Terrestrial and Aquatic Ecology Commons^™

The Effects Of Scour And Marginal Inundation On Trinity River Invertebrate Biomass And Density With Potential Implications For Juvenile Salmonid Food Resources, Benjamin King

Cal Poly Humboldt theses and projects

Regulated flow releases on the Trinity River in northern California have shifted the timing of high flows from winter to late spring and reduced their magnitude. The timing and extent of scour from high flow events and the timing and duration of marginal (bankside) habitat inundation has shifted as a result. Literature is sparse regarding the effects of these hydrologic alterations on Trinity River benthic macroinvertebrate (BMI) communities, an important food resource for juvenile salmonids. In the 2023 water year, a wet winter coupled with additional flow releases from Lewiston Dam provided the opportunity to analyze the impact of scour …

Effects Of Habitat Selection And Individual Quality On The Reproductive Success Of Barn Owls (Tyto Furcata), Jaime E. Carlino

Cal Poly Humboldt theses and projects

The hypothesis of adaptive breeding habitat selection proposes congruence between the evolved selection of habitats and fitness components such as reproductive success. However, mismatches between habitat selection and observed fitness outcomes are not unusual and can arise for multiple reasons. Variation in individual qualities of animals has also been found to affect reproduction and survival. I examined associations between barn owl nest box selection, reproductive output, and plumage characteristics previously shown to correspond to individual quality. I found that barn owls selected tall nest boxes made of wood, mounted high off the ground, and with increased proportions of grassland around …

Bird Predation On Coho Salmon (Oncorhynchus Kisutch) In Humboldt Bay, Colton J. Dixon

Cal Poly Humboldt theses and projects

Coho Salmon (Oncorhynchus kisutch) populations along the west coast of the United States are declining. In Humboldt County, located in northwestern California, Coho Salmon have been in decline since their federal listing as threatened in 1997, primarily due to habitat loss from logging, agriculture, and urban development. Although these anthropogenic factors caused salmon populations to decline, bird predation may also be hindering population recovery, as evidenced by the recovery of Passive Integrated Transponder (PIT) tags, originally implanted in Coho Salmon, from bird colonies in Humboldt Bay. This study examines predation by Double-crested Cormorants (Phalacrocorax auritus), Caspian …

Pond Characteristics That Influence Oviposition Site Selection By Two Pond-Breeding Amphibians, Northern Red-Legged Frog (Rana Aurora) And Northwestern Salamander (Ambystoma Gracile), Jessica Jones

Cal Poly Humboldt theses and projects

Pond-breeding amphibians connect aquatic and terrestrial habitats through their biphasic life cycle, and understanding pond characteristics that support oviposition sites for multiple species is important for amphibian conservation. Two common amphibians in the Pacific Northwest, Northern red-legged frog (Rana aurora) and Northwestern salamander (Ambystoma gracile) often oviposit in the same pond; however, prior studies have focused on pond use by one species or the other, but not both together. I surveyed pond and oviposition site characteristics of 26 ponds in Humboldt County, CA, 10 of which were used only by R. aurora and 16 of which …

Long Term Trends In Mortality Rates Of A Smallmouth Bass Population, Caleb D. Anderson

Journal of Earth and Life Science

Smallmouth bass Micropterus dolomieu are known as a popular sport fish for anglers. When a known smallmouth bass fishery appears to have a dwindling population, it raises questions about the population health. A common indicator of the health of the population is the mortality rate. By comparing mortality, conclusions can be made on whether smallmouth bass are dying at a different rate in the system over time. Therefore, the objective of this study was to see if there had been a significant change in smallmouth bass mortality over a span of thirty years in Round Lake (DOW:010204), Aitkin County, Minnesota. …

Relationship Between Northern Pike And Walleye Cpue In Minnesota Lakes, Simon Oslund

Journal of Earth and Life Science

Northern pike Esox lucius and walleye Sander vitreus are both top predators in freshwater systems. Due to their predatorial nature, high populations of one species can prohibit populations of the other species from thriving, specifically northern pike foraging on walleye. This information is tracked by the Minnesota Department of Natural Resources through catch per unit effort (CPUE). CPUE data was gathered for all lakes in Beltrami County, Minnesota, and a regression analysis was done to test for a relationship between pike and walleye. It was found that the relationship between northern pike and walleye CPUE was significant (P = 0.02). …

The Effects Of Length, Weight, Age, And Gender On Mercury Concentrations In Burbot In North-Central Minnesota Lakes, Liam Hanley

Journal of Earth and Life Science

Burbot Lota lota in north-central Minnesota lakes have the potential to reach large sizes and consume large volumes of prey. This caveat may make burbot susceptible to higher rates of biocontamination, bioaccumulation and biomagnification. The objective of this study was to determine how changes in age, length, gender, weight, and lake affect total mercury concentrations in burbot. In this experiment 28 burbot were angled from three lakes: Cass (n = 17), Winnibigoshish (n = 4), and Bad Medicine (n = 7). Then tissue samples were taken from each fish and were lyophilized and homogenized. Homogenized tissue samples were analyzed by …

Relationship Between Fishing Hours And Number Of Fish Harvested From Upper Red Lake, Dylan Ohlenkamp

Journal of Earth and Life Science

Total hours fishermen spend fishing and total amount of fish harvested per year are some of the most important pieces of knowledge gained from creel surveys. They provide crucial information that assesses fisheries mortality and pressure. MN DNR uses their results from creel surveys to improve or impose regulations, and to maintain healthy fisheries. Based on results from similar studies, there is expected to be a positive relationship between hours fished and fish harvested. To determine the relationship between these two variables on Upper Red Lake, data from two years were selected when the variables were at their highest and …

A Guide To Otoliths Of Minnesota Fishes, Baylor J. Short

Journal of Earth and Life Science

Investigations into the diet patterns of piscivores can provide crucial information on predator-prey relationships, population dynamics, and responses to changing ecosystems. However, digestive processes often remove or alter physical characteristics that are traditionally used to identify consumed fish. This problem has been addressed to some degree with advances in molecular technologies, although these methods can be costly and require specific training and equipment to do so. In contrast, bony structures such as otoliths, vertebrae, cleithra, and others frequently have morphologies that are unique among families, genera, and species. Because these structures are resistant to digestion, they can be used to …

The Effect Of Triaenophorus Crassus On The Condition Of Coregonus Artedi, Alexander Surma

Journal of Earth and Life Science

Cisco Coregonus artedi is, historically, the largest commercial fishery in the Great Lakes. The species is also important to commercial and recreational fisheries in inland lakes. Tapeworm Triaenophorus crassus larvae embed themselves into the flesh of Ciscoes, rendering the fish unmarketable to humans. Triaenophorus crassus is common in inland waters such as Leech Lake and Cass Lake, MN. One Canadian researcher has suggested that the parasite negatively affects the growth and weight of Ciscoes. Poor condition can reduce fecundity, leading to lower recruitment rates. This would mean a detrimental impact on not only individual fish, but the health of …

Treatment With The Immunocontraceptive Vaccine, Gonacon, Induces Temporary Fertility Control In Free-Ranging Prairie Dog Populations In Colorado, Usa, Aaron B. Shiels, Jackson Runte, Emily W. Ruell, Douglas C. Eckery, Gary W. Witmer, Daniel J. Salkeld

United States Department of Agriculture Wildlife Services: Staff Publications

Context

Prairie dogs (Cynomys spp.) are rodents enjoyed by some humans; yet, they cause crop and property damage, and carry zoonotic disease. Non-lethal control of prairie dogs is of interest in urban/suburban settings. The injectable immunocontraceptive vaccine GonaCon (active ingredient is gonadotropin-releasing hormone [GnRH]) has been shown to be effective at reducing fertility in equine and deer, and is a US EPA-registered vaccine for use in these ungulate species.

Aims

To conduct a replicated field study to test efficacy of GonaCon in black-tailed prairie dogs (C. ludovicianus), and if found to be efficacious, to help facilitate …

Comparison Of Ketamine-Xylazine, Butorphanol-Azaperone-Medetomidine, And Nalbuphine-Medetomidine-Azaperone For Raccoon (Procyon Lotor) Immobilization, Shylo R. Johnson, Christine K. Ellis, Chad Wickham, Molly R. Selleck, Amy T. Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoons (Procyon lotor) are frequently handled using chemical immobilization in North America for management and research. In a controlled environment, we compared three drug combinations: ketamine-xylazine (KX), butorphanol-azaperone-medetomidine (BAM), and nalbuphinemedetomidine- azaperone (NalMed-A) for raccoon immobilization. In crossover comparisons, raccoons received a mean of the following: 8.66 mg/kg ketamine and 1.74 mg/kg xylazine (0.104 mL/kg KX); 0.464 mg/kg butorphanol, 0.155 mg/kg azaperone, and 0.185 mg/kg medetomidine (0.017 mL/kg BAM); and 0.800 mg/kg nalbuphine, 0.200 mg/kg azaperone, and 0.200 mg/kg medetomidine (0.020 mL/kg NalMed-A). Induction time was shortest with KX (mean6SE, 10.060.7 min) and longest with NalMed-A (13.061.3 min). …

Using Prescribed Fire And Biosolids Applications As Grassland Management Tools: Do Wildlife Respond?, Brian E. Washburn, Michael J. Begier

United States Department of Agriculture Wildlife Services: Staff Publications

Prescribed burning is a management tool commonly used in forested ecosystems in the southeastern United States, but the influence of this method on grassland vegetation and wildlife in this geographic region is unknown. During 2009–2015, we conducted a study to determine if the application of prescribed burning and/or long-term biosolid applications alter plant communities and/or wildlife use of grassland areas at Marine Corps Air Station Cherry Point, Havelock, North Carolina. We monitored vegetation growth, measured plant community composition, and documented wildlife activity in four study plots for 3 years after the implementation of annual winter prescribed burns. Prescribed burning reduced …

Potential Landscape Connectivity For Invasive Wild Pigs (Sus Scrofa) Across The Northern Prairies Of North America, Corey J. Kramer, Melanie R. Boudreau, Ryan Powers, Kurt C. Vercauteren, Ryan S. Miller, Ryan K. Brook

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding landscape scale connectivity is an essential component in the management of invasive species since connectivity facilitates their invasion potential. Invasive wild pigs (Sus scrofa) are among the most prolific invaders on the planet, causing billions of dollars in agricultural and environmental damage annually. Newly introduced to Canada in the 1980s, we examined wild pig invasion potential across the northern prairies from western Canada into the currently wild pig-free northern U.S. states. We used GPS collar data collected in the Canadian prairies to quantify resource selection and incorporated results into an electric circuit theory framework to evaluate potential …

Rapid Point-Of-Care Testing For Detection Of Antibodies To Toxoplasma Gondii In Black Vultures And Ring-Billed Gulls From Pennsylvania, Alexa Rosypal Von Dohlen, Sydney Randall, Jordyan Grays, Mark A. Dugo, Brian J. Hunt, Justin Brown, Kyle Van Why, Sawsan Ammar, Richard Gerhold

United States Department of Agriculture Wildlife Services: Staff Publications

Toxoplasma gondii is a zoonotic protozoan parasite that infects most warm-blooded animals, including birds. Scavenging birds are epidemiologically important hosts because they can serve as indicators of environmental T. gondii levels. A rapid point-of-care (POC) test that detects antibodies to T. gondii in humans is commercially available. In this research, we assessed the ability of the human POC test to detect anti–T. gondii antibodies in 106 black vultures (Coragyps atratus) and 23 ring-billed gulls (Larus delawarensis) from Pennsylvania, USA. Serum samples were tested with the POC test and compared to the modified …

Low Secondary Risks For Turkey Vultures From A Sodium Nitrite Toxic Bait For Wild Pigs, Justin A. Foster, John C. Kinsey, Michael J. Lavelle, Kurt C. Vercauteren, Nathan P. Snow

United States Department of Agriculture Wildlife Services: Staff Publications

An acute and orally‐delivered toxic bait for wild pigs (Sus scrofa) containing sodium nitrite (SN) is being developed and tested for potential registration in the U.S. We evaluated oral toxicity of SN and risk of secondary consumption in a common avian scavenger, the turkey vulture (Carthartes aura), by 1) conducting an acute oral toxicity test (LD₅₀) for turkey vultures by oral gavage, and 2) allowing turkey vultures to feed on whole carcasses and digestive tracts of wild pigs that died from consuming SN‐laden bait. Captive tests were conducted during fall 2016 and spring 2017 in the …

A Method For Characterizing Disease Emergence Curves From Paired Pathogen Detection And Serology Data, Joshua Hewitt, Grete Wilson-Henjum, Derek T. Collins, Jourdan M. Ringenberg, Christopher A. Quintanal, Robert Pleszewski, Jeffrey C. Chandler, Thomas J. Deliberto, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. Wildlife disease surveillance programs and research studies track infection and identify risk factors for wild populations, humans and agriculture. Often, several types of samples are collected from individuals to provide more complete information about an animal's infection history. Methods that jointly analyse multiple data streams to study disease emergence and drivers of infection via epidemiological process models remain underdeveloped. Joint-analysis methods can more thoroughly analyse all available data, more precisely quantifying epidemic processes, outbreak status, and risks.

2. We contribute a paired data modelling approach that analyses multiple samples from individuals. We use ‘characterization maps’ to link paired data …

Torque Teno Sus Virus 1: A Potential Surrogate Pathogen To Study Pig-Transmitted Transboundary Animal Diseases, Xiaolong Li, Brandon M. Parker, Raoul K. Boughton, James C. Beasley, Timothy J. Smyser, James D. Austin, Kim M. Pepin, Ryan S. Miller, Kurt C. Vercauteren, Samantha M. Wisely

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding the epidemiology and transmission dynamics of transboundary animal diseases (TADs) among wild pigs (Sus scrofa) will aid in preventing the introduction or containment of TADs among wild populations. Given the challenges associated with studying TADs in free-ranging populations, a surrogate pathogen system may predict how pathogens may circulate and be maintained within wild free-ranging swine populations, how they may spill over into domestic populations, and how management actions may impact transmission. We assessed the suitability of Torque teno sus virus 1 (TTSuV1) to serve as a surrogate pathogen for molecular epidemiological studies in wild pigs by investigating …

Common Grackle (Quiscalus Quiscula) Predation Of A Great Lakes Piping Plover (Charadrius Melodus) Nest And Its Conservation Implications, Jade R. Arneson, Dennis A. Peloquin, Thomas G. Prestby, Sarah P. Saunders

United States Department of Agriculture Wildlife Services: Staff Publications

Common grackle (Quiscalus quiscula) was observed consuming eggs from an exclosed (protected) Great Lakes piping plover (Charadrius melodus) nest in the lower bay of Green Bay, Lake Michigan in Wisconsin, USA during June 2023. The observation, captured by a trail camera, is the first photographic documentation of grackle predation in any of the three piping plover breeding populations. This behavior adds common grackle to the suite of egg predators and has critical implications for this shorebird species, particularly in the Great Lakes region where piping plover is listed as federally endangered and common grackles are relatively …

Quantifying The Ecological Effects Of Salix Fragilis On Riparian Habitat In Kittitas County, Washington, Landon Shaffer

All Master's Theses

Invasive species threaten plant community structure and function globally. Riparian areas, the zone near streams where water influences vegetation, are especially sensitive to invasive species colonization, suffering large-scale shifts in community composition. Salix fragilis (crack willow) is a nonnative riparian species abundant in the lower elevation tributaries of central Washington. Some speculate whether this willow should be listed as invasive in Washington, despite a lack of regional supporting evidence. I studied riparian communities dominated by either S. fragilis or native species in the Kittitas Valley and measured biodiversity, quantified differences in solar attenuation, and compared leaf decomposition rates to learn …