Life Sciences Commons^™

Limitations Of Invasive Snake Control Tools In The Context Of A New Invasion On An Island With Abundant Prey, Shane R. Siers, Melia G. Nafus, Jereid E. Calaor, Rachel M. Volsteadt, Matthew S. Grassi, Megan Volsteadt, Aaron F. Collins, Patrick D. Barnhart, Logan T. Huse, Amy A. Yackel Adams, Diane L. Vice

USDA Wildlife Services: Staff Publications

In October 2020, a new population of invasive brown treesnakes (Boiga irregularis) was discovered on the 33-ha Cocos Island, 2.5 km off the south coast of Guam, United States. Cocos Island is a unique conservation resource, providing refuge for many lizards and birds, including endangered species, which were extirpated from mainland Guam by invasive predators including brown treesnakes. We sought to evaluate the usefulness of toxic baiting with acetaminophen-treated carrion baits and cage trapping, common tools for the control of brown treesnakes on mainland Guam, as potential eradication tools on Cocos Island. We evaluated multiple bait types and …

A Systematic Map Of Human-Carnivore Coexistence, Cassandre C. Venumière-Lefebvre, Stewart W. Breck, Kevin R. Crooks

USDA Wildlife Services: Staff Publications

Carnivore populations globally have largely declined, and coexistence, where humans and carnivores share landscapes, plays a crucial role in carnivore conservation. However, the term “coexistence” is often used in scientific and popular literature without being clearly defined. Herein, we provide a global perspective on what coexistence is and how it is studied. We conducted a systematic map of 366 articles published between 1987 and 2020 to characterize human-carnivore coexistence literature according to coexistence definitions, temporal trends, geographic and taxonomic focus, and four thematic aspects of coexistence: carnivore ecology, human endeavors, social conflict and human-carnivore conflict. We used chi-squared tests and …

Great Expectations: Deconstructing The Process Pathways Underlying Beaver-Related Restoration, Caroline S. Nash, Gordon E. Grant, Susan Charnley, Jason B. Dunham, Hannah Gosnell, Mark B. Hausner, David S. Pilliod, Jimmy Taylor

USDA Wildlife Services: Staff Publications

Beaver-related restoration is a process-based strategy that seeks to address wide-ranging ecological objectives by reestablishing dam building in degraded stream systems. Although the beaver-related restoration has broad appeal, especially in water-limited systems, its effectiveness is not yet well documented. In this article, we present a process-expectation framework that links beaver-related restoration tactics to commonly expected outcomes by identifying the set of process pathways that must occur to achieve those expected outcomes. We explore the contingency implicit within this framework using social and biophysical data from project and research sites. This analysis reveals that outcomes are often predicated on complex process …

Evaluating Potential Effects Of Solar Power Facilities On Wildlife From An Animal Behavior Perspective, Rachel Y. Chock, Barbara Clucas, Elizabeth K. Peterson, Bradley Blackwell, Daniel T. Blumstein, Kathleen Church, Esteban Fernández-Juricic, Gabriel Francescoli, Alison L. Greggor, Paul Kemp, Gabriela M. Pinho, Peter M. Sanzenbacher, Bruce A. Schulte, Pauline Toni

USDA Wildlife Services: Staff Publications

Solar power is a renewable energy source with great potential to help meet increasing global energy demands and reduce our reliance on fossil fuels. However, research is scarce on how solar facilities affect wildlife. With input from professionals in ecology, conservation, and energy, we conducted a research-prioritization process and identified key questions needed to better understand impacts of solar facilities on wildlife. We focused on animal behavior, which can be used to identify population responses before mortality or other fitness consequences are documented. Behavioral studies can also offer approaches to understand the mechanisms leading to negative interactions (e.g., collision, singeing, …

Best Management Practices For Trapping Furbearers In The United States, H. Bryant White, Gordon R. Batcheller, Edward K. Boggess, Clifford L. Brown, Joseph W. Butfiloski, Thomas A. Decker, John D. Erb, Michael W. Fall, David A. Hamilton, Tim L. Hiller, George F. Hubert Jr., Matthew J. Lovallo, John F. Olson, Nathan M. Roberts

USDA Wildlife Services: Staff Publications

Humans have used wild furbearers for various purposes for thousands of years. Today, furbearers are sustainably used by the public for their pelts, leather, bones, glands, meat, or other purposes. In North America, contemporary harvest of furbearers has evolved along with trap technologies and societal concerns, and is now highly regulated and more closely coupled with harvest analysis and population monitoring. Traps and regulated trapping programs provide personal or cultural rewards that can also support conservation, and can assist with advancing ecological knowledge through research, protecting endangered species, restoring populations or habitats, protecting personal property, and enhancing public health and …

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. …

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). …

A Potential New Tool For The Toolbox: Assessing Gene Drives For Eradicating Invasive Rodent Populations, K. J. Campbell, J.R. Saah, P.R. Brown, J. Godwin, G.R. Howald, A. Piaggio, P. Thomas, D.M. Tompkins, D. Threadgill, J. Delborne, D.M. Kanavy, T. Kuiken, H. Packard, M. Serr, A. Shiels

USDA Wildlife Services: Staff Publications

Invasive rodents have significant negative impacts on island biodiversity. All but the smallest of rodent eradications currently rely on island-wide rodenticide applications. Although significant advances have been made in mitigating unintended impacts, rodent eradication on inhabited islands remains extremely challenging. Current tools restrict eradication eff orts to fewer than 15% of islands with critically endangered or endangered species threatened by invasive rodents. The Genetic Biocontrol of Invasive Rodents partnership is an interdisciplinary collaboration to develop and evaluate gene drive technology for eradicating invasive rodent populations on islands. Technological approaches currently being investigated include the production of multiple strains of Mus …

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 …

Impacts Of Biomass Production At Civil Airports On Grassland Bird Conservation And Aviation Strike Risk, Tara J. Conkling, Jerrold L. Belant, Travis L. Devault, James A. Martin

USDA Wildlife Services: Staff Publications

Growing concerns about climate change, foreign oil dependency, and environmental quality have fostered interest in perennial native grasses (e.g., switchgrass [Panicum virgatum]) for bioenergy production while also maintaining biodiversity and ecosystem function. However, biomass cultivation in marginal landscapes such as airport grasslands may have detrimental effects on aviation safety as well as conservation efforts for grassland birds. In 2011–2013, we investigated effects of vegetation composition and harvest frequency on seasonal species richness and habitat use of grassland birds and modeled relative abundance, aviation risk, and conservation value of birds associated with biomass crops. Avian relative abundance was greater …

Using Species Distribution Models To Define Nesting Habitat Of The Eastern Metapopulation Of Double-Crested Cormorants, Kate L. Sheehan, Samuel T. Esswein, Brian S. Dorr, Greg K. Yarrow, Ron J. Johnson

USDA Wildlife Services: Staff Publications

When organisms with similar phenotypes have conflicting management and conservation initiatives, approaches are needed to differentiate among subpopulations or discrete groups. For example, the eastern metapopulation of the double-crested cormorant (Phalacrocorax auritus) has a migratory phenotype that is culled because they are viewed as a threat to commercial and natural resources, whereas resident birds are targeted for conservation. Understanding the distinct breeding habitats of resident versus migratory cormorants would aid in identification and management decisions. Here, we use species distribution models (SDM: Maxent) of cormorant nesting habitat to examine the eastern P. auritus metapopulation and the predicted breeding …

Improving The Odds: Assessing Bait Availability Before Rodent Eradications To Aid In Selecting Bait Application Rates, Madeleine Pott, Alexander S. Wegmann, Richard Griffiths, Araceli Samaniego-Herrera, Richard J. Cuthbert, M. De L. Brooke, William C. Pitt, Are R. Berentsen, Nick D. Holmes, Gregg R. Howald, Karina Ramos-Rendon, James C. Russell

USDA Wildlife Services: Staff Publications

Rodent eradications undertaken on tropical islands are more likely to fail than eradications undertaken at higher latitudes. We report on 12 independent rodent eradication projects undertaken on tropical islands that utilized the results of an in situ bait availability study prior to eradication to inform, a priori, the bait application rate selected for the eradication. These projects also monitored bait availability during the eradication. The results from our analysis verified the utility of bait availability studies to future rodent eradication campaigns and confirmed the influence of two environmental factors that can affect bait availability over time: precipitation prior to the …

Managing Hybridization Of A Recovering Endangered Species: The Red Wolf Canis Rufus As A Case Study, Eric M. Gese, Fred F. Knowlton, Jennifer R. Adams, Karen Beck, Todd K. Fuller, Dennis L. Murray, Todd D. Steury, Michael K. Stoskopf, Will T. Waddell, Lisette P. Waits

USDA Wildlife Services: Staff Publications

Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered species recovery effort for the red wolf Canis rufus is a classic system for understanding and addressing the challenges of hybridization. From 1987‒1993, 63 red wolves were released from captivity in eastern North Carolina, USA, to establish a free-ranging, non-essential experimental population. By 1999, managers recognized hybridization with invasive coyotes Canis latrans was the single greatest threat to successful recovery, and an adaptive management plan was adopted with innovative approaches for managing the …