Ecology and Evolutionary Biology Commons^™

The Interactive Effects Of Pesticide Exposure And Infectious Disease On Amphibian Hosts, Katherine M. Pochini

Open Access Theses

Natural systems are home to a multitude of natural and anthropogenic stressors, which draw an array of effects on ecological communities. While these effects have been investigated individually, it is important, given the routine co-occurrence of these stressors, to understand their interactive effects. Pesticide exposure and infectious disease are two common, co-occurring stressors that each have documented detrimental effects on species and, as evidence suggests, may have interactive effects. Moreover, existing research suggests that these interactive effects are highly context dependent, eliciting different results based on species, disease agent, toxin, and environment. Given the variability with which species may experience …

Behavioral Differences Between Native And Exotic Invertebrate Prey Affect Susceptibility To Predation By A Native Amphibian Predator, Zachary Cava

Biology Theses

Invasive species threaten global biodiversity via mechanisms that include altering the dynamics and structure of native food webs. Whereas much research has focused on how exotic species respond to native predators, less is known about how native predators are affected by invasive prey. Here I investigate the response of a rare and threatened native predator—the Eastern Hellbender (Cryptobranchus alleganiensis) to a high-profile invasive crayfish species, Orconectes rusticus. Hellbenders have declined throughout much of their range, and although the potential for exotic predators (i.e. sport fish) to negatively impact C. alleganiensis has been addressed, effects of exotic prey …

Temperature Variability And Multiple Environmental Stressors: How Will Tadpole Performance Change With Our Climate?, Diana C. Macklem, Tracy A. G. Rittenhouse, Ashley M. Helton, Jason H. O'Connor, Jaron T. Kolek

University Scholar Projects

This project seeks to analyze how predicted changes in climate and its interactions with other environmental factors will influence tadpole growth and development. Our first study examined how the frequency and magnitude of temperature variability affect wood frog and gray tree frog tadpole performance. We found that performance responses to repeatedly fluctuating treatments did not differ significantly from constant temperatures held at the same mean for wood frog tadpoles. However, elevated mean temperatures of 26 degrees Celsius caused tadpoles to metamorphose early, suggesting a potential developmental threshold. We found that gray tree frog performance was affected by fluctuating temperature treatments, …

Tiger Salamanders Disappearing In Region, Dennis M. Ferraro

School of Biological Sciences: Faculty Publications

"Where have all the salamanders gone?" 'This is a question I have been increasingly asked over the past five to six years from area residents. It seems we are observing a dramatic population decline of the western barred tiger salamander in parts of Southeast Nebraska. The western barred tiger salamander (Ambystoma mavortium) is one of only two salamanders in Nebraska. Over the past two years, none have been found in southeast Nebraska.

Salamanders, like all amphibians, are excellent indicator species. In many cases they act like the iconic canary in the mine shaft, telling us when to run …

Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker

Master's Theses

With current declines of vertebrate taxa meeting or exceeding those of historic mass extinction events, there is a growing need to investigate the main drivers of declines. Amphibians are perhaps at greatest risk of global climate change and land-use changes than most other vertebrate classes and also have significant roles in ecosystem processes – combined, this creates a cause for concern. I designed a study that would investigate the effects of current and predicted climate change and land-use changes on amphibians using species distribution models and a field study to identify the potential consequences of amphibian species declines by investigating …

Spatial Capture–Recapture: A Promising Method For Analyzing Data Collected Using Artificial Cover Objects, Chris Sutherland, David Mun'oz, David Miller, Evan Grant

Environmental Conservation Faculty Publication Series

Spatial capture–recapture (SCR) is a relatively recent development in ecological statistics that provides a spatial context for estimating abundance and space use patterns, and improves inference about absolute population density. SCR has been applied to individual encounter data collected noninvasively using methods such as camera traps, hair snares, and scat surveys. Despite the widespread use of capture based surveys to monitor amphibians and reptiles, there are few applications of SCR in the herpetological literature. We demonstrate the utility of the application of SCR for studies of reptiles and amphibians by analyzing capture–recapture data from Red-Backed Salamanders, Plethodon cinereus, collected using …

Spatial Capture–Recapture: A Promising Method For Analyzing Data Collected Using Artificial Cover Objects, Chris Sutherland, David Mun'oz, David Miller, Evan Grant

Chris Sutherland