Life Sciences Commons^™

Trophic Cascades Alter Eco-Evolutionary Dynamics And Body Size Evolution, Thomas M. Luhring, John Delong

School of Biological Sciences: Faculty Publications

Trait evolution in predator–prey systems can feed back to the dynamics of interacting species as well as cascade to impact the dynamics of indirectly linked species (eco-evolutionary trophic cascades; EETCs). A key mediator of trophic cascades is body mass, as it both strongly influences and evolves in response to predator–prey interactions. Here, we use Gillespie ecoevolutionary models to explore EETCs resulting from top predator loss and mediated by body mass evolution. Our four-trophic-level food chain model uses allometric scaling to link body mass to different functions (ecological pleiotropy) and is realistically parameterized from the FORAGE database to mimic the parameter …

Coyotes, Rick Tischaefer

Wildlife Damage Management Technical Series

The coyote (Canis latrans; Figure 1) is a medium-sized member of the canid family. Once primarily found in western deserts and grasslands, coyotes have expanded their range across North America and into diverse habitats, including urban areas. This expansion occurred during a time of extensive habitat change and efforts by people to suppress coyote populations to prevent damage. Coyotes can cause a variety of conflicts related to agriculture, natural resources, property, and human health and safety. This document highlights a variety of methods for reducing those conflicts. Coyotes are a highly adaptable species and may become habituated to some management …

Predators As Agents Of Selection And Diversification, Jerald B. Johnson, Mark C. Belk

Faculty Publications

Predation is ubiquitous in nature and can be an important component of both ecological and evolutionary interactions. One of the most striking features of predators is how often they cause evolutionary diversification in natural systems. Here, we review several ways that this can occur, exploring empirical evidence and suggesting promising areas for future work. We also introduce several papers recently accepted in Diversity that demonstrate just how important and varied predation can be as an agent of natural selection. We conclude that there is still much to be done in this field, especially in areas where multiple predator species prey …

Distribution And Activity Patterns Of Large Carnivores And Their Implications For Human–Carnivore Conflict Management In Namibia, Summer Fink, Richard Chandler, Michael Chamberlain, Steven Castleberry, Shannon Glosenger-Thrasher

Human–Wildlife Interactions

Human–wildlife conflicts (HWCs) are increasing globally and contributing to the decline of wildlife species. In sub-Saharan African countries such as Namibia, most of the suitable land has been or is currently being converted to crop and livestock production to support income or subsistence agriculture. These changes in land use often incur increased levels of HWCs because of crop and livestock depredation by native species. To quantify livestock predation risks posed by carnivores in Namibia, we deployed 30 trail cameras on a 6,500-ha farm in the Khomas region of Namibia from May to July 2018. We developed occupancy models to make …

Identification Of Predation Events In Wild Fish Using Novel Acoustic Transmitters, Amy A. Weinz, Jordan K. Matley, Natalie V. Klinard, Aaron T. Fisk, Scott F. Colborne

Great Lakes Institute for Environmental Research Publications

Background: Acoustic telemetry is a commonly used tool to gain knowledge about aquatic animal ecology through the study of their movements. In telemetry studies researchers must make inferences regarding the movements and the fates of tagged animals. Until recently, predation has been inferred in telemetry data using a variety of methods including abrupt changes in movement patterns or habitat use. An acoustic telemetry transmitter has been developed to detect predation events of tagged animals, and while they have performed well in controlled laboratory trials, literature regarding the application of these novel transmitters in field settings is limited. The objective of …

Quantifying The Ecological Drivers And Impacts Of Parrotfish Predation On Caribbean Corals Communities, Hannah Sima Rempel

Master's Theses

Parrotfishes (Scarinae) are dominant Caribbean herbivores that play an important role in reducing coral-algae competition by grazing algae; yet some species are also occasional coral predators (corallivores) and thereby can have direct negative impacts on coral growth and survivorship. There is concern that parrotfish corallivory may contribute to substantial long-term declines in targeted coral species, particularly in areas with a high biomass of parrotfishes and low cover of corals. However, the capacity of target coral species to heal from parrotfish predation and the ecological drivers of corallivory are poorly understood.

In Chapter 1, we examined the patterns of coral healing …

Effects Of Freshwater Crayfish On Influenza A Virus Persistence In Water, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Several investigations have recently assessed the ability of some aquatic invertebrates to act as tools for avian influenza A virus (IAV) surveillance as well as their potential role(s) in IAV ecology. Because of this, as well as the high IAV seroprevalence rates noted in select mesocarnivores that commonly inhabit aquatic and semi-aquatic habitats, we evaluated the effects that freshwater crayfish have on IAV in water at three dose levels and monitored for the presence of IAV in crayfish tissues (gill and green gland) and haemolymph at multiple time points. At relatively high, medium 432 and low (approximately 10 , 10 …

Temporal Factors Affecting Foraging Patterns Of A Diurnal Orb-Weaving Spider, Micrathena Gracilis (Araneae: Araneidae), Mitchell Davis Long

Undergraduate Honors Theses

Several studies have investigated the ecological factors that affect behavior in Micrathena gracilis, a diurnal orb-weaving spider that forages on flying insects during the day. However, none yet have considered how the temporal distributions of prey and predator occurrences shape their daily behavioral rhythms, especially web construction, which involves a heavy energetic investment well in advance of potential nutritional benefit. Recently, several orb-weaving spider species have been shown to exhibit a variety of abnormal rhythms, suggesting that circadian clock-controlled rhythms may play an unexpected role in behavioral evolution. Despite the appearance of significant insect abundance in the evenings, M. gracilis …

The Effects Of Leaf Litter On Predation Cue Response In Gray Tree Frog Tadpoles, Hyla Versicolor, Dani Mccauley

Undergraduate Distinction Papers

Plant litter is an important resource for consumers, particularly in freshwater environments where it influences the development processes of larval amphibians. Leaf litter alters the physiochemical environment by lowering dissolved oxygen while increasing nitrogen, tannin, and phenolic acid levels. Many anuran species show plastic responses to the threat of predation. This is communicated through a kairomone when a tadpole is consumed, allowing surviving tadpoles to alter their behavior and morphology to evade predators. The purpose of this study was to analyze the interactive effects of leaf litter and predation on gray treefrog tadpoles (Hyla versicolor). The chemical output of the …

Does The Morphologically Constrained Species Alfaro Cultratus Display Sexual Dimorphism?, Kelsie Bonnett, Kaitlyn Golden, Jerald B. Johnson

Library/Life Sciences Undergraduate Poster Competition 2020

Is there a difference between male and female anal fin length in relation to body length in Alfaro cultratus?

1. Does overall anal fin length (adjusted for body length) differ between sexes?

2. Does the rate at which anal fin length changes as body size increases differ between sexes?

3. Does predation affect these differences?

Spider Prey Of Mud-Dauber Wasps In Southeastern Nebraska, Earl Agpawa, Tyler Corey, Eileen Hebets

UCARE Research Products

Predator-prey interactions between organisms provide a window into behaviors, adaptions, and evolutionary histories of both groups. One group of organisms of would be female spider-specialist mud-dauber wasps (Hymenoptera: Sphecidae) who seek out and sting spiders to bring back to their nests for their larvae to feed upon. This interaction provides a unique means of quantifying the diversity and abundance of the prey they capture. In this study, we inventoried spiders from within collected nests of mud-dauber wasps Sceliphron caementarium (Drury) and Chalybion californicum (Saussure) from agricultural land and in a forest corridor. It was found that nests collected in agricultural …

Anthropogenic Disturbance And Population Viability Of Woodland Caribou In Ontario, John M. Fryxell, Tal Avgar, Boyan Liu, James A. Baker, Arthur R. Rodgers, Jennifer Shuter, Ian D. Thompson, Douglas E. B. Reid, Andrew M. Kittle, Anna Mosser, Steven G. Newmaster, Tom D. Nudds, Garrett M. Street, Glen S. Brown, Brent Patterson

Wildland Resources Faculty Publications

One of the most challenging tasks in wildlife conservation and management is to clarify how spatial variation in land cover due to anthropogenic disturbance influences wildlife demography and long‐term viability. To evaluate this, we compared rates of survival and population growth by woodland caribou (Rangifer tarandus caribou) from 2 study sites in northern Ontario, Canada that differed in the degree of anthropogenic disturbance because of commercial logging and road development, resulting in differences in predation risk due to gray wolves (Canis lupus). We used an individual‐based model for population viability analysis (PVA) that incorporated adaptive patterns …

Common Ravens, Luke W. Peebles, Jack O. Spencer Jr.

Wildlife Damage Management Technical Series

Damage Management Methods for Common Ravens

Type of Control -- Available Management Options

Exclusion -- Often ineffective or impractical

Fertility Control -- None available

Frightening Devices -- Effigies • Pyrotechnics and propane cannons • Lasers and flashing lights

Habitat Modification -- Bale and bury garbage • Install dumpsters with secure lids • Remove or bury dead livestock • Remove abandoned houses, sheds, and barns to eliminate nesting structures

Nest Treatment -- Allowed with proper Federal and State permits; Egg oiling or addling and nest destruction

Repellents -- Methiocarb (EPA Reg. No. 56228-33) • Methyl anthranilate (food-grade grape flavoring agent)

Shooting …

Predator-Based Selection And The Impact Of Edge Sympatry On Components Of Coralsnake Mimicry, Lauren E. Wilson

Electronic Theses and Dissertations

Studying warning coloration and mimicry is an effective way to understand predator-driven selection and phenotypic diversity. The presence (sympatry) or absence (allopatry) of a toxic model plays a role in shaping mimetic phenotypes. However, the impact of edge sympatry and allopatry on predation of mimetic phenotypes is not well understood. We studied coralsnake mimicry to test how edge sympatry and allopatry affect predation on mimetic phenotypes. Specifically, we tested 1) if overall attack rates varied with edge sympatry of coralsnakes 2) which color patterns conferred a fitness advantage 3) which specific mimetic signal components are important in driving predatory attacks …

Bottom-Up Herbivore-Plant Feedbacks Trump Trophic Cascades In A Wolf-Elk-Grassland System, Trevor C. Weeks

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Top-down predator-prey effects that alter the abundance, biomass, or productivity of a population community across more than one link in a food web are referred to as trophic cascades. While these effects have been extensively studied in aquatic environments, fewer studies have examined trophic cascades in terrestrial ecosystems. And fewer still terrestrial studies have tested for trophic cascades between vertebrates and grassland vegetation. Across the globe, grassland plant biomass is driven by both precipitation and non-linear positive feedbacks between grazing and plant productivity, as predicted by the Intermediate Grazing Hypothesis. Yet little is known about the role that apex carnivores …

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

Abstract

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with multiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation responded only to one or the other (but not both), resulting in unpredictable outcomes. These changes in …

Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon

Cal Poly Humboldt theses and projects

Survival of juvenile ungulates is known to be highly variable, yet it is fundamental to understanding the dynamics and trends of wildlife populations. Factors influencing calf survival are poorly understood in northwestern California where Roosevelt elk (Cervus canadensis roosevelti) are known to exist. The objectives of this study were 1) to estimate summer and annual survival rates and determine recruitment rates for Roosevelt elk calves in the area, 2) to evaluate differences in calf survival by examining the effects of individual and population level covariates on summer and annual calf survival, 3) to identify factors influencing the timing …

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with mul- tiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation re- sponded only to one or the other (but not both), resulting in unpredictable outcomes. …