Terrestrial and Aquatic Ecology Commons^™

Ecotourism In Costa Rica: Environmental Impacts And Management, Emily Mckeone

Department of Environmental Studies: Undergraduate Student Theses

Globally we are witnessing growing environmental destruction, particularly to the natural resource bases of underdeveloped countries. If ecotourism can generate profits for local economies, while protecting and conserving the natural resource base of that community, it could be a strong alternative for numerous countries. Evidence suggests that the ecotourism industry has been expanding at a rapid rate in recent decades (Dasenbrock 2002). It is important to understand the positive and negative ecological impacts of the industry as this rapid growth rate continues.

The main objective of this study is to highlight the strengths and weaknesses of the ecotourism industry in …

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results.  In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks.  Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …

Multiple And Long-Term Effects Of An Introduced Predatory Crab, Catherine E. De Rivera, Edwin D. Grosholz, Gregory M. Ruiz

Environmental Science and Management Faculty Publications and Presentations

Despite the importance of invasions, few studies have explored their long-term consequences in marine systems or examined multiple types of population-level effects. Initial effects, however, may not persist over longer time frames; effects have been shown to wane in freshwater systems. We combined 14 yr of field surveys (1993 to 2006) with manipulative experiments to examine the potential for multiple effects of a nonindigenous crab Carcinus maenas on the native shore crab Hemigrapsus oregonensis over time in central California. H. oregonensis abundance was negatively correlated with C. maenas abundance. However, H. oregonensis abundance rebounded to pre-invasion levels once C. maenas …

Trophic Ecology Of Burrowing Owls In Natural And Agricultural Habitats And An Analysis Of Predator Communities Using Stable Isotopes Of Carbon And Nitrogen, Kathlyn Jean Mcvey

Boise State University Theses and Dissertations

Stable isotopes of carbon and nitrogen can provide powerful tools for estimating the trophic positions of animals and determining the source or the primary producer of a food web. I used stable isotopes analysis of carbon (δ¹³C) and nitrogen (δ¹⁵N) to investigate the trophic position of burrowing owls (Athene cunicularia) in agricultural and natural habitats and trophic relationships of a community of vertebrate predators in the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA), located in southern Idaho.

Burrowing owl populations have declined across much of North America owing to loss …

Use Of Shallow Estuarine Habitats By Nekton In The Mobile-Tensaw River Delta, Alabama, Lawrence P. Rozas, John F. Valentine, Charles Martin, Latina Steele

Biology Faculty Publications

We compared nekton density, composition, and biomass in fall 2009 and spring 2010 among three major habitat types (marsh, SAV=submerged aquatic vegetation dominated by Vallisneria americana, SNB=shallow nonvegetated bottom) commonly found throughout the Mobile-Tensaw River Delta (MTD) using 1-m2drop samplers. In the sampling design, habitat selection was based on vegetation composition. Sample locations (TR=Tensaw River, CB=Chocolatta Bay, and BC=Below Causeway) were selected based on their degree of tidal connectivity with the wider estuary (BC > TR > CB). Nekton distributional patterns varied among both locations and habitat types. Species richness was greater at BC than CB. The young of most …

Co-Development Of Biological Soil Crusts, Soil-Geomorphology, And Landscape Biogeochemistry In The Mojave Desert, Nevada, U.S.A. – Implications For Ecological Management, Amanda Jean Williams

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biological soil crusts (BSCs) are complex matrices of soil particles, mosses, lichens, and cyanobacteria that prevent erosion and influence water and energy balances, soil fertility, and vascular plant germination. The processes that form BSCs, the factors that control their distribution, and the ecosystem feedbacks that they sustain are poorly understood. This dissertation employed a novel interdisciplinary approach to address those research unknowns through investigations of the micromorphological structure, soil-geomorphic relationships, and biogeochemical feedbacks of BSCs in the Mojave Desert.

A micromorphological study of BSCs resulted in a succession model that illustrates how crust formative processes and structures change through time. …

A Study Of Habitat Selection And Fluctuating Asymmetry Of Amybstoma Tigrinum At Henderson Island Wildlife Management Area In Jefferson County Tn., Christopher Scott Ogle

Electronic Theses and Dissertations

Studies were conducted on a population of tiger salamanders, Ambystoma tigrinum, at Henderson Island Wildlife Management Area in Jefferson County, TN. Tests were conducted to locate the nonbreeding habitat of the salamanders and to detect any difference in fluctuating asymmetry (FA) between larval populations in a large, permanent pond and an ephemeral wetland. Drift fences were installed with pitfall traps at selected locations around each pond to determine nonbreeding habitat use by adults. Most adult salamanders were found using a blackberry (Rubus sp.) dominated old-field, a grassy field, and a shrub-grass mix field, which were all adjacent …

A Mark–Recapture Technique For Monitoring Feral Swine Populations, Matthew M. Reidy, Tyler A. Campbell, David G. Hewitt

United States Department of Agriculture Wildlife Services: Staff Publications

Techniques to monitor populations of feral swine (Sus scrofa) relative to damage control activities are needed on rangelands. Our objectives were to describe and assess a mark–recapture technique using tetracycline hydrochloride (TH) for monitoring feral swine populations. We established bait stations at study sites in southern and central Texas. During 1 d, we replaced normal soured corn bait with bait containing TH and counted the number of feral swine that consumed bait with observers. We conducted feral swine removal using box-style traps and helicopters, at which time we collected teeth for TH analysis. In southern Texas, we estimated …

Community Classification And Distribution Patterns Of Freshwater Mussels Of Strawberry River, Arkansas, Sujata Poudel, David E. Tenenbaum Ph.D, John L. Harris, Alan D. Christian Ph.D

Interdisciplinary Perspectives: a Graduate Student Research Showcase

The purpose of this study is to determine if there are distinct communities of freshwater mussels in the Strawberry River, Arkansas, and if environmental variables influenced these communities.  The Strawberry River watershed is located in the Ozark Mountains in northcentral Arkansas.  Based on previous studies of interior highland mussels, we expected distinct low, mid, and high order stream mussel communities. Mussels were surveyed from headwaters to mouth and resulted in 38 species from 57 sites.  Environmental variables of land cover, geology, soiltype, and drainage area were calculated at local and subwatershed scale using GIS. Mussel presence/absence and environmental variables were …

A Nebraska Bird-Finding Guide, Paul A. Johnsgard

Zea E-Books Collection

Nebraska lies in the transition zone between North American eastern and western avifaunas and is home to more than 200 breeding and 150 migrant species. This definitive guide to Nebraska birdwatching by the state’s preeminent ornithologist includes a county-by-county rundown of the best sites, a calendar of migrations, an annotated checklist of regularly occurring Nebraska birds, and recommendations for optical equipment, publications and reference materials, and contact information for conservation and ornithological groups. It features 48 maps as well as photographs and drawings by the author.

Paul Johnsgard, Foundation Professor Emeritus of Biological Sciences at the University of Nebraska–Lincoln, is …

The Aquarium Trade As An Invasion Pathway In The Pacific Northwest, Angela L. Strecker, Philip M. Campbell, Julian D. Olden

Environmental Science and Management Faculty Publications and Presentations

The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of …

Does Thermal Stress Cause Females Of The Plant Bryum Argenteum To Manipulate The Sex Ratios Of Their Offspring?, Elisha Rhodes, Lloyd Stark

Festival of Communities: UG Symposium (Posters)

About half of all moss taxa exhibit female-biased sex ratios, and bryophyte male rarity remains largely unexplained. One possible explanation is differential stress tolerance of spores due to maternal sporophyte manipulation during stress. To test this hypothesis, sporophytes of the species Bryum argenteum were subjected to thermal stress and observed for growth abnormalities and sporophyte abortions. Data display a correlation between increased temperature and increased sporophyte abortions as well as increased time to complete meiosis, possibly indicating decreased fitness. Continued global warming may create more stressful environments for sporophytes resulting in the elimination of males from local populations.

Wetland Management Guidelines For Nebraska's Wildlife Management Areas, Ted Lagrange, Randy Stutheit

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

Prior to Euro-American settlement, wetlands covered about 6% of the Nebraska landscape. Since settlement, the state’s wetlands have suffered serious decline. For example, approximately 90% of Rainwater Basin playa wetlands and 90% of the eastern saline wetlands have been destroyed or are highly degraded. Remaining wetlands are threatened by conversion to other uses (e.g. agriculture), invasive and aggressive vegetation, siltation, and lack of proper management. Only through sound management can the wetlands on our Wildlife Management Areas (WMA) be preserved for the citizens of Nebraska, as well as the native plants and wildlife dependent on them.

This section is directed …

The Future Of Blue-Winged And Golden-Winged Warblers In Connecticut, Robert A. Askins

Biology Faculty Publications

No abstract provided.

Review Of Nature's Ghosts: Confronting Extinction From The Age Of Jefferson To The Age Of Ecology. By Mark V. Barrow, Jr., Peter A. Bednekoff

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

The saving of bison occupies a central place in Nature's Ghosts, but Mark Barrow's chronicle extends over a century both before and after. The story starts with Thomas Jefferson and fossils that came to be recognized as mastodons, mammoths, and giant ground sloths. "Jefferson and most of his contemporaries were certain that the natural world was orderly, static, and new." In such a worldview, extinction was unthinkable. Fossil evidence plus the historical extinctions of dodos, moas, and great auks forced reconsideration.

This book ranges across centuries and continents, and only a few parts of it are explicitly about the Great …

Health And Fertility Implications Related To Seasonal Changes In Kidney Fat Index Of White-Tailed Jackrabbits In South Dakota, Dustin Schaible, Charles D. Dieter

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

White-tailed jackrabbit (Lepus townsendii) populations in the Northern Plains have been in a general decline for the past decade or longer. A suggested reason for this population decline was reduced body condition of individual jackrabbits due to habitat changes. In order to evaluate body condition, we determined the kidney fat index of 314 white-tailed jackrabbits harvested in 44 counties throughout South Dakota. We removed and weighed kidneys and all perirenal fat associated with the kidneys from collected jackrabbits. We measured kidney weight to determine times of high metabolic activity as indicated by an increase in mass. Body condition was …

Activation Of Amp-Activated Protein Kinase As An Early Indicator For Stress In The Lobster, Homarus Americanus, Stephanie Podolski

All Theses And Dissertations

Variations in water temperature, salinity, pH, and oxygen concentration are stressors that marine invertebrates face on a daily basis. Each of these physiological stressors creates a large cellular demand for energy. In mammals, energy metabolism is regulated by the enzyme AMP-activated protein kinase (AMPK), which is highly conserved during evolution. This project was designed to test the hypothesis that AMPK is present and activated by temperature, hypoxia, and anoxia stress in the lobster, Homarus americanus.

Animals were exposed to a rapid and progressive increase in temperature (6ºC per hour) beginning at 14 ºC. We measured lactate concentrations and AMPK …

Examining Trends In Taste Preferences, Market Demand, And Annual Catch In An Indigenous Marine Turtle Fishery In Southwest Madagascar, Kristin Jones

Independent Study Project (ISP) Collection

The worldwide exploitation of marine turtles has been common throughout human history, turtle products including carapaces for decoration and use, skin for leather, and eggs and meat for consumption. The hunting of marine turtles has long established economic importance among Madagascar's coastal inhabitants and is an activity traditionally associated with integral cultural and spiritual values. Due to overexploitation and a combination of relatively newer threats such as pollution, habitat loss, and incidental fisheries take, however, all marine turtle species in the Indian Ocean are considered to be endangered or critically endangered. Although Madagascar's marine turtles have been legally protected from …

Review Of The Ecology And Management Of Prairies In The Central United States. By Chris Helzer., David J. Gibson

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

This relatively short book is an informative and easyto- read account of the author's philosophy and advice on how to manage prairies in the Central U.S., an area corresponding to the eastern portion of the Great Plains where tall- and mixed-grass prairie occurred. With fragmentation and huge losses of this region's natural prairie habitat, there is a growing appreciation for active management of remnants and prairie restoration. This book provides an excellent introduction to this topic.

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending March 30, 2011, Margaret N. Rees

Limnological Studies

Project 1

• Technical assistance with the implementation of the Interagency Monitoring Action Plan (I-MAP) for Quagga Mussels is ongoing. During this quarter, analysis was completed for 13 juvenile/adult samples and analyses of the remaining samples are underway.
• Both research projects are well underway with 14 sample sets collected for Veliger abundance and settlement at different depths of Lake Mead and 12 samples collected for Growth of adult quagga mussels within Las Vegas Wash/Las Vegas Bay.

Project 2

• Annual summary sheets are under development for the topics listed within the Limnological and Aquatic Resource Monitoring and Research Plan for Lakes Mead …