Other Ecology and Evolutionary Biology Commons^™

Pronghorn Survival And Resource Selection In Western Nebraska's Agriculturally Dominated Landscape, Katie Piecora

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska’s pronghorn population has been stable over the last decade, yet their presence on the landscape remains a contentious subject amongst private landowners. Conversion of grassland for crop production and increased anthropogenic activity has drastically altered pronghorn behavior throughout their current range, however basic ecology and resource use by pronghorn in Nebraska remains poorly understood. Establishing baseline population metrics and seasonal patterns of resource use for this population at the eastern periphery of the species range is critical to guide management actions. We deployed GPS collars on 110 adult pronghorn to quantify survival, mortality risk, and seasonal resource selection in …

Spatial And Temporal Distribution Of The Forensically Significant Blow Flies Of Los Angeles County, California, United States (Diptera: Calliphoridae), Royce T. Cumming

School of Natural Resources: Dissertations, Theses, and Student Research

Forensic entomology although not a commonly used discipline in the forensic sciences, does have its niche and when used by investigators is respected in crinimolegal investigations (Greenberg and Kunich, 2005). With many species of forensically significant insects being regionally specific, it is often difficult for forensic entomologists to as confidently translate regionally specific studies across drastically differing geographic regions (Brundage, et al., 2011).

The purpose of this study is to help create a better temporal and geographic distributional understanding of the blow fly species present in Los Angeles County, California, United States. Twenty-five locations from four ecoregions (coastal mountains, urban, …

Density And Mass Effect On The Development Of Phormia Regina, Brandon H. Strauss

School of Natural Resources: Dissertations, Theses, and Student Research

Forensic entomology is the application of the study of arthropods to the criminal justice system. This is primarily done through the development of a post mortem interval (PMI) based the insect evidence present. A practitioner must be able to determine the age of the insect through temperature data. One factor influencing the temperature dependent development is gregarious behavior. Current literature describes a faster development rate due to an increase in feeding efficiency and temperatures produced by this aggregate. However, there is very little literature defining a minimum number needed to induce this effect and little to none on it for …

The Biological Significance And Utility Of Feeding By Dermestes Maculatus, Braymond Adams

School of Natural Resources: Dissertations, Theses, and Student Research

With their efficient feeding habits and tolerance to very low moisture and humidity, beetles in the Family Dermestidae are especially adapted to variable environments and habitats. Dermestid cultures have been in use since 1922 in cleaning tissue and flesh from bones, and proven benefit in multiple fields, including zoology, ornithology, and forensics. Dermestid feeding behaviors when coupled with known life stage and insect succession information aids in providing significant entomological evidence. However, the feeding activities of insects, like those of vertebrate scavengers and predators, change remains and may leave artifacts that can be sometimes be difficult to assign to a …

Examining Patterns In Nest Predation Using Artificial Nests, Victoria L. Simonsen

School of Natural Resources: Dissertations, Theses, and Student Research

The use of artificial nests to study the predation of avian nests has faced disregard by ecologists due to inconsistencies found between the survival rates of real and artificial nests across studies and reviews. The negative perception of artificial nests providing an inconsistent assessment of survival has thus fostered the perception that artificial nests are a secondary option to be used to overcome logistical hurdles associated with achieving sufficient sample sizes in systems where study species are rare or elusive, or as merely a preliminary method to study predation across gradients. We argue that the greatest mistake ecologists have made …

Competition Among Three Forensically Important Blow Fly Species (Diptera: Calliphoridae): Phormia Regina, Lucilia Sericata, And Chrysomya Rufifacies, Amber Macinnis

School of Natural Resources: Dissertations, Theses, and Student Research

The aim of this study was to use interspecific competition between three species of blow flies (Diptera: Calliphoridae) to determine if interspecific competition might explain the successional patterns. A replacement series model was used for three species of blowflies: Phormia regina, Lucilia sericata, and Chrysomya rufifacies. A total of 20 maggots were used for each treatment and the proportion of each species was varied. The graphic evidence and the relative crowding coefficient of P. regina versus L. sericata indicated a significant competitive advantage of P. regina. One of the life history traits of L. sericata is that it oviposits on …

Gaur (Bos Gaurus) Abundance, Distribution, And Habitat Use Patterns In Kuiburi National Park, Southwestern Thailand, Supatcharee Tanasarnpaiboon

School of Natural Resources: Dissertations, Theses, and Student Research

Population status of gaur (Bos gaurus), a wild cattle, in most habitats where they are present, is still unknown. As the use of camera traps in wildlife studies are widespread, I developed photographic individual identification procedures and utilized encounter histories of gaur individuals from camera trap data to estimate gaur abundance and density using the spatially explicit capture-recapture analysis. The study was conducted at Kuiburi National Park, southwestern Thailand, comprised of dry evergreen forest, moist evergreen forest, and man-modified secondary forest during November 2013- January 2015. I conducted 71 direct observations in a savannah-like habitat area to observe …

Assessment Of Disturbance Effects Of An Existing Wind Energy Facility On Greater Prairie-Chicken (Tympanuchus Cupido Pinnatus) Breeding Season Ecology In The Sandhills Of Nebraska, Jocelyn O. Harrison

School of Natural Resources: Dissertations, Theses, and Student Research

Recent wind energy development in the Great Plains of North America has given rise to concerns of potential impacts on the greater prairie-chicken (Tympanuchus cupido pinnatus). Recent studies in fragmented landscapes have suggested greater prairie-chickens may avoid wind facilities, which may lead to habitat loss and negative impacts on reproduction and survival. But, it is unknown if there is a similar effect in contiguous grass landscapes. Thus, we investigated the effect of a pre-existing, 36-turbine wind energy facility on greater prairie-chicken nesting, brood-rearing, and spatial ecology in the Nebraska Sandhills. We captured and marked 78 female greater prairie-chickens …

Fear Effects On Pheasant Reproductive Ecology And A Curriculum To Teach Wildlife Habitat Selection, Jessica Laskowski

School of Natural Resources: Dissertations, Theses, and Student Research

Predation risk is an important source of selection that shapes prey density, distribution and abundance. The immediate impacts of predator consumption on prey populations are widespread and well-studied, and a growing body of research demonstrates immediate impacts of predator-induced fear (independent of prey mortality) on prey behavior, physiology and life-history expression. However, predation risk is often seasonally variable and while it is clear that consumption effects often carry over to influence prey population demography for years after predators have disappeared, the temporal carry-over effects of fear on prey populations remain largely unexplored. We assessed effects of fall hunting activity by …

Amphibian Occupancy And Functional Connectivity Of Restored Wetlands In The Missouri River Floodplain, Michelle L. Hellman

School of Natural Resources: Dissertations, Theses, and Student Research

Wetland decline may threaten many taxa including shorebirds, amphibians, and fish. As agencies increase restoration of wetland habitat, monitoring is crucial to inform the process. Permeable skin sensitive to water quality and biphasic life histories requiring both terrestrial and aquatic habitat make amphibians good indicators of wetland health. I modeled amphibian occupancy in restored Missouri River bends to determine habitat characteristics associated with the presence of amphibians.

Occupancy modeling acknowledges imperfect detection and allows the inclusion of detection covariates. To assess detection I examined two methods currently used to assess anuran occupancy in wetlands, aural anuran surveys and tadpole dip-netting. …

Stopover Decisions Of Migratory Shorebirds: An Assessment Of Habitat Use, Food Availability, Behavior And Phenology, Ryan Stutzman

School of Natural Resources: Dissertations, Theses, and Student Research

Habitat loss and alteration from land use change, species invasion, and more recently, climate change has reduced biodiversity and ecosystem function worldwide. Habitat decisions have important implications to individual fitness as well as population dynamics and community structure. Resource limitation, predation, competition, and unfavorable abiotic conditions all have the potential to influence survival and future reproductive potential. Understanding how changes to ecosystem structure and function impact species and populations of conservation concern is essential for conservation delivery to be effective. Similar to many migratory species, shorebird populations are declining worldwide and declines may be related to the loss of important …

Habitat Use And Abundance Patterns Of Sandhill Cranes In The Central Platte River Valley, Nebraska, 2003–2010, Todd Joseph Buckley

School of Natural Resources: Dissertations, Theses, and Student Research

The Central Platte River Valley (CPRV) in Nebraska is an important spring stopover area for the midcontinent population of sandhill cranes. Alterations to crop rotation and loss habitat in the CPRV pose a risk to the population. Personnel drove designated routes in the CPRV from 2003–2010 to record the presence of cranes in agricultural fields and estimate abundance. I developed and evaluated models to predict habitat use and flock sizes. Alfalfa was predicted to receive the highest use followed by corn, soybeans, winter wheat, grassland, and shrubland. Use of all habitats and flock size increased as field area increased. Flock …

Impact Of Alternative Range Management Systems On Grasslands In The Central Platte River Valley, Nebraska, Luis E. Ramirez

School of Natural Resources: Dissertations, Theses, and Student Research

Land management strategies can directly and indirectly affect plant assemblages and their behavior. Little research has been performed in south central Nebraska to quantify the effect of fire and grazing interactions on species composition, vegetation structure, forage quality, and potential cost associated with land management.

I evaluate the effect of season-long continuous, patch-burning, and rotational grazing approaches on vegetation and ranching costs to determine their value as conservation tools. This study includes data collected between 2007 and 2009 from grasslands in south central Nebraska. I found that land management influence plant assemblages by shifting communities when grazing and/or fire are …

Discontinuities: Predicting Invasions And Extinctions, Aaron Lotz

School of Natural Resources: Dissertations, Theses, and Student Research

In this dissertation, I explore multiple tenets of the textural discontinuity hypothesis, which states that hierarchical landscape structures with scale-specific pattern entrain attributes of animals inhabiting the landscape. Landscapes form hierarchies that are structured by vegetative, geomorphological and contagious disturbance processes. The spatial and temporal patterns inherent in landscapes reflect numerous processes, interacting on distinct scales, which shape the assembly of animal communities. Analysis of body mass patterns and functional group distributions has been suggested as methods to provide insight about these underlying hierarchical processes. Scientists have posited that species at the edges of body mass aggregations may be exposed …

Carbon Dynamics In A Phragmites Australis Invaded Riparian Wetland, Steven Walters

School of Natural Resources: Dissertations, Theses, and Student Research

Invasive plant species are widely recognized as a major threat to biodiversity and ecosystem stability. Wetland ecosystems tend to be much more susceptible to invasions because of their location on the landscape where water, nutrients, and the impacts of disturbances accumulate. Invasive plants have the ability to alter ecosystem processes and community/population dynamics. The ability of invasive plants to alter these processes can have profound economic consequences. In the United States, control of invasive wetland species alone costs approximately 155 million dollars annually. The state of Nebraska spends 2 million dollars annually controlling invasive plant species in the Platte River …