Animal Sciences Commons^™

Characterizing The Habitat Use Of Pacific Coast Feeding Group Gray Whales (Eschrichtius Robustus) And The Spatial And Temporal Variability Of Their Benthic And Planktonic Invertebrate Prey In Northern California, Robyn E. Norman

Cal Poly Humboldt theses and projects

As opportunistic foragers, the Eastern North Pacific population (~20,000) of gray whales (Eschrichtius robustus) feed on diverse benthic and planktonic invertebrates in northern Alaska foraging grounds before they undertake one of the largest yearly migrations of any mammal to breed in Baja California, Mexico. While most of the population travels to the summer foraging grounds in Alaska, a sub-group of whales (~230) called the Pacific Coast Feeding Group (PCFG) summer between British Columbia, Canada, and northern California. The diet of PCFG whales typically includes high-density and/or high-caloric prey items like mysids and diverse species of amphipods, yet a …

Estimating Daily Growth Of Age-0 Channel Catfish In A Free-Flowing, Commercially Exploited Midwestern River, Kaleb B. Wood

Masters Theses

The larval stage in fishes is an important stage in the life history, as their survival dictates the ability of the population to sustain itself as an adult population. While there is a plethora of information available for juvenile and adult life stages of Channel Catfish (Ictalurus punctatus), very little is understood about their larval life stage. This study sought to determine overall density, growth rates, and size structure of cohorts of age-0 Channel Catfish during a study year on the Wabash River. In 2018, I sampled age-0 Channel Catfish using a benthic trawl from May to September. …

Using Community Science To Monitor Eastern Box Turtles And Engage Public In Conservation, Sarah Zoppa

Masters Theses

The eastern box turtle (Terrapene carolina carolina; EBT) is a charismatic species with populations in decline due to habitat loss, disease, and other anthropogenic factors. However, due to their cryptic nature, studying an EBT population can be a difficult and intensive process. To investigate EBT populations in Coles County, Illinois, we used a combination of community science and computer-based pattern analysis to develop an approach to tracking individual turtles. Citizen volunteers submitted photos of encountered eastern box turtle carapaces for shell pattern analysis along with GPS coordinates of the encounter. We have received 220 submissions from 47 community volunteers. …

Can Edna Be Used To Locate Shawnee Hills Cavefish Forbesichthys Papilliferus?, Megan Brandt, Timothy Spier Phd, Gary Zeruth Phd

Murray State Theses and Dissertations

Traditional stream fish sampling methods, such as seining and electrofishing, are time consuming, expensive, and limited to short stretches of stream. However, the analysis of environmental DNA (eDNA) from water samples promises to be a quick, inexpensive method for detecting fish. The streams of the Land Between the Lakes Recreational Area (LBL) are unique, undisturbed streams which contain many interesting fish species for which little information exists. One such rare species is the Shawnee Hills Cavefish Forbesichthys papilliferus, which is known to exist in a few LBL streams. However, the complete distribution of the Shawnee Hills Cavefish in LBL …

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). …

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 …

Migration-Associated Variation In Blood Parasitism, Body Condition, And Stress In Gambel’S White-Crowned Sparrows (Zonotrichia Leucophrys Gambelii), Julianna Deibel

Scripps Senior Theses

Migration is a widespread behavior in animals which both causes and is motivated by fluctuations in nutrient availability. Migration is ecologically important, as it connects areas of differing primary productivities and carries pathogens over distance. The relationship between migration and disease is complex, sensitive to anthropogenic disturbance, and influenced by ecological cycles as well as host, vector and parasite life cycles. Four central migration-infection mechanisms have been proposed: migratory susceptibility, migratory exposure, migratory escape, and migratory culling. These mechanisms may yield increased or decreased infection post-migration, based on migration’s physiological tax and the concentration of pathogens along migratory pathways.

To …

Natural Selection On Feralization Genes Contributed To The Invasive Spread Of Wild Pigs Throughout The United States, Niek W. G. Barmentlo, Patrick G. Meirmans, William H. Stiver, Joseph G. Yarkovich, Blake E. Mccann, Antoinette J. Piaggio, Dominic Wright, Timothy J. Smyser, Mirte Bosse

United States Department of Agriculture Wildlife Services: Staff Publications

Despite a long presence in the contiguous United States (US), the distribution of invasive wild pigs (Sus scrofa × domesticus) has expanded rapidly since the 1980s, suggesting a more recent evolutionary shift towards greater invasiveness. Contemporary populations of wild pigs represent exoferal hybrid descendants of domestic pigs and European wild boar, with such hybridization expected to enrich genetic diversity and increase the adaptive potential of populations. Our objective was to characterize how genetic enrichment through hybridization increases the invasiveness of populations by identifying signals of selection and the ancestral origins of selected loci. Our study focused on invasive …

Influence Of Habitat And Baiting Strategy On Oral Rabies Vaccine Bait Uptake By Raccoons In The Southeastern United States, Jacob E. Hill, Madison L. Miller, Richard B. Chipman, Amy T. Gilbert, James C. Beasley, Guha Dharmarajan, Olin E. Rhodea

United States Department of Agriculture Wildlife Services: Staff Publications

terrestrial wildlife species. However, there is currently a limited understanding of how different baiting strategies influence raccoon (Procyon lotor) uptake of ORV baits in non-agricultural habitats in the Southeastern United States, which may hinder the refinement of ORV management for raccoons in this region. Using a combination of new and existing data, we investigated the role of baited area (0.16 vs 3 km²), bait density (75 versus 150 baits/km²) and season (spring versus fall) on placebo ORV bait uptake by raccoons in four rural, non-agricultural habitats in the southeastern United States (bottomland hardwood forest, …

Prevalence Of Avian Influenza Virus In Atypical Wild Birds Host Groups During An Outbreak Of Highly Pathogenic Strain Ea/Am H5n1, Jourdan M. Ringenberg, Kelsey Weir, Lee Humberg, Carl Voglewede, Mitch Oswald, J. Jeffrey Root, Krista Dilione, Even Casey, Michael Milleson, Timothy Linder, Juliann Lenoch

United States Department of Agriculture Wildlife Services: Staff Publications

The global outbreak of highly pathogenic avian influenza (HPAI) H5N1 Eurasian lineage goose/Guangdong clade 2.3.4.4b virus that was detected in North America in 2021 is the largest in history and has significantly impacted wild bird populations and domestic poultry across the continent. Synanthropic birds may play an important role in transmitting the virus laterally to other wild bird species and domestic poultry. Understanding the dynamics of HPAI in atypical, or nonreservoir, wild bird hosts may help inform management decisions and potential risk factors to both wild and domestic bird populations. Following the confirmation of infections of HPAI H5N1 in domestic …

Evaluation Of Mitigation Translocation As A Management Tool To Reduce Conflicts Between Humans And American Kestrels, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Raptor‐aircraft collisions (bird strikes) pose a serious safety risk to civil aircraft. Even smaller raptors, such as American kestrels (Falco sparverius), can be problematic within airport environments. Given widespread declines in kestrel populations, public interest, logistical and financial constraints, and other factors, managing kestrels at airports presents some unique challenges. I conducted a study to determine which biological (e.g., age and sex of the bird) and logistical factors (e.g., month and translocation distance) might influence the return of American kestrels live‐captured and translocated from 42 civil airports and military airbases within the contiguous USA during 2016–2021. American kestrels …

Discovery Of A Novel Invasive Rodent Species On Wake Atoll With A Desert Southwest Usa Origin, Antoinette J. Piaggio, Eric Lanners, Daniel R. Taylor, Aaron B. Shiels, Marjorie Matocq, John Eisemann

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species, particularly omnivorous rodents, have damaged island ecosystems around the world. The unique flora and fauna of island systems have typically not evolved with omnivorous rodents and are heavily impacted by their introduction. Wake Atoll of the southern Pacific Ocean is a 707-hectare coral island complex of three islands managed by the United States Department of Defense (DoD). DoD restricts civilian access to the atoll but aircraft and seacraft regularly visit the island to transport military equipment and to sustain the year-round military and contractor personnel stationed on the atoll. Wake Atoll had been invaded by Rattus rattus complex …

Efficacy Of Gonacon Fertility Control Against Prairie Dogs And Potential For Uses On Other Rodent Species, Aaron B. Shiels, Emily W. Ruell, Jason E. Bruemmer

United States Department of Agriculture Wildlife Services: Staff Publications

Use of a contraceptive (i.e., fertility control) is attractive for rodent management where lethal control is unwanted. Although population reduction is generally unachievable with small-scale, short-term contraceptive use, reduced juvenile recruitment is achievable. The injectable immunocontraceptive vaccine GonaCon (active ingredient: gonadotropin releasing hormone [GnRH]) was registered in 2022 by the United States Environmental Protection Agency (EPA) for controlling fertility of female prairie dogs (Cynomys, a type of ground squirrel) in urban/suburban settings. Here we: 1) describe past research, including a replicated field study in Colorado (GonaCon treatment vs. control sites) testing efficacy of GonaCon in prairie dogs, which …

Agricultural And Ecological Resources Safeguarded By The Prevention Of Wild Pig Population Expansion, Colin Jareb, Kim M. Pepin, Ryan S. Miller, Stephanie A. Shwiff, Sophie C. Mckee

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most destructive invasive species in the United States, known for causing extensive damage to agricultural commodities, natural resources, and property, and for transmitting diseases to livestock. Following the establishment of the National Feral Swine Damage Management Program (NFSDMP) in 2014, the expansion of wild pig populations has been successfully slowed. This paper combines two modeling approaches across eight separate models to characterize the expansion of wild pig populations in the absence of intervention by the NFSDMP and forecasts the value of a subset of resources safeguarded from the threat of …

Oral Rabies Vaccination Of Raccoons (Procyon Lotor) Across A Development Intensity Gradient In Burlington, Vermont, Usa, 2015–2017, Emily M. Beasley, Kathleen M. Nelson, Dennis Slate, Amy T. Gilbert, Frederick E. Pogmore, Richard B. Chipman, Amy J. Davis

United States Department of Agriculture Wildlife Services: Staff Publications

Management of the raccoon rabies virus variant in North America is conducted primarily using oral rabies vaccination (ORV). When a sufficient proportion of the population is vaccinated (60%), rabies transmission can be eliminated. To date, ORV programs have successfully controlled and eliminated raccoon rabies in rural areas, but there has been less success in urban areas. We studied the proportions of rabies virus neutralizing antibodies (RVNA) in a raccoon (Procyon lotor) population during a 3-year ORV trial in developed areas of Burlington, Vermont, United States. We used a modified N-mixture model to estimate raccoon abundance, RVNA seroprevalence, and …

Ethyl-Iophenoxic Acid As A Serum Marker For Oral Baiting Of Tasmanian Devils, Ruth Pye, David Nichols, Sally A. Nofs, Amy T. Gilbert, Andrew S. Flies

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baits containing vaccines, medicants or toxicants have been delivered to a broad range of wildlife species to protect against or treat disease, or suppress populations. Ethyl-Iophenoxic acid (Et-IPA) is used as a biomarker to determine oral bait consumption by wildlife species to assess and refine baiting strategies. Et-IPA is a persistent biomarker in many eutherian mammal species but not in the two marsupial species, swamp wallaby (Wallabia bicolor) and brushtail possum (Trichosurus vulpecula), tested to date. Et-IPA has not previously been evaluated in carnivorous marsupials. The Tasmanian devil (Sarcophilus harrisii), the largest extant …

Estimating Landscape Spread Of A Low-Prevalence Disease Using Multiple Surveillance Methods, Abigail Feuka, Aakash Pandey, Melinda Cosgrove, Megan Moriarty, Anthony Duffiney, Henry Campa Iii, Kurt C. Vercuteren, Kimberly M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. Diseases occurring at low prevalence in free-ranging wildlife can be difficult to study and predict at a landscape scale. This problem is compounded by imperfect pathogen detection.

2. We used data from multiple surveillance methods to determine factors influencing spread of a low-prevalence disease, bovine tuberculosis (bTB), among white-tailed deer (Odocoileus virginianus) in a bTB endemic area over a 10-year period. We fit dynamic occupancy models to predict spatial spread of bTB through a county in Michigan, USA, within the bTB endemic area, while accounting for imperfect detection and a suite of ecological processes potentially driving bTB …

Effects Of The Immunocontraceptive Gonacon On Pregnancy In Brucella-Seropositive American Bison (Bison Bison), Rebecca K. Frey, Morgan E. Wehtje, Pauline Nol, Patrick R. Clarke, Jack C. Rhyan, Matthew P. Mccollum, Lowell A. Miller, Douglas C. Eckery

United States Department of Agriculture Wildlife Services: Staff Publications

The purpose of this study was to determine if the number of pregnancies in naturally infected Brucella abortus-positive bison (Bison bison) cows would be reduced over a period of 5 yr after one treatment with 3000 mg gonadotropin-releasing hormone immunocontraceptive (GonaCon) compared to a similar group of naturally infected B. abortus-positive bison cows not treated with GonaCon. In each of the 5 yr, GonaCon-treated cows produced fewer offspring in relation to number of cows than the nontreated cows. Fisher’s Exact test comparing offspring produced during the first reproductive season showed a significant difference between the …

Efficacy Of X-Ray Phytosanitary Irradiation On The Infectivity And Reproduction Of Angiostrongylus Cantonensis In Experimentally Infected Rats, Susan I. Jarvi, Lisa M. Kaluna, Steven C. Hess, Lindsey Hamilton, Carmen Antaky, Robert T. Sugihara, Israel L. Leinbach, Yaeko Tagami, Argon Steel, Kathleen Howe, Steven Jacquier, Forrest Cookman, Jocelyn Diaz, John Jacob, Peter Follett

United States Department of Agriculture Wildlife Services: Staff Publications

Angiostrongylus cantonensis is a globally distributed nematode and the leading cause of eosinophilic meningitis in humans. As a global hotspot for this disease, Hawaii’s agricultural exports may be contributing to the spread of A. cantonensis. Phytosanitary irradiation doses of 150 or 400 Gy provide quarantine security against multiple insect pests. We evaluated the in vitro and in vivo effects of phytosanitary irradiation on infectious, third-stage A. cantonensis juveniles. In vitro experiments directly exposed juveniles to irradiation doses ranging from 200 to 1,000 Gy. Results showed low mortality and no dose response across all treatments 27 days post-irradiation. …

An Effective Method For Long-Term Control Of American Bullfrogs Syntopic With Special-Status Native Amphibians In California, Usa, Jeff A. Alvarez, Jeffery T. Wilcox

Human–Wildlife Interactions

American bullfrogs (Lithobates catesbeianus) are invasive in western North America and are well established in California, USA, where they are widespread. This invasive species has been implicated in the decrease of native amphibian populations and is believed to have contributed to the decline of threatened and endangered amphibians regionally. We utilized air rifles, tin alloy pellets, and 2 shooters to systematically control L. catesbeianus in both lentic and lotic habitat types within 2 counties in California. We visited sites monthly (April through November) for approximately 8 and 14 years to lethally target and remove L. catesbeianus …