsity of literature; that written is chiefly concerned with the genera Arborimus and Phenacomys. The location of the county places it in an area of scrambled geological history resulting in a diverse mixture of faunal and floral elements. Logging, agriculture, and grazing activities have altered and continue to alter the natural habitats. These interests have permanently changed both the floristic and faunistic composition of the county.

The aims of this study …