Zoology Commons^™

Relationships Between Survival And Habitat Suitability Of Semi- Aquatic Mammals, Isidro Barela, Leslie M. Burger, Jimmy Taylor, Kristine O. Evans, Ryo Ogawa, Lance Mcclintic, Guiming Wang

United States Department of Agriculture Wildlife Services: Staff Publications

Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche-based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), …

Two New Nematodes From The Families Molineidae And Strongyloididae (Nemata): Parasites Of Caenolestes (Mammalia: Paucituberculata: Caenolestidae) From The Andes Of Ecuador, Ricardo Guerrero

MANTER: Journal of Parasite Biodiversity

A new genus and species of Molineinae (Nemata: Trichostrongyloidea) is described. It is similar to Molineus but differs in ray 4 being longest instead of shortest. In addition, a new species of Parastrongyloides is described that is characterized by a short digitiform appendix on the tail and spicule tips with fine points. It is the second species known with two morphotypes of the females.

Resumen:

Se describe un nuevo género y especie de Molineinae (Nemata: Trichostrongyloidea), similar a Molineus pero difiere en que en la bolsa caudal el rayo 4 es el más largo en lugar de sewr el …

The Nebraska Bird Review, 2020 Annual Color Section

Nebraska Bird Review

Our theme this year is Odd Couples: two or more different species captured in the same photo frame. Examples appear on the first three pages of photos.

Blue Jay with Great Horned Owl in Plum Creek SRA, Dawson Co., 23 Dec. 2019. Photo by Elizabeth Winter.

Green Heron with Baltimore Oriole on Dark Island Trail, Merrick Co., June 2020. Photo by Colleen Childers.

Wilson’s Phalarope surrounded by Longbilled Dowitchers and Stilt Sandpipers along highway 30 east of North Platte, Lincoln Co., 12 May 2020. Photo by Boni Edwards.

Downy Woodpecker with Carolina Wren on suet feeder in photographer’s yard, La …

Winter Field Report, December 2019-February 2020, W. Ross Silcock

Nebraska Bird Review

As with any of these Seasonal Reports, there was plenty to entertain us and to contemplate this winter. The most obvious feature of this winter’s reports was the taxonomically widespread incidence of midwinter occurrences of species normally absent at that time. Snow, Ross’s, and Greater White-fronted Geese occurred in good numbers, and Jan to early Feb reports of dabbling and diving ducks often far from expected winter occurrence locations were notable. Among passerines, notable midwinter reports were of Gray Catbird, Brown Thrasher, and Northern Mockingbird, Nebraska’s first record for Feb of American Pipit, and 6th winter record of Lesser Goldfinch. …

2019-2020 Christmas Bird Counts, Don Paseka

Nebraska Bird Review

Mergansers reached a new high of 104 counted in nine circles, which topped the count of 97 from 2017. A single Surf Scoter was found in the Lower Platte circle, which was only the fourth time that this species has been found on a Nebraska CBC. Lone birds were also found at Lake McConaughy in 1999, 2010 and 2015. A good North Platte find were two Barrow’s Goldeneye. Several species, however, were counted in numbers much below the norm. The lone Wood Duck found at Branched Oak was the lowest count for that species since 2004, when they were missed …

Effects Of Inactivated Mycobacterium Bovis Vaccination On Molokai-Origin Wild Pigs Experimentally Infected With Virulent M. Bovis, Pauline Nol, Morgan Wehte, Richard A. Bowen, Suelee Robbe-Austerman, Tyler Thacker, Kristina Lantz, Jack Rhyan, Laurie A. Baeten, Ramón A. Juste, Iker A. Sevilla, Christian Gortazar, Joaquín Vicente

United States Department of Agriculture Wildlife Services: Staff Publications

The wild pig population on Molokai, Hawaii, USA is a possible reservoir for bovine tuberculosis, caused by Mycobacterium bovis, and has been implicated in decades past as the source of disease for the island’s domestic cattle. Heat-inactivated vaccines have been effective for reducing disease prevalence in wild boar in Spain and could prove useful for managing M. bovis in Molokai wild pigs. We designed an experiment to test this vaccine in wild pigs of Molokai genetics. Fifteen 3–4-month-old pigs were orally administered 10⁶–10⁷ colony forming units (cfu) of heat-inactivated M. bovis (Vaccinates; n = 8; 0.2 …

Rabies Management Implications Based On Raccoon Population Density Indexes, Dennis Slate, Brandi D. Saidy, Ashlee Simmons, Kathleen M. Nelson, Amy Davis, Timothy P. Algeo, Stacey A. Elmore, Richard B. Chipman

United States Department of Agriculture Wildlife Services: Staff Publications

An estimate or index of target species density is important in determining oral rabies vaccination (ORV) bait densities to control and eliminate specific rabies variants. From 1997–2011, we indexed raccoon (Procyon lotor) densities 253 times based on cumulative captures on 163 sites from Maine to Alabama, USA, near ORV zones created to prevent raccoon rabies from spreading to new areas. We conducted indexing under a common cage trapping protocol near the time of annual ORV to aid in bait density decisions. Unique raccoons (n = 8,415) accounted for 68.0% of captures (n = 12,367). We recaptured raccoons 2,669 times. We …

Economic Estimates Of Invasive Wild Pig Damage To Crops In 12 Us States, Sophie Mckee, Aaron Anderson, Keith Carlisle, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

We report the results of a survey on invasive wild pig (Sus scrofa L.) damage and control in 12 US states (Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, and Texas). The crops chosen for this study represent the “second-tier” in terms of economic importance after the six crops that were the subject of Anderson et al. (2016). The survey was distributed by the USDA National Agricultural Statistical Service (NASS) in the summer of 2019 to a sample of producers in each of the states (except California) of the following six crops: hay, pecans (Carya …

Individual And Population Fitness Consequences Associated With Large Carnivore Use Of Residential Development, Heather Johnson, David L. Lewis, Stewart W. Breck

United States Department of Agriculture Wildlife Services: Staff Publications

Large carnivores are negotiating increasingly developed landscapes, but little is known about how such behavioral plasticity influences their demographic rates and population trends. Some investigators have suggested that the ability of carnivores to behaviorally adapt to human development will enable their persistence, and yet, others have suggested that such landscapes are likely to serve as population sinks or ecological traps. To understand how plasticity in black bear (Ursus americanus) use of residential development influences their population dynamics, we conducted a 6-yr study near Durango, Colorado, USA. Using space-use data on individual bears, we examined the influence of use of residential …

Effects Of Deepwater Horizon Oil On Feather Structure And Thermoregulation In Gulls: Does Rehabilitation Work?, Katherine Horak, Nicole L. Barrett, Jeremy W. Ellis, Emma M. Campbell, Nicholas G. Dannemiller, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Impacts of large-scale oil spills on avian species are far-reaching.While media attention often focuses on lethal impacts, sub-lethal effects and the impacts of rehabilitation receive less attention. The objective of our study was to characterize effects of moderate external oiling and subsequent rehabilitation on feather structure and thermoregulation in gulls. We captured 30 wild ring-billed gulls (Larus delawarensis) and randomly assigned each individual to an experimental group: 1) controls, 2) rehabilitated birds (externally oiled, rehabilitated by washing), or 3) oiled birds (externally oiled, not rehabilitated). We externally oiled birds with weathered MC252 Deepwater Horizon oil (water for controls) …

Migratory Flyways May Affect Population Structure In Double‐Crested Cormorants, Steven J.A. Kimble, Brian S. Dorr, Katie C. Hanson-Dorr, Olin E. Rhodes Jr., Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Double‐crested cormorants (Phalacrocorax auritus) recovered from a demographic bottleneck so well that they are now considered a nuisance species at breeding and wintering grounds across the United States and Canada. Management of this species could be improved by refining genetic population boundaries and assigning individuals to their natal population. Further, recent radio‐telemetry data suggest the existence of Interior and Atlantic migratory flyways, which could reduce gene flow and result in substantial genetic isolation. In this study, we used 1,784 individuals collected across the eastern United States, a large panel of microsatellite markers developed for this species, and individuals banded as …

Optimal Bait Density For Delivery Of Acute Toxicants To Vertebrate Pests, Kim M. Pepin, Nathan P. Snow, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baiting is a fundamental method for delivering toxicants to pest species. Planning baiting strategies is challenging because bait-consumption rates depend on dynamic processes including space use and demographics of the target species. To determine cost-effective strategies for optimizing baiting, we developed a spatially explicit model of population dynamics using field-based measures of wild-pig (Sus scrofa) space use, bait consumption, and mortality probabilities. The most cost-effective baiting strategy depended strongly on the population reduction objective and initial density. A wide range of baiting strategies were cost-effective when the objective was 80% population reduction. In contrast, only a narrow range of …

Brodifacoum Residues In Fish Three Years After An Island-Wide Rat Eradication Attempt In The Tropical Pacific, Shane R. Siers, Aaron B. Shiels, Steven F. Volker, Kristen Rex, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive rats are known to threaten natural resources and human health and safety. Island-wide rat eradication attempts have been increasing in number and scale during the past several decades, as has the frequency of eradication success. The most common method to remove all rats from an island is to broadcast anticoagulant rodenticide bait into every rat’s home range on the island. Broadcast of toxicants can put humans and other nontarget species in marine and terrestrial environments at risk of exposure. The persistence of anticoagulant residues is somewhat unknown, particularly in marine environments. Three years after ~ 18,000 kg of 25 …

The Enigmatic Spelaeorhynchidae Oudemans, 1902 (Acari: Mesostigmata) Blood-Feeding Ectoparasites Infesting Neotropical Bats, With Catalog And Notes On A Collection From The Manú Biosphere Reserve In Peru, Donald Gettinger, Madalyne Epperson, Candy Hermasillo, Scott L. Gardner

MANTER: Journal of Parasite Biodiversity

A survey of ectoparasites associated with bats collected along an elevational transect in the Manú Biosphere Reserve, Peru, includes specimens of two species of an unusual and rarely collected family of parasitic mites, the Spelaeorhynchidae Oudemans, and reveals information on the natural occurrence of these infections. In lowland rainforest (450–1,000 m) along the Rio Alto Madre de Dios, Spelaeorhynchus soaresi Peracchi was recorded exclusively infecting two species of frugivorous Carollia, C. brevicauda and C. perspicillata. At higher elevations in the mountains and cloud forests, Spelaeorhynchus praecursor Neumann exclusively infected two species of nectarivorous Anoura, A. cultrata and A. …

Insights About Diversity Of Tetrabothriidae (Eucestoda) Among Holarctic Alcidae (Charadriiformes): What Is Tetrabothrius Jagerskioeldi?, Eric P. Hoberg, Kaylen Marie Soudachanh

MANTER: Journal of Parasite Biodiversity

Tetrabothriid cestodes are characteristic helminths that infect species of seabirds globally. We begin with the exploration of the diversity of tapeworms of the genus Tetrabothrius Rudolphi, 1819 (Eucestoda: Tetrabothriidae), some of which are distributed among seabirds of the family Alcidae (Charadriiformes) at boreal to higher latitudes of Holarctic seas. During the course of 2 decades of field inventory from 1975 through the early 1990s (in addition to earlier collections assembled by Robert L. Rausch and colleagues in Alaska initiated in the late 1940s), an extensive series of tapeworm specimens attributable to species of Tetrabothrius was recovered from seabirds across the …

The Abyssinian Art Of Louis Agassiz Fuertes In The Field Museum, Paul A. Johnsgard

Zea E-Books Collection

This book documents the paintings and drawings executed by Louis Agassiz Fuertes during the Field Museum of Natural History’s seven-month expedition to Ethiopia (Abyssinia) in 1926–27. During that time Fuertes completed 70 field watercolors that illustrate 55 species of birds and four species of mammals. He also executed 34 pencil drawings, which illustrate 13 species of mammals and 11 species of birds, plus numerous miscellaneous sketches and small watercolors. This book identifies and describes the biology of all 69 species of birds and mammals illustrated by Fuertes and includes 32 color reproductions of Fuertes’s watercolors that were published as a …

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

United States Department of Agriculture Wildlife Services: Staff Publications

1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for …

Gulls As Sources Of Environmental Contamination By Colistin-Resistant Bacteria, Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. Mccurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler

United States Department of Agriculture Wildlife Services: Staff Publications

In 2015, the mcr-1 gene was discovered in Escherichia coli in domestic swine in China that conferred resistance to colistin, an antibiotic of last resort used in treating multi-drug resistant bacterial infections in humans. Since then, mcr-1 was found in other human and animal populations, including wild gulls. Because gulls could disseminate the mcr-1 gene, we conducted an experiment to assess whether gulls are readily colonized with mcr-1 positive E. coli, their shedding patterns, transmission among conspecifics, and environmental deposition. Shedding of mcr-1 E. coli by small gull flocks followed a lognormal curve and gulls shed one strain >101 …

Piscivorous Bird Use Of Aquaculture And Natural Water Bodies In Mississippi, Paul C. Burr, Jimmy I. Avery, Garrett M. Street, Bronson K. Strickland, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Double crested cormorants (Phalacrocorax auritus) and great egrets (Ardea alba) have an extensive history of human wildlife conflict with the aquaculture industry of western Mississippi, USA, due to

their depredation of cultured catfish (Ictalurus spp.). Although aquaculture is abundant, western Mississippi also contains naturally occurring water bodies that offer alternative forage opportunities to these species. How cormorants or egrets distribute themselves among these 2 foraging options is unknown, but it has been generally assumed each species uses aquaculture disproportionately more because of the high density of available prey. To test this assumption, we surveyed these …

Control Or Eradication: Problems In The Management Of Invasive Birds, Michael L. Avery, Chris J. Feare

United States Department of Agriculture Wildlife Services: Staff Publications

Humans have captured, transported and intentionally released wild birds for centuries (Blackburn et al., 2009). Motivations for such purposeful introductions include food (West and Zhou, 2007), religion (Agoramoorthy and Hsu, 2007), sport (McDowall, 1994), biocontrol (Bennett and Hughes, 1959; Kurdila, 1995) and aesthetics (Ryan, 1906; Thomson, 1922). Many purposeful bird introductions were the work of acclimatization societies, particularly in North America, New Zealand and Australia. These societies were formed in the 19th century by European settlers to transport bird species from their homelands in efforts to establish them in the newly settled regions (Thomson, 1922; Dunlap, 1997). As a result …

Spring Field Report, March-May 2020, W. Ross Silcock

Nebraska Bird Review

Although there were numerous early arrival dates, most were in the range of historically earliest expected dates; notable, however, was a lone record-early Whiterumped Sandpiper, nicely photographed. Record late by a month was a juvenile Redtailed (Harlan’s) Hawk, also confirmed by photo. Perhaps most prominent this spring were the large numbers of several species. Most eye-popping were record spring totals of 22 Glossy Ibises, 11 Yellow-bellied Flycatchers, 14 Veeries, including five in the Panhandle, 48 Gray-cheeked Thrushes, 20 Bay-breasted Warblers, not long ago a rare bird in spring, 45 Golden-winged Warblers and 27 Canada Warblers, both of which were about …

The Nebraska Bird Review, Volume 88 March 2020 Number 1

Nebraska Bird Review

Winter Field Report, Dec. 2019 - Feb. 2020, by W. Ross Silcock …2

2019-2020 Christmas Bird Counts …18, 27-41

Annual Color Photo Section …19-26

Annual Treasurer's Report for 2019, by Jan Johnson …42

Subscription and Organization Information …43

Obituary: Thomas Henry Kunz (1938–2020), Allen Kurta, Winifred F. Frick, M. Brock Fenton, Polly Campbell, Gary F. Mccracken, Robert M. Timm, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Dr. Thomas Henry Kunz, an internationally recognized expert on the ecology and behavior of bats and Professor at Boston University, passed away on April 13, 2020 in Dedham, Massachusetts, at the age of 81 as the result of complications from COVID-19. “Tom,” to his many friends and colleagues, was born on June 11, 1938 in Independence, Missouri, to William H. and Edna F. (Dornfeld) Kunz. He married Margaret Louise Brown on December 27, 1962 in Faucett, Missouri, Margaret’s hometown. Two children were born to Margaret and Tom—Pamela Kunz (Jeffrey Kwan) and David Kunz (Nicole, née D’Angelo), and five grandchildren.

As …

Mixed Ancestry From Wild And Domestic Lineages Contributes To The Rapid Expansion Of Invasive Feral Swine, Timothy J. Smyser, Michael A. Tabak, Chris Slootmaker, Michael S. Robeson Ii, Ryan S. Miller, Mirte Bosse, Hendrik-Jan Megens, Martien A.M. Groenen, Samuel Rezende Paiva, Danielle Assis De Faria, Harvey D. Blackburn, Brandon S. Schmit, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive alien species are a significant threat to both economic and ecological systems. Identifying the processes that give rise to invasive populations is essential for implementing effective control strategies. We conducted an ancestry analysis of invasive feral swine (Sus scrofa, Linnaeus, 1758), a highly destructive ungulate that is widely distributed throughout the contiguous United States, to describe introduction pathways, sources of newly emergent populations and processes contributing to an ongoing invasion. Comparisons of high-density single nucleotide polymorphism genotypes for 6,566 invasive feral swine to a comprehensive reference set of S. scrofa revealed that the vast majority of feral swine were …

The Role Of European Starlings (Sturnus Vulgaris) In The Dissemination Of Multidrug- Resistant Escherichia Coli Among Concentrated Animal Feeding Operations, Jeffrey C. Chandler, Jennifer E. Anders, Nicolas A. Blouin, James C. Carlson, Jeffrey T. Lejeune, Lawrence D. Goodridge, Baolin Wang, Leslie A. Day, Anna M. Mangan, Dustin A. Reid, Shannon M. Coleman, Matthew W. Hopken, Bledar Bisha

United States Department of Agriculture Wildlife Services: Staff Publications

Antimicrobial use in livestock production is a driver for the development and proliferation of antimicrobial resistance (AMR). Wildlife interactions with livestock, acquiring associated AMR bacteria and genes, and wildlife’s subsequent dispersal across the landscape are hypothesized to play an important role in the ecology of AMR. Here, we examined priority AMR phenotypes and genotypes of Escherichia coli isolated from the gastrointestinal tracts of european starlings (Sturnus vulgaris) found on concentrated animal feeding operations (CAFOs). European starlings may be present in high numbers on cAfos (>100,000 birds), interact with urban environments, and can migrate distances exceeding 1,500 km in North …

Reporting The Limits Of Detection And Quantification For Environmental Dna Assays, Katy E. Klymus, Christopher M. Merkes, Michael J. Allison, Caren S. Goldberg, Caren C. Helbing, Margaret E. Hunter, Craig A. Jackson, Richard F. Lance, Anna M. Mangan, Emy M. Monroe, Antoinette J. Piaggio, Joel P. Stokdyk, Chris C. Wilson, Catherine A. Richter

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Environmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully established, with one area being the calculation and interpretation of assay limit of detection (LOD) and limit of quantification (LOQ).

Aims: Here, we propose establishing consistent methods for determining and reporting of LOD and LOQ for single‐species quantitative PCR (qPCR) eDNA studies.

Materials …

Safety, Immunogenicity, And Efficacy Of Intramuscular And Oral Delivery Of Era-G333 Recombinant Rabies Virus Vaccine To Big Brown Bats (Eptesicus Fuscus), Amy T. Gilbert, Xianfu Wu, Felix R. Jackson, Richard Franka, Gary F. Mccracken, Charles E. Rupprecht

United States Department of Agriculture Wildlife Services: Staff Publications

Attenuated strains of rabies virus (RABV) have been used for oral vaccination of wild carnivores in Europe and North America. However, some RABV vaccines caused clinical rabies in target animals. To improve the safety of attenuated RABV as an oral vaccine for field use, strategies using selection of escape mutants under monoclonal antibody neutralization pressure and reverse genetics–defined mutations have been used. We tested the safety, immunogenicity, and efficacy of one RABV construct, ERA-g333, developed with reverse genetics by intramuscular (IM) or oral (PO) routes in big brown bats (Eptesicus fuscus). Twenty-five bats received 5×10⁶ mouse intracerebral …

Psychological Drivers Of Risk-Reducing Behaviors To Limit Human–Wildlife Conflict, Stacy A. Lischka, Tara L. Teel, Heather E. Johnson, Courtney Larson, Stewart Breck, Kevin R. Crooks

United States Department of Agriculture Wildlife Services: Staff Publications

Conflicts between people and wild animals are increasing globally, often with serious consequences

for both. Local regulations or ordinances are frequently used to promote human behaviors that minimize these conflicts (risk-reducing behaviors), but compliance with ordinances can be highly variable. While efforts to increase compliance could be improved through applications of conservation psychology, little is known about the relative influence of different factors motivating compliance. Using concepts from psychology and risk theory, we conducted a longitudinal study pairing data from mail surveys with direct observations of compliance with a wildlife ordinance requiring residents to secure residential garbage from black bears …

Timing And Extent Of Crop Damage By Wild Pigs (Sus Scrofa Linnaeus) To Corn And Peanut Fields, C. M. Boyce, Kurt C. Vercauteren, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

The global expansion of wild pigs over the last few decades has resulted in an increase in extent and distribution of damages to crops, placing a growing strain on agricultural producers and land managers. Despite the extent of wild pig damage to agriculture, there is little data regarding timing and spatial variability of damage to corn (Zea mays Linnaeus) and we found no data regarding the effect of these factors on peanuts (Arachis hypogaea Linnaeus). Our objective was to determine the timing and extent of wild pig damage to corn and peanut fields, as well as the extent …

Validation Of A Screening Method For The Detection Of Colistin-Resistant E. Coli Containing Mcr-1 In Feral Swine Feces, Jeffrey C. Chandler, Alan B. Franklin, S. N. Bevins, Kevin T. Bentler, Jonas Bonnedahl, Christina A. Ahlstrom, Bledar Bisha, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

A method was developed and validated for the detection of colistin-resistant Escherichia coli containing mcr-1 in the feces of feral swine. Following optimization of an enrichment method using EC broth supplemented with colistin (1 μg/mL) and vancomycin (8 μg/mL), aliquots derived from 100 feral swine fecal samples were spiked with of one of five different mcr-1 positive E. coli strains (between 10⁰ and 10⁴ CFU/g), for a total of 1110 samples tested. Enrichments were then screened using a simple boil-prep and a previously developed real-time PCR assay for mcr-1 detection. The sensitivity of the method was determined in …