National Wildlife Research Center

NWRC Website

4101 LaPorte Avenue
Fort Collins, CO 80521
tel: (970) 266-6000 fax: (970) 266-6032

The U.S. Department of Agriculture's National Wildlife Research Center (NWRC) is the federal institution devoted to resolving problems caused by the interaction of wild animals and society. The Center applies scientific expertise to the development of practical methods to resolve these problems and to maintain the quality of the environments shared with wildlife.

This site contains publications of the NWRC or its staff. Material prepared by employees of the US Government in the course of their official duties cannot be copyrighted.


The past and future roles of competition and habitat in the range-wide occupancy dynamics of Northern Spotted Owls, Charles B. Yackulic, Larissa L. Bailey, Katie M. Dugger, Raymond J. Davis, Alan B. Franklin, Eric D. Forsman, Steven H. Ackers, Lawrence S. Andrews, Lowell V. Diller, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, Christopher McCafferty, Janice A. Reid, Jeremy T. Rockweit, and Stan G. Sovern

Mind the Gap: Experimental Tests to Improve Efficacy of Fladry for Nonlethal Management of Coyotes, Julie K. Young, John Draper, and Stewart Breck

Persistence and conspecific observations improve problem-solving abilities of coyotes, Julie K. Young, Laura Touzot, and Stacey P. Brummer

Allowable Take of Black Vultures in the Eastern United States, Guthrie Zimmerman, Brian A. Millsap, Michael L. Avery, John R. Sauer, Michael C. Runge, and Kenneth D. Richkus


Identifying individual cougars (Puma concolor) in remote camera images – implications for population estimates, Peter D. Alexander and Eric M. Gese

Environmental effects are stronger than human effects on mammalian predator-prey relationships in arid Australian ecosystems, Benjamin L. Allen, Alana Fawcett, Alison Anker, Richard M. Engeman, Allan Lisle, and Luke K.-P. Leung

Absence of native flower visitors for the endangered Hawaiian mint Stenogyne angustifolia: Impending ecological extinction?, Clare E. Aslan, Christina T. Liang, Aaron B. Shiels, and William Haines

Operationalizing resilience for conservation objectives: the 4S’s, Clare E. Aslan, Brian Petersen, Aaron B. Shiels, William Haines, and Christina T. Lang

Monk and Rose-Ringed Parakeets, Michael L. Avery and Aaron B. Shiels

Reimmunization increases contraceptive effectiveness of gonadotropin-releasing hormone vaccine (GonaCon-Equine) in freeranging horses (Equus caballus): Limitations and side effects, Dan L. Baker, Jenny G. Powers, Jason I. Ransom, Blake E. McCann, Michael W. Oehler, Jason E. Bruemmer, Nathan L. Galloway, Douglas C. Eckery, and Terry M. Nett

Comparison of mixing methods and associated residual levels of zinc phosphide on cabbage bait for rodent management, Roger A. Baldwin, Benjamin G. Abbo, and David A. Goldade

The elusive search for an effective repellent against voles: an assessment of anthraquinone for citrus crops, Roger A. Baldwin, Ryan Meinerz, Gary W. Witmer, and Scott J. Werner

Frogs (Coqui Frogs, Greenhouse Frogs, Cuban Tree Frogs, and Cane Toads), Karen H. Beard, Steve A. Johnson, and Aaron B. Shiels

Research Priorities for Managing Invasive Wild Pigs in North America, James C. Beasley, Stephen S. Ditchkoff, John J. Mayer, Mark D. Smith, and Kurt C. Vercauteren

Livestock abundance predicts vampire bat demography, immune profiles and bacterial infection risk, Daniel J. Becker, Gábor Á. Czirják, Dmitriy V. Volokhov, Alexandra B. Bentz, Jorge E. Carrera, Melinda S. Camus, Kristen J. Navara, Vladimir E. Chizhikov, M. Brock Fenton, Nancy B. Simmons, Sergio E. Recuenco, Amy T. Gilbert, Sonia Altizer, and Daniel G. Streicker

BOOK REVIEW, Are R. Berentsen

Seroconversion of Raccoons Following Two Oral Rabies Vaccination Baiting Strategies, Are R. Berentsen, Erin M. Patrick, Chad Blass, Keith Wehner, Brett Dunlap, Bradley Hicks, Robert Hale, Richard B. Chipman, and Kurt C. VerCauteren

Ecology of the Small Indian Mongoose (Herpestes auropunctatus) in North America, Are R. R. Berentsen, William C. Pitt, and Robert T. Sugihara

Is Razor-wire an Effective Deterrent for Birds Perching on Security Fences at Airports?, David L. Bergman and Brian E. Washburn

European Starling (Sturnus vulgaris) reproduction undeterred by predator scent inside nest boxes, Bradley Blackwell, Thomas W. Seamans, Morgan B. Pfeiffer, and Bruce N. Buckingham

Management of Wintering Short-eared Owls at Airports in the Lower Great Lakes Region, Aaron Bowden, Robert J. Hromack, Christopher H. Loftis, and Brian E. Washburn

A Review of African Swine Fever and the Potential for Introduction into the United States and the Possibility of Subsequent Establishment in Feral Swine and Native Ticks, Vienna R. Brown and Sarah N. Bevins

A Review of Classical Swine Fever virus and Routes of introduction into the United States and the Potential for virus establishment, Vienna R. Brown and Sarah N. Bevins

Resource partitioning between kit foxes (Vulpes macrotis) and coyotes (Canis latrans): a comparison of historical and contemporary dietary overlap, P. A. Byerly, R. C. Lonsinger, E. M. Gese, A. J. Kozlowski, and L. P. Waits

Prophage induction reduces Shiga toxin producing Escherichia coli (STEC) and Salmonella enterica on tomatoes and spinach: A model study, Brigitte Cadieux, Anna Colavecchio, Julie Jeukens, Luca Freschi, Jean-Guillaume Emond-Rheault, Irena Kukavica-Ibrulj, Roger C. Levesque, Sakjia Bekal, Jeffrey C. Chandler, Shannon M. Coleman, Bledar Bisha, and Lawrence D. Goodridge

Nutritional depletion of total mixed rations by red-winged blackbirds and projected impacts on dairy cow performance, James C. Carlson, Randal S. Stahl, John J. Wagner, Terry E. Engle, Shelagh T. DeLiberto, Dustin A. Reid, and Scott J. Werner

Nutritional depletion of total mixed rations by European starlings: Projected effects on dairy cow performance and potential intervention strategies to mitigate damage, James C. Carlson, R. S. Stahl, S. T. DeLiberto, J. J. Wagner, T. E. Engle, R. M. Engeman, C. S. Olson, J. W. Ellis, and S. J. Werner

Nutritional depletion of total mixed rations by European starlings: Projected effects on dairy cow performance and potential intervention strategies to mitigate damage, James C. Carlson, R. S. Stahl, S. T. DeLiberto, J. J. Wagner, T. E. Engle, R. M. Engeman, C. S. Olson, J. W. Ellis, and S. J. Werner

Short communication: A countrywide survey of antimicrobialresistant indicator bacteria in Kosovo’s dairy farms, Jeffrey C. Chandler, Sulaiman F. Aljasir, Afrim Hamidi, Driton Sylejmani, Kenneth G. Gerow, and Bledar Bisha

Plumage Changes in Double-crested Cormorants (Phalacrocorax auritus) Within the Breeding Season: the Risks of Aging by Plumage, Jennifer E. Chastant and D. Tommy King

Brown Tree Snakes Methods and Approaches for Control, Larry Clark, Craig S. Clark, and Shane Siers

Impacts of biomass production at civil airports on grassland bird conservation and aviation strike risk, Tara J. Conkling, Jerrold L. Belant, Travis L. DeVault, and James A. Martin

Using Off-the-Shelf Technologies to Mass Manufacture Oral Vaccine Baits for Wildlife, Lucila M. Corro, Daniel W. Tripp, Scott A. Stelting, and Michael W. Miller

Potential of Double-crested Cormorants (Phalacrocorax auritus), American White Pelicans (Pelecanus erythrorhynchos), and Wood Storks (Mycteria americana) to Transmit a Hypervirulent Strain of Aeromonas hydrophila between Channel Catfish Culture Ponds, Fred L. Cunningham, Madison M. Jubirt, Katie C. Hanson-Dorr, Lorelei Ford, Paul Fioranelli, and Larry A. Hanson

Costs and effectiveness of damage management of an overabundant species (Sus scrofa) using aerial gunning, Amy J. Davis, Bruce Leland, Michael Bodenchuk, Kurt C. VerCauteren, and Kim M. Pepin

Quantifying site-level usage and certainty of absence for an invasive species through occupancy analysis of camera-trap data, Amy J. Davis, Ryan McCreary, Jeremiah Psiropoulos, Gary Brennan, Terry Cox, Andrew Partin, and Kim M. Pepin

Accounting for observation processes across multiple levels of uncertainty improves inference of species distributions and guides adaptive sampling of environmental DNA, Amy J. Davis, Kelly E. Williams, Nathan P. Snow, Kim M. Pepin, and Antoinette J. Piaggio

Effects of immunization against bone morphogenetic protein-15 and growth differentiation factor-9 on ovarian function in mares, Kelli A. Davis, Kristin M. Klohonatz, Darcy S.O. Mora, Hannah M. Twenter, Peter E. Graham, Pablo Pinedo, Douglas C. Eckery, and Jason E. Bruemmer

Efficacy of repellent-treated structural barriers for Richardson’s ground squirrels (Urocitellus richardsonii (Sabine)) and house mice (Mus musculus L.), Shelagh T. DeLiberto, Hailey E. McLean, and Scott J. Werner

Black - billed Magpie Agonistic Mobbing Attack on a Bullsnake, James J. DeLutes III and Richard M. Engeman

PITUOPHIS CATENIFER SAYI (Bullsnake). AGONISTIC MOBBING ATTACK., James J. Delutes III and Richard M. Engeman

How Behavior of Nontarget Species Affects Perceived Accuracy of Scat Detection Dog Surveys, Karen E. DeMatteo, Linsey W. Blake, Julie K. Young, and Barbara Davenport

Estimating Interspecific Economic Risk of Bird Strikes With Aircraft, Travis L. DeVault, Bradley F. Blackwell, Thomas W. Seamans, Michael J. Begier, Jason D. Kougher, Jenny E. Washburn, Phyllis R. Miller, and Richard A. Dolbeer

Individual variation in avian avoidance behaviours in response to repeated, simulated vehicle approach, Travis L. DeVault, T. W. Seamans, B. F. Blackwell, S. L. Lima, and E. Fernandez-Juricic

Persistence of maternal antibodies to influenza A virus among captive mallards (Anas platyrhynchos), Katherine L. Dirsmith, J. Jeffrey Root, Kevin T. Bentler, Heather J. Sullivan, Andrea B. Liebowitz, Lauren H. Petersen, Hailey E. McLean, and Susan A. Shriner

Evaluating Blackbird Behavioral Response Toward Unmanned Aircraft Systems (UASs): Exploiting Antipredator Behavior to Enhance Avoidance, Conor C. Egan, Lucas Wandrie, Bradley F. Blackwell, Esteban Fernandez-Juricic, and Page E. Klug

Chapter 11 An International Perspective on the Regulation of Rodenticides, John D. Eisemann, Penny M. Fisher, Alan Buckle, and Simon Humphrys

Towards canine rabies elimination: Economic comparisons of three project sites, J. L. Elser, B. G. Hatch, L. H. Taylor, L. H. Nel, and S. A. Shwiff

Common Ravens Conditioned to a Nutritious Seasonal Aquatic Food Source in Rocky Mountain National Park, Richard M. Engeman

Diverse examples from managing invasive vertebrate species on inhabited islands of the United States, Richard M. Engeman, Michael L. Avery, Aaron B. Shiels, Are R. Berentsen, Kurt C. VerCauteren, Robert T. Sugihara, Anthony G. Duffiney, Craig S. Clark, and John D. Eisemann

Objectives and integrated approaches for the control of brown tree snakes: An updated overview, Richard M. Engeman, Aaron B. Shiels, and Craig S. Clark

Prevalence and amount of feral swine damage to three row crops at planting, Richard M. Engeman, Jason Terry, Leif R. Stephens, and Kenneth S. Gruver

Influenza D Virus Infection in Feral Swine Populations, United States, Lucas Ferguson, Kaijian Luo, Alicia K. Olivier, Fred L. Cunningham, Sherry Blackmon, Katie Hanson-Dorr, Hailiang Sun, John Baroch, Mark W. Lutman, Bianca Quade, William Epperson, Richard Webby, Thomas J. DeLiberto, and Xiu-Feng Wan

Species With Greater Aerial Maneuverability Have Higher Frequency of Collisions With Aircraft: A Comparative Study, Esteban Fernandez-Juricic, James Brand, Bradley F. Blackwell, Thomas W. Seamans, and Travis L. DeVault

Effectiveness of GonaCon as an immunocontraceptive in colony-housed cats, Amy Fischer, Valerie A.W. Benka, Joyce R. Briggs, Marc-Antoine Driancourt, Joanne Maki, Darcy S.O. Mora, Kevin N. Morris, Kayla A. Myers, Linda Rhodes, Lindsey M. Vansandt, George Robert Weedon, Julie Wolf, and Julie K. Levy

Predicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl, Alan. B. Franklin, Sarah N. Bevins, Jeremy W. Ellis, Ryan S. Miller, Susan A. Shriner, J. Jeffrey Root, Daniel P. Walsh, and Thomas J. Deliberto

Grass is not always greener: rodenticide exposure of a threatened species near marijuana growing operations, Alan B. Franklin, Peter C. Carlson, Angela Rex, Jeremy T. Rockwelt, David Garza, Emily Culhane, Steven F. Volker, Robert J. Dusek, Valerie I. Shearn-Bochsler, Mourad W. Gabriel, and Katherine E. Horak

Accounting for location uncertainty in azimuthal telemetry data improves ecological inference, Brian D. Gerber, Mevin B. Hooten, Christopher P. Peck, Mindy B. Rice, James H. Gammonley, Anthony D. Apa, and Amy J. Davis

Sharing an environment with sick conspecifics alters odors of healthy animals, Stephanie S. Gervasi, Maryanne Opiekun, Talia Martin, Gary K. Beauchamp, and Bruce A. Kimball

Influence of behavioral state, sex, and season on resource selection by jaguars (Panthera onca): Always on the prowl?, Eric M. Gese, Patricia A. Terletzky, Sandra M. C. Cavalcanti, and Christopher M. U. Neale

Cross-fostering as a conservation tool to augment endangered carnivore populations, Eric M. Gese, William T. Waddell, Patricia A. Terletzky, Chris F. Lucash, Scott R. McLellan, and Susan K. Behrns

FIELD TRIALS OF ONTARIO RABIES VACCINE BAIT IN THE NORTHEASTERN USA, 2012–14, Amy Gilbert, Shylo R. Johnson, Kathleen M. Nelson, Richard B. Chipman, Kurt C. VerCauteren, Timothy P. Algeo, Charles E. Rupprecht, and Dennis Slate


Efficacy of Ontario Rabies Vaccine Baits (ONRAB) against rabies infection in raccoons, Amy Gilbert, Shylo Johnson, Nikki Walker, Chad Wickham, Alex Beath, and Kurt C. Vercauteren

Assessing bird avoidance of high-contrast lights using a choice test approach: implications for reducing human-induced avian mortality, Benjamin Goller, Bradley F. Blackwell, Travis L. DeVault, Patrice E. Baumhardt, and Esteban Fernandez-Juricic

Detection of Inflammation via Volatile Cues in Human Urine, Amy R. Gordon, Bruce A. Kimball, Kimmo Sorjonen, Bianka Karshikoff, John Axelsson, Mats Lekander, Johan N. Lundstrom, and Mats J. Olsson

Evaluating an Alleged Mimic of the Monarch Butterfly: Neophasia (Lepidoptera: Pieridae) Butterflies are Palatable to Avian Predators, Dale A. Halbritter, Johnalyn M. Gordon, Kandy L. Keacher, Michael L. Avery, and Jaret C. Daniels

Assessing the potential impacts of a changing climate on the distribution of a rabies virus vector, Mark A. Hayes and Antoinette J. Piaggio


Invasion ecology of wild pigs (Sus scrofa) in Florida, USA: the role of humans in the expansion and colonization of an invasive wild ungulate, Felipe A. Hernandez, Brandon M. Parker, Cortney L. Pylant, Timothy J. Smyser, Antoinette J. Piaggio, Stacey L. Lance, Michael P. Milleson, James D. Austin, and Samantha M. Wisely

Feral Goats and Sheep, Steven C. Hess, Dirk H. Van Vuren, and Gary W. Witmer

Effects of vulture exclusion on carrion consumption by facultative scavengers, Jacob E. Hill, Travis L. DeVault, James C. Beasley, Olin E. Rhodes Jr., and Jerrod L. Belant

Roads do not increase carrion use by a vertebrate scavenging community, Jacob E. Hill, Travis L. DeVault, James C. Beasley, Olin E. Rhodes Jr., and Jerrold L. Belant

Valuing the absence of feral swine in the United States: A partial equilibrium approach, J. J. Holderieath, D. L. Pendell, J. C. Hadrich, A. Anderson, C. Slootmaker, E. Harper, and S. A. Shwiff

Trace element concentrations in the small Indian mongoose (Herpestes auropunctatus) from Hawaii, USA, Sawako Horai, Yusuke Nakashima, Kanae Nawada, Izumi Watanabe, Tatsuya Kunisue, Shintaro Abe, Fumio Yamada, and Robert Sugihara

Pharmacokinetics of Anticoagulant Rodenticides in Target and Non-target Organisms, Katherine Horak, Penny M. Fisher, and Brian M. Hopkins

Assessment of zinc phosphide bait shyness and tools for reducing flavor aversions, Katherine Horak, N. M. Hofmann, and B. A. Kimball

Modeling the distributions of tegu lizards in native and potential invasive ranges, Catherine S. Jarnevich, Mark A. Hayes, Lee A. Fitzgerald, Amy A. Yackel Adams, Bryan G. Falk, Michelle A. M. Collier, Lea R. Bonewell, Page E. Klug, Sergio Naretto, and Robert N. Reed

Assessing Ecological and Social Outcomes of a Bear-Proofing Experiment, Heather Johnson, David L. Lewis, Stacy A. Lischka, and Stewart W. Breck

Feral swine Sus scrofa: a new threat to the remaining breeding wetlands of the Vulnerable reticulated flatwoods salamander Ambystoma bishopi, Kelly C. Jones, Thomas A. Gorman, Brandon K. Rincon, John Allen, Carola A. Haas, and Richard M. Engeman

Neutralizing antibodies against flaviviruses, Babanki virus, and Rift Valley fever virus in Ugandan bats, Rebekah C. Kading, Robert M. Kityo, Eric C. Mossel, Erin M. Borland, Teddie Nakayiki, Betty Nalikka, Luke Nyakarahuka, Jeremy P. Ledermann, Nicholas A. Panella, Amy T. Gilbert, Mary B. Crabtree, Julian Kerbis Peterhans, Jonathan S. Towner, Brian R. Amman, Tara K. Sealy, Stuart T. Nichol, Ann M. Powers, Julius J. Lutwama, and Barry R. Miller

Foraging behavior of red-winged blackbirds (Agelaius phoeniceus) on sunflower (Helianthus annuus) with varying coverage of anthraquinone-based repellent, Brandon K. Kaiser, Mike Ostlie, and Page E. Klug

Social conformity affects experimental measurement of boldness in male but not female monk parakeets (Myiopsitta monachus), Kaan Kerman, Kathryn E. Sieving, Colette St. Mary, and Michael L. Avery

Estimating stand-level economic impacts of black bear damage to intensively managed forests, Kristina N. Kline, Jimmy D. Taylor, and Anita T. Morzillo

HUMAN–BLACK BEAR CONFLICTS, Carl W. Lackey, Stewart W. Breck, Brian F. Wakeling, and Bryant White

Development and Evaluation of a Bait Station for Selectively Dispensing Bait to Invasive Wild Pigs, Michael Lavelle, Nathan P. Snow, Joe M. Halseth, John C. Kinsey, Justin A. Foster, and Kurt C. VerCauteren

Evaluation of movement behaviors to inform toxic baiting strategies for invasive wild pigs (Sus scrofa), Michael Lavelle, Nathan P. Snow, Joseph M. Halseth, Eric H. VanNatta, Heather N. Sanders, and Kurt C. VerCauteren

The effect of wildfire on population dynamics for two native small mammal species in a coastal heathland in Queensland, Australia, Adam C. Liedloff, John C. Wilson, and Richard M. Engeman

Genetic evidence supports sporadic and independent introductions of subtype H5 low pathogenic avian influenza A viruses from wild birds to domestic poultry in North America, Lei Li, Andrew S. Bowman, Thomas J. DeLiberto, Mary L. Killian, Scott Krauss, Jacqueline M. Nolting, Mia Kim Torchetti, Andrew M. Ramey, Andrew B. Reeves, David E. Stallknecht, Richard J. Webby, and Xiu-Feng Wan

Evolutionary pathway for the 2017 emergence of a novel highly pathogenic avian influenza A(H7N9) virus among domestic poultry in Tennessee, United States, Lei Li, Thomas J. DeLiberto, Mary L. Killian, Mia K. Torchetti, and Xiu-Feng Wan

Development of on-shore behavior among polar bears (Ursus maritimus) in the southern Beaufort Sea: inherited or learned?, Kate M. Lillie, Eric M. Gese, Todd C. Atwood, and Sarah A. Sonsthagen


European Starlings, George M. Linz, Ron J. Johnson, and James Thiele

A conceptual model for the integration of social and ecological information to understand human-wildlife interactions, Stacy A. Lischka, Tara L. Teel, Heather E. Johnson, Sarah E. Reed, Stewart Breck, Andrew Don Carlos, and Kevin R. Crooks

Estimating densities for sympatric kit foxes (Vulpes macrotis) and coyotes (Canis latrans) using noninvasive genetic sampling, R. C. Lonsinger, P. M. Lukacs, E. M. Gese, R. N. Knight, and L. P. Waits

An assessment of the US endangered species act recovery plans: using physiology to support conservation, Jessica L. Mahoney, Page E. Klug, and Wendy L. Reed

Spatial processes decouple management from objectives in a heterogeneous landscape: predator control as a case study, Peter J. Mahoney, Julie K. Young, Kent R. Hersey, Randy T. Larsen, Brock R. McMillan, and David C. Stoner

A molecular analysis to assess codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) predation by orchard birds, Anna M. Mangan, Antoinette J. Piaggio, Matthew W. Hopken, Scott J. Werner, and Liba Pejchar

Post‑fledging movement and spatial ecology of the endangered Cape Vulture (Gyps coprotheres), Francis R. Martens, Morgan B. Pfeiffer, Colleen T. Downs, and Jan A. Venter

Fertility control for managing free-roaming feral cattle in Hong Kong, Giovanna Massei, Ka-Kei Koon, Siu-Iun Law, Matt Gomm, Darcy S. O. Mora, Rebecca Callaby, Kate Palphramand, and Douglas C. Eckery