Life Sciences Commons^™

Non-Invasive Methods For Measuring And Monitoring Stress Physiology In Imperiled Amphibians, Edward J. Narayan, Zachery R. Forsburg, Drew R. Davis, Caitlin R. Gabor

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Global climate change is negatively impacting global biodiversity and ectothermic vertebrates, with amphibians being the most imperiled vertebrate taxa. Increased mean global atmospheric temperatures, high rates of habitat degradation, and exposure to infectious diseases, such as chytridiomycosis, have contributed to population declines and extinctions of rare and endangered amphibian species. Field-based monitoring of physiological endocrine traits can help determine the sub-lethal effects of environmental stressors and provide early alerts when populations are chronically stressed. Recent advances in amphibian stress endocrinology include the development and use of non-invasive methods to quantify the glucocorticoid, or stress biomarker, corticosterone. Non-invasive methods, such as …

Impact Of The Human Footprint On Anthropogenic Mortality Of North American Reptiles, Jacob E. Hill, Travis L. Devault, Jerrold L. Belant

USDA Wildlife Services: Staff Publications

Human activities frequently result in reptile mortality, but how direct anthropogenic mortality compares to natural morality has not been thoroughly investigated. There has also been a limited examination of how anthropogenic reptile mortality changes as a function of the human footprint. We conducted a synthesis of causespecific North American reptile mortality studies based on telemetry, documenting 550 mortalities of known cause among 2461 monitored individuals in 57 studies. Overall 78% of mortality was the result of direct natural causes, whereas 22% was directly caused by humans. The single largest source of mortality was predation, accounting for 62% of mortality overall. …

Spatial And Seasonal Differences In The Top Predators Of Easter Island: Essential Data For Implementing The New Rapa Nui Multiple‐Uses Marine Protected Area, Naiti A. Morales, Erin E. Easton, Alan M. Friedlander, Euan S. Harvey, Rodrigo Garcia, Carlos F. Gaymer

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

1. Reef fishes are an important component of marine biodiversity, and changes in the composition of the assemblage structure may indicate ecological, climatic, or anthropogenic disturbances. To examine spatial differences in the reef fish assemblage structure around Easter Island, eight sites were sampled during autumn and summer 2016–2017 with baited remote underwater video systems.
2. To determine seasonal changes, quarterly (seasonal) sampling was conducted at five of those eight sites. Fifteen pelagic species of fishes were recorded during this study, some of which have not previously been recorded in scuba surveys, including the Galapagos shark (Carcharhinus galapagensis, Snodgrass & Heller, …

From Traps To Snapshots: Examining The Ecology Of Feral Predators And Native Small Mammals In Southeastern Australia Through Case Studies Of Two Faunal Sampling Methods, Katherine Karson

Independent Study Project (ISP) Collection

The red fox (Vulpes vulpes) and feral cat (Felis catus) are introduced mesopredators that significantly threaten native small mammal species in Australia. For decades, environmental managers have attempted to mitigate the effects of these introduced species. However, ecosystems are highly complex, making it difficult to assess the impacts of feral predators on communities of native fauna independent of other disturbances such as fire regime and habitat fragmentation. Cost-effective ecological monitoring programs are imperative for evaluating threats to native species and informing environmental decisions. New technology has become increasingly present in wildlife monitoring, and camera trapping has provided an alternative to …

Operationalizing Ecological Resilience Concepts For Managing Species And Ecosystems At Risk, Jeanne C. Chambers, Craig R. Allen, Samuel A. Cushman

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

This review provides an overview and integration of the use of resilience concepts to guide natural resources management actions. We emphasize ecosystems and landscapes and provide examples of the use of these concepts from empirical research in applied ecology. We begin with a discussion of definitions and concepts of ecological resilience and related terms that are applicable to management. We suggest that a resilience-based framework for management facilitates regional planning by providing the ability to locate management actions where they will have the greatest benefits and determine effective management strategies. We review the six key components of a resilience-based framework, …

Sex‐Biased Survival Contributes To Population Decline In A Long‐Lived Seabird, The Magellanic Penguin, Natasha J. Gownaris, P. D. Boersma

Environmental Studies Faculty Publications

We developed a Hidden Markov mark–recapture model (R package marked) to examine sex‐specific demography in Magellanic Penguins (Spheniscus magellanicus ). Our model was based on 33 yr of resightings at Punta Tombo, Argentina, where we banded ~44,000 chicks from 1983 to 2010. Because we sexed only 57% of individuals over their lifetime, we treated sex as an uncertain state in our model. Our goals were to provide insight into the population dynamics of this declining colony, to inform conservation of this species, and to highlight the importance of considering sex‐specific vital rates in demographic seabird studies. Like many other …

Cause‐Specific Mortality Of The World’S Terrestrial Vertebrates, Jacob E. Hill, Travis L. Devault, Jerrold L. Belant

USDA Wildlife Services: Staff Publications

Aim: Vertebrates are declining worldwide, yet a comprehensive examination of the sources of mortality is lacking. We conducted a global synthesis of terrestrial vertebrate cause‐specific mortality to compare the sources of mortality across taxa and determine predictors of susceptibility to these sources of mortality.

Location: Worldwide.

Time period: 1970–2018.

Major taxa studied: Mammals, birds, reptiles and amphibians.

Methods: We searched for studies that used telemetry to determine the cause of death of terrestrial vertebrates. We determined whether each mortality was caused by anthropogenic or natural sources and further classified mortalities within these two categories (e.g. harvest, vehicle collision and predation). …

Mind The Gap: Experimental Tests To Improve Efficacy Of Fladry For Nonlethal Management Of Coyotes, Julie K. Young, John Draper, Stewart Breck

USDA Wildlife Services: Staff Publications

Coyotes (Canis latrans) are the top predator of livestock in the contiguous United States. Developing more effective nonlethal tools to prevent coyote depredation will facilitate coexistence between livestock producers and coyotes. Fladry is a nonlethal deterrent designed to defend livestock by creating a visual barrier to wolves (C. lupus). Fladry may also be effective with coyotes, but large gap spacing between flags may reduce its efficacy. To address this issue, we performed 2 experiments on captive coyotes using fladry modified to reduce gap spacing at the U.S. Department of Agriculture, Predator Research Facility in Millville, Utah, USA, during 2015–2016 and …

Home Range, Habitat Use And Thermal Ecology Of The Florida Box Turtle (Terrapene Bauri) On An Anthropogenic Island In Southwestern Florida, Christina Demetrio

Antioch University Full-Text Dissertations & Theses

Limited information is available on the ecology of Terrapene bauri (Florida Box Turtle) in mangrove ecosystems. Radio-telemetry and iButton data loggers were used to study the home range, habitat use, and thermal ecology of ten Florida Box Turtles on an anthropogenic island in the mangrove-dominated region of southwestern Florida. The effects of weather variables on movement and activity were also examined. Home range analysis using Minimum Convex Polygons (MCP) and Kernel Density Estimates (KDE) determined an average home range size of 0.81 ha (MCP) and 2.32 ha (95% KDE). Box Turtles moved an average distance of 6.3 m per day …