Population Biology Commons^™

Differential Equation Modeling For Sustainable Resource Management: A Steady-State Optimal Harvesting Approach, Iordanka N. Panayotova, Aleksei Talonov

CODEE Journal

Mathematical models based on differential equations provide a powerful framework for connecting real-world data to informed decision-making. In this work, we present a student-accessible project that uses an optimal-control framework to study the sustainable management of biological resources.

Motivated by fisheries management, we examine a predator--prey system in which harvesting decisions must balance ecological and economic considerations. The model is formulated as an optimal control problem that seeks to maximize the total discounted net revenue from harvesting. Rather than solving for the complete time-dependent harvesting trajectory, we restrict the analysis to positive controlled coexistence equilibria and characterize an interior stationary …

History And Distribution Of The Dark Ibises (Glossy Ibis Plegadis Falcinellus And White-Faced Ibis P. Chihi) In Arkansas, R. Tumlison, P. D. Rodriguez

Journal of the Arkansas Academy of Science

The Glossy Ibis (Plegadis falcinellus) and White-faced Ibis (P. chihi) sometimes are reported simply as Dark Ibises due to difficulty in identifying them when mature characters are not clearly visible. We evaluated reports verified on citizen science websites to examine the origins and distributions of these migratory species in Arkansas. The Glossy Ibis was first documented in Arkansas in 1956, has been reported in 21 of our 75 counties, and is found more commonly in eastern Arkansas. The White-faced Ibis was first reported in Arkansas in 1971, has been reported in 41 of our 75 counties, …

Optimal Control And Bifurcation Analysis Of A Predator–Prey Model With Self-Limiting Growth And Predator Disease, Dipo Aldila, Muhammad Akmal Fasya, Bevina D. Handari, Chidozie Williams Chukwu, Olumuyiwa James Peter

Mathematical Modelling and Numerical Simulation with Applications

We propose and analyze an eco-epidemiological predator–prey model that incorporates self-limitation and disease transmission within the predator population. The model is formulated as a system of ordinary differential equations describing logistic prey growth under the interspecific interaction with the predator. On the other hand, the predator population is divided into susceptible and infected classes, whose growth is constrained by prey availability. Three biologically relevant equilibria are identified: predator extinction, disease-free coexistence, and coexistence with endemic disease. The existence and stability of these equilibria are determined by key ecological and epidemiological thresholds, including the basic reproduction number. Using numerical continuation methods, …

Optimal Control Strategies For Infectious Diseases: A Numerical Simulation Approach, M. Abu Salek, Jannatun Nayeem, Romana Yesmin, M. Haider Ali Biswas, M. Humayun Kabir

Mathematical Modelling and Numerical Simulation with Applications

Various infectious diseases, such as Tuberculosis and Hepatitis B virus (HBV), caused by Mycobacterium bacteria and hepatitis B virus, respectively, pose serious threats worldwide. This paper examines the spread of these diseases using a mathematical model that incorporates control measures, including vaccination and awareness programs. We use a system of differential equations with control variables and apply Pontryagin's principle to determine optimal control strategies. The stability of the Disease Free Equilibrium (DFE) has been analysed and demonstrated to be both locally and globally asymptotically stable when the basic reproduction number remains below unity, thereby ensuring disease elimination. Furthermore, the Endemic …

Dynamical Analysis And Optimal Control Of The Mpox Transmission Model With Stratified Susceptibility, Tuhfatul Janan, Fatmawati Fatmawati, Cicik Alfiniyah, Santi Martini, Dipo Aldila, Agus Hasan

Mathematical Modelling and Numerical Simulation with Applications

This study develops a mathematical model of Mpox transmission that combines stratified susceptibility (low-risk and high-risk groups) with vaccinated and asymptomatically infected compartments. The analysis of the model begins with examining the well-posedness, boundedness, and nonnegativity conditions for the solutions. The local stabilities of the equilibria are examined through the Jacobian matrix and phase plane analysis, while the global stabilities are provided through Lyapunov functions. The estimated parameters are verified using epidemiological data on Mpox cases in the United States, with an MAPE of 2.20% and R_0 > 1, indicating that Mpox remains endemic. Sensitivity analysis indicates that the contact rate …

(Si16-21) Dynamical Study Of A Hassell-Varley Model With Nonlinear Harvesting And Fear Effect In Prey, Aditya Bhattacharya, Anindita Bhattacharyya

Applications and Applied Mathematics: An International Journal (AAM)

In this article, a one predator-one prey model incorporating Richards’ type growth in prey population, Hassell-Varley type functional response and Michaelis-Menten type prey harvesting is proposed and analyzed. Richards’ type growth with fear factor is incorporated in the proposed model to generalize the reduction effect of predator-induced fear on the rate of growth of the prey population. Positivity and boundedness of the system’s solutions are first established to ensure biological feasibility of the model. Existence and stability conditions of various types of equilibrium points associated with the model such as trivial equilibrium, axial (predator–free) equilibrium and coexistence equilibrium are obtained …

Reproductive Biology Of Hybopsis Amblops, The Bigeye Chub, In The Flint River Of Alabama, Crissy L. Tarver, Bruce W. Stallsmith

Southeastern Fishes Council Proceedings

The purpose of this study was to establish a reproductive schedule and examine reproductive traits that shape fecundity of the Bigeye Chub, Hybopsis amblops Leuciscidae in the Flint River system of north Alabama. Traits associated with reproduction, growth, and maturation were assessed. Specimens were collected and examined monthly from August, 2013 until July, 2014. This Bigeye Chub population primarily spawns in April and May as indicated by gonadosomatic index (GSI), ovarian condition and clutch size. Mean GSI values began to rise in February, peaking in April and May at over 13% for females and 1.6% for males. There was a …

Non-Native Seagrass, Halophila Stipulacea, Reaches Northern Caribbean, Elizabeth R. Whitman, Elizabeth W. Stoner, Stephanie K. Archer

Gulf and Caribbean Research

Halophila stipulacea, a seagrass native to the western Indian Ocean, has become an established invader throughout the western Atlantic, where it often outcompetes native seagrass species across diverse environmental conditions. Here, we report its presence in the northern Bahamas, ca. 2300 km northwest of the first Caribbean record in Grenada and 304 km northeast of the recent observation in Florida, USA. This range expansion represents the northernmost Caribbean record to date and highlights the species’ capacity for long-distance dispersal and continued spread within the region. Our observation underscores the need for coordinated monitoring efforts to track the trajectory of …

Manatee Dock Sign Distribution And Its Influence On Publicly-Sourced Sighting Reports In Alabama, Daniela Payán Arias, Sophia C. Corde, Ruth H. Carmichael

Gulf and Caribbean Research

No abstract provided.

Current Threat To The Native Endemic Muckalee Crayfish (Procambarus Gibbus) From An Invasive Crayfish (Faxonius Palmeri Creolanus) And Tests Of Cold Tolerance As A Limiting Factor, Alexandria L. Exum, Nickeya Wynn, William Ellerbee, Madaline Toth, Otto T. Lorenz

Georgia Journal of Science

Surveys for native and invasive crayfish were conducted in Muckalee creek in 2015 and 2021. Both surveys used passive minnow traps and examined upstream and downstream sites, including at the mouth of the creek where it connects with the Flint River. The Flint River has been overrun with an invasive crayfish species, Faxonius palmeri creolanus (Creole Painted Crayfish) and its range has spread rapidly throughout southwest Georgia. In Muckalee Creek there were only a few F. p. creolanus found during each survey and both times they were only found at the mouth of the creek. One hypothesis on why they …

Dynamics And Optimal Intervention Strategies In A Shigellosis Transmission Model, Mehmet Gümüs, Shewafera Wondimagegnhu Teklu, Kemal Türk

Mathematical Modelling and Numerical Simulation with Applications

This research explores how water treatment contributes to limiting the transmission of Shigellosis, an infection caused by bacteria from the Shigella genus. A mathematical framework is formulated to evaluate the influence of protective strategies and water purification on the spread of the disease. To confirm the model's biological relevance, its well-posedness is investigated. The basic reproduction number $(\mathfrak{R}_0)$, a critical indicator of disease behavior, is derived using the matrix operator method. Findings indicate that if $\mathfrak{R}_01$, the infection persists, with the endemic equilibrium exhibiting local asymptotic stability. A comprehensive cost-effectiveness analysis reveals that combining environmental protection with water treatment represents …

Examining The Performance Of An Insect Generalist Reared On Unused Host Plants In Colorado, Maxwell J. Meyer, Kanshita Dam, Kailey G. Hicks, Emma J. Sellers, Mykaela M. Tanino-Springsteen, Jd Reigrut, Dhaval K. Vyas, Shannon M. Murphy

DU Undergraduate Research Journal Archive

Dietary generalist insects are important to ecological communities because they are commonly found in many environments and play important roles in ecosystem services like pollination and decomposition. Although dietary generalist herbivores eat a broad range of plant species, regional populations of these species may have significantly narrower or specialized diet breadths. Fall webworm (Hyphantria cunea, hereafter FW) is a dietary generalist at the species level, but we do not know if there is dietary generalism at the population level or how generalism varies across populations. In Colorado, FW larvae feed on only a few plant species, but many plant species …

Bat Occurrence And Microclimatic Conditions Of The Sima Del Órgano Cave, Mexico, Luis A. Hernández, Jaime E. Gómez, Cyntia Reyes

International Journal of Speleology

Caves represent an important type of shelter for many species of bats, particularly in karstic regions. In Mexico, about 60 bat species regularly use caves as roosts. The microclimate of a cave is a key component of the overall cave ecosystem. So, an adequate microclimate can minimize the energetic costs of bats associated with thermoregulation, gestation, embryonic development, parental care, lactation and social interaction. Cave environments are among the least known and most threatened on the planet, which is why we aimed to determine the monthly occurrence of bat species in the Sima del Órgano Cave, estimate the population size …

Quantifying The Decline In Avian Biodiversity: A Global Crisis And Its Implications For Environmental Education, Canaline Osaka

The International Journal of Ecopsychology (IJE)

People care about what they love—and it’s easy to love--and fall in love, with birds. The

opportunities to promote bird diversity are legion, and applicable throughout K-12 education. For example, the Eastern Bluebird needs to nest in the cavities of dead trees, a habitat drastically denuded by large scale farming—or in specialized nesting boxes. A nationwide effort to build and install these boxes has brought the population back to healthy numbers since its 1970 low point. (Once one knows what they look like, one cannot miss these roadside homes—Western Bluebirds also benefit.) Students can also engineer bird houses and deters, …

Occurrence Of Spotted Wing Drosophila (Drosophila Suzukii) In Wild Berries In Forested Areas Of Marquette And Keweenaw Counties, Upper Peninsula Of Michigan, Alexis M. Shatrau, Erika I. Hersch-Green

The Great Lakes Entomologist

Spotted-wing Drosophila (SWD, Drosophila suzukii Matsumura, Diptera: Drosophilidae) is an invasive fly that targets unripe soft-fruits causing premature ripening, dehiscence, and rotting. While the presence of SWD in agricultural systems is well-documented, much less is known about the host range of SWD in wild areas, especially in more northern latitudes where colder temperatures and short summers are thought to restrict their life-cycles and limit population growth. In 2019 and 2020, we collected wild berries from two counties in the Upper Peninsula of Michigan, with long, cold winters, to determine the prevalence, host range, and seasonal/temporal variation of SWD. We found …

Offal Wildlife Watching: Connecting Hunters, Wildlife Researchers, And The Public Through Participatory Science, Ellen M. Candler, Grace Milanowski, Amy Rager, Joseph K. Bump

Journal of Extension

Offal Wildlife Watching is a participatory science project that engages deer hunters in wildlife research. The goal of the project is to better understand the ecology of scavenger species that visit deer gut piles across Minnesota. We asked hunters to deploy remote cameras at white-tailed deer gut piles that resulted from their freshly killed deer. Thus far 117 hunters have contributed images and recorded at least 49 different scavenger species. This project is a natural fit in Extension programs and can easily be adapted to other hunted species, biomes, and locations.

Fta™ Card Use For Detection Of Mycoplasma Gallisepticum In Wild Birds, Linda Purvis, Dawn E.W. Drumtra

Georgia Journal of Science

Flinders Technology Associates (FTA) cards are increasingly accepted as an accurate method for nucleic acid detection, including testing for the presence of various avian diseases. However, the accuracy of FTA cards for detection of Mycoplasma gallisepticum (MG) in wild birds has not been published. Traditional techniques for testing MG in birds include serum plate agglutanation (SPA), hemagglutination inhibition (HI), polymerase chain reaction (PCR), and enzyme linked immunosorbent assay (ELISA) all of which are time consuming and require significant financial investment into specialized equipment. We tested the efficacy of using FTA cards to detect MG in wild bird carcasses collected in …

Macroinvertebrate Community Dynamics In A Recovering, Hypersaline Estuary, Catherine M. Eckert, Claudia A. Tamez, Erin E. Easton, David W. Hicks

Gulf and Caribbean Research

The Bahia Grande is a 6,500—acre tidal basin located at the southernmost tip of Texas. Tidal flow into this coastal estuary was cut off in the 1930s, causing the basin to dry up for ~70 y. A pilot channel connecting the Bahia Grande to tidal waters was constructed in 2005, allowing flooding of the basin to occur. Throughout the period reported herein (2005–2019), the system remained characterized by persistent spatial and temporal episodes of extreme hypersalinity (>70)—a critical factor influencing estuarine community composition and driving key ecological processes. With additional rehabilitation actions forthcoming, characterization of the estuary is essential …

History, Annotated Gazetteer, And Bibliography Of Ornithology In Kalimantan, Indonesian Borneo, Frederick H. Sheldon, Mohammad Irham, Daisy G. S. Kho, Erik Meijaard, Subir B. Shakya, Dewi M. Prawiradilaga, Sebastianus (Bas) Van Balen

Occasional Papers of the Museum of Natural Science, Louisiana State University

Kalimantan comprises nearly three quarters of the island of Borneo and is the place where scientific study of Bornean birds began. We describe the history of bird research in Kalimantan from its beginning, highlighting the ornithologists who explored the region and how their interests and methods changed over time, from a concentration on specimen collection, to examinations of community ecology, to conservation in the face of habitat change and species depletion, to the latest investigations using satellite, genetic, and digital technology. We also highlight some future directions for research, especially the need for more work on basic ecology and biogeography. …

Ina Scuba: Mobilization Of French West Indies Scuba Diving Clubs To Rapidly Improve Knowledge On Threatened Marine Species. Case Of The White-Spotted Eagle Ray (Aetobatus Narinari)., Océane Beaufort, Rocio Prieto González

Gulf and Caribbean Research

The White—Spotted Eagle Ray (Aetobatus narinari), listed as Endangered on the IUCN Red List since 2021, is experiencing alarming population declines, underscoring the urgent need for targeted conservation efforts. This species, which plays a vital ecological role in marine food webs, has biological and ecological characteristics that make it particularly vulnerable to habitat degradation and anthropogenic pressures, particularly fishing, tourism, and maritime traffic. In the French West Indies (FWI), the paucity of data on the White—Spotted Eagle Ray remains a major obstacle to the development of effective, island—specific conservation strategies. To address this gap, the INA Scuba participatory …

Oyster Horizons: Spatial Prioritization For Oyster Restoration At Alabama Living Shorelines, Trinity Henry-Jack, Aaron Bland, Christa Russell, Ronald Baker

Gulf and Caribbean Research

No abstract provided.

Cost-Effective Strategies For Feral Swine Control: Exploring Trapping Equipment Cooperatives, Phil Kenkel, Riza Radmehr, Rodney Holcomb, Mckenzie Boyce

Human–Wildlife Interactions

Feral swine (Sus scrofa) in the United States have become a growing concern, with a population of ≥6 million and causing annual damages of ≥$1.5 billion USD. Because of their high reproductive capacity, effective control methods are crucial to reducing or slowing their population growth. While remotely monitored and triggered traps have proven to be an effective control strategy, the cost of sophisticated trapping equipment, which can cost ≥$7,000 USD, is often cost prohibitive for many landowners. Despite the pressing need to address the challenge of making effective feral swine control methods more affordable, there are few studies …

Maturation Of An Off-Channel Habitat Concept To Conserve Native Fishes In The Lower Colorado River, Paul C. Marsh, Thomas E. Dowling, Thomas F. Turner, Megan J. Osborne, Brian R. Kesner

Monographs of the Western North American Naturalist

Two endemic, “large river” fishes of the Colorado River basin of western North America, bonytail Gila elegans and razorback sucker Xyrauchen texanus, are among several critically endangered species in the system. Wild populations of bonytail are gone, and there are no self-sustaining populations of razorback sucker anywhere; reproduction occurs but recruitment does not. Both species have been under intensive management in the Lower Colorado River since the 1980s. Today, with the single exception of Lake Mead, remaining populations are composed entirely of repatriated individuals that depend on stocking for their continued existence. In 2003, a conceptual off-channel habitat (OCH) …

Reproductive Characteristics Of The Stripetail Darter (Etheostoma Kennicotti) Relative To Monogenean Gill Parasite Infection In Estill Fork In North Alabama, Joy L. Garcia, Zeina Celine Sleiman, Corinne N. Preacher, Bruce Stallsmith

Southeastern Fishes Council Proceedings

What relationship exists between Aethycteron sp. gill parasite infection and the reproductive characteristics of stripetail darters, Etheostoma kennicotti? 450 E. kennicotti were collected over 11 months from Estill Fork in Jackson County, Alabama. Gonads were removed and photographed. All oocytes were counted and then classified into one of four developmental stages based on size and appearance. Gill parasites belonging to the monogenean genus Aethycteron were excised, photographed, and counted. Sexual dimorphism in length and mass was observed in E. kennicotti. The number of males found at the 25> mm SL range far outnumbered the females while almost all …

A Coupled Model Of Population, Poaching, And Economic Dynamics To Assess Rhino Conservation Through Legal Trade, Henry Doyle, Kylie Champagne, Ditto Rajpal, Grace Seebeck, David J. Gerberry

Spora: A Journal of Biomathematics

Rhinoceros populations in Africa are in peril largely due to the high value of their horns and the poaching that ensues. The strategy of legalizing the international trade of rhino horn is receiving increased support among both the people and government officials in Africa. Many in the international conservation community remain opposed to the idea. The legalization strategy is straightforward in theory: legalizing the trade of rhino horn will introduce a large quantity of horn to the market, the increased supply will lead to lower prices for rhino horn, and lower prices will reduce the overall poaching pressure these animals …

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. …

Diving At High Altitude: O2 Transport And Utilization In The Ruddy Duck And Torrent Duck In The Andes, Kevin G. Mccracken, Graham R. Scott, Luis Alza, Andrea Astie, Ciska Bakkeren, Emil Bautista, Mariana Bulgarella, Rebecca Cheek G. Cheek, Beverly A. Chua, Neal J. Dawson, Alexis Diaz, Catherine M. Ivy, Peter B. Frappell, Cecilia Kopuchian, Sabine L. Laguë, John N. Maina, Violeta Muñoz-Fuentes, Elizabeth R. Schell, Matthew M. Smith, Ryan J. Sprenger, Pablo L. Tubaro, Elizabeth R. Schell, Matthew M. Smith, Ryan J. Sprenger, Pablo L. Tubaro, Thomas Valqui, Roy E. Weber, Daniela Wilner, Robert E. Wilson, Julia M. York, William K. Milsom

Occasional Papers of the Museum of Natural Science, Louisiana State University

Hypoxia and cold temperatures create unique physiological challenges for high-altitude organisms that can vary depending on lifestyle. While nearly all studies of air-breathing animals at high altitude are from terrestrial species, species that breath-hold dive underwater at high altitude encounter a very different set of selective pressures influencing their phenotype. The goal of this publication is to highlight the changes in O2 transport and utilization in high-altitude diving birds relative to divers at sea level, and the extent to which these changes are qualitatively distinct from phenotypic changes in non-diving species at high altitude. For example, while high capacities for …

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 …

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 …

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 …