Ecology and Evolutionary Biology Commons^™

Dynamic Patterns Of Resource Selection In Northern Bobwhite Across The Annual Cycle In A Region With Poor Edaphic Conditions, Autumn S. Randall

Theses and Dissertations--Forestry and Natural Resources

Developing successful management strategies requires an understanding of how an organism's resource needs change over the course of its life cycle. For almost a century, northern bobwhite (Colinus virginianus) populations have been declining range-wide, mostly as a result of habitat loss and degradation. Resource selection studies conducted at coarse-temporal resolutions and in areas with fertile soils form the majority of current management recommendations for bobwhites. In this thesis, we quantified resource selection patterns for 1,302 bobwhites in a region with poor soil conditions with respect to several common management practices (fire, fallow fields, supplemental feeding, and brush management …

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 …

Informing Standardized Wood Turtle (Glyptemys Insculpta) Population Monitoring: Influences Of Sampling Approach And Turtle Behavior On Model Estimation, Allyson N. Beard

Graduate Theses, Dissertations, and Problem Reports (ETD)

To better understand wood turtle (Glyptemys insculpta) population trends, two standardized population survey protocols were recently developed for use by state monitoring programs. The protocols were independently developed, tested, and deployed for population monitoring in the eastern and upper midwestern United States. It was unknown if the sampling designs result in similar detection success or if data from the two protocols are compatible for broad-scale analyses. Additionally, neither monitoring protocol includes a sampling design that allows for the separation of detection (p) into availability (p_a), and detection given availability (p_d). …

The Genetic Diversity Of An Endangered Buttercup, Ranunculus Triternatus, Ryan Garcia

All Master's Theses

Ranunculus triternatus, a rare endemic species of the Columbia River Gorge, faces conservation challenges due to its limited range and fragmented populations. This study assesses the genetic diversity of R. triternatus and compares it with its widespread congener, Ranunculus glaberrimus, using inter-primer binding site (iPBS) markers. Genetic data from 80 individuals across eight populations were analyzed using Nei’s genetic diversity, Shannon’s diversity index, and AMOVA. Results showed R. triternatus had higher genetic diversity than western populations of R. glaberrimus, with eastern populations of R. glaberrimus displaying greater diversity than western ones. PCA, UPGMA, and STRUCTURE analysis revealed …

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). …

Using Novel And Traditional Survey Techniques To Monitor Small Mammal Species In Northwestern California, Sydney Mccluskey

Cal Poly Humboldt theses and projects

Small mammal species play a critical role in forest ecosystems contributing significantly to overall forest biodiversity and ecological dynamics. Forest-dwelling species are among the most vulnerable to habitat loss and fragmentation. It is essential to develop efficient techniques for monitoring small mammal populations in forested ecosystems to inform conservation efforts and management plans; yet, monitoring small mammals in these habitats can be particularly challenging due to their size, activity patterns, and frequently nocturnal nature. In this study, I aimed to address two primary research objectives: 1) compare the effectiveness of 3 distinct camera-trap survey techniques (i.e., ground, tree, and tube) …

Interactions Between New Zealand Mud Snails (Potamopyrgus Antipodarum) And Toxic Cyanoabacteria (Anabaena) In Baduwa’T (Mad River), Humboldt County, California, Cecilia F. Kennelly

Cal Poly Humboldt theses and projects

Invasive species in freshwater systems are circulated around the globe, wreaking havoc on natural communities. The New Zealand mud snail (Potamopyrgus antipodarum) is a very successful aquatic invader that has established populations in freshwater streams, lakes, and rivers around the globe. The goal of this project was to evaluate the interactions of invasive New Zealand mud snails (NZMS) and toxic cyanobacteria Anabaena in the Mad River in Humboldt County, California. These two species of concern are found in similar habitats along the river, but their whether NZMS consume Anabaena or affect toxin production is unknown. First, I conducted …

Trophic Interactions Of Sympatric Cyprinodontiform Fishes Inhabiting Louisiana Saltmarshes, Ryan Heines

Dissertations, Master's Theses and Master's Reports

Resident saltmarsh nekton, namely Cyprinodontiform fishes, play key ecological roles in supporting terrestrial and aquatic food webs. These fishes are highly abundant across the saltmarsh landscape of coastal Louisiana and have evolved to tolerate the highly variable environmental conditions that are characteristic of these habitats. The objective of this research is to consider mechanisms enabling this diverse community of fishes to cooccur in the spatially limited saltmarsh habitats of coastal Louisiana. In Chapter 2, bulk stable isotope ratios of carbon (δ13C), sulfur (δ34S) and nitrogen (δ15N) were used to quantify the intra- and inter-specific resource use of six sympatric Cyprinodontiform …

Biology And Ecology Of Neonectria Magnoliae And Neonectria Punicea, Two Understudied Neonectria Species In West Virginia, Hannah Marie Petronek

Graduate Theses, Dissertations, and Problem Reports (ETD)

The family Nectriaceae includes numerous phytopathogenic fungi that cause canker diseases on both angiosperm and conifer hosts worldwide. Numerous Neonectria spp. cause cankers on hardwoods and conifers in North America, but their roles in contributing to tree decline and mortality outside of beech bark disease are largely understudied. One such pathogen, Neonectria magnoliae, causes perennial cankers on two native hosts in central Appalachia: Fraser magnolia (Magnolia fraseri) and tulip-poplar (Liriodendron tulipifera). We also recently confirmed N. magnoliae from non-native star magnolia (Magnolia stellata) in West Virginia. Both native hosts occur in the central …

Maximum Entropy Species Distribution Modeling For The Spring Ephemeral Herb Bloodroot (Sanguinaria Canadensis) In Eastern North America, Velan Manivannan

Williams Honors College, Honors Research Projects

The spring ephemeral plant Bloodroot (Sanguinaria canadensis) has a widespread native range in North America, spanning much of the eastern United States and Canada. While its current NatureServe conservation status is designated as ‘secure’ (NatureServe, 2023), its status as a spring ephemeral places it at a heightened risk for climate change-induced phenological mismatch with advancing forest canopy closure. Additionally, under continued anthropogenic climate change, Bloodroot may also experience range shifts or contractions as the edges of its present range warm past physiological thresholds. To determine the potential for range shifts and contractions under future warming, I generated a …

Movement Behavior And Metapopulation Connectivity Of Stream Salamanders In Response To Disturbance Events, Kathryn M. Greene

Theses and Dissertations--Biology

Metapopulations are shaped by the dispersal between populations in a landscape. Disturbance events can disrupt this connectivity resulting in local population extinction. For my dissertation, I used a combination of empirical and theoretical techniques to examine dispersal in response to disturbance and assessed it’s population-level consequences. My research used capture-mark-recapture sampling techniques to evaluate stream salamander movement in response to (1) a supraseasonal drought and (2) mountaintop-removal-mining (MTR) and valley-filling (VF) and (3) agent-based simulation modeling to evaluate population extinction risk in response to varying dispersal and mortality rates.

First, I evaluated the effects of a supraseasonal drought, a severe …

Steps Towards Operationalizing One Health Approaches, Kim M. Pepin, Keith M. Carlisle, Dean Anderson, Michael G. Baker, Richard B. Chipman, Jackie Benschop, Nigel P. French, Suzie Greenhalgh, Scott Mcdougall, Petra Muellner, Emil Murphy, Dion R. J. Neale, Michael J. Plank, David T. S. Hayman

United States Department of Agriculture Wildlife Services: Staff Publications

One Health recognizes the health of humans, agriculture, wildlife, and the environment are interrelated. The concept has been embraced by international health and environmental authorities such as WHO, WOAH, FAO, and UNEP, but One Health approaches have been more practiced by researchers than national or international authorities. To identify priorities for operationalizing One Health beyond research contexts, we conducted 41 semi-structured interviews with professionals across One Health sectors (public health, environment, agriculture, wildlife) and institutional contexts, who focus on national-scale and international applications. We identify important challenges, solutions, and priorities for delivering the One Health agenda through government action. Participants …

Changing Fire Regimes And Nuanced Impacts On A Critically Imperiled Species, Jeremy T. Rockweit, Katie M. Dugger, Damon B. Lesmeister, Raymond J. Davis, Alan B. Franklin, J. Mark Higley

United States Department of Agriculture Wildlife Services: Staff Publications

Wildfire activity throughout western North America is increasing which can have important consequences for species persistence. Native species have evolved disturbance-adapted traits that confer resilience to natural disturbance provided disturbances operate within their historical range of variability. This resilience can erode as disturbance regimes change and begin operating outside this range. We assessed wildfire impacts during 1987–2018 on the northern spotted owl, an imperiled species with complex relationships with late and early seral forest in the Pacific Northwest, USA. We analyzed population- and individual-level wildfire impacts across the frequent-fire portion of the owl’s geographic range at two spatial scales and …

Heating Decoys To Mimic Thermal Signatures Of Live Animals For Drones, Landon R. Jones, Cerise Mensah, Jared S. Elmore, Kristine O. Evans, Morgan B. Pfeiffer, Brad F. Blackwell, Raymond B. Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

Method name

Heating animal decoys to mimic thermal signatures for drones

Abstract

Thermal sensors mounted on drones (unoccupied aircraft systems) are popular and effective tools for monitoring cryptic animal species, although few studies have quantified sampling error of ani- mal counts from thermal images. Using decoys is one effective strategy to quantify bias and count accuracy; however, plastic decoys do not mimic thermal signatures of representative species. Our objective was to produce heat signatures in animal decoys to realistically match thermal images of live animals obtained from a drone-based sensor. We tested commercially available methods to heat plastic decoys of …

Competitive Behaviors Between Black Vultures (Coragyps Atratus) And Turkey Vultures (Cathartes Aura) During Scavenging / Comportamientos Competitivos Entre Coragyps Atratus Y Cathartes Aura Durante El Carroñeo, Amanda M. Herbert, Patrick A. Zollner, Landon R. Jones, Marian L. Wahl, Grant N. Burcham, Bryan M. Kluever, Lee A. Humberg, Brandon M. Quinby

United States Department of Agriculture Wildlife Services: Staff Publications

Abstract

Interference competition occurs when an individual prohibits another’s access to a resource through antagonistic interactions. Despite considerable research on scavenger interactions at carrion, the limited evidence for competitive interactions between black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) relies upon the frequency of antagonistic interactions without considering other forms of competition. Using remote cameras, we recorded the duration of aggression, scavenging, and vigilance behaviors exhibited by individual black vultures and turkey vultures scavenging stillborn domestic cattle carcasses within flocks composed of one or both vulture species. We tested for differences of durations of each …

The Texas Feral Swine Eradication And Control Pilot Program, David R. Pipkin, Bruce R. Leland, Katherine Garwood, Linda Tschirhart-Hejl, Michael J. Bodenchuk, John M. Tomecek

United States Department of Agriculture Wildlife Services: Staff Publications

The United States Agriculture Improvement Act of 2018 (the 2018 Farm Bill) established the Feral Swine Eradication and Control Pilot Program. The program funded US$75M for 5 years, split evenly between the Natural Resources Conservation Service (NRCS) and the Animal and Plant Health Inspection Service (APHIS), both programs within the United States Department of Agriculture. The agencies solicited joint programs from states with high densities of feral swine in two phases. In Texas, NRCS and APHIS submitted three multi-county project areas along watersheds for Phase I funding and one eradication effort along with two crop protection projects in Phase II. …

Spatiotemporal Partitioning Of Two Invasive Ungulates In Guam [Abstract], Kelly J. Koriakin, Kurt C. Vercauteren, Nathan P. Snow, D. Buck Jolley

United States Department of Agriculture Wildlife Services: Staff Publications

Interspecific interactions are crucial in shaping ecosystem dynamics (Connell 1983, Tilman 1987, Barbosa and Castellanos 2005). Non-native ungulates have been introduced across the globe (Ferretti and Lovari 2014, Volery et al. 2021) and in environments where multiple invasives thrive, these co-occurring sympatric species may shift spatiotemporal patterns to minimize interspecific competition (Schoener 1974, Chesson 2000). Spatiotemporal shifts can lead to cascading effects to the native flora and fauna (Simberloff and Von Holle 1999). Given the potential negative impacts, understanding these interactions is vital for effective management of these ecosystems.

Two invasive ungulates, the wild pig (Sus scrofa) and …

Multi-Year Effectiveness Of Pzp-22 In Free-Roaming Suburban White-Tailed Deer, Allen T. Rutberg, Kali M. Pereira, Kayla A. Grams, John W. Turner Jr.

Human–Wildlife Interactions

To address the challenge that is posed to the use of fertility control to mitigate human–deer (Cervidae) conflicts by the need to regularly re-inoculate free-roaming animals, we captured, ear-tagged, and hand-injected 68 individual adult female white-tailed deer (Odocoileus virginianus) with the PZP-22 immunocontraceptive vaccine from February through April, 2014 to 2017, in the Village of Hastings-on-Hudson, New York, USA. Approximately 2.5 years after initial treatments, we booster-darted 29 of the previously treated females with either PZP-22 or native PZP (ZonaStat-D). We observed fawn production between 2014 and 2021. The combination of initial PZP-22 hand-treatments followed by single dart-delivered PZP …

Spatial Predictors Of Human–Black Bear Interactions In Nova Scotia, Canada, Jason I. Airst, Tricia B. Fleming

Human–Wildlife Interactions

The increased global frequency of human–wildlife conflict with large, wild carnivores and omnivores negatively impacts human, wildlife, and ecosystem health. The goal of this study was to determine what landscape characteristics best predicted where human–black bear (Ursus americanus) interactions occurred in Nova Scotia, Canada, to support management efforts. We compared the location of 3,278 human–bear conflict reports and 867 non-conflict reports collected between 2017 and 2021 to 12,000 randomly generated locations. Data were analyzed using logistic additive mixed models. We found that interactions (conflict and non-conflict reports) occurred near roads and farther from forests and surface water features. …

Waterbird-Perceived Damage, Control Measures, And Economic Implications For Rice Production In The Brazilian Cerrado, Demetrio Luis Guadagnin, Alexandre Afonso Meyer, João Augusto Rossi Borges, Fernanda Maia Justo

Human–Wildlife Interactions

Waterbirds have the potential to inflict economic damage to crops. However, is rice (Oryza sativa) production in the Brazilian Cerrado significantly affected by waterbirds? This study aimed to assess the extent of waterbird damage on irrigated rice production in Central Brazil. We conducted surveys of waterbird populations in rice agroecosystem habitats throughout the cultivation cycle and analyzed the expenses associated with waterbird-induced yield losses and the control measures employed by farmers. The 2 most prevalent waterbird species observed were Dendrocygna viduatta and D. autumnalis, comprising 68.6% of all recorded waterbirds. These species were more frequently encountered and …

Survival Of Translocated Coyotes In The Chicago Metropolitan Area, Usa, Charlotte R. Milling, Chris Anchor, Stanley D. Gehrt

Human–Wildlife Interactions

For nuisance animals, the general public perceives translocation to be a humane alternative to lethal control measures, but survival of translocated wildlife is often quite low due in part to increased movement post-release. Thus, for common species whose relocation generally serves a social rather than conservation purpose, translocation might not be correctly characterized when presented as nonlethal. We quantified release site fidelity and survival of coyotes (Canis latrans) fitted with very high frequency radio-collars and translocated within the Chicago Metropolitan Area, Illinois, USA, from 2000 to 2006. We also compared survival for 14 weeks post-collaring for our translocated …

The Energetics Of Seasonality In Wild Diademed Sifaka (Propithecus Diadema): A Technical And Biological Validation Of Fecal Triiodothyronine Radioimmunassay, Casey Farmer

Graduate Research Theses & Dissertations

The energetic state of an animal has vital consequences for its fitness, but it can be difficult to detect through behavioral observations. The development of techniques to determine an animals’ energetic state non-invasively would allow conservation planners to rapidly assess the energy balance and conservation potential of individuals, groups, and populations. Thyroid hormones like triiodothyronine (T3) regulate and reflect metabolic state in mammals. T3 is a non-invasive biomarker that can be detected in feces and could potentially be used for this purpose. I perform the first validation of a commercially available T3 radioimmunoassay designed for humans on a wild strepsirrhine …

Population Demographics Of Channel Catfish In The Lower Wabash River, Valerie J. Thompson

Masters Theses

Inland fisheries are experiencing increasing demands due to anthropogenic stressors, especially within large river systems that support both recreational and commercial fisheries. Riverine species are sensitive to habitat degradation, species introductions, and exploitation, so continued monitoring and management of these communities are vital to maintain abundance and diversity within these systems. The North American catfish family, Ictaluridae, supports both recreational and commercial fisheries throughout the United States. Channel Catfish Ictalurus punctatus are heavily studied and managed compared to other sport catfishes in this family because of their economic and ecological significance. One important Channel Catfish fishery exists in the lower …

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 …

Landscape-Scale Epidemiological Dynamics Of Sars-Cov-2 In White-Tailed Deer, Joshua Hewitt, Grete Wilson-Henjum, Derek T. Collins, Timothy J. Linder, Julianna B. Lenoch, Jonathan D. Heale, Christopher A. Quintanal, Robert Pleszewski, Dillon S. Mcbride, Andrew S. Bowman, Jeffrey C. Chandler, Susan A. Shriner, Sarah N. Bevins, Dennis J. Kohler, Richard B. Chipman, Allen L. Gosser, David L. Bergman, Thomas J. Deliberto, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding pathogen emergence in new host species is fundamental for developing prevention and response plans for human and animal health. We leveraged a large-scale surveillance dataset coordinated by United States Department of Agriculture, Animal and Plant Health Inspection Service and State Natural Resources Agencies to quantify the outbreak dynamics of SARS-CoV-2 in North American white-tailed deer (Odocoileus virginianus; WTD) throughout its range in the United States. Local epidemics in WTD were well approximated by a single-outbreak peak followed by fade out. Outbreaks peaked early in the northeast and mid- Atlantic. Local effective reproduction ratios of SARS-CoV-2 were between …

Probabilistic Genetic Identification Of Wild Boar Hybridization To Support Control Of Invasive Wild Pigs (Sus Scrofa), Timothy J. Smyser, Peter Pfaffelhuber, Rachael M. Giglio, Matthew G. Desaix, Amy J. Davis, Courtney F. Bowden, Michael A. Tabak, Arianna Manunza, Valentin Adrian Bâlteanu, Marcel Amills, Laura Iacolina, Pamela Walker, Carl Lessard, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

The rapid expansion of wild pigs (Sus scrofa) throughout the United States has been fueled by unlawful introductions, with invasive populations causing extensive crop losses, damaging native ecosystems, and serving as a reservoir for disease. Multiple states have passed laws prohibiting the possession or transport of wild pigs. However, genetic and phenotypic similarities between domestic pigs and invasive wild pigs—which overwhelmingly represent domestic pig and wild boar hybrids—pose a challenge for the enforcement of such regulations. We sought to exploit wild boar ancestry as a common attribute among the vast majority of invasive wild pigs as a means …

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. …

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 …

Eradication Of Feral Swine From A Barrier Island In Florida, Usa: An Examination Of Effort And Multi-Method, Multi-Species Population Indexing, Richard M. Engeman, Eric A. Tillman, Betsy A. Evans, John C. Griffin, Garrison Grobaski, Bradley S. Smith, John Stark, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Feral swine (Sus scrofa) were targeted for and successfully eradicated from Saint Vincent Island (SVI), a National Wildlife Refuge (NWR) along the coast of Florida’s panhandle to protect its habitats and uncharacteristically high diversity of wildlife species for barrier islands in the region, including federal and state-listed threatened and endangered species. The eradication effort was initiated in early 2015 and concluded in 2019. A total of 438 feral swine were removed from the Island, 417 by federal control experts and 21 by recreational hunters. In general, the amount of effort needed to eradicate each feral swine slowly increased …