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Full-Text Articles in Biology

Examining Patterns In Nest Predation Using Artificial Nests, Victoria L. Simonsen Nov 2018

Examining Patterns In Nest Predation Using Artificial Nests, Victoria L. Simonsen

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

The use of artificial nests to study the predation of avian nests has faced disregard by ecologists due to inconsistencies found between the survival rates of real and artificial nests across studies and reviews. The negative perception of artificial nests providing an inconsistent assessment of survival has thus fostered the perception that artificial nests are a secondary option to be used to overcome logistical hurdles associated with achieving sufficient sample sizes in systems where study species are rare or elusive, or as merely a preliminary method to study predation across gradients. We argue that the greatest mistake ecologists have made …


Males And Females Evolve Riskier Traits In Populations With Eavesdropping Parasitoids, Oliver M. Beckers, William E. Wagner Oct 2018

Males And Females Evolve Riskier Traits In Populations With Eavesdropping Parasitoids, Oliver M. Beckers, William E. Wagner

School of Biological Sciences: Faculty Publications

Predation and/or parasitism often limits the evolution of conspicuous male traits and female preferences because conspicuous traits can attract predators or parasites and it is costly for females to associate with males that attract predators or parasites. As a result, males and females in high-risk populations are expected to evolve safer mating behaviors compared to individuals from low-risk populations. We tested this antagonistic selection hypothesis in the field cricket Gryllus lineaticeps. Males produce chirped songs, and both female crickets and the eavesdropping parasitoid fly Ormia ochracea prefer faster chirp rates. The flies attack the field crickets late in the …


Small Mammals In Cornfields And Associated Peripheral Habitats In Central Nebraska, Tyson J. Spanel, Keith Geluso Jun 2018

Small Mammals In Cornfields And Associated Peripheral Habitats In Central Nebraska, Tyson J. Spanel, Keith Geluso

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

In the Great Plains, many native grasslands have been converted to agricultural fields during the last two centuries. Peripheral habitats along edges of crop fields generally consist of linear habitats along roads, with many of these habitats used by native fauna. Our study examined capture rates and species composition of small mammals in cornfields, herbaceous roadside ditches, and wooded shelterbelts in central Nebraska. We captured nine species of small mammals. The Prairie Vole (Microtus ochrogaster) and Western Harvest Mouse (Reithrodontomys megalotis) were captured almost exclusively in roadside ditches, the White-footed Deermouse (Peromyscus leucopus) was …


Predators Modify The Temperature Dependence Of Life-History Trade-Offs, Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John Delong Jun 2018

Predators Modify The Temperature Dependence Of Life-History Trade-Offs, Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John Delong

School of Biological Sciences: Faculty Publications

Although life histories are shaped by temperature and predation, their joint influence on the interdependence of life-history traits is poorly understood. Shifts in one life-history trait often necessitate shifts in another—structured in some cases by trade-offs— leading to differing life-history strategies among environments. The offspring size–number trade-off connects three traits whereby a constant reproductive allocation (R) constrains how the number (O) and size (S) of offspring change. Increasing temperature and size-independent predation decrease size at and time to reproduction which can lower R through reduced time for resource accrual or size-constrained fecundity. We investigated how O, S, and R in …


Body Size Downgrading Of Mammals Over The Late Quaternary, Felisa A. Smith, Rosemary E. Elliott Smith, S. Kathleen Lyons, Jonathan L. Payne Apr 2018

Body Size Downgrading Of Mammals Over The Late Quaternary, Felisa A. Smith, Rosemary E. Elliott Smith, S. Kathleen Lyons, Jonathan L. Payne

School of Biological Sciences: Faculty Publications

Since the late Pleistocene, large-bodied mammals have been extirpated from much of Earth. Although all habitable continents once harbored giant mammals, the few remaining species are largely confined to Africa. This decline is coincident with the global expansion of hominins over the late Quaternary. Here, we quantify mammalian extinction selectivity, continental body size distributions, and taxonomic diversity over five time periods spanning the past 125,000 years and stretching approximately 200 years into the future. We demonstrate that size-selective extinction was already under way in the oldest interval and occurred on all continents, within all trophic modes, and across all time …


Energetic Tradeoffs Control The Size Distribution Of Aquatic Mammals, William Gearty, Craig R. Mcclain, Jonathan Payne Apr 2018

Energetic Tradeoffs Control The Size Distribution Of Aquatic Mammals, William Gearty, Craig R. Mcclain, Jonathan Payne

School of Biological Sciences: Faculty Publications

Four extant lineages of mammals have invaded and diversified in the water: Sirenia, Cetacea, Pinnipedia, and Lutrinae. Most of these aquatic clades are larger bodied, on average, than their closest land-dwelling relatives, but the extent to which potential ecological, biomechanical, and physiological controls contributed to this pattern remains untested quantitatively. Here, we use previously published data on the body masses of 3,859 living and 2,999 fossil mammal species to examine the evolutionary trajectories of body size in aquatic mammals through both comparative phylogenetic analysis and examination of the fossil record. Both methods indicate that the evolution of an aquatic lifestyle …


Olfactory Learning Capabilities Of Paraphrynus Laevifrons, John Perez Mar 2018

Olfactory Learning Capabilities Of Paraphrynus Laevifrons, John Perez

Honors Theses

Amblypygids, a species of nocturnal arachnids from the tropics and subtropics are incredibly intelligent and are able to not only navigate through difficult tropical terrain but also, it is believed, possess olfactory learning capabilities that aid in navigation and recollection of environments. It is hypothesized that through sensitive olfactory receptors on their antenniform legs and highly developed mushroom bodies, Amblypygi can not only learn smells but also learn to associate smells with certain stimuli such as a crevice to take refuge in. To test this hypothesis, Paraphrynus laevifrons, a species of amplypygid was subjected to four different learning treatment groups …


Eight-Legged Encounters—Arachnids, Volunteers, And Art Help To Bridge The Gap Between Informal And Formal Science Learning, Eileen Hebets, Melissa Welch-Lazoritz, Pawl Tisdale, Patricia Wonch Hill Feb 2018

Eight-Legged Encounters—Arachnids, Volunteers, And Art Help To Bridge The Gap Between Informal And Formal Science Learning, Eileen Hebets, Melissa Welch-Lazoritz, Pawl Tisdale, Patricia Wonch Hill

Eileen Hebets Publications

Increased integration and synergy between formal and informal learning environments is proposed to provide multiple benefits to science learners. In an effort to better bridge these two learning contexts, we developed an educational model that employs the charismatic nature of arachnids to engage the public of all ages in science learning; learning that aligns with the Next Generation Science Standards (NGSS Disciplinary Core Ideas associated with Biodiversity and Evolution). We created, implemented, and evaluated a family-focused, interactive science event—Eight-Legged Encounters (ELE)—which encompasses more than twenty modular activities. Volunteers facilitated participant involvement at each activity station and original …


Convergent Body Size Evolution Of Crocodyliformes Upon Entering The Aquatic Realm, William Gearty, Jonathan Payne Jan 2018

Convergent Body Size Evolution Of Crocodyliformes Upon Entering The Aquatic Realm, William Gearty, Jonathan Payne

School of Biological Sciences: Posters and Presentations

Twenty-four species of crocodile populate the globe today, but this richness represents a minute fraction of the diversity and disparity of Crocodyliformes since their origin early in the Triassic. Across this clade, three major diversification events into the aquatic realm have occurred. Aquatic and terrestrial habitats impose differing selective pressures on body size. However, previous research on this topic in Crocodyliformes remains qualitative in nature. In this study, our goal was to quantify the influence of habitat (terrestrial versus aquatic) on the evolution of body size in Crocodyliformes. We find a history of repeated body size increase and convergence following …