Terrestrial and Aquatic Ecology Commons^™

Egg Plastron Of The Bog Copper Butterfly Tharsalea (Epidemia) Epixanthe (Bsd. & Le C. [1835]) (Lycaenidae: Lycaeninae), David M. Wright

The Taxonomic Report of the International Lepidoptera Survey

The egg of the Bog Copper butterfly, Tharsalea (Epidemia) epixanthe, has a prominent highly-sculptured chorionic surface. Trapped within the chorion is a labyrinth of air spaces which has been proposed as a plastron for gas exchange while the egg is submerged in water. Data derived from scanning electron microscopy (SEM) confirms the plastron should function as predicted. Furthermore, the insulating air spaces should prevent water loss of the diapausing first instar larvae while overwintering.

Assessing The Dispersal And Recruitment Of Stocked Walleye Fry In A Northern Minnesota Chain Of Lakes, Joseph W. Amundson

Biology Graduate Theses

As part of Minnesota's Walleye Sander vitreus egg take practice, 10% of eggs taken for hatchery purposes are stocked back into the donor lake. For Andrusia, part of the Cass Lake Chain of Lakes (Chain), this practice can result in elevated fry densities (mean: 17,000 fry/littoral hectare). However, if fry are able to disperse and use all available littoral hectares throughout the Chain, fry densities would be intermediate to typical stocking densities for Minnesota lakes (1,200 - 2,400 fry/littoral hectare). In 2016-2018, 3-3.5 million fry were mass-marked by immersion in oxytetracycline (OTC) prior to stocking into Andrusia to allow differentiation …

Free-Ranging And Feral Cats, Alex Dutcher, Kyle Pias, Grant Sizemore, Stephen M. Vantassel

Wildlife Damage Management Technical Series

Domestic cats (Felis catus) are a common household pet in the United States, with an estimated 25.4% of households owning cats (American Veterinary Medical Association 2018). While an increasing number of cat owners keep their pet cats exclusively indoors, a portion of society maintains that domestic cats are entitled to a free-ranging lifestyle and may even consider unowned domestic cats to be wildlife. Although wildlife managers recognize the beliefs of many concerned stakeholders, including advocates who use strong emotional appeals on behalf of cats, it remains that free-ranging and feral domestic cats are an invasive species spread by humans (Lowe …

An Opportunistic Survey Reveals An Unexpected Coronavirus Diversity Hotspot In North America, Hon S. Ip, Kathryn M. Griffin, Jeffrey D. Messer, Megan E. Winzeler, Susan A. Shriner, Mary Lea Killian, Mia Kim Torchetti, Thomas J. Deliberto, Brian R. Amman, Caitlin M. Cossaboom, R. Reid Harvey, Natalie M. Wendling, Hannah Rettler, Dean Taylor, Jonathan S. Towner, Casey Barton Behravesh, David S. Blehert

United States Department of Agriculture Wildlife Services: Staff Publications

In summer 2020, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was detected on mink farms in Utah. An interagency One Health response was initiated to assess the extent of the outbreak and included sampling animals from on or near affected mink farms and testing them for SARS-CoV-2 and non-SARS coronaviruses. Among the 365 animals sampled, including domestic cats, mink, rodents, raccoons, and skunks, 261 (72%) of the animals harbored at least one coronavirus. Among the samples that could be further characterized, 127 alphacoronaviruses and 88 betacoronaviruses (including 74 detections of SARS-CoV-2 in mink) were identified. Moreover, at least 10% (n …

Variations, Validations, Degradations, And Noninvasive Determination Of Pregnancy Using Fecal Steroid Metabolites In Free-Ranging Pronghorn, Cole A. Bleke, Eric M. Gese, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Pregnancy status is a key parameter used to assess reproductive performance of a species as it represents a starting point for measuring vital rates. Vital rates allow managers to determine trends in populations such as neonate survival and recruitment; two important factors in ungulate population growth rates. Techniques to determine pregnancy have generally involved capture and restraint of the animal to obtain blood samples for determining serum hormone levels. Non-invasive pregnancy assessment, via feces, eliminates any hazards between handler and animal, as well as removes handling-induced physiological biases. Using noninvasive fecal sampling, we conducted hormone validations, investigated pregnancy rates, and …

Cytoarchitectural Characteristics Associated With Cognitive Flexibility In Raccoons, Joanna Jacob, Molly Kent, Sarah Benson-Amram, Suzana Herculano-Houzel, Mary Ann Raghanti, Emily Ploppert, Jack Drake, Bilal Hindi, Nick R. Natale, Sarah Daniels, Rachel Fanelli, Anderson Miller, Tim Landis, Amy Gilbert, Shylo Johnson, Annie Lai, Molly Hyer, Amanda Rzucidlo, Chris Anchor, Stan Gehrt, Kelly Lambert

United States Department of Agriculture Wildlife Services: Staff Publications

With rates of psychiatric illnesses such as depression continuing to rise, additional preclinical models are needed to facilitate translational neuroscience research. In the current study, the raccoon (Procyon lotor) was investigated due to its similarities with primate brains, including comparable proportional neuronal densities, cortical magnification of the forepaw area, and cortical gyrification. Specifically, we report on the cytoarchitectural characteristics of raccoons profiled as high, intermediate, or low solvers in a multiaccess problem-solving task. Isotropic fractionation indicated that high-solvers had significantly more cells in the hippocampus (HC) than the other solving groups; further, a nonsignificant trend suggested that this …

Satellite-Detected Ammonia Changes In The United States: Natural Or Anthropogenic Impacts, Yaqian He, Rongting Xu, Stephen A. Prior, Di Yang, Anni Yang, Jian Chen

United States Department of Agriculture Wildlife Services: Staff Publications

Ammonia (NH3) is the most abundant alkaline component and can react with atmospheric acidic species to form aerosols that can lead to numerous environmental and health issues. Increasing atmospheric NH3 over agricultural regions in the US has been documented. However, spatiotemporal changes of NH3 concentrations over the entire US are still not thoroughly understood, and the factors that drive these changes remain unknown. Herein, we applied the Atmospheric Infrared Sounder (AIRS) monthly NH3 dataset to explore spatiotemporal changes in atmospheric NH3 and the empirical relationships with synthetic N fertilizer application, livestock manure production, and climate factors across the entire US …

Adaptation Of An Artificial Bait To An Automated Aerial Delivery System For Landscape-Scale Brown Treesnake Suppression, Rafael A. Garcia, Thomas W. Mcauliffe, Lorelie P. Bumanlag, Shane R. Siers, Bruce A. Kimball

United States Department of Agriculture Wildlife Services: Staff Publications

Dead neonatal mice are currently used as bait for delivery of toxin to invasive brown treesnakes (Boiga irregularis) on Guam; once deployed in the field the mice are highly attractive to the snakes but only for about four days. An artificial bait containing a mixture of fats mimicking those in skin of the mice is also highly attractive to the snakes and remains attractive 2–3 times longer. The artificial bait, however, costs more than the mice, and is more difficult to attach to the capsules of a novel aerial bait delivery system. This paper describes a reformulation of the bait …

Movement, Space-Use And Resource Preferences Of European Golden Jackals In Human-Dominated Landscapes: Insights From A Telemetry Study, Skye Fenton, Paul R. Moorcroft, Duško Ćirović, József Lanszki, Miklós Heltai, Francesca Cagnacci, Stewart Breck, Neda Bogdanović, Ilija Pantelić, Kornél Ács, Nathan Ranc

United States Department of Agriculture Wildlife Services: Staff Publications

During the last half-century, the distribution of golden jackals (Canis aureus) has rapidly increased throughout Europe. Today, golden jackals are thriving in human-dominated landscapes across Southeastern and Central Europe. Most studies on golden jackals have focused on large-scale distribution patterns; to date, little is known about the species’ fine-scale spatial ecology. In this study, we analyzed the movement behavior, space-use and resource selection of six golden jackals fitted with GPS-GSM collars in two study areas in Hungary and Serbia. Two of the jackals were a breeding pair. We found that home range size averaged 11.2 km² (90% …

Effects Of Translocation On Survival Of Nuisance Bears, Javan Bauder, D. Ruid, N. M. Roberts, B. Kohn, M. L. Allen

United States Department of Agriculture Wildlife Services: Staff Publications

Effective mitigation of human–wildlife conflict should aim to reduce conflicts while also minimizing wildlife mortality. Translocation is often used to mitigate human–wildlife conflict but translocated individuals may have reduced survival, which could negatively affect population growth and social acceptance of translocation as a management tool. Yet, non-translocated nuisance individuals may also have low survival due to inherent risks associated with nuisance behavior. We used a 38-year dataset of 1233 marked and translocated nuisance American black bears (Ursus americanus) as a model system with which to evaluate the impacts of translocation on nuisance bear survival. We used multi-state mark-recapture models to …

Threading The Needle: How Humans Influence Predator–Prey Spatiotemporal Interactions In A Multiple-Predator System, Asia Murphy, Duane R. Diefenbach, Mark Ternent, Matt Lovallo, David Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Perceived predation risk and the resulting antipredator behaviour varies across space, time and predator identity. Communities with multiple predators that interact and differ in their use of space, time of activity and hunting mode create a complex landscape for prey to avoid predation. Anthropogenic presence and disturbance have the potential to shift interactions among predators and prey and the where and when encounters occur. We examined how white-tailed deer Odocoileus virginianus fawn spatiotemporal antipredator behaviour differed along an anthropogenic disturbance gradient that had black bears Ursus americanus, coyotes Canis latrans, bobcats Lynx rufus and humans present. We quantified (a) spatial …

Scaup Depredation On Arkansas Baitfish And Sportfish Aquaculture, Stephen A. Clements, Brian S. Dorr, J. Brian Davis, Luke A. Roy, Carole R. Engle, Katie Hanson-Dorr, Anita M. Kelly

United States Department of Agriculture Wildlife Services: Staff Publications

Lesser scaup (Aythya affinis) and greater scaup (A. marila), hereafter scaup, consume a variety of aquatic invertebrates, plants, and occasionally small fish. Scaup have foraged on commercial aquaculture farms in the southern United States for decades. However, the types, abundance, and rate of fish exploitation by scaup on baitfish and sportfish farms are not well documented. Thus, information is needed to understand how fish and other foods influence scaup use of aquatic resources, and any potential economic effects of depredation of fish. From November–March in winters 2016–2017 and 2017–2018, we conducted 1,458 pond surveys to …

Improving Animal Monitoring Using Small Unmanned Aircraft Systems (Suas) And Deep Learning Networks, Meilun Zhou, Jared A. Elmore, Sathishkumar Samiappan, Kristine O. Evans, Morgan Pfeiffer, Bradley F. Blackwell, Raymond B. Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

In recent years, small unmanned aircraft systems (sUAS) have been used widely to monitor animals because of their customizability, ease of operating, ability to access difficult to navigate places, and potential to minimize disturbance to animals. Automatic identification and classification of animals through images acquired using a sUAS may solve critical problems such as monitoring large areas with high vehicle traffic for animals to prevent collisions, such as animal-aircraft collisions on airports. In this research we demonstrate automated identification of four animal species using deep learning animal classification models trained on sUAS collected images. We used a sUAS mounted with …

Spatial Variation In Direct And Indirect Contact Rates At The Wildlife-Livestock Interface For Informing Disease Management, Anni Yang, Raoul K. Boughton, Ryan S. Miller, Bethany Wight, Wesley M. Anderson, James C. Beasley, Kurt C. Vercauteren, Kim M. Pepin, George Wittemyer

United States Department of Agriculture Wildlife Services: Staff Publications

Little is known about disease transmission relevant contact rates at the wildlife-livestock interface and the factors shaping them. Indirect contact via shared resources is thought to be important but remains unquantified in most systems, making it challenging to evaluate the impact of livestock management practices on contact networks. Free-ranging wild pigs (Sus scrofa) in North America are an invasive, socially-structured species with an expanding distribution that pose a threat to livestock health given their potential to transmit numerous livestock diseases, such as pseudorabies, brucellosis, trichinellosis, and echinococcosis, among many others. Our objective in this study was to quantify …

Plague Exposure In Mammalian Wildlife Across The Western United States, Sarah N. Bevins, Jeffrey C. Chandler, Nicole Barrett, Brandon S. Schmit, Gerald W. Wiscomb, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Plague is caused by a bacterial pathogen (Yersinia pestis) that can infect a wide range of mammal species, but its presence in wildlife is often underappreciated. Using a large-scale data set (n = 44,857) that details the extent of Y. pestis exposure in wildlife, we document exposure in 18 wildlife species, including coyotes (Canis latrans), bobcats (Lynx rufus), and black bears (Ursus americanus). Evidence of plague activity is widespread, with seropositive animals detected in every western state in the contiguous United States. Pathogen monitoring systems in wildlife that are both large scale …

Data-Driven Management—A Dynamic Occupancy Approach To Enhanced Rabies Surveillance Prioritization, Amy J. Davis, Jordana D. Kirby, Richard B. Chipman, Kathleen M. Nelson, Amy T. Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

Rabies lyssavirus (RABV) is enzootic in raccoons across the eastern United States. Intensive management of RABV by oral rabies vaccination (ORV) has prevented its spread westward and shown evidence of local elimination in raccoon populations of the northeastern US. The USDA, Wildlife Services, National Rabies Management Program (NRMP) collaborates with other agencies to implement broad-scale ORV and conducts extensive monitoring to measure the effectiveness of the management. Enhanced Rabies Surveillance (ERS) was initiated during 2005 and updated in 2016 to direct surveillance efforts toward higher-value specimens by assigning points to different methods of encountering specimens for collection (strange-acting, roadkill, surveillance-trapped, …

Initial Assessment Of Potential Relationships Between Plant Communities And The Soil Microbiome In Closed Forest And Longleaf Pine Restoration Sites., Sean Davis, Ian Kennedy

Symposium of Student Scholars

Longleaf pine is an endangered ecosystem characterized by high levels of biodiversity.

Our study took place in the Sheffield Wildlife Management Area located in the Piedmont ecoregion of Georgia in Paulding County. Fifty plots of 10 x 30 m² were setup on south or north facing slopes, some in covered forest, and some in an area actively being restored for the longleaf pine. All trees above 1.37 m were identified and had their diameter measured, and species diversity, relative density, dominance, and frequency were determined. Herbaceous plant cover percentages were recorded in select plots. Soil samples were also collected …

A Reevaluation Of The Phylogeography Of The Chattahoochee Slimy Salamander (Plethodon Chattahoochee) Using Next-Generation Genomic Data, Jadin Cross

Symposium of Student Scholars

The Plethodon glutinosus species complex is a group of large-bodied, lungless salamanders that are widespread across the eastern United States. Species in this group are morphologically cryptic and were originally delimited using allozyme data, but in most cases, the extent of contemporary gene flow between named taxa has not be rigorously evaluated. The Appalachian Mountains of northern Georgia are home to several members of this group—including P. glutinosus, P. teyahalee, P. chlorobryonis, and P. chattahoochee. P. chattahoochee has been found to be especially cryptic both morphologically and genetically as both intraspecific genetic variation and species boundaries within …

Invader Removal Triggers Competitive Release In A Threatened Avian Predator, J. David Wiens, Katie M. Dugger, J. Mark Higley, Damon B. Lesmeister, Alan B. Franklin, Keith A. Hamm, Gary C. White, Krista E. Dilione, David C. Simon, Robin R. Bown, Peter C. Carlson, Charles B. Yackulic, James D. Nichols, James E. Hines, Raymond J. Davis, David W. Lamphear, Christopher Mccafferty, Trent L. Mcdonald, Stan G. Sovern

United States Department of Agriculture Wildlife Services: Staff Publications

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before-after control-impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl …

Nicarbazin As An Oral Contraceptive In Eared Doves, Lourdes Olivera, Silvia Pereyra, Georgget Banchero, Guillermo Tellechea, Jorge Sawchik, Michael L. Avery, Ethel Rodríguez

United States Department of Agriculture Wildlife Services: Staff Publications

Eared doves (Zenaida auriculata) are responsible for substantial losses in cereal and oil crops as well as in dairy and feedlot production in the southern cone of South America. Various strategies have been shown to be effective in reducing damage at the farm scale, but in some scenarios, it is necessary to also incorporate population control methods due to excessive bird population size. An alternative approach to reduce pest bird populations is the use of contraceptive methods, minimizing the impact on the environment and non-target populations. Nicarbazin is registered in the United States as a contraceptive for Branta …

Avian Influenza A Virus Susceptibility, Infection, Transmission, And Antibody Kinetics In European Starlings, Jeremy W. Ellis, J. Jeffrey Root, Loredana M. Mccurdy, Kevin T. Bentler, Nicole L. Barrett, Kaci K. Vandalen, Katherine L. Dirsmith, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Avian influenza A viruses (IAVs) pose risks to public, agricultural, and wildlife health. Bridge hosts are spillover hosts that share habitat with both maintenance hosts (e.g., mallards) and target hosts (e.g., poultry). We conducted a comprehensive assessment of European starlings (Sturnus vulgaris), a common visitor to both urban and agricultural environments, to assess whether this species might act as a potential maintenance or bridge host for IAVs. First, we experimentally inoculated starlings with a wild bird IAV to investigate susceptibility and replication kinetics. Next, we evaluated whether IAV might spill over to starlings from sharing resources with a …

Mesopredator Frugivory Has No Effect On Seed Viability And Emergence Under Experimental Conditions, John P. Draper, Trisha B. Atwood, Noelle G. Beckman, Karin M. Kettenring, Julie K. Young

United States Department of Agriculture Wildlife Services: Staff Publications

Members of the order Carnivora are a unique and important seed disperser who consume and deposit undamaged seeds while providing regular long-distance seed dispersal opportunities. Some members of Carnivora, such as coyotes (Canis latrans), are undergoing range expansions which may help the plant species they consume colonize new locations or replace dispersal services provided by recently extirpated species. In this study, we evaluated aspects of the seed dispersal effectiveness of coyotes and gut passage time to determine the potential dispersal distances for three commonly consumed and commonly occurring plant species (Amelanchier alnifolia, Celtis ehrenbergiana, and Juniperus osteosperma). We also investigated …

Distilling Professional Opinion To Gauge Vulnerability Of Guam Avifauna To Brown Treesnake Predation, Robert M. Mcelderry, Eben H. Paxton, Andre V. Nguyen, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The avifauna of Guam was devastated by the introduction of the Brown Treesnake, and the restoration of native birds would need to address the problem with eradication or suppression of BTS. With eradication of the snake unlikely in the near term, and suppression capabilities limited to specific finite areas, key information for reintroductions is how low BTS abundance will likely need to be for each bird species to be re-established based on their vulnerability to BTS predation. Here, we estimate vulnerability, which can no longer be measured directly, so biologists who are familiar with one or more of seven Guam …

Notes On Eastern North American Butterflies, David J. Hoag, Harry Pavulaan, Brian Taber, Kenneth Lorenzen, Richard D. Ullrich

The Taxonomic Report of the International Lepidoptera Survey

Editor’s Note (Harry Pavulaan). New natural history elements and distribution records of several eastern North American butterflies are reported. While diversity and distribution of butterflies in the eastern United States are commonly believed to be fully known, the findings presented here show that much is yet to be learned of our butterfly fauna.

Includes:

1. Pages 1-3

Lethe eurydice and L. appalachia Larvae (Nymphalidae: Satyrinae) Eat Their Shed Cuticle (Exuvia) Soon after Molting in Vermont, USA by David J. Hoag

Abstract

Larvae of Lethe eurydice and L. appalachia were observed eating their newly shed cuticle (exuvia). Further studies are needed …

Host-Parasite Interactions Within Food Webs, Adam Zvanut Hasik

Graduate Theses and Dissertations

Parasitism is one of the most common life history strategies employed in nature, yet the effects of parasites are often thought to be minimal, and the vast majority of studies fail to consider parasites and their effects on host organisms. This is likely a problem, as the magnitude of parasite-mediated effects on their hosts can be quite large. Additionally, the effects of parasites are known to extend beyond the host to affect other species interactions. I used a series of approaches to gain a more integral understanding of host-parasite interactions by studying (1) the effects of parasites on biotic interactions …

Of Biodiversity, Boundaries, And Distribution: The Myxomycetes Of The Philippines And Beyond, Sittie Aisha Bustamante Macabago

Graduate Theses and Dissertations

This dissertation contains a compilation of independently performed studies primarily focusing on the myxomycetes (plasmodial slime molds) from the Philippines and integrating local and worldwide data to demonstrate regional and global trends. The major themes include the following: (I) a review of the diverse group of spore-producing amoeboid protists, including the myxomycetes; (II-IV) diversity assessments in three different groups of islands in the Philippine archipelago; (V) mapping the myxomycetes found in the Philippines for databasing and analyzing the geocoded data; (VI) a study on regional boundaries, including the Philippines, using myxomycete species composition; and, (VII) creating a global species distribution …

Range-Wide Declines Of Northern Spotted Owl Populations In The Pacific Northwest: A Meta-Analysis, Alan B. Franklin, Katie M. Dugger, Damon B. Lesmeister, Raymond J. Davis, J. David Wiens, Gary C. White, James D. Nichols, James E. Hines, Charles B. Yackulic, Carl J. Schwarz, Steven H. Ackers, L. Steven Andrews, Larissa L. Bailey, Robin Bown, Jesse Burgher, Kenneth P. Burnham, Peter C. Carlson, Tara Chestnut, Mary M. Conner, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, Julianna M. Jenkins, William L. Kendall, David W. Lamphear, Christopher Mccafferty, Trent L. Mcdonald, Janice A. Reid, Jeremy T. Rockweit, David C. Simon, Stan G. Sovern, James K. Swingle, Heather Wise

United States Department of Agriculture Wildlife Services: Staff Publications

The northern spotted owl (Strix occidentalis caurina) inhabits older coniferous forests in the Pacific Northwest and has been at the center of forest management issues in this region. The immediate threats to this federally listed species include habitat loss and competition with barred owls (Strix varia), which invaded from eastern North America. We conducted a prospective meta-analysis to assess population trends and factors affecting those trends in northern spotted owls using 26 years of survey and capture-recapture data from 11 study areas across the owls' geographic range to analyze demographic traits, rates of population change, and occupancy parameters for spotted …

Determination Of Freedom-From-Rabies For Small Indian Mongoose Populations In The United States Virgin Islands, 2019–2020, A. Springer Browne, Hannah M. Cranford, Clint N. Morgan, James A. Ellison, Are Berentsen, Nicholas Wiese, Alexandra Medley, John Rossow, Leanne Jankelunas, Alan S. Mckinley, Claudia D. Lombard, Nicole F. Angeli, Thomas Kelley, Jennifer Valiulus, Bethany Bradford, Valicia J. Burke-France, Cosme J. Harrison, Irene Guendel, Marissa Taylor, Gerard L. Blanchard, Jeffrey B. Doty, David J. Worthington, David Horner, Keith R. Garcia, Joseph Roth, Brett R. Ellis, Kristine M. Bisgard, Ryan Wallace, Esther M. Ellis

United States Department of Agriculture Wildlife Services: Staff Publications

Mongooses, a nonnative species, are a known reservoir of rabies virus in the Caribbean region. A cross-sectional study of mongooses at 41 field sites on the US Virgin Islands of St. Croix, St. John, and St. Thomas captured 312 mongooses (32% capture rate). We determined the absence of rabies virus by antigen testing and rabies virus exposure by antibody testing in mongoose populations on all three islands. USVI is the first Caribbean state to determine freedom-from-rabies for its mongoose populations with a scientifically-led robust cross-sectional study. Ongoing surveillance activities will determine if other domestic and wildlife populations in USVI are …

Testing A Bite-Shortened Hook To Minimize Fish Handling In A Recreational Fishery, Holden E. Harris, Brian K. Whalen, Andrew G. Gude, Michael S. Allen

United States Department of Agriculture Wildlife Services: Staff Publications

Discard mortality can make fishing unsustainable, even in catch-and-release or highly regulated fisheries. However, fishing practices and gears that minimize hook injury, handling, and air exposure can considerably improve fitness and survival in released fish. This study tested whether modified hooks could allow anglers to successfully land and then release fish in the water and without handling. Standard, barbless, and bite-shortened hooks were used to catch Spotted Seatrout Cynoscion nebulosus (n > 75 per hook type), and logistic models were used to assess the differences in landing success and hook self-release success by hook type and categorical fish size. Average landing …

Landscape Of Stress: Tree Mortality Influences Physiological Stress And Survival In A Native Mesocarnivore, Jennifer R. Kordosky, Eric M. Gese, Craig M. Thompson, Patricia A. Terletzky, Lorin A. Neuman-Lee, Jon D. Schneiderman, Kathryn L. Purcell, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Climate change and anthropogenic modifications to the landscape can have both positive and negative effects on an animal. Linking landscape change to physiological stress and fitness of an animal is a fundamental tenet to be examined in applied ecology. Cortisol is a glucocorticoid hormone that can be used to indicate an animal’s physiological stress response. In the Sierra Nevada Mountains of California, fishers (Pekania pennanti) are a threatened mesocarnivore that have been subjected to rapid landscape changes due to anthropogenic modifications and tree mortality related to a 4-year drought. We measured cortisol concentrations in the hair of 64 …