Population Biology Commons^™

Bearpaw Reserve Wildlife Monitoring And Mapping With The Wildlands Conservancy, Hope Hansen

Scripps Senior Theses

For my Environmental Analysis Capstone, I worked in a small group to monitor and map the wildlife at Bearpaw Reserve. Bearpaw Reserve, located in Forest Falls, California, is a 600 acre tract of wilderness that is owned by The Wildlands Conservancy. Bearpaw is located about an hour from Claremont, in the San Bernardino Mountains. The Wildlands Conservancy makes management decisions about its reserves while applying conservation research to the real world.

My group’s task was to use trail cameras to gather data on the wildlife at Bearpaw, then visualize this information into a GIS map. We used a combination of …

Sediment Redox-Driven Iron Flux And Phytoplankton Community Responses: Implications For Cyanobacterial Suppression And Functional Stability Across Boreal Lakes, Julia K. Kozak

Theses and Dissertations (Comprehensive)

Freshwater eutrophication contributes towards the development of cyanobacterial harmful algal blooms (cHABs), but nutrient availability alone does not fully explain variation in phytoplankton community composition or physiological performance. While phosphorus (P) availability has been known to regulate phytoplanktonic biomass, iron (Fe) is an important micronutrient supporting Fe-heavy processes within cyanobacteria (i.e., nitrogen fixation and photosynthetic electron transport). Sediment Fe availability in freshwater ecosystems is regulated by reduction oxidation (redox) conditions at the sediment-water interface (SWI), where nitrate (NO₃^-) has been found to maintain oxidizing conditions and prevent the reduction of Fe(III) to more readily bioavailable soluble Fe(II), …

Moose On The Move: Seasonal Movement Ecology And Hunter Accessibility Of Male Moose In Interior Alaska, Forrest Rosenbower

Biological Sciences

Moose (Alces alces) are an important subsistence and sport harvested species in Alaska, yet seasonal patterns of male moose movement and habitat selection remain poorly understood. This knowledge gap limits our ability to anticipate hunter accessibility and effectively manage populations. In this thesis, I evaluated seasonal space use, movement behavior, and habitat selection of 78 GPS-collared adult males across three study areas in Interior Alaska during 2023 and 2024. In Chapter 1, I quantified seasonal overlap in space use and assessed hunter accessibility. We compared space use between the winter survey season 2023 and fall hunting season 2024. Population level …

A Previously Unrecognized Cryptic Taxon Within The Eastern United States Celastrina (Tutt) Species Complex, Harry Pavulaan

The Taxonomic Report of the International Lepidoptera Survey

A unique population of Celastrina is described from the highest elevations, 2784-6643’ (848-2027 m), of the southern Appalachian Mountains, centered on Great Smoky Mountains National Park. Life history aspects are still incomplete, calling for future field research.

A Previously Unrecognized Cryptic Taxon Within The Eastern United States Celastrina (Tutt) Species Complex, Harry Pavulaan

The Taxonomic Report of the International Lepidoptera Survey

A unique population of Celastrina is described from the highest elevations, 2784-6643’ (848-2027 m), of the southern Appalachian Mountains, centered on Great Smoky Mountains National Park. Life history aspects are still incomplete, calling for future field research.

Phenological Flexibility In Nesting Grassland Birds Over A Half Century Informs Timing Of Management, Kristin S. Ellis, Michael J. Anteau, Lawrence D. Igl, Garrett J. Macdonald, Neal D. Niemuth, Aaron T. Pearse, Jill A. Shaffer, Christine A. Ribic, Josh L. Vest, Masanori Abe, Daniel S. Ackerman, Marissa A. Ahlering, Johanna N. Alpert, Anahit Amiri, Kent Andersson, Jacqueline K. Augustine, Kristel K. Bakker, Jeffrey L. Beck, Adam C. Behney, Jacy S. Bernath-Plaisted, Todd R. Bogenschutz, Eric K. Bollinger, Lauren E. Bortolotti, Andy J. Boyce, Jeffrey D. Brawn, Fred C. Bryant, Andrew J. Campomizzi, Jay D. Carlisle, J Matthew Carroll, Rachel Carroll, John P. Carroll, Justin R. Clarke, Michael R. Conover, Reesa Y. Conrey, Jaime J. Coon, Kyle A. Cutting, Stephen K. Davis, Dawn M. Davis, Duane R. Diefenbach, Jonathan B. Dinkins, R Andrew Dreelin, Victoria J. Dreitz, Courtney J. Duchardt, Michael W. Eichholz, Susan N. Ellis-Felege, Kevin S. Ellison, Bradley C. Fedy, Samantha D. Fino, Robert J. Fletcher Jr, Dillon T. Fogarty, Samuel D. Fuhlendorf, Pamela R. Garrettson, Robert J. Gates, Erin L. Gelling, James J. Giacomo, Alex Glass, Cheri L. Gratto-Trevor, Ryan D. Haffele, Christian A. Hagen, Vanessa B. Harriman, Samuel W H Harryman, David A. Haukos, Robert T. Haynam, Heather A. Herakovich, James R. Herkert, Fidel Hernandez, Jason M. Hill, H Jeffrey Homan, Torre J. Hovick, Jonathan A. Jenks, William E. Jensen, Aaron N. Johnston, Sydney-Marie Jones, Carly S. Kelly, Kaylan M. Kemink, Silka L F Kempema, Dylan C. Kesler, Christopher P. Kirol, Robert W. Klaver, Page E. Klug, Jesse L. Kolar, Nicola Koper, Kyle J. Kuechle, Jonathan D. Lautenbach, Zoe M. Lebrun-Southcott, David W. Londe, Scott R. Loss, Cullen M. Mackenzie, Patrick A. Magee, Douglas L. Manzer, John P. Mccarty, Gywm Mckee, Ann E. Mckellar, Lance B. Mcnew, James R. Miller, Megan C. Milligan, Ashlee K. Minor, Rocco J. Murano, Les D. Murray, David E. Naugle, Clayton K. Nielsen, Christopher J. Norment, Sarah B. Ogden, Lindsay A. Parsons, Brian D. Peer, Noah G. Perlut, James C. Pittman, Christopher D. Pollentier, Larkin A. Powell, Aaron C. Pratt, John P. Pulliam, Nancy M. Raginski, Dan R. Reinking, Kaitlyn M. Reintsma, Terry Z. Riley, Kevin M. Ringelman, Joseph R. Robb, Scott K. Robinson, Andres N. Rosales, Charlotte L. Roy, Kayla A. Ruth, Brett K. Sandercock, Kevin K. Sedivec, Steve K. Sherrod, Justin J. Shew, Mason L. Sieges, Jenny L. Sika, Susan K. Skagen, Cassandra G. Skaggs, Joseph Smith, Jennifer A. Smith, Kurt D. Smith, Alex J. Solem, Joshua D. Stafford, Glenn E. Stauffer, Matthew D. Stephenson, Lee Sutcliffe, Amber E. Swicegood, Jason Tack, Evan P. Tanner, Catrina V. Terry, Wendy P. Tori, Ashley M. Unger, Kelly R. Vanbeek, William E. Vetter, Jay A. Vonbank, Brett L. Walker, Michael D. Whitson, Maiken Winter, Kimberly A. With, Donald H. Wolfe, Amy A. Yakel Adams, Benjamin Zuckerberg

United States Department of Agriculture Wildlife Services: Staff Publications

The timing of biological events for wildlife species reflects and influences ecological and evolutionary processes and helps guide management actions to meet conservation objectives. Climate change may cause phenological shifts across trophic levels and ecosystems, which can have broad ecological impacts. Shifts may also result in mistiming between management practices based on historical conditions and current biological events, reducing the effectiveness of natural resource management and conservation efforts. We analyzed nesting phenology patterns over recent decades across North America for 44 species of grassland-nesting birds, including waterfowl, upland gamebirds, shorebirds, and passerines, many of which have experienced precipitous population declines. …

Phenotypic Variation Between Surface And Cave-Adapted Poeciliids And Its Effect On Metabolism, Karch Knipp, Michael Tobler, Soren Johnson

Undergraduate Research Symposium

Cave-adapted organisms often exhibit pronounced morphological changes relative to their surface counterparts, a phenomenon known as troglomorphy. In Poecilia mexicana (Atlantic molly), these differences include variation in coloration between surface and cave populations. Troglobitic organisms also typically exhibit reduced metabolic rates, likely as an adaptation to environments with low primary productivity. This makes P. mexicana an ideal system for investigating the evolution of metabolic traits. In this study, we leveraged variation in coloration among cave-dwelling mollies to examine potential associations with resting metabolic rate (RMR). Coloration was quantified using PCR values, and individuals were categorized as “yellow” or “non-yellow.” We …

Under The Surface: Human Disturbance Reduces Species Richness In Glade Microhabitats, Maddie Smith, Becky Hansis-O'Neill, Aimee Dunlap Phd

Undergraduate Research Symposium

Human disturbance can alter microhabitats in ways that affect biodiversity, especially in sensitive ecosystems like glades where many animals rely on rocks for thermoregulation and refuge. This study examined how rock displacement by human activity influences species richness and community composition in glade habitats at Shaw Nature Reserve and Victoria Glades Conservation Area. We hypothesized that disturbed rocks would be less suitable for wildlife and would support fewer species. From September to November 2025, about 30 rocks per site were pseudo-randomly selected and monitored. Each rock was classified as displaced or nondisplaced, and all organisms found beneath them were recorded. …

Bifurcation Dynamics Of A Harvested Predator-Prey Model, Hala H. Emam, Mohamed F. Abouelenein, Mona Anis, M. Y. Hamada, F. A. Atia, H. El-Metwally

Mathematical Modelling and Numerical Simulation with Applications

In ecosystems, the harvesting effect is essential to preserving the relationships between prey and predator. This work examines a model of predator-prey in discrete time with harvesting. The Jacobian matrix's eigenvalues are calculated for the associated fixed points. We examine the dynamical and qualitative analysis of this model, look into the criteria for stability and bifurcation, and analyze analytical results that show the rich dynamics and complexity of this model. We give sufficient circumstances for the Period-doubling at the interior equilibrium point by employing the harvesting effect. The discrete system's chaos control is carried out, and the outcomes are supported …

Intraspecific And Intersexual Variations In Morphometrics And Shell Utilization Of Hermit Crab, Areopaguristes Perspicax (Anomura: Diogenidae), Along Karachi Coast, Pakistan, Altaf Hussain Narejo, Noor Us Saher

Journal of Bioresource Management

The present research aimed to evaluate the distribution, sexual dimorphism, and relative growth of Areopaguristes perspicax (Nobili, 1906) along with host shell relationship and selection along the coast of Karachi, Pakistan. Data of hermit crab and gastropod shells were gathered from the four (Manora, Buleji, Sandspit, and Mubarak) coastal sites of two (rocky and sandy) habitats along the Pakistan coast (2017-2019). For morphometric studies, the crabs were sorted, weighed, and measured for the metric variables: cephalothoracic shield length (CSL), hermit crab total length (HCTL), chela length (CL), chela width (CW), and hermit crab weight (HCW), while for host shell relationship, …

Distribution And Diversity Of Ponyfishes (Perciformes, Leiognathidae) In The Waters Of Sonmiani’S Bay, Balochistan, Pakistan, Noor Hawa, Noor Us Saher

Journal of Bioresource Management

The current research was conducted during October 2020 to September 2021 in bay waters of Sonmiani, Balochistan as aimed to fill the paucity of diversity and distribution of research for the bay waters. Monthly fish samples were collected using gill net and beach seine during high and low tide. In the present study, out of nine species, the six species were identified as a new report species belongs to Leiognathidae family. Secutor interruptus (N=132) was the most abundant species whereas the least abundant species collected during the study period was Karalla daura (N=1). Highest diversity (1.37) was estimated during the …

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 …

Genomic Analysis Reveals New Subspecies Of Cercyonis Scudder, 1875 (Nymphalidae: Satyrinae: Satyrini), Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Todd L. Stout, Michael S. Fisher, Robb Hannawacker, Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

Genomic analysis of Cercyonis (Cercyonis) Scudder, 1875 (Nymphalidae Rafinesque, 1815) partitions the subgenus into three species groups and reveals five new subspecies from the USA (type localities in parentheses): Cercyonis (Cercyonis) pegala koosharem Stout and Grishin, ssp. n. (Utah, Sevier Co.), Cercyonis (Cercyonis) pegala lasala Grishin, M. Fisher, and Hannawacker ssp. n. (Utah, Grand Co.), Cercyonis (Cercyonis) pegala hortoni Grishin, ssp. n. (Arizona, Gila Co.), Cercyonis (Cercyonis) meadii maculana Grishin, ssp. n. (Colorado, Montezuma Co.), and Cercyonis (Cercyonis) meadii rimana Grishin, ssp. n. (Arizona, Yavapai Co.). A neotype is designated for Satyrus boopis Behr, 1864 (USA, California, Contra Costa Co.). …

A Decision Analytic Approach To Hierarchical Decisions For Double-Crested Cormorant Conflict Resolution, Kelly F. Robinson, Travis O. Brenden, Alex Maguffee, Charles R. Bronte, Randall M. Claramunt, Thomas R. Cooper, Robin L. Debruyne, Brian S. Dorr, James F. Farquhar, Jana R. Lantry, James R. Jackson, David G. Fielder, Rachel L. Pierce, Doug Schultz

United States Department of Agriculture Wildlife Services: Staff Publications

Double-crested cormorants (Nannopterum auritum) are piscivorous, migratory waterbirds that often conflict with fisheries interests in North America, stemming from depredation effects on fish populations. A new permitting process in the United States allows natural resource agencies to request permits for lethal take of cormorants in special instances like depredation of managed fish stocks. This rule does not include guidance for when cormorant take might be actionable. We developed a hierarchical structured decision making (SDM) framework for evaluating whether, when, and how much cormorant take might be necessary. A broad-scale, or “umbrella,” SDM framework established the overarching problem, objectives …

An Evaluation Of Next Generation Biological Control Methods For The Invasive Brown Treesnake In The Mariana Islands, Jonathan Q. Richmond, Tim Harvey-Samuel, Melia G. Nafus, Adam Perez, Renee Bellinger, Antoinette J. Piaggio, Riley Taitingfong, Margaret E. Hunter, Robert N. Fisher

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Modeling Population Growth With Logistic And Modified Logistic Equations, Mihil Dimpal Patel

Discovery Day - Daytona Beach

Population growth models are essential tools for understanding how biological populations change over time under environmental constraints. This study examines population dynamics by comparing the classical exponential growth model with the logistic growth model. While exponential growth assumes unlimited resources and results in unbounded population increase, the logistic model incorporates a carrying capacity that limits growth as resources become scarce. To better represent real-world conditions, the logistic model is extended by introducing modifications such as harvesting terms and time-varying carrying capacities, which account for external removal of individuals and changing environmental limits. The equilibria of these models are determined, and …

A Genetic Analysis Of The Rare Endemic Astragalus Ripleyi Barneby, Juan Antonio Jaramillo-Chico

Master's Theses

Astragalus ripleyi Barneby is a rare endemic species found in the San Luis Valley of the southern portions of the Rocky Mountains in Colorado and New Mexico. Though not federally listed as endangered, the species is on the Bureau of Land Management’s Sensitive Species List, warranting protection and continued management. This study aims to provide information about the genetic health of the species to inform conservation efforts and provide updated management recommendations. A genetic health analysis was conducted investigating the levels of diversity present in the species, how genetic diversity is structured across the known range of the species and …

From Genes To Streams: Mitochondrial Approaches To Population Monitoring Of The Santa Ana Sucker Catostomus Santaanae, Mariana Antonio

Electronic Theses, Projects, and Dissertations

This study was developed to use aquatic environmental DNA (eDNA) as a tool to detect the presence of the Santa Ana sucker (Catostomus santaanae), a federally threatened fish species, across the Santa Ana River in Southern California. Environmental DNA is any genetic material that an organism sheds into the environment. We can get an idea of what aquatic species are present when sampling water at a given site. We sequenced the complete mitochondrial genome (mitogenome) of the Santa Ana sucker and designed custom DNA primers to improve eDNA detection accuracy. These primers were selected based on high genetic …

Influence Of Genetic Relationships On The Spatial Distribution Of Breeding Eastern Wild Turkeys (Meleagris Gallopavo Silvestris) In West-Central Louisiana, Rachel D. Price

LSU Master's Theses

Eastern wild turkeys (Meleagris gallopavo silvestris) have a complex social system influenced by dominance hierarchies and exhibit seasonal variation in gregarious behaviors. Previous work has examined the influence of kin relationships on interactions between same sex conspecifics and flock associations, but information on how genetic relatedness influences interactions between individuals remains lacking. We constructed a dyad-based social network using high-resolution GPS data from 179 female and 68 male wild turkeys in west-central Louisiana during the 28-day period before a females’ 1^st nest initiation to quantify interaction probability based on genetic relatedness and age. Our findings suggest that …

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, …