Population Biology Commons^™

Data Of Soil, Vegetation And Bird Species Found On Double-Crested Cormorant Colonies In The Southeastern United States, Leah Moran Veum, Brian S. Dorr, Katie Hanson-Dorr, R. J. Moore, Scott A. Rush

United States Department of Agriculture Wildlife Services: Staff Publications

This data article provides the methods and procedures followed to collect and analyse soil, vegetation and bird data on three different treatment islands in Guntersville Reservoir, Alabama. Samples were collected from randomly selected plot points from islands that were placed into three different treatment types: Colony (currently occupied by Double-crested Cormorants) (Phalacrocorax auritus; n 1⁄4 5), Historic (historically occupied by cormorants and currently abandoned; n 1⁄4 3) and Reference (never occupied by cormorants; n 1⁄4 4). We compared vegetation and tree metrics such as structure and diversity, as well as soil chemistry and bird diversity and communities among islands within …

The Tail Wagging The Dog: Positive Attitude Towards Livestock Guarding Dogs Do Not Mitigate Pastoralists’ Opinions Of Wolves Or Grizzly Bears, Daniel Kinka, Julie K. Young

United States Department of Agriculture Wildlife Services: Staff Publications

While the re-establishment of grizzly bears (Ursus arctos) and wolves (Canis lupus) in the American West marks a success for conservation, it has been contentious among pastoralists. Coincidentally, livestock guarding dogs (LGDs; Canis familiaris) have been widely adopted by producers of domestic sheep (Ovis aries) in the United States to mitigate livestock depredation by wild carnivores. We surveyed pastoralists to measure how experience with and attitudes towards LGDs related to attitudes towards livestock predators, and found positive responses regarding LGDs and negative responses regarding wolves and grizzly bears. The more respondents agreed that LGDs reduce the need for lethal management …

The Changing Role Of Rodenticides And Their Alternatives In The Management Of Commensal Rodents, Gary Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Rodents cause substantial damage and losses of foodstuffs around the world. They also transmit many diseases to humans and livestock. While various methods are used to reduce damage caused by rodents, rodenticides remain an important tool in the toolbox. However, like all tools, rodenticides have advantages and disadvantages. Several considerations are shaping the future of rodenticide use, including manufacturing and registration costs, concern about toxicity levels and nontarget animal hazards, potential hazards to children, reduced effectiveness of some formulations, and humaneness to the targeted rodents. Many of these disadvantages apply to anticoagulant rodenticides, and their use is being more restricted …

A Delicate Balance: The Effects Of Habitat Type On Frog Communities: A Three-Pronged Study Examining The Effects Of Differing Habitat Characteristics On Anuran Diversity At El Centro De Investigación Sumak Kawsay In Situ, Ecuador, Zane Libke

Independent Study Project (ISP) Collection

We conducted 60 hours of visual encounter surveys and 3 hours of calling surveys on 6 different habitat types near Sumak Kawsay in situ Reserva (SKIS) near Mera, Pastaza, Ecuador. We defined habitat types defined by two variables: type of forest and proximity to water. The aim of the study was to determine what effect each variable has on anuran community composition. We compared the effectiveness of the two survey methods as well. High anuran community dissimilarity was found between each habitat type surveyed, indicating that both forest type and proximity to water are important factors that shape species richness …

Tracking Canada Geese Near Airports: Using Spatial Data To Better Inform Management, Ryan Askren, Brett E. Dorak, Heath M. Hagy, Michael W. Eichholz, Brian E. Washburn, Michael P. Ward

United States Department of Agriculture Wildlife Services: Staff Publications

The adaptation of birds to urban environments has created direct hazards to air transportation with the potential for catastrophic incidents. Bird–aircraft collisions involving Canada geese (Branta canadensis; goose) pose greater risks to aircraft than many bird species due to their size and flocking behavior. However, information on factors driving movements of geese near airports and within aircraft arrival/departure areas for application to management are limited. To address this need, we deployed 31 neck collar-mounted global positioning system transmitters on Canada geese near Midway International Airport in Chicago, Illinois, USA during November 2015 to February 2016. We used the movement data …

Effectiveness Of Snap And A24-Automated Traps And Broadcast Anticoagulant Bait In Suppressing Commensal Rodents In Hawaii, Aaron B. Shiels, Tyler Bogardus, Jobriath Rohrer, Kapua Kawelo

United States Department of Agriculture Wildlife Services: Staff Publications

Commensal rodents (invasive rats, Rattus spp.; house mice, Mus musculus) are well established globally. They threaten human health by disease transfer and impact economies by causing agricultural damage. On island landscapes, they are frequent predators of native species and affect biodiversity. To provide managers with better information regarding methods to suppress commensal rodent populations in remote island forests, in 2016 we evaluated the effectiveness of continuous rat trapping using snap-traps, Goodnature® A24 self-resetting rat traps, and a 1-time (2-application) hand-broadcast of anticoagulant rodenticide bait pellets (Diphacinone-50) applied at 13.8 kg/ha per application in a 5-ha forest on Oahu, Hawaii, USA. …

Application Strategy For An Anthraquinonebased Repellent And The Protection Of Soybeans From Canada Goose Depredation, Scott J. Werner, Matthew Gottlob, Charles D. Dieter, Joshua D. Stafford

United States Department of Agriculture Wildlife Services: Staff Publications

Agricultural crops can sustain extensive damage caused by Canada geese (Branta canadensis) when these crops are planted near wetlands or brood-rearing sites. From 2000 to 2015, South Dakota Game, Fish and Parks spent >$5.6 million to manage damages caused by Canada geese to agricultural crops (primarily soybeans) in South Dakota, USA. For the purpose of developing a repellent application strategy for nonlethal goose damage management, we comparatively evaluated the width of anthraquinone applications (i.e., 9.4 L Flight Control® Plus goose repellent/ha [active ingredient: 50% 9,10-anthraquinone] at 0–36 m versus 0–73 m perpendicular to the edge of wetlands in 2014), the …

A Review Of Rat Lungworm Infection And Recent Data On Its Definitive Hosts In Hawaii, Chris Niebuhr, Susan I. Jarvi, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

Rat lungworm (Angiostrongylus cantonensis) is a zoonotic nematode that causes rat lungworm disease (angiostrongyliasis), a potentially debilitating form of meningitis, in humans worldwide. The definitive hosts for rat lungworm are primarily members of the genus Rattus, with gastropods as intermediate hosts. This parasite has emerged as an important public health concern in the United States, especially in Hawaii, where the number of human cases has increased in the last decade. Here we discuss the current knowledge of the rat lungworm, including information on the life cycle and host species, as well as updates on known infection levels. Three species of …

Estimating Waterbird Abundance On Catfish Aquaculture Ponds Using An Unmanned Aerial System, Paul C. Burr, Sathishkumar Samiappan, Lee A. Hathcock, Robert J. Moorhead, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

In this study, we examined the use of an unmanned aerial system (UAS) to monitor fish-eating birds on catfish (Ictalurus spp.) aquaculture facilities in Mississippi, USA. We tested 2 automated computer algorithms to identify bird species using mosaicked imagery taken from a UAS platform. One algorithm identified birds based on color alone (color segmentation), and the other algorithm used shape recognition (template matching), and the results of each algorithm were compared directly to manual counts of the same imagery. We captured digital imagery of great egrets (Ardea alba), great blue herons (A. herodias), and doublecrested cormorants (Phalacrocorax auritus) on aquaculture …

Economic And Livestock Health Impacts Of Birds On Dairies: Evidence From A Survey Of Washington Dairy Operators, Julie L. Elser, Amber L. Adams Progar, Karen M.M. Steensma, Tyler P. Caskin, Susan R. Kerr, Stephanie A. Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

The survey described in this research paper aimed to investigate the economic and health impacts of birds on dairies. Birds are common pests on dairies, consuming and contaminating feed intended for cattle. As a result, dairy operators experience increased feed costs and increased pathogen and disease risk. We surveyed dairy operators attending the 2017 Washington Dairy Conference to examine the impact of birds on dairies in Washington State. Dairy operators reported feed losses valued at $55 per cow resulting in annual losses totaling $5.5 million in the Western region of the state and $9.2 million in the Eastern region of …

Double-Crested Cormorant Colony Effects On Soil Chemistry, Vegetation Structure And Avian Diversity, Leah Moran Veum, Brian S. Dorr, Katie C. Hanson-Dorr, R.J. Moore, Scott A. Rush

United States Department of Agriculture Wildlife Services: Staff Publications

Effects of Double-crested Cormorants (Phalacrocorax auritus) on vegetation, soil chemistry and tree health have been documented from their breeding colonies in the northern breeding grounds of Canada and the United States (U.S.) but not for areas within the southeastern United States where breeding activity is relatively novel. We compared vegetation and tree metrics such as structure diversity, and soil chemistry among colony islands, uninhabited islands, and abandoned colony islands within Guntersville Reservoir, a temperate forest ecosystem. Avian diversity and community structure were also quantified on these islands. Concentrations of potassium (K), phosphorus (P) and nitrate (NO3 −) in soil were …

Bourbon Virus In Wild And Domestic Animals, Missouri, Usa, 2012–2013, Katelin C. Jackson, Thomas Gidlewski, J. Jeffrey Root, Angela M. Bosco-Lauth, R. Ryan Lash, Jessica R. Harmon, Aaron C. Brault, Nicholas A. Panella, William L. Nicholson, Nicholas Komar

United States Department of Agriculture Wildlife Services: Staff Publications

Bourbon virus (BRBV) was first isolated from a febrile patient with a history of tick bites in Bourbon County, Kansas, USA; the patient later died from severe illness in 2014 (1). Several additional human BRBV infections were reported subsequently from the midwestern and southern United States (2). BRBV belongs to the family Orthomyxoviridae, genus Thogotovirus, which is distributed worldwide and includes Araguari, Aransas Bay, Dhori, Jos, Thogoto, and Upolu viruses (1,3). Thogoto and Dhori viruses have been associated with human disease (4–6). Viruses within the genus Thogotovirus have been associated with hard or soft ticks (7). Recent studies suggest that …

New Wilson’S Phalarope Nesting Record From The Central Platte River Valley, Mormon Island, Hall County, Nebraska, Andrew J. Caven, Bethany L. Ostrom, Aurora Fowler, Joshua D. Wiese, Kelsey C. King

Nebraska Bird Review

The southeastern portion of the Wilson’s Phalarope’s (Phalaropus tricolor) breeding range encompasses parts of Nebraska (Colwell and Jehl 1994), including the Sandhills and northern Panhandle (Silcock and Jorgensen 2018). Additionally, there have been a number of breeding records from southcentral and southeastern Nebraska within the Rainwater Basin ecoregion since the mid-1990s (Mollhoff 2016, Silcock and Jorgensen 2018). However, there is very little evidence of regular breeding activity in the nearby Central Platte River Valley (CPRV), which spans from Chapman west to Overton, Nebraska, and is considered a globally important area for waterbirds (Johnsgard and Brown 2013, Silcock and Jorgensen 2018). …

Summer Field Report, June - July 2019, W. Ross Silcock

Nebraska Bird Review

There was a lot to ponder this summer, including several notable breeding records of waterbirds, including the 3rd for Canvasback and an “unprecedented” breeding season for Eared Grebe in the Rainwater Basin. Intriguing summer occurrences that might presage or indicate nesting were large numbers of Redhead and Ring-necked Duck in larger wetlands, the 3rd Jun record of Dusky Flycatcher, first Jun record of Baird’s Sparrow, 3rd summer record of Ash-throated Flycatcher, and a Sage Thrasher in Jun in Kimball County. Additional breeding records of interest were the 10 Peregrine Falcons fledged at three Omaha sites, possible nesting by Mississippi Kites …

The Nebraska Bird Review, Volume 87 September 2019 Number 3

Nebraska Bird Review

Summer Field Report, June - July 2019, by W. Ross Silcock …74-95

2018 (30th) Report of the NOU Records Committee, by Mark A. Brogie … 96-109

New Wilson's Phalarope Nesting Record from the Central Platte River Valley, Mormon Island, Hall County, Nebraska by Andrew J. Caven, Bethany Ostrom, Aurora Fowler, Joshua D. Wiese, Kelsey C. King …110-114

Subscription and Organization Information …115

Predicting Functional Responses In Agro-Ecosystems From Animal Movement Data To Improve Management Of Invasive Pests, Mark Q. Wilber, Sarah M. Chinn, James C. Beasley, Raoul K. Bourghton, Ryan K. Brooks, Stephen S. Ditchkoff, Justin W. Fischer, Steve B. Hartley, Lindsey K. Holmstrom, John C. Kilgo, Jesse S. Lewis, Ryan S. Miller, Nathan P. Snow, Kurt C. Vercauteren, Samantha M. Wisely, Colleen T. Webb, Kim M. Peen

United States Department of Agriculture Wildlife Services: Staff Publications

Functional responses describe how changing resource availability affects consumer resource use, thus providing a mechanistic approach to prediction of the invasibility and potential damage of invasive alien species (IAS). However, functional responses can be context dependent, varying with resource characteristics and availability, consumer attributes, and environmental variables. Identifying context dependencies can allow invasion and damage risk to be predicted across different ecoregions. Understanding how ecological factors shape the functional response in agro-ecosystems can improve predictions of hotspots of highest impact and inform strategies to mitigate damage across locations with varying crop types and availability. We linked heterogeneous movement data across …

Landscape Factors That Influence European Starling (Sturnus Vulgaris) Nest Box Occupancy At Nasa Plum Brook Station (Pbs), Erie County, Ohio, Usa, Morgan Pfeiffer, Thomas W. Seamans, Bruce N. Buckingham, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

During the last decade at NASA Plum Brook Station (PBS), Erie County, Ohio, United States, there has been a nearly 50% decrease in European Starling (Sturnus vulgaris) occupancy (nests with ≥1 egg) of nest boxes designed to be used by starlings. Increased availability of natural cavities, from invertebrate pests, might have altered nest box occupation rates. It was hypothesized that starling nest box occupation rates would be a function of an index of potentially suitable tree cavities for nesting starlings, the semi-colonial nature of breeding starlings, and access to foraging areas (e.g., mowed lawns near buildings). Specifically, it was predicted …

Comparison Of The Efficacy Of Four Drug Combinations For Immobilization Of Wild Pigs, Christine K. Ellis, Morgan E. Wehtje, Lisa L. Wolfe, Peregrine L. Wolff, Clayton D. Hilton, Mark C. Fisher, Shari Green, Michael P. Glow, Joeseph M. Halseth, Michael J. Lavelle, Nathan P. Snow, Eric H. Vannatta, Jack C. Rhyan, Kurt C. Vercauteren, William R. Lance, Pauline Nol

United States Department of Agriculture Wildlife Services: Staff Publications

Field immobilization of native or invasive wild pigs (Sus scrofa) is challenging. Drug combinations commonly used often result in unsatisfactory immobilization, poor recovery, and adverse side effects, leading to unsafe handling conditions for both animals and humans. We compared four chemical immobilization combinations, medetomidine–midazolam–butorphanol (MMB), butorphanol–azaperone–medetomidine (BAM™), nalbuphine–medetomidine–azaperone (NalMed-A), and tiletamine– zolazepam–xylazine (TZX), to determine which drug combinations might provide better chemical immobilization of wild pigs. We achieved adequate immobilization with no post-recovery morbidity withMMB. Adequate immobilization was achieved with BAM™; however, we observed post-recovery morbidity. Both MMB and BAM™ produced more optimal results relative to body temperature, recovery, and …

Vision In An Abundant North American Bird: The Red-Winged Blackbird, Esteban Fernández-Juricic, Patrice E. Baumhardt, Luke P. Tyrrell, Amanda Elmore, Shelagh T. Deliberto, Scott J. Werner

United States Department of Agriculture Wildlife Services: Staff Publications

Avian vision is fundamentally different from human vision; however, even within birds there are substantial between species differences in visual perception in terms of visual acuity, visual coverage, and color vision. However, there are not many species that have all these visual traits described, which can constrain our ability to study the evolution of visual systems in birds. To start addressing this gap, we characterized multiple traits of the visual system (visual coverage, visual acuity, centers of acute vision, and color vision) of the Red-winged Blackbird (Agelaius phoeniceus), one of the most abundant and studied birds in North America. We …

Low Secondary Risks For Captive Coyotes From A Sodium Nitrite Toxic Bait For Invasive Wild Pigs, Nathan P. Snow, Katherine E. Horak, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

An acute toxic bait is being developed to deliver micro‐encapsulated sodium nitrite (SN) to stimulate severe methemoglobinemia and humane death for invasive wild pigs (Sus scrofa), thereby providing a new tool for reducing their populations. During April 2016, we evaluated sensitivity to SN and outcomes of secondary consumption in the ubiquitous mammalian scavenger, coyote (Canis latrans), to determine secondary risks of consuming carcasses of wild pigs that died from consuming the SN toxic bait. At the National Wildlife Research Center in Fort Collins, Colorado, USA, we first evaluated whether coyotes fed carcasses of domestic pigs killed by consumption of SN …

2018 (30th) Report Of The Nou Records Committee, Mark A. Brogie

Nebraska Bird Review

2018 Additions/Deletions to the "Official List of the Birds of Nebraska”: There was one new species added in 2018. Fulvous Whistling-Duck (Dendrocygna bicolor) Accidental - Class 1-P. With this addition, the “Official List of the Birds of Nebraska” stands at 463 species.

2018 Changes in Frequency of Occurrence

Changes Involving Nebraska Species Due to Taxonomic Revisions

NOURC Accepted Records (Received in 2018)

NOURC Unaccepted Records (Received in 2018)

The Value Of Inspection Stations For Detecting Nonindigenous Species Lacking Agricultural Significance: The Mexican Treefrog, Smilisca Baudinii Complex (Duméril And Bibron 1841) (Hylidae), Interdicted In Florida, Usa, From A Shipment Of Peppers, Louis A. Somma

Papers in Herpetology

A Mexican Treefrog, Smilisca baudinii, a nonindigenous species, was interdicted for the first time from an imported shipment of peppers. The value of agriculture inspection stations used to make these interdictions is discussed. This is a single cargo interception (Stage 1: Colautti and MacIsaac 2004) and the first record for S. baudinii intercepted in Florida. Currently no evidence suggests that S. baudinii has been successfully introduced into and established in Florida, although this species could survive climatic conditions in the southern part of the state and at the scheduled destination of this shipment.

Cargo transport of alien species is a …

Validation Of A Death Assay For Angiostrongylus Cantonensis Larvae (L3) Using Propidium Iodide In A Rat Model (Rattus Norvegicus), Susan I. Jarvi, John Jacob, Robert T. Sugihara, Israel L. Leinbach, Ina H. Klasner, Lisa M. Kaluna, Kirsten A. Snook, M. Kathleen Howe, Steven H. Jacquier, Ingo Lange, Abigail L. Atkinson, Ashley R. Deane, Chris N. Niebuhr, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

Angiostrongylus cantonensis is a pathogenic nematode and the cause of neuroangiostrongyliasis, an eosinophilic meningitis more commonly known as rat lungworm disease. Transmission is thought to be primarily due to ingestion of infective third stage larvae (L3) in gastropods, on produce, or in contaminated water. The gold standard to determine the effects of physical and chemical treatments on the infectivity of A. cantonensis L3 larvae is to infect rodents with treated L3 larvae and monitor for infection, but animal studies are laborious and expensive and also raise ethical concerns. This study demonstrates propidium iodide (PI) to be a reliable marker of …

Contact Rates With Nesting Birds Before And After Invasive Snake Removal: Estimating The Effects Of Trap-Based Control, Amy A. Yackel Adams, Melia G. Nafus, Page E. Klug, Björn Lardner, M.J. Mazurek, Julie A. Savidge, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive predators are responsible for almost 60% of all vertebrate extinctions worldwide with the most vulnerable faunas occurring on islands. The brown treesnake (Boiga irregularis) is a notorious invasive predator that caused the extirpation or extinction of most native forest birds on Guam. The success of avian reintroduction efforts on Guam will depend on whether snake-control techniques sufficiently reduce contact rates between brown treesnakes and reintroduced birds. Mouse-lure traps can successfully reduce brown treesnake populations at local scales. Over a 22-week period both with and without active snake removal, we evaluated snake-trap contact rates for mouse- and bird-lure traps. Bird-lure …

An Evaluation Of The Registration And Use Prospects For Four Candidate Toxicants For Controlling Invasive Mongooses (Herpestes Javanicus Auropunctatus), Emily W. Ruell, Chris N. Niebuhr, Robert T. Sugihara, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The eradication or control of invasive small Indian mongooses from islands likely requires toxic baiting when removal by trapping proves insufficient. The one toxic bait currently registered for mongooses in the United States has relatively low palatability and efficacy for mongooses. Developing and registering a new pesticide can be very expensive, while funding for developing toxicants for mongooses is limited. Once registered, use of a toxic bait may be hindered by other factors, such as public opposition to an inhumane toxicant, poorer efficacy than expected, or if the toxic bait is difficult for applicators to apply or store. Therefore, we …

Transmission Dynamics Of Toxoplasma Gondii In Arctic Foxes (Vulpes Lagopus): A Long-Term Mark-Recapture Serologic Study At Karrak Lake, Nunavut, Canada, Emilie Bouchard, Stacey A. Elmore, Ray T. Alisauskas, Gustaf Samelius, Alvin A. Gajadhar, Keaton Schmidt, Sasha Ross, Emily J. Jenkins

United States Department of Agriculture Wildlife Services: Staff Publications

Transmission dynamics of Toxoplasma gondii, a parasite of importance for wildlife and human health, are enigmatic in the Arctic tundra, where free-ranging wild and domestic felid definitive hosts are absent and rarely observed, respectively. Through a multiyear mark-recapture study (2011– 17), serosurveillance was conducted to investigate transmission of T. gondii in Arctic foxes (Vulpes lagopus) in the Karrak Lake region, Nunavut, Canada. Sera from adult foxes and fox pups were tested for antibodies to T. gondii by using serologic methods, including the indirect fluorescent antibody test, direct agglutination test, and modified agglutination test. The overall seroprevalence was 39% in adults …

Not All Surveillance Data Are Created Equal—A Multi‐Method Dynamic Occupancy Approach To Determine Rabies Elimination From Wildlife, Amy J. Davis, Jordona D. Kirby, Richard B. Chipman, Kathleen M. Nelson, Tatiana Xifara, Colleen T. Webb, Ryan Wallace, Amy T. Gilbert, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. A necessary component of elimination programmes for wildlife disease is effective surveillance. The ability to distinguish between disease freedom and non‐detection can mean the difference between a successful elimination campaign and new epizootics. Understanding the contribution of different surveillance methods helps to optimize and better allocate effort and develop more effective surveillance programmes.

2. We evaluated the probability of rabies virus elimination (disease freedom) in an enzootic area with active management using dynamic occupancy modelling of 10 years of raccoon rabies virus (RABV) surveillance data (2006–2015) collected from three states in the eastern United States. We estimated detection probability …

Survival, Fidelity, And Dispersal Of Double-Crested Cormorants On Two Lake Michigan Islands, Christopher R. Ayers, Katie C. Hanson-Dorr, Ken Stromborg, Todd W. Arnold, Jacob S. Ivan, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Colony fidelity and dispersal can have important consequences on the population dynamics of colonial-nesting birds. We studied survival and inter-colony movements of Double-crested Cormorants (Phalacrocorax auritus; cormorants) nesting at Spider and Pilot islands, located 9 km apart in western Lake Michigan, during 2008–2014. We used live resighting and dead recovery data from both colonies, plus dead recoveries from throughout North America, in a multistate live and dead encounter model to estimate annual survival, inter-colony movements, plus temporary and permanent emigration to unmonitored sites. Annual survival averaged 0.37 (annual process variation, ˆ = 0.07) for hatch-year, 0.78 (ˆ= 0.08) for secondyear, …

Use Of Unmanned Aircraft Systems (Uas) And Multispectral Imagery For Quantifying Agricultural Areas Damaged By Wild Pigs, Justin W. Fischer, Kelsey Greiner, Mark W. Lutman, Bryson L. Webber, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) cause extensive damage to agricultural crops, resulting in lost production and income. A major challenge associated with assessing damage to crops is locating and quantifying damaged areas within agricultural fields. We evaluated a novel method using multispectral high-resolution aerial imagery, collected from sensors mounted on unmanned aircraft systems (UAS), and feature extraction techniques to detect and map areas of corn fields damaged by wild pigs in southern Missouri, USA. Damaged areas were extracted from orthomosaics using visible and near-infrared band combinations, an object-based classification approach, and hierarchical learning cycles. To validate estimates we also collected ground …

Confronting Models With Data: The Challenges Of Estimating Disease Spillover, Paul C. Cross, Diann J. Prosser, Andrew M. Ramey, Ephraim M. Hanks, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

For pathogens known to transmit across host species, strategic investment in disease control requires knowledge about where and when spillover transmission is likely. One approach to estimating spillover is to directly correlate observed spillover events with covariates. An alternative is to mechanistically combine information on host density, distribution and pathogen prevalence to predict where and when spillover events are expected to occur. We use several case studies at the wildlife–livestock disease interface to highlight the challenges, and potential solutions, to estimating spatiotemporal variation in spillover risk. Datasets on multiple host species often do not align in space, time or resolution, …