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Full-Text Articles in Life Sciences

Factors Influencing Mortality Of Stocked Rainbow Trout In Black Hills Reservoirs, Charles A. Mordhorst Jan 2022

Factors Influencing Mortality Of Stocked Rainbow Trout In Black Hills Reservoirs, Charles A. Mordhorst

Electronic Theses and Dissertations

Because return to angler is an important outcome of put-and-take fisheries, understanding mortality of stocked Rainbow Trout is fundamental to managing these fisheries. Harvest rates of stocked Rainbow Trout Oncorhynchus mykiss in the Black Hills of South Dakota are believed to be below management objectives. Rainbow Trout not harvested by anglers are assumed to be lost to various sources of mortality, raising concerns about the cost of the Rainbow Trout stocking program relative to the benefit provided to anglers. (Simpson 2008). This study evaluated the factors influencing mortality of Rainbow Trout stocked into Black Hills reservoirs. We assessed the effects …


Eastern Redcedar (Juniperus Virginiana L.) Encroachment On South-Central South Dakota Rangelands: Impact On Plant Communities, Austin K. Domeier Jan 2022

Eastern Redcedar (Juniperus Virginiana L.) Encroachment On South-Central South Dakota Rangelands: Impact On Plant Communities, Austin K. Domeier

Electronic Theses and Dissertations

Grasslands historically covered 46 million km2 of Earth’s surface representing nearly 42% of the living vegetation. Encroachment of woody species onto grasslands and savannas is a widely researched global phenomenon, with eastern redcedar (ERC) (Juniperus virginiana L.) trees being the most prominent woody encroacher in the Northern Great Plains (NGP) due to the lack of prescribed fire and planted ERC escaping from shelterbelts. This encroachment poses a threat to native plant communities in terms of their reproduction, regeneration, and diversity. ERC are fierce competitors and can establish in most soil types, are drought tolerant, and prolific seed reproducers. These qualities …


Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura Jan 2022

Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura

Electronic Theses and Dissertations

The tallgrass prairie of North America has changed drastically since colonial settlement, with up to 99% of this region converted for agriculture and other land-uses. Concurrent with grassland conversion, grassland birds have experienced the most extreme, consistent, and widespread population declines of any avian guild. Agricultural lands in the U.S. Midwest were able to provide adequate habitat for several bird species until the 1950’s; however, altered and intensified management practices have degraded much of remaining suitable habitat and undermined ecosystem functions. Consequently, many grassland birds have been identified as Species of Greatest Conservation Need (SGCN) in many State Wildlife Action …


Living In A Gradient: The Influence Of Water Temperature Variation On Development, Settling Time And Survival Of Pallid Sturgeon Larvae In The Missouri River, Maria Elizabeth Erceg Jan 2022

Living In A Gradient: The Influence Of Water Temperature Variation On Development, Settling Time And Survival Of Pallid Sturgeon Larvae In The Missouri River, Maria Elizabeth Erceg

Electronic Theses and Dissertations

Pallid Sturgeon (Scaphirhynchus albus) are a federally endangered species experiencing widespread reproduction and recruitment failures. Recruitment failure is hypothesized to be caused by habitat modifications made to the Missouri River that disrupt connectivity and alter temperature profiles downstream of constructed dams. Hypolimnetic releases from Missouri River dams affect the temperature downstream, creating colder conditions during the downstream drifting phase for dispersing larvae. Understanding the influence of water temperature changes on larval development is crucial for recovery efforts. In this study, we evaluated the effects of water temperature daily heating rate on energy use, settling behavior, and growth rate of endogenously …


Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor Jan 2022

Post-Fledging Habitat Selection And Movements Of Juvenile Mallards In The Prairie Pothole Region, Cynthia E. Anchor

Electronic Theses and Dissertations

The Prairie Pothole Region (PPR) of North America provides critical habitat for waterfowl across life stages, but anthropogenic changes to the landscape have negatively impacted habitat quality for waterfowl. The mallard (Anas platyrhynchos) is abundant and socioeconomically valuable in the PPR, as it is a preferred target species of waterfowl hunters. Extensive research has evaluated breeding ecology of mallards in the PPR, but the period between juvenile mallards fledging and migrating has rarely been studied. The post-fledging ecology of juvenile mallards is a vital consideration for comprehensive waterfowl management. Further, juvenile mallards are a significant portion of hunter harvest at …


Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels Jan 2022

Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels

Electronic Theses and Dissertations

Conventional agricultural practices can have unintended consequences on the environment and wildlife. Insects and birds are declining at rapid rates around the world, and the current conventional agricultural paradigm is a major driver through habitat loss and the intensification of production. Invertebrates in agroecosystems provide services to both farmers and the rest of society. Regenerative systems may promote the functioning of an agroecosystem by influencing invertebrate abundance, diversity, and ecosystem services and mitigate bird and insect declines through conservation practices that increase soil health, reduce disturbances, and increase biological diversity. Here I address knowledge gaps of the effects of regenerative …


A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud Jan 2022

A Post-Pneumonia Epizootic Evaluation Of The Rapid City, South Dakota Bighorn Sheep Herd, Amanda N. Ensrud

Electronic Theses and Dissertations

Pneumonia is a major factor affecting populations of free-ranging bighorn sheep (Ovis canadensis) across western North America. Pneumonia can occur in large-scale epizootics, during which greater than half of the population typically dies. After these epizootics, surviving ewes continue to conceive and bear lambs. However, lamb recruitment may remain low due to periodic or annual pneumonia outbreaks causing high lamb mortality rates, sometimes greater than 90%. Our study focused on the Rapid City, South Dakota bighorn sheep (BHS) herd that has recorded pneumonia-induced population decline since 2009. The first objective was to improve lamb health and survival by identifying and …


Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield Jan 2022

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …