Population Biology Commons^™

Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers

Biology Faculty Research

Regional species diversity generally increases with primary productivity whereas local diversity–productivity relationships are highly variable. This scale-dependence of the biodiversity–productivity relationship highlights the importance of understanding the mechanisms that govern variation in species composition among local communities, which is known as β-diversity. Hypotheses to explain changes in β-diversity with productivity invoke multiple mechanisms operating at local and regional scales, but the relative importance of these mechanisms is unknown. Here we show that changes in the strength of local density-dependent interactions within and among tree species explain changes in β-diversity across a subcontinental-productivity gradient. Stronger conspecific relative to …

Family Living Sets The Stage For Cooperative Breeding And Ecological Resilience In Birds, Michael Griesser, Szymon M. Drobniak, Shinichi Nakagawa, Carlos A. Botero

Biology Faculty Research

Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent–offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that …

A Global Community Effort To Decipher The Unique Biology Of Annual Killifish, Nibia Berois, Graciela Garcia, Rafael O. De Sá

Biology Faculty Publications

Over the past 50 years, annual killifishes arose as alternative model organisms for studies of vertebrate biology. The annual fish offers exceptional advantages for studies of genetics, genomics, developmental biology, population dynamics, ecology, biogeography, and evolution. They inhabit extremely variable freshwater environments in Africa and South America, have a short lifespan and a set of unique and fascinating developmental characteristics. Embryos survive within the dry substrate during the dry season, whereas the adult population dies. Thus, the survival of the populations is entirely dependent on the buried embryos that hatch the next rainy season. Although Old and New World species …

Costs Of Group Locomotion: How Infant-Carrying And Group Members Mediate Walking Speed Decisions In North American And East African Populations, Leah M. Bouterse

Honors Projects

A major portion of humans’ activity-based energy expenditure is taken up by locomotion, particularly walking. Humans can offset the energetic expenditure of walking in numerous ways, both evolutionary (such as changes in body shape) and culturally. Behaviorally, people can choose to walk in a variety of ways, including alone or with a group, carrying loads, and walking quickly or more slowly. All of these behaviors have energetic outcomes and as such can be important windows into how populations and groups adjust to different constraints. While sex differences in speed of paired walkers have been established by others, the dynamics of …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

The Santa Ana Speckled Dace (Rhinichthys Osculus): Phylogeography And Molecular Evolution Of The Mitochondrial Dna Control Region, James Jay Vanmeter

Electronic Theses, Projects, and Dissertations

The purpose of this genetic study of the Santa Ana Speckled Dace Rhinichthys osculus was three-fold. The first goal was to characterize the molecular structure of the mtDNA control region of R. osculus. An 1143 base-pair region of the mitochondrial DNA genome, which included the complete control region was sequenced for all individuals. Analysis of the sequence data revealed that the molecular structure of the speckled dace control region was similar to the molecular structure described for other vertebrate taxa. The speckled dace control region contains three major domains, which vary in base frequency as well as in the frequency …

Sexual Selection, Speciation And Constraints On Geographical Range Overlap In Birds, Christopher Cooney, Joseph A. Tobias, Jason T. Weir, Carlos A. Botero, Nathalie Seddon

Biology Faculty Research

The role of sexual selection as a driver of speciation remains unresolved, not least because we lack a clear empirical understanding of its influence on different phases of the speciation process. Here, using data from 1306 recent avian speciation events, we show that plumage dichromatism (a proxy for sexual selection) does not predict diversification rates, but instead explains the rate at which young lineages achieve geographical range overlap. Importantly, this effect is only significant when range overlap is narrow (< 20%). These findings are consistent with a ‘differential fusion’ model wherein sexual selection reduces rates of fusion among lineages undergoing secondary contact, facilitating parapatry or limited co-existence, whereas more extensive sympatry is contingent on additional factors such as ecological differentiation. Our results provide a more mechanistic explanation for why sexual selection appears to drive early stages of speciation while playing a seemingly limited role in determining broad-scale patterns of diversification.

Mitigating The Conflict Between Pitfall-Trap Sampling And Conservation Of Terrestrial Subterranean Communities In Caves, Peter Kozel, Tanja Pipan, Nina Šajna, Slavko Polak, Tone Novak

International Journal of Speleology

Subterranean habitats are known for their rich endemic fauna and high vulnerability to disturbance. Many methods and techniques are used to sample the biodiversity of terrestrial invertebrate fauna in caves, among which pitfall trapping remains one of the most frequently used and effective ones. However, this method has turned out to be harmful to subterranean communities if applied inappropriately. Traditionally, pitfall traps have been placed in caves solely on the ground. Here we present an optimized technique of pitfall trapping to achieve a balance between sampling completeness and minimal disturbance of the fauna in the cave. Monthly we placed traps …

Plant-Microbial Interactions Are Strong Determinants Of Plant Population And Community Dynamics, Yan-Yi Anny Chung 9485698

Biology ETDs

Plant-microbial interactions are ubiquitous and yet the consequences of these interactions on plant population and community dynamics are relatively unknown. Here, we used two different classes of plant-microbial interactions to examine their effects on key plant population and community characteristics such as commonness and rarity, competition and coexistence, as well as community stability.

Vertically-transmitted endophytes had stage-dependent effects on the population growth of two grass species Poa sylvestris and Poa alsodes, and generally increased host population growth rates. However, it was the intrinsic demographic advantage of P. sylvestris that allowed its population to grow at a much faster rate …

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …

Assessment Of The Calling Detection Probability Throughout The Day Of Two Invasive Populations Of Bullfrog (Lithobates Catesbeianus) In Uruguay, Gabriel Laufer, Noelia Gobel, Alvaro Soutullo, Claudio Martinez-Debat, Rafael O. De Sá

Biology Faculty Publications

Bullfrog invasion is a major conservation concern in South America, so there is an urgent need to detect and monitor its many invasion foci. Amphibian sampling methods commonly use calling display, specifically the nuptial calls of males. With the aim of obtaining the better day period to sample and monitor Lithobates catesbeianus presence, we recorded its calls at three ponds in two invaded localities in Uruguay (Aceguá, Cerro Largo, and San Carlos, Maldonado) during the reproductive season. Then, we studied the records, obtaining a subsample of calling intensity at the first 5 minutes for each hour. We detected that vocalization …

Gregariousness Does Not Vary With Geography, Developmental Stage, Or Group Relatedness In Feeding Redheaded Pine Sawfly Larvae, John W. Terbot Ii, Ryan L. Gaynor, Catherine R. Linnen

Biology Faculty Publications

Aggregations are widespread across the animal kingdom, yet the underlying proximate and ultimate causes are still largely unknown. An ideal system to investigate this simple, social behavior is the pine sawfly genus Neodiprion, which is experimentally tractable and exhibits interspecific variation in larval gregariousness. To assess intraspecific variation in this trait, we characterized aggregative tendency within a single widespread species, the redheaded pine sawfly (N. lecontei). To do so, we developed a quantitative assay in which we measured interindividual distances over a 90-min video. This assay revealed minimal behavioral differences: (1) between early-feeding and late-feeding larval instars, …

Trap-Neuter-Return Programs And The Importance Of Associated Public Awareness, Nicolette Sliwa

Biology: Student Scholarship & Creative Works

The focus of this paper is to describe a typical Trap-Neuter-Return (TNR) program and highlight the major pros and cons surrounding this somewhat controversial method of managing the overwhelming free-roaming cat population. The effects of the species’ overabundance on the environment and human health are also discussed. Citing studies completed on TNR programs around the globe as well as mathematical models, the effectiveness of this method is compared to other, currently used alternatives. Finally, it has been suggested that the general awareness level a neighborhood possesses about the true goals of TNR programs has a potentially significant impact on the …

Monitoring Anuran Populations In Bosque Protector Candelaria: A Multi-Year Comparison Of Frog Populations In An Ecuadorian Cloud Forest, Mindee Goodrum

Independent Study Project (ISP) Collection

For many years, amphibian populations around the world have been declining due to climate change, habitat loss or change, and diseases such as Ranavirus or the Chytrid fungus. However, there is still a great lack of information regarding the diversity of frogs, especially in the cloud forests of Ecuador where this study was conducted. This study was conducted in April and May of 2017 in the Ecominga Reserve of Cerro Candelaria in El Placer, Ecuador. The objective was to conduct visual-encounter surveys of several sites in the reserve and compare the results to studies that have been conducted in the …

Hitching A Ride: First Record Of A Least Chipmunk (Tamias Minimus) In Eastern Nebraska, Keith Geluso, Michael L. Forsberg

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

On 10 October 2016, a Least Chipmunk (Tamias minimus) was discovered in a residential area of Lincoln, Lancaster County, Nebraska. The closest populations of Least Chipmunks reside > 640 km to the west in northwestern Nebraska and southeastern Wyoming. The most parsimonious explanation for this unusual observation is that the chipmunk was transported to the city by humans. A likely scenario is that the chipmunk hitched a ride to Lincoln in a motor vehicle on 2 October 2016, when one of us drove 1500 km in a single day from Jackson, Teton County, Wyoming, after residing in that area …

Biotic And Abiotic Factors Predicting The Global Distribution And Population Density Of An Invasive Large Mammal, Jesse S. Lewis, Mathew L. Farnsworth, Christopher L. Burdett, David M. Theobald, Miranda Gray, Ryan S. Miller

Other Publications in Wildlife Management

Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal …

Estimating Seasonal Variation In Condition Of Yellow Perch, Emily Anne Powers

Biology Graduate Theses

Research has shown that Yellow Perch Perca flavescens, found throughout lakes and streams of North America, are good indicators of environmental health. Due to the correlation between fish condition and ecosystem health it is essential to reliably estimate condition to better manage our fisheries. Therefore, the study objectives were to measure the seasonal changes in adult Yellow Perch percent dry weight (PDW), and compare the reliability of bioelectrical impedance analysis (BIA) and morphometric-based estimates of condition. The seasonal fluctuations in average monthly PDW were measured over a two- year period and were sinusoidal in shape with peaks in August 2015 …

Evaluating Trophic Rewilding As A Conservation Technique, Aaron Sieve

Biology: Student Scholarship & Creative Works

The focus for this paper is to define specifically trophic rewilding, determine its efficacy as a conservation technique, and explore ways to lessen one of its key limitations. Trophic rewilding is the conservation technique whereby an extirpated keystone species or ecosystem engineer is reintroduced into a degraded habitat to restore ecological function by triggering trophic cascades. The technique is evaluated through analysis of the concepts of trophic cascades and ecosystem engineers. Key limitations of trophic rewilding are that a lack of population control in reintroduced may cause issues, that many times not enough is known about trophic cascades to be …

Fisheries Management Paper No.283 - Abalone Resource Of Western Australia Harvest Strategy 2106 - 2021, Department Of Fisheries Western Australia

Fisheries Management Papers

Harvest strategies for aquatic resources managed by the Western Australian Department of Fisheries (the Department) are formal documents prepared to support the decision-making processes required to ensure the management of these resources are consistent with the principles of Ecologically Sustainable Development (ESD). The objectives of ESD are reflected in the objects of the Fish Resources Management Act 1994 (FRMA) and Section 9 of the Aquatic Resources Management Act, which will replace the FRMA once proclaimed.

The publication of these strategies is intended to make the decision-making considerations and processes for the management of specified aquatic resources publicly transparent and provide …

Minnesota Fish Taxonomic Key 2017 Edition, Warren Lamb

Journal of Earth and Life Science

Minnesota’s landscape is maze of lakes and river that are home to a recorded total of 163 species of fish. This document is a complete and current dichotomous taxonomic key of the Minnesota fishes. This key was based on the 1972 “Northern Fishes” key (Eddy 1972), and updated based on Dr. Jay Hatch’s article “Minnesota Fishes: Just How Many Are There?” (Hatch 2016). Any new species or family additions were also referenced to the 7th edition of the American Fisheries society “Names of North American Fishes” (Page et al. 2013) to assess whether a fish species is currently recognized by …

Redd Habitat Selection For Brook Trout In The Necktie River Bemidji, Mn, William Varela, Zachary Buckley

Journal of Earth and Life Science

The presence of quality suitable habitat is important for the success of naturally reproducing Brook Trout populations. Therefore, measuring redd habitat Brook Trout select for was the focus of this study. Brook Trout redds were observed during the spawning season of 2016. We identified a total of 18 redds in the Necktie River in late October and early November. Specific environmental variables associated with redd selection were measured: velocity, in-stream cover, canopy cover, bank overhang, river width, substrate type and size, temperature, and max-depth. The same environmental variables were measured for 30 randomly selected sites. Redds were distributed in riffles …

Influence Of Time Spent In Captivity On Aggressive Behaviors Of Gray Wolves Canis Lupus, Chelsea Knutson

Journal of Earth and Life Science

Knowledge of the characteristics that promote group success is key to understanding the adaptive advantages of sociality for many group-oriented species. In this study, nine Gray Wolves Canis lupis were each observed twelve times over a period of six months to determine if the amount of time spent in the wild/captivity had any effect on aggressive behaviors. The number of aggressive behaviors were recorded for each wolf during each observation. The nine wolves were separated into three groups depending on their upbringing; born and raised in captivity, born in the wild and raised in captivity, and born and raised in …

Evolutionary Linkage Of Mimetic And Non-Mimetic Color Traits In A Coral Snake Mimicry Complex, John D. Curlis Jr

College of Graduate Studies: Theses & Dissertations

Color polymorphism in aposematic mimicry systems is a perplexing phenomenon for evolutionary biologists, as theoretically the benefits of converging on a model phenotype should constrain the evolution of phenotypic diversity in these systems (i.e., color polymorphism should not occur). Nevertheless, color polymorphism in mimicry systems is prevalent throughout many taxa. In some of these systems, the evolution of color polymorphism results in the existence of non-mimetic morphs, such as those that are cryptic. The case of ground snakes (Sonora semiannulata) is unique in that color polymorphism encompasses both mimetic and cryptic morphs, as well as individual mimetic and …

Inbreeding Depression In The Introduced Spider Latrodectus Geometricus, Margaret A. Howard

Honors College Theses

The brown widow spider (Latrodectus geometricus) is thought to be native to South America or Southern Africa, but its distribution has expanded to most continents by human introduction. In the continental USA, L. geometricus was first documented in south Florida in the 1930’s. In the early 2000’s a population expansion occurred, and this species is now found in Florida, Georgia, South Carolina, Alabama, Mississippi, Louisiana, Texas, and southern California. Introduced species may face many obstacles when establishing a new population. One common obstacle might be severe inbreeding following founder events or genetic bottlenecks. The purpose of this study was …

Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms.

Honors College Theses

Invasive species are a significant conservation concern given their contribution to native species decline. The barnacle, Megabalanus coccopoma, is a common invasive species in tropical and subtropical regions of both the Pacific and Atlantic oceans. Little is known about the life history and ecology of M. coccopoma, and data on reproductive biology could provide valuable insight into its propensity to establish introduced populations. Most species of barnacle (including M. coccopoma) are hermaphroditic, but self-fertilization is rare in species studied to date. A recent genetic study of introduced M. coccopoma populations in the southeastern US showed high levels of …

Effects Of Wildfires On Rattlesnake (Crotalus Oreganus) Growth And Movement In Washington State, Joseph Chase

All Master's Theses

Fire is a dominant force in the Pacific Northwest that shapes ecosystems and influences wildlife, yet little is known of its effects on local predators. Northern Pacific rattlesnakes (Crotalus oreganus) comprise an excellent model to investigate how fire may influence wildlife because they are important predators that contribute to controlling prey populations, but are also unable to readily escape from wildfires. We developed a novel technique to assess growth rates of rattlesnakes by using digital photography to analyze differences in widths of their rattle segments laid down over time. We compared growth rates of rattlesnakes in habitats that …

Burbot Growth Rates In A Northern Mesotrophic Lake, Samuel J. Peterson

Journal of Earth and Life Science

Burbot Lota lota has a circumpolar distribution throughout cold-water areas and is the only freshwater member of the family Gadidae. There are currently very few management techniques applied to Burbot throughout their northern extent. Growth is an indicator of fish health, biomass, and habitat quality; therefore, the objective of this study was to determine the growth rate of Burbot in Lake Bemidji. Burbot (n = 45) were collected along three sites on Lake Bemidji for years 2015-2017. Age was determined from sagittal otoliths, the marginal zones of which were opaque from December to May and translucent from June to November. …

Effects Of Catch-And-Release Angling On Egg Densities In Largemouth Bass Nests, Tyler Robinson

Journal of Earth and Life Science

Predation during early life stages of Centrarchidae offspring are a major cause of decreased reproductive success. For five-weeks Largemouth Bass Micropterus salmoides defend their broods from invaders such as Yellow Perch Perca flavescens and Bluegill Lepomis macrochirus. The focus of this study was to determine if predation upon Largemouth Bass broods increased as removal time from the nest via catch-and-release angling increased. Sampling was conducted on the Whitefish Chain, MN from 7 May - 7 June 2016, where a total of 29 nests were located and sampled. Three treatment groups were used; immediate catch-and-release, three-minute, and a seven- minute …

Effect Of Abiotic Factors On Bluegill Size Structure In Nine Central Minnesota Lakes, Ryan Henry

Journal of Earth and Life Science

Bluegill are the most targeted species of fish in Minnesota. In recent years, the abundance of slow growing, small Bluegill has increased within the state. Angler harvest of Bluegill can reduce the average length of Bluegill up to four times the original length. Abiotic factors such as maximum depth, average water clarity, littoral area, and percent littoral area can influence the dynamics of a lake system. There has been limited research on whether these abiotic factors can influence the size structure of a Bluegill population. The objective of this study is to determine if there is a direct relationship between …

Biotic Interchange Has Structured Western Hemisphere Mammal Communities, Danielle Fraser, S. Kathleen Lyons

School of Biological Sciences: Faculty Publications

Aim.— Many hypotheses posit that species-rich tropical communities are dominated by speciesspecies interactions, apparent as competitive exclusion or character displacement, whereas species-poor temperate communities are dominated by species-environment interactions. Recent studies demonstrate a strong influence of macroevolutionary and biogeographic factors. We simultaneously test for the effects of species interactions, climate, and biotic interchange on Western Hemisphere mammal communities using a phylogenetic and functional diversity approach.

Location.— Western Hemisphere.

Time period.— Modern

Major taxa studied.— Mammalia

Methods.— Using Western Hemisphere mammal distributional and body mass data, we calculate body mass dispersion, phylogenetic diversity (Net Relatedness Index), and assemblage-averaged rates of co-occurrence …