Population Biology Commons^™

Distributional Records Of Blanding’S Turtles (Emydoidea Blandingii) In Nebraska, Sam Thede, Dan Fogell, Keith Geluso

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Blanding’s Turtle (Emydoidea blandingii) is a species of concern in North America as many populations have declined across its distribution. Environmental factors associated with alteration of natural ecosystems have played a role in declines leading to many isolated populations. Most populations exist in the Great Lakes region with a number of outlying populations, such as Nebraska. Understanding the current distribution of the species will facilitate regional management strategies to protect this species into the future. In Nebraska, Blanding’s Turtles were known from 23 counties prior to this study. Herein, we report on eight new county records, five (Blaine, …

Nitrogen Addition Additively Boosts Climate-Driven Salsola Tragus (Russian Thistle) Invasion Into Southwestern Usa Grasslands, Melissa A. Bacigalupa

Biology ETDs

Effective management of invasive, non-native plants requires understanding key drivers of invasion, including nitrogen enrichment from atmospheric deposition and agriculture. Long-term studies are essential for capturing complex invasion dynamics yet remain uncommon. We used 22 years of observations and 14 years of nitrogen experiments to examine invasion by Salsola tragus (Russian thistle) into three semi-arid grasslands of central New Mexico. Invasion patterns varied, with rapid expansion in Chihuahuan Desert grassland and the Desert-Plains ecotone but stability in Plains grassland. Under ambient nitrogen, precipitation most strongly correlated with Russian thistle biomass and high native grass biomass was associated with Russian thistle …

Simulated Walleye Responses To Various Harvest Regulations In A Nebraska Reservoir, Mikael Ranta, Melissa Wuellner, Keith D. Koupal

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Recreational fishing provides sociological and economic benefits, and fish populations are managed by state agencies to meet angler expectations. One of the most popular species in Midwest reservoirs are walleye (Sander vitreus), and most of these fisheries have established restrictions on the number and sizes of fish harvested. Regulations are set based on population structure and dynamics and management goals, but often agencies have incomplete information needed to establish regulations. Predictive models can provide insight on population responses and inform managers of the tradeoffs between angler restrictions and population sustainability. Lake McConaughy, Nebraska, supports a popular walleye fishery. …

Update To: Advancing Butterfly Systematics Through Genomic Analysis, Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Nick Grishin

The Taxonomic Report of the International Lepidoptera Survey

In this update, we propose (type species or type localities in parentheses): Lochris Grishin, nom. nov. (Lasaia oileus Godman, 1903; Lepidoptera: Riodinidae) as a new substitute name for Locris Grishin, 2025 preoccupied by Locris Stål, 1866 (Cercopis rubra Fabricius, 1794; Hemiptera: Cercopidae), 5 new species, and 5 new subspecies: Emesis (Mandania) mandarina Grishin, sp. n. (Brazil: Santa Catarina) and Emesis (Mandania) mandela Grishin, sp. n. (Venezuela, Carabobo) in Riodinidae Grote, 1895 (1827); others in Hesperiidae Latreille, 1809: Telegonus (Rhabdoides) flavifimbro Grishin, sp. n. (Colombia), Urbanus (Urbanoides) dolus Grishin, sp. n. (Colombia: …

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 …

Stream Fish Assemblage Dynamics And Barriers To Aquatic Connectivity In The Ichawaynochaway Creek Watershed, Georgia, Usa, Jake R. Duhé

LSU Master's Theses

Stream fishes in the southeastern United States are adapted to hydrological disturbances such as droughts. However, this region is projected to experience increasingly frequent and severe disturbances that will elevate water demands given increasing agricultural and urban development. Further, road-stream crossings (RSCs) are abundant features in these streams that can exacerbate drought-mediated stream fragmentation and impede movements by many aquatic organisms, including fishes, when poorly constructed. These compounding effects may adversely affect the diversity and abundances of resident stream fishes, but their interactions remain poorly understood, warranting rigorous testing of how droughts and RSCs influence stream fish dynamics. I assessed …

Occupancy Sampling To Examine Spatial Distribution Of Oklahoma Salamanders (Eurycea Tynerensis) Among Headwater Streams In The Ozark Highlands, Sophia Anreder

Biological Sciences Undergraduate Honors Theses

Water conditions are changing globally due to climate change (Gleick, 1989). Headwater streams specifically are vulnerable to changes in hydrology, water quality, and physical characteristics from anthropogenic practices due to their small watersheds with shallow soils, yet they are often not a priority in conservation (Campbell et al., 2011; Abell et al., 2017). Within streams, plethodontid (i.e., lungless) salamanders, which are also sensitive to environmental changes, may be restricted in their distribution due to undefined stream characteristics and predation by fish (Welsh and Droege, 2002; Kuhajda et al., 2015). To better understand the pressures that influence stream salamander occupancy, I …

Catching A Fever: A Comparison Of Vachellia Xanthophloea Populations In The Limpopo And Luvuvhu River Floodplains Of The Makuleke Contractual Park, Kianie B. David

School of Natural Resources: Dissertations, Theses, and Student Research

This study investigates patterns of stand structure regeneration, growth characteristics, and coarse woody debris (CWD) patterns in Vachellia xanthophloea (fever tree) stands within the Makuleke Contractual Park (MCP), a semi-arid savanna system in northern Kruger National Park (KNP), South Africa. Fieldwork was conducted across two stand types: a monospecific fever tree stand in Rietbok Vlei and a mixed-species stand in the Western Nhlangaluwe Floodplain where fever tree is established with Faidherbia albida (ana tree). Data were collected from 20 total 1/4-acre (1,011 m²) circular plots between both stands in 2024 and 2025, including seedling root collar diameter (RCD), …

Evolutionary Dynamics Of Artificial Agents: Exploration And Learning In Games, Brian Mintz

Dartmouth College Ph.D Dissertations

The natural world abounds with examples of complex behavior in humans and many other species. Evolutionary game theory is a powerful mathematical framework to understand the origins of many such behaviors like cooperation. Since these behaviors are often selected against initially, understanding why they are so widespread has been a longstanding question. Rather than assuming agents' rationality, like in traditional game theory, this approach studies the mutation and selection of strategies themselves. However most behavior is neither perfectly rational nor entirely determined by genetics. This dissertation works to bridge the gap between these two perspectives by analyzing models where individuals …

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 …

An Unusual Trumpeter Swan (Cygnus Buccinator) In Nebraska: Albinism Or Leucism?, Jacob C. Cooper, Peggy M. Huss, Eugene A. Huryn, Cody Mcgregor

Nebraska Bird Review

On 26 January 2025, we observed a large mixed flock of Trumpeter Swans (Cygnus buccinator) and Tundra Swans (C. columbianus) at Hansen Reservoir ca. 7 miles (11 km) NNW of North Platte along the east side of Nebraska Highway 97. The flock of 158 swans consisted of 4 “Whistling” Tundra Swans (C. c. columbianus), 153 typical Trumpeter Swans, and one individual that we were not immediately able to identify. Our unknown swan was in the company of a family group of Trumpeter Swans but immediately stood out due to its broad yellow base of …

Nebraska Ornithologists' Union Tri-State Meeting With Iowa Ornithologists' Union And South Dakota Ornithologists' Union, South Sioux City, Nebraska, May 16-18, 2025

Nebraska Bird Review

The NOU Spring Meeting was held at the Salvation Army Western Plains Camp in South Sioux City, Nebraska, in conjunction with the IOU and SDOU, with approximately 180 attending. The organizers of the meeting included Chris Anderson and Mark Schmidtbauer from South Dakota, Tyler Harms and Kevin Murphy from Iowa, and Ruth Stearns, Joel Jorgenson, and Paul Pearson from Nebraska.

A scientific poster session featuring the work of 9 ornithological researchers from UN-Kearney, USD-Vermillion, and Hitchcock Nature Center was held Friday evening. Thanks to Dr. Jacob Cooper from UNK, Dr. David Swanson from USD, and the students who participated.

Field …

Nou Tri-State Meeting—South Sioux City [Spring 2025 Nou Meeting Species Tally]

Nebraska Bird Review

Bird species tally (185) for the Spring 2025 NOU Tri-State Meeting, South Sioux City (Nebraska Ornithologists’ Union Tri-State Meeting with Iowa Ornithologists’ Union and South Dakota Ornithologists’ Union, South Sioux City, Nebraska, May 16–18, 2025)

Abstracts Of Posters Presented At South Sioux City Nou Meeting

Nebraska Bird Review

A scientific poster session featuring the work of 9 ornithological researchers from UN-Kearney, USD-Vermillion and Hitchcock Nature Center was held Friday evening. Thanks to Dr. Jacob Cooper from UNK, Dr. David Swanson from USD, and the students who participated.

Wandering from the River: On- and Off-River Abundance of Interior Least Terns along the 59-Mile Reach of the Missouri National Recreational River. Zoe Donelan, Hannah Slattery, Kyle Jorgensen, and David L. Swanson, University of South Dakota, Department of Biology.

Preliminary Results of Raptor Migration Monitoring at Hitchcock Nature Center. Kellie Hayden, Jerry Toll, and Sandy Reinken, Hitchcock Nature Center, Pottawattamie Conservation, …

Spring Field Report, March–May 2025, W. Ross Silcock

Nebraska Bird Review

Perhaps the most important takeaway this spring is the continuing phenomenon of large numbers of species with early spring arrival dates. Although about half as many as 2024, there were 64 examples of either tied or new early arrival dates, most obviously of insectivores such as swifts, flycatchers, vireos, swallows, pipits, longspurs, and 10 warbler species. Among these, record or near-record early were Whip-poor-will, Black-necked Stilt, Marbled Godwit, Black Tern, Olive-sided Flycatcher, Purple Martin, Rock Wren, Gray Catbird in central, Spotted Towhee in north and west, and Hooded Warbler.

Following along logically perhaps with early arrival dates were a number …

The Nebraska Bird Review (June 2025) 93(2), Whole Issue

Nebraska Bird Review

Spring Field Report, March–May 2025, by W. Ross Silcock

NOU Spring Field Days and Annual Meeting in South Sioux City, May 16–18, 2025

Abstracts of posters presented at Spring 2025 NOU Meeting

Spring 2025 NOU Meeting Species Tally

An Unusual Trumpeter Swan (Cygnus buccinator) in Nebraska: Albinism or Leucism? by Jacob C. Cooper, Peggy M. Huss, Eugene A. Huryn, and Cody McGregor

Subscription and Organization Information

Advancing Butterfly Systematics Through Genomic Analysis, Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

Within the framework of an ongoing comparative genomic study of global butterfly diversity, we construct phylogenetic trees combining all protein-coding genes assembled from the whole genome shotgun data. When viewed in the context of current taxonomy and phenotypic knowledge, the genome-wide phylogeny points to further advances in butterfly systematics, which are presented here. We assign major clades with comparable levels of genetic divergence to the same taxonomic rank and apply criteria involving relative population divergence and gene flow to define species boundaries. As a result, one genus, 13 subgenera, 62 species, and five subspecies are proposed as new (type species …

Pollinator Plant Communities Within Restored Montane Longleaf Pine Ecosystems, Hanen Van Rossem

Master's Theses

Historically the fire-dependent and biodiverse longleaf pine (Pinus palustris) ecosystem was the dominant ecosystem of the Southeastern US. This ecosystem’s range was massively reduced due to land conversion and fire exclusion, causing the decline of many native species. Efforts to restore and protect longleaf pine stands are now ongoing with the goal of expanding habitat and refuge for threatened species. Differences in restoration practices and prior land use may influence the extent to which restored habitat patches can support pollinators and their plants. This study compared pollinator plant biodiversity between restored neighboring montane longleaf pine stands that differed in …

Sex, Skulls, And Selection: An Exploration Of Blakely Island's Deer Population And Their Ecology Through Genetic Sex Differentiation Of Juvenile Crania, Blair P. Graves

Honors Projects

As an isolated landmass with no natural predators, Blakely Island serves as an effective study site for the study of evolutionary factors relating to insular populations of large mammals. A disparity in the adult sex ratio of local deer has been observed, but the demographics of juveniles must still be ascertained through genetic methods. This study aims to further research concerning the development of a replicable and non-toxic procedure through which undergraduate students can identify the sex of numerous juvenile deer crania. Specifically, differing decalcification lengths, DNA extraction kit methods, and amelogenin primer sets were evaluated for relative success in …

Balancing Burrowing Owl (Athene Cunicularia Hypugaea) Protections While Maintaining Renewable Energy Development Within The San Joaquin Valley, Madison Lenzi Mcginn

Master's Projects and Capstones

Balancing the needs of wildlife and people has long been a complex challenge. The San Joaquin Valley exemplifies this tension, as space for agriculture and urbanization compete for land use of native grasslands– often resulting in the conversion of grasslands for agriculture fields, commercialized areas, or energy development. With an increasing number of agricultural landscapes going fallow and the passing of SB-100 in 2018, solar farm development has emerged as an attractive option to offset financial losses from unproductive farmland. However, the same landscapes favored for solar development also provide suitable habitat for sensitive species such the western burrowing owl …