Terrestrial and Aquatic Ecology Commons^™

Foot Injuries In Michigan, Usa, Gray Wolves (Canis Lupus), 1992–2014, Daniel J. O'Brien, Dean E. Beyer Jr., Erin Largent, Julie R. Melotti, Caitlin N. Ott-Conn, Donald H. Lonsway, Thomas M. Cooley, Robert Atkinson, Michelle Clayson, Kelly A. Straka

United States Department of Agriculture Wildlife Services: Staff Publications

The range of gray wolves (Canis lupus) in the contiguous US is expanding. Research and monitoring to support population recovery and management often involves capture via foothold traps. A population-level epidemiologic assessment of the effect of trap injuries on wolf survival remains needed to inform management. We describe the baseline rate, type, and severity of foot injuries of wolves born 1992–2013 in Michigan’s Upper Peninsula, evaluate the reliability of field-scoring trap-related injuries, and the effect of injuries on wolf survival. We assessed foot injuries by physical and radiographic exam at postmortem and/or time of capture for 351 wolves using the …

Olfactory Lures In Predator Control Do Not Increase Predation Risk To Birds In Areas Of Conservation Concern, Page Klug, Amy A. Yackel Adams, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Lethal control of predators is often undertaken to protect species of conservation concern. Traps are frequently baited to increase capture efficacy, but baited traps can potentially increase predation risk by attracting predators to protected areas. This is especially important if targeted predators can escape capture due to low trap success. Snake traps using live mouse lures may be beneficial if traps effectively remove snakes in the presence of birds and do not attract additional snakes to the area.

Aims. The present study evaluated whether mouse-lure traps in areas occupied by birds (simulated by deploying birdlure traps) could influence predation …

Wild Pig Removal Reduces Pathogenic Bacteria In Low-Order Streams, Sara A. Bolds, B. Graeme Lockaby, Latif Kalin, Stephen S. Ditchkoff, Mark D. Smith, Kurt Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive wild pig populations have undergone enormous increases in the United States and particularly across the southern U.S. in recent years. High fecundity rates and abilities to adapt quickly to varied habitats have enabled pig populations to become entrenched and difficult to eliminate. The pigs cause many negative impacts on ecosystems including degradation of water quality through infusion of fecal contamination and other non-point source pollutants. Our goal was to determine the effects of pig removal on water quality in streams that were known to be significantly polluted by pig activity Bolds (J Environ Qual 50: 441–453, 2021). We compared …

Plague Risk In The Western United States Over Seven Decades Of Environmental Change, Colin J. Carlson, Sarah N. Bevins, Boris V. Schmid

United States Department of Agriculture Wildlife Services: Staff Publications

After several pandemics over the last two millennia, the wildlife reservoirs of plague (Yersinia pestis) now persist around the world, including in the western United States. Routine surveillance in this region has generated comprehensive records of human cases and animal seroprevalence, creating a unique opportunity to test how plague reservoirs are responding to environmental change. Here, we test whether animal and human data suggest that plague reservoirs and spillover risk have shifted since 1950. To do so, we develop a new method for detecting the impact of climate change on infectious disease distributions, capable of disentangling long-term trends (signal) and …

Evaluating Avian Use Of Cover Crops In The Corn Belt, Megan Figura

Electronic Theses and Dissertations

The tallgrass prairie of North America has changed drastically since colonial settlement, with up to 99% of this region converted for agriculture and other land-uses. Concurrent with grassland conversion, grassland birds have experienced the most extreme, consistent, and widespread population declines of any avian guild. Agricultural lands in the U.S. Midwest were able to provide adequate habitat for several bird species until the 1950’s; however, altered and intensified management practices have degraded much of remaining suitable habitat and undermined ecosystem functions. Consequently, many grassland birds have been identified as Species of Greatest Conservation Need (SGCN) in many State Wildlife Action …

Zebra Mussel Length-Weight Relationships Across Various Substrate Types In Lake Bemidji, Mitch Kehne

Journal of Earth and Life Science

As of November 2021, zebra mussels were confirmed in 270 Minnesotan lakes with another 232 lakes listed as infested due to their connection or proximity to where zebra mussels have been found. With lack of effective treatments to impede their spread, zebra mussels continue to colonize new areas causing ecological as well as economic harm. The goal of this study was to establish a length-weight relationship for the zebra mussel population in Lake Bemidji using shell length (SL) and wet weight (WW), as well as to assess substrate type and log transformed shell length as predictors of log transformed zebra …

Experimental Elucidation Of The Life Cycle Of Drepanocephalus Spathans (Digenea: Echinostomatidae) With Notes On The Morphological Plasticity Of D. Spathans In The United States, Neely R. Alberson, Thomas G. Rosser, Tommy King, Ethan T. Woodyard, Lester Khoo, Wes A. Baumgartner, Daviod J. Wise, Linda M. Pote, Fred L. Cunningham, Matt J. Griffin

United States Department of Agriculture Wildlife Services: Staff Publications

The echinostomatid Drepanocephalus spathans (syn. Drepanocephalus auritus) parasitizes the doublecrested cormorant Phalacrocorax auritus. In North America, the marsh rams-horn snail Planorbella trivolvis and ghost rams-horn snail Biomphalaria havanensis serve as snail intermediate hosts, both of which inhabit catfish aquaculture ponds in the southeastern United States. Studies have demonstrated D. spathans exposure can be lethal to juvenile channel catfish Ictalurus punctatus. Two studies were undertaken to elucidate the life cycle of D. spathans to establish a developmental time line. In both studies, D. spathans cercariae collected from naturally infected P. trivolvis individuals were used to infect channel catfish …

Scavenging Vs Hunting Affects Behavioral Traits Of An Opportunistic Carnivore, Mitchell A. Parsons, Andrew Garcia, Julie K. Young

United States Department of Agriculture Wildlife Services: Staff Publications

Background. Human-induced changes to ecosystems transform the availability of resources to predators, including altering prey populations and increasing access to anthropogenic foods. Opportunistic predators are likely to respond to altered food resources by changing the proportion of food they hunt versus scavenge. These shifts in foraging behavior will affect species interactions through multiple pathways, including by changing other aspects of predator behavior such as boldness, innovation, and social structure. Methods. To understand how foraging behavior impacts predator behavior, we conducted a controlled experiment to simulate hunting by introducing a prey model to captive coyotes (Canis latrans) and compared their behavior …

Influence Of Landscape Attributes On Virginia Opossum Density, David A. Bernasconi, Wesley C. Dixon, Matthew T. Hamilton, James L. Helton, Richard B. Chipman, Amy T. Gilbert, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

TheVirginia opossum (Didelphis virginiana), North America's only marsupial, has a range extending from southern Ontario, Canada, to the Yucatan Peninsula, Mexico, and from the Atlantic seaboard to the Pacific. Despite the Virginia opossum's taxonomic uniqueness in relation to other mammals in North America and rapidly expanding distribution, its ecology remains relatively understudied. Our poor understanding of the ecology of this important mesopredator is especially pronounced in the rural southeastern United States. Our goal was to estimate effects of habitat on opossum density within an extensive multiyear spatial capture‐recapture study. Additionally, we compared the results of this spatial capture‐recapture …

Multidisciplinary Engagement For Fencing Research Informs Efficacy And Rancher-To-Researcher Knowledge Exchange, Matthew Hyde, Stewart W. Breck, Alex Few, Jared Beaver, Joshua Schrecengost, Jim Stone, Cameron Krebs, Russell Talmo, Kari Eneas, Rae Nickerson, Kyran E. Kunkel, Julie K. Young

United States Department of Agriculture Wildlife Services: Staff Publications

Across much of the Western United States, recovery of large carnivore populations is creating new challenges for livestock producers. Reducing the risks of sharing the landscape with recovering wildlife populations is critical to private working lands, which play an vital role in securing future energy, water, food, and fiber for an ever-expanding human population. Fencing is an important mitigation practice that many ranchers, land managers, and conservationists implement to reduce carnivore-livestock conflict. While fencing strategies have been reviewed in the literature, research seldom incorporates knowledge from the people who utilize fencing the most (i.e., livestock producers). Incorporating producers and practitioners …

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …

Fertilizer Use In Aquaculture, Bartholomew W. Green

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Aquaculture ponds traditionally are fertilized to stimulate primary productivity, which serves as the base of the pond natural food web and provides ancillary ecosystem services. Fertilizer can be made regularly or based on some water quality variable or measure of algal productivity. Nutrients from chemical fertilizers are available sooner for phytoplankton growth compared to organic fertilizers that first must undergo microbial decomposition before nitrogen and phosphorus concentrations increase. Primary production increases with increased fertilizer application if productivity is limited by primary nutrients rather than by light. In semi-intensive and intensive production systems, natural pond productivity enhanced by targeted fertilization protocols …

Longevity Of An Immunocontraceptive Vaccine Effect On Fecundity In Rats, Rebecca Pinkham, Douglas C. Eckery, Richard E. Mauldin, M. Gomm, F. Hill, F. Vial, G. Massei

United States Department of Agriculture Wildlife Services: Staff Publications

Increases in human-wildlife conflicts alongside cultural shifts against lethal control methods are driving the need for alternative wildlife management tools such as fertility control. Contraceptive formulations suitable for oral delivery would permit broader remote application in wildlife species.

This study evaluated the contraceptive effect and immune response to two novel injectable immunocontraceptive formulations targeting the Gonadotropin Releasing Hormone (GnRH): MAF-IMX294 and MAF-IMX294P conjugates, both identified as having potential as oral contraceptives. The study also explored whether in multiparous species immunocontraceptives may either totally prevent reproduction or also affect litter size.

Female rats, chosen as a model species, were given three …

Rapid Changes In Public Perception Toward A Conservation Initiative, Rebecca Niemiec, Richard E.W. Berl, Mireille Gonzalez, Tara L. Teel, Jonathan Salerno, Stewart Breck, Cassiopeia Camara, Matthew Collins, Courtney Scholtz, Dana Hoag, Kevin R. Crooks

United States Department of Agriculture Wildlife Services: Staff Publications

Rapid, widespread changes in public perceptions and behaviors have the potential to influence conservation outcomes. However, few studies have documented whether and how such shifts occur throughout the span of a conservation initiative. We examined the 2020 ballot initiative to reintroduce wolves into Colorado, which passed with less support than prior surveys had estimated. We conducted a postelection survey of Colorado residents using the same methods as our preelection survey to compare responses between surveys and to official election results. Reported voting in favor of wolf reintroduction in the postelection survey decreased in comparison to voting intentions shared in the …

A Model For Leveraging Animal Movement To Understand Spatio-Temporal Disease Dynamics, Mark Q. Wilber, Anni Yang, Raoul Boughton, Kezia R. Manlove, Ryan S. Miller, Kim M. Pepin, George Wittemyer

United States Department of Agriculture Wildlife Services: Staff Publications

The ongoing explosion of fine-resolution movement data in animal systems provides a unique opportunity to empirically quantify spatial, temporal and individual variation in transmission risk and improve our ability to forecast disease outbreaks. However, we lack a generalizable model that can leverage movement data to quantify transmission risk and how it affects pathogen invasion and persistence on heterogeneous landscapes. We developed a flexible model ‘Movement-driven modelling of spatio-temporal infection risk’ (MoveSTIR) that leverages diverse data on animal movement to derive metrics of direct and indirect contact by decomposing transmission into constituent processes of contact formation and duration and pathogen deposition …

Large- And Small-Scale Climate Influences Spring Migration Departure Probability Of American White Pelicans, D. Tommy King, Guiming Wang, Fred L. Cunningham

United States Department of Agriculture Wildlife Services: Staff Publications

Endogenous (e.g., age and sex) and exogenous (e.g., climate and resource availability) factors influence avian migration phenology. However, little is known regarding the migration ecology of birds at the non-breeding grounds, including the American white pelican (Pelecanus erythrorhynchos). We used Global Positioning System transmitters to track the movements and migration of 51 pelicans from 2002 to 2012. We used the Kaplan–Meier model to estimate pelican spring migration probabilities to quantify partial migration with 94 spring migration events and used the Cox proportional hazards model to evaluate the effects of the North Atlantic Oscillation index (NAOI), Southern Oscillation Index (SOI), and …

Adaptive Risk-Based Targeted Surveillance For Foreign Animal Diseases At The Wildlife-Livestock Interface, Ryan S. Miller, Sarah N. Bevins, Gericke Cook, Ross Free, Kim M. Pepin, Thomas Gidlewski, Vienna Brown

United States Department of Agriculture Wildlife Services: Staff Publications

Animal disease surveillance is an important component of the national veterinary infrastructure to protect animal agriculture and facilitates identification of foreign animal disease (FAD) introduction. Once introduced, pathogens shared among domestic and wild animals are especially challenging to manage due to the complex ecology of spillover and spillback. Thus, early identification of FAD in wildlife is critical to minimize outbreak severity and potential impacts on animal agriculture as well as potential impacts on wildlife and biodiversity. As a result, national surveillance and monitoring programs that include wildlife are becoming increasingly common. Designing surveillance systems in wildlife or, more importantly, at …

Evidence For Irruptive Fluctuation In Axis Deer Of Hawai‘I, Steven C. Hess, Jonathan Sprague, Jacob Muise

United States Department of Agriculture Wildlife Services: Staff Publications

Axis deer on the Hawaiian Islands of Maui, Lāna‘i, and Moloka‘i simultaneously experienced one of the most dramatic population crashes on record in 2020-2021, which coincided with extended drought conditions and prompted an emergency declaration for these islands. This phenomenon has been anecdotally documented during previous drought events in 2011-2012, but never formally studied. Newspaper articles document abundant deer becoming a nuisance to agriculture and natural resources, and then experiencing high mortality during droughts. This phenomenon fits Caughley’s (1970) operational definition of eruptive (sic) fluctuation “…as an increase in numbers over at least two generations, followed by a marked decline.” …

Cultivation Of Industrial Hemp On And Near Airports: Implications For Wildlife Use And Risk To Aviation Safety, Bradley F. Blackwell, Page E. Klug, Lee A. Humberg, Zachary T. Brym, Bryan M. Kluever, Jenna Edwards

United States Department of Agriculture Wildlife Services: Staff Publications

Industrial hemp (Cannabis sativa L.; hemp) is an emerging crop in the United States with little known about bird use or the potential for birds to become an agricultural pest. We identified birds associated with hemp fields, using repeated visits to oilseed plots in North Dakota, USA (n = 6) and cannabinoid (CBD) plots in Florida, USA (n = 4) from August to November 2020. We did not control for plot area or density; our observations were descriptive only. We observed 10 species in hemp, 12 species flying over hemp, and 11 species both foraging in and …

Industrial Hemp As A Resource For Birds In Agroecosystems: Human-Wildlife Conflict Or Conservation Opportunity?, Emily A. Kotten, Iona Hennessy, Bryan M. Kluever, Bradley F. Blackwell, Lee A. Humberg, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Industrial hemp (Cannabis sativa L.; hemp) is an emerging crop in the United States with little known about bird use or the potential for birds to become an agricultural pest. We identified birds associated with hemp fields, using repeated visits to oilseed plots in North Dakota, USA (n = 6) and cannabinoid (CBD) plots in Florida, USA (n = 4) from August to November 2020. We did not control for plot area or density; our observations were descriptive only. We observed 10 species in hemp, 12 species flying over hemp, and 11 species both foraging in and …

An Examination Of Ethical Attitudes Towards Wild Pig (Sus Scrofa) Toxicants In The United States, Keith Carlisle, Erin E. Harper, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

This research aims to understand ethical attitudes of the U.S. public towards the use of a toxicant to control wild pigs (Sus scrofa), a destructive invasive species whose population growth is proving difficult to control through conventional management methods. Using a nationwide self-administered survey with 2,186 completed and returned questionnaires, we found that among six different lethal control methods, toxicant usage was the only method that a majority of respondents (51%) found to be unethical, with no significant differences between rural and urban respondents or between respondents from counties with wild pigs and counties where the species is absent. The …

Relationship Between Reproductive Hormones And Migration Distance In A Polygynous Songbird, The Red‑Winged Blackbird (Agelaius Phoeniceus), Michelle A. Eshleman, Page E. Klug, Esther Morales‑Vega, Björn Wissel, Timothy J. Grelves

United States Department of Agriculture Wildlife Services: Staff Publications

Many bird species migrate to southern overwintering locations to avoid harsh conditions at their breeding grounds, but at the cost of an energetically demanding migration that may delay their spring reproductive development. Previous work on the relationship between migration distance and reproductive readiness has primarily focused on early season baseline testosterone in both males and females. However, for females, testosterone alone may not be the appropriate measurement of reproductive development. Estradiol, a metabolite of testosterone that is essential for breeding behaviors and reproduction, should also be measured. Furthermore, baseline testosterone varies throughout the day and may change due to social …

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

United States Department of Agriculture 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 …

Frugivory And Seed Dispersal By Carnivorans, John P. Draper, Julie K. Young, Eugene W. Schupp, Noelle G. Beckman, Trisha B. Atwood

United States Department of Agriculture Wildlife Services: Staff Publications

Seed dispersal is critical to the ecological performance of sexually reproducing plant species and the communities that they form. The Mammalian order Carnivora provide valuable and effective seed dispersal services but tend to be overlooked in much of the seed dispersal literature. Here we review the literature on the role of Carnivorans in seed dispersal, with a literature search in the Scopus reference database. Overall, we found that Carnivorans are prolific seed dispersers. Carnivorans’ diverse and plastic diets allow them to consume large volumes of over a hundred families of fruit and disperse large quantities of seeds across landscapes. Gut …

Aboveground Carbon Responses To Experimental And Natural Hurricane Impacts In A Subtropical Wet Forest In Puerto Rico, Hervé Chevalier, Nicholas V.L. Brokaw, Sheila E. Ward, Jess K. Zimmerman, Aaron B. Shiels, John Bithorn, Samuel Matta Carmona

United States Department of Agriculture Wildlife Services: Staff Publications

Climate change and disturbance make it difficult to project long-term patterns of carbon sequestration in tropical forests, but large ecosystem experiments in these forests can inform predictions. The Canopy Trimming Experiment (CTE) manipulates two key components of hurricane disturbance, canopy openness and detritus deposition, in a tropical forest in Puerto Rico. We documented how the CTE and a real hurricane affected tree recruitment, biomass, and aboveground carbon storage over 15 years. In the CTE treatments, we trimmed branches, but we did not fell trees. We expected that during the 14-year period after initial canopy trimming, regrowth of branches and stems …

Behavioral States In Space And Time: Understanding Landscape Use By An Invasive Mammal, Steven M. Gray, John M. Humphreys, Robert A. Montgomery, Dwayne R. Etter, Kurt C. Vercauteren, Daniel B. Kramer, Gary J. Roloff

United States Department of Agriculture Wildlife Services: Staff Publications

Animal movement models can be used to understand species behavior and assist with implementation of management activities. We explored behavioral states of an invasive wild pig (Sus scrofa) population that recently colonized central Michigan, USA, 2014–2018. To quantify environmental factors related to wild pig movement ecology and spatio‐temporal landscape use, we predicted wild pig behavioral states relative to land cover type, landscape structure (i.e., edge and patch cohesion), and weather conditions. We used global positioning system (GPS)‐collars and monitored 8 wild pigs from 2014–2018. We fit local convex hulls and calculated movement metrics revealing 3 wild pig behavioral states (resting, …

Concentration-Response Of An Anthraquinone-Based Repellent For Raccoons (Procyon Lotor), Shylo Johnson, Shelagh T. Deliberto, Kathleen Urchek, Amy T. Gilbert, Scott J. Werner

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife repellents can be part of non-lethal management strategies to reduce the negative impacts of wildlife to property, agricultural production, and human health and safety. Raccoons (Procyon lotor) are associated with negative impacts in all three of these areas. Anthraquinone is a useful avian repellent and its utility as a mammalian repellent is still being explored. Our objective was to evaluate laboratory efficacy of an anthraquinone-based repellent for raccoons using different concentrations. We fed captive raccoons whole corn treated at 0.5%, 1%, 1.5% and 2% anthraquinone and examined their behavioral response related to feeding repellency including consumption and change in …

Accounting For Animal Movement Improves Vaccination Strategies Against Wildlife Disease In Heterogeneous Landscapes, Katherine M. Mcclure, Guillaume Bastille-Rousseau, Amy J. Davis, Carolyn A. Stengel, Kathleen M. Nelson, Richard B. Chipman, George Wittemyer, Zaid Abdo, Amy Gilbert, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is used to deliver vaccines to wildlife to prevent, control, and eliminate infectious diseases. A central challenge is how to spatially distribute baits to maximize encounters by target animal populations, particularly in urban and suburban areas where wildlife such as raccoons (Procyon lotor) are abundant and baits are delivered along roads. Methods from movement ecology that quantify movement and habitat selection could help to optimize baiting strategies by more effectively targeting wildlife populations across space. We developed a spatially explicit, individual-based model of raccoon movement and oral rabies vaccine seroconversion to examine whether and when baiting …

Using Noninvasive Genetics For Estimating Density And Assessing Diet Of Urban And Rural Coyotes In Florida, Usa, Bryan M. Kluever, Martin B. Main, Stewart W. Breck, Robert C. Lonsinger, John H. Humphrey, Justin W. Fischer, Michael P. Milleson Usda Aphis Wildlife Services, Gainesville, Antionette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Coyotes (Canis latrans) are expanding their range and due to conflicts with the public and concerns of Coyotes affecting natural resources such as game or sensitive species, there is interest and often a demand to monitor Coyote populations. A challenge to monitoring is that traditional invasive methods involving live-capture of individual animals are costly and can be controversial. Natural resource management agencies can benefit from contemporary noninvasive genetic sampling approaches aimed at determining key aspects of Coyote ecology (e.g., population density and food habits). However, the efficacy of such approaches under different environmental conditions is poorly understood. Our …

Invasive Predators Affect Community-Wide Pollinator Visitation, Christina T. Liang, Aaron B. Shiels, William P. Haines, Manette E. Sandor, Clare E. Aslan

United States Department of Agriculture Wildlife Services: Staff Publications

Disruption of plant–pollinator interactions by invasive predators is poorly understood but may pose a critical threat for native ecosystems. In a multiyear field experiment in Hawai’i, we suppressed abundances of globally invasive predators and then observed insect visitation to flowers of six native plant species. Three plant species are federally endangered (Haplostachys haplostachya, Silene lanceolata, Tetramolopium arenarium) and three are common throughout their range (Bidens menziesii, Dubautia linearis, Sida fallax). Insect visitors were primarily generalist pollinators, including taxa that occur worldwide such as solitary bees (e.g., Lasioglossum impavidum), social bees (e.g., …