Natural Resources Management and Policy Commons^™

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 …

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 …

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 …

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, …

Typha (Cattail) Invasion In North American Wetlands: Biology, Regional Problems, Impacts, Ecosystem Services, And Management, Sheel Bansal, Shane C. Lishawa, Sue Newman, Brian A. Tangen, Douglas Wilcox, Dennis Albert, Michael J. Anteau, Michael J. Chimney, Ryann L. Cressey, Edward Dekeyser, Kenneth J. Elgersma, Sarah A. Finkelstein, Joanna Freeland, Richard Grosshans, Page E. Klug, Daniel J. Larkin, Beth A. Lawrence, George Linz, Joy Marburger, Gregory Noe, Clint Otto, Nicholas Reo, Jennifer Richards, Curtis Richardson, Leroy Rodgers, Amy J. Schrank, Dan Svedarsky, Steven Travis, Nancy Tuchman, Lisamarie Windham-Myers

United States Department of Agriculture Wildlife Services: Staff Publications

Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural …

Extreme Site Fidelity As An Optimal Strategy In An Unpredictable And Homogeneous Environment, Brian D. Gerber, Mevin B. Hooten, Christopher P. Peck, Mindy B. Rice, James H. Gammonley, Anthony D. Apa, Amy J. Davis

United States Department of Agriculture Wildlife Services: Staff Publications

1. Animal site fidelity structures space use, population demography and ultimately gene flow. Understanding the adaptive selection for site fidelity patterns provides a mechanistic understanding to both spatial and population processes. This can be achieved by linking space use with environmental variability (spatial and temporal) and demographic parameters. However, rarely is the environmental context that drives the selection for site fidelity behaviour fully considered.

2. We use ecological theory to understand whether the spatial and temporal variability in breeding site quality can explain the site fidelity behaviour and demographic patterns of Gunnison sage‐grouse (Centrocercus minimus). We examined female site fidelity …

Ecological Interventions To Prevent And Manage Zoonotic Pathogen Spillover, Susanne H. Sokolow, Nicole Nova, Kim M. Pepin, Alison J. Peel, Juliet R.C. Pulliam, Kezia Manlove, Paul C. Cross, Daniel J. Becker, Raina K. Plowright, Hamish Mccallum, Giulio A. De Leo

United States Department of Agriculture Wildlife Services: Staff Publications

Spillover of a pathogen from awildlife reservoir into a human or livestock host requires the pathogen to overcome a hierarchical series of barriers. Interventions aimed at one or more of these barriers may be able to prevent the occurrence of spillover. Here, we demonstrate how interventions that target the ecological context in which spillover occurs (i.e. ecological interventions) can complement conventional approaches like vaccination, treatment, disinfection and chemical control. Accelerating spillover owing to environmental change requires effective, affordable, durable and scalable solutions that fully harness the complex processes involved in cross-species pathogen spillover.

This article is part of the theme …

Scavenging In The Anthropocene: Human Impact Drives Vertebrate Scavenger Species Richness At A Global Scale, Esther Sebastián‐González, Jomar Magalhães Barbosa, Juan M. Pérez‐García, Zebensui Morales‐Reyes, Francisco Botella, Pedro P. Olea, Patricia Mateo‐Tomás, Marcos Moleón, Fernando Hiraldo, Eneko Arrondo, José A. Donázar, Ainara Cortés‐Avizanda, Nuria Selva, Sergio A. Lambertucci, Aishwarya Bhattacharjee, Alexis Brewer, Erin Abernethy, Olin E. Rhodes Jr., Kelsey Turner, James C. Beasley, Travis L. Devault, Andrés Ordiz, Camilla Wikenros, Barbara Zimmermann, Petter Wabakken, Christopher C. Wilmers, Justine A. Smith, Corinne J. Kendall, Darcy Ogada, Evan R. Buechley, Ethan Frehner, Maximilian L. Allen, Heiko U. Wittmer, James R.A. Butler, Johan T. Du Toit, John Read, David Wilson, Klemen Jerina, Miha Krofel, Rich Kostecke, Richard Inger, Arockianathan Samson, Lara Naves‐Alegre, José A. Sánchez‐Zapata

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large‐scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion‐consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using …

The Economic Impacts Of Blackbird (Icteridae) Damage To Sunflower In The Usa, Karina Ernst, Julie Elser, George Linz, Hans Kandel, Jason Holderieath, Samantha Degroot, Steven Shwiff, Stephanie Shwiff

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Blackbird (Icteridae) damage to ripening sunflower (Helianthus annuus L.) has been a persistent economic issue in the USA for the last five decades. To quantify losses, we surveyed blackbird damage from 2001 to 2013 (excluding 2004) to physiologically mature sunflower in eight states: North Dakota, South Dakota, Texas, Nebraska, Minnesota, Colorado, Kansas, and Vermont.

RESULTS:We pooled data gathered during the most recent 5 years (2009 to 2013) of the survey and found losses averaged $US2.5 million and $US11.3 million for confectionery and oilseed hybrids, respectively. Three states, North Dakota, South Dakota, and Nebraska, had sufficient acreage and bird damage …

Habitat Selection By American Beaverat Multiple Spatial Scales, Guiming Wang, Lance F. Mcclintic, Jimmy D. Taylor

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Semiaquatic mammals require both aquatic and terrestrial habitats, particularly interfaces between the two habitats. As ecosystem engineers, American beaver (Castor canadensis) consume and fell a great amount of deciduous trees. We tested the prediction that open water and amounts of food resources, including hardwood forests (i.e., deciduous trees as the dominant form of vegetation), herbaceous and woody wetlands, and shrubs, would influence the second-order habitat selection (i.e., placing home ranges on the landscape) by American beaver, whereas the third-order habitat selection of American beaver would be associated with woody wetland and shrub edges. We investigated hierarchical habitat selection by …

Epidemic Growth Rates And Host Movement Patterns Shape Management Performance For Pathogen Spillover At The Wildlife–Livestock Interface, Kezia R. Manlove, Laura M. Sampson, Benny Borremans, E. Frances Cassirer, Ryan S. Miller, Kim M. Pepin, Thomas E. Besser, Paul C. Cross

United States Department of Agriculture Wildlife Services: Staff Publications

Managing pathogen spillover at the wildlife–livestock interface is a key step towards improving global animal health, food security and wildlife conservation. However, predicting the effectiveness of management actions across host–pathogen systems with different life histories is an on-going challenge since data on intervention effectiveness are expensive to collect and results are system-specific.We developed a simulation model to explore how the efficacies of different management strategies vary according to host movement patterns and epidemic growth rates. The model suggested that fast-growing, fast-moving epidemics like avian influenza were best-managed with actions like biosecurity or containment, which limited and localized overall spillover risk. …

Effects Of Forest Management On Densities And Nest Survival Of Breeding Birds In Upland Hardwood Ecosystems, Michael Barnes

Electronic Theses & Dissertations

Over the past 50 years, significant declines in 47% of Neotropical migrant bird species have been documented in North America. Declines are most likely due to the loss and fragmentation of breeding, wintering, and stopover habitat mainly caused by agriculture and urban development. This loss of critical habitat results in population sinks that need to be maintained by immigration from a population source found in continuously forested landscapes. However, in landscapes harvested for timber, forest management practices alter the landscape and as a result, affect breeding bird abundances and nest success. The objective of our study was to determine the …

Board Invited Review: Prospects For Improving Management Of Animal Disease Introductions Using Disease-Dynamic Models, Ryan S. Miller, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Management and policy decisions are continually made to mitigate disease introductions in animal populations despite often limited surveillance data or knowledge of disease transmission processes. Science-based management is broadly recognized as leading to more effective decisions yet application of models to actively guide disease surveillance and mitigate risks remains limited. Disease-dynamic models are an efficient method of providing information for management decisions because of their ability to integrate and evaluate multiple, complex processes simultaneously while accounting for uncertainty common in animal diseases. Here we review disease introduction pathways and transmission processes crucial for informing disease management and models at the …

Improving Risk Assessment Of The Emergence Of Novel Influenza A Viruses By Incorporating Environmental Surveillance, Kim M. Pepin, Matthew W. Hopken, Susan A. Shriner, Erica Spackman, Zaid Abdo, Colin Parrish, Steven Steven, James O. Lloyd-Smith, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Reassortment is an evolutionary mechanism by which influenza A viruses (IAV) generate genetic novelty. Reassortment is an important driver of host jumps and is widespread according to retrospective surveillance studies.However, predicting the epidemiological risk of reassortant emergence in novel hosts from surveillance data remains challenging. IAV strains persist and cooccur in the environment, promoting co-infection during environmental transmission. These conditions offer opportunity to understand reassortant emergence in reservoir and spillover hosts. Specifically, environmental RNA could provide rich information for understanding the evolutionary ecology of segmented viruses, and transform our ability to quantify epidemiological risk to spillover hosts. However, significant challenges …

Individual-Level Antibody Dynamics Reveal Potential Drivers Of Influenza A Seasonality In Wild Pig Populations, Kim M. Pepin, Kerri Pedersen, Xiu-Feng Wan, Fred L. Cunningham, Colleen T. Webb, Mark Q. Wilber

United States Department of Agriculture Wildlife Services: Staff Publications

Swine are important in the ecology of influenza A virus (IAV) globally. Understanding the ecological role of wild pigs in IAV ecology has been limited because surveillance in wild pigs is often for antibodies (serosurveillance) rather than IAVs, as in humans and domestic swine. As IAV antibodies can persist long after an infection, serosurveillance data are not necessarily indicative of current infection risk. However, antibody responses to IAV infections cause a predictable antibody response, thus time of infection can be inferred from antibody levels in serological samples, enabling identification of risk factors of infection at estimated times of infection. Recent …

Taking The Bait: Species Taking Oral Rabies Vaccine Baits Intended For Raccoons, Betsy S. Haley, Are R. Berentsen, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoon rabies in eastern USA is managed by strategically distributing oral rabies vaccine (ORV) baits. The attractiveness, palativity, density, and non-target species bait take affect ORV effectiveness. We examined raccoon and non-target species differences in investigating/removing fish-meal polymer and coated sachet baits applied to simulate two aerial bait distribution densities. Bait densities of 150 baits/km2 and 75 baits/km2 were evaluated, respectively, in zones expected to have high and low

Racc oon densities. Three primary non-target species visited baits: coyotes, white-tailed deer, and feral swine. The proportion of bait stations visited by raccoons during 1 week observation periods ranged from 50 …

Using Unmanned Aerial Vehicles For Bird Harassment On Fish Ponds, Ciera A. Rhoades, Peter J. Allen, D. Tommy King

United States Department of Agriculture Wildlife Services: Staff Publications

The effects of aquaculture decline on piscivorous birds in the Mississippi Delta concern catfish farmers, with possible increases in fish loss and disease transmission. Piscivorous birds quickly habituate to most current methods of harassment (loud noises and visual disturbances) leading to increased depredation and disease. Our study was designed to test the efficacy of using unmanned aerial vehicles (UAVs) to effectively control piscivorous birds at fish farms. We hypothesized that a UAV would be more efficient at reducing the number of fish-eating birds on fish ponds than current forms of harassment. We conducted pre-treatment bird surveys, harassment observations, and post-treatment …

Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Habitat creation is an important tool for conservation to counteract habitat loss and degradation. Vernal pools are susceptible to destruction due to limited detection, protection, and regulation. These wetlands provide fishless breeding habitat for many amphibian species including spotted salamanders (Ambystoma maculatum) in eastern North America. Determining whether created vernal pool habitat is successful is often determined by demographic data of colonizing populations. I suggest that hormone levels, population genetics, and disease prevalence can improve our understanding of population health in created habitat. The goal of this dissertation was to assess the health of spotted salamander larvae in …

A Bioeconomic Model For The Optimization Of Local Canine Rabies Control, Aaron Anderson, Johann Kotze, Stephanie A. Shwiff, Brody Hatch, Chris Slootmaker, Anne Conan, Darryn Knobel, Louis H. Nel

United States Department of Agriculture Wildlife Services: Staff Publications

We present a new modeling tool that can be used to maximize the impact of canine rabies management resources that are available at the local level. The model is accessible through a web-based interface that allows for flexibility in the management strategies that can be investigated. Rabies vaccination, sterilization, chemo-contraception, and euthanasia can be specified and limited to specific demographic groups. Additionally, we allowed for considerable complexity in the specification of management costs. In many areas, the costs of contacting additional dogs increases as management effort increases, and this can have important strategic implications. We illustrated the application of the …

Black Bear Use Of Forest Roads In Western Washington, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Radiolocations (108) of 20 black bears were used to assess use or avoidance of 3 forest road types in western Washington. Distances of bears to each type of road were compared to distances of 108 random points using t-tests. Females and males avoided 2-lane roads, while only males avoided 1-lane roads, the most common road type in the area. Females, but not males, were located closer to overgrown, spur roads than expected. This road type has substantial cover of grasses, forbs, and berry-producing shrubs along with protective tree cover. This situation may provide easy travel for females along with security …

No Detection Of Brodifacoum Residues In The Marine And Terrestrial Food Web Three Years After Rat Eradication At Palmyra Atoll, Central Pacific, A. Wegmann, G. Howald, S. Kropidlowski, N. Holmes, A.B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive alien species represent one of the greatest threats to native plants and animals on islands. Rats (Rattus spp.) have invaded most of the world’s oceanic islands, causing lasting or irreversible damage to ecosystems and biodiversity. To counter this threat, techniques to eradicate invasive rats from islands have been developed and applied across the globe. Eradication of alien rats from large or complex island ecosystems has only been successful with the use of bait containing a rodenticide. While effective at eradicating rats from islands, rodenticide can persist in the ecosystem longer than the time required to eradicate the target rat …

Home Range And Habitat Use Of West Virginia Canis Latrans (Coyote), Lauren M. Mastro, Dana J. Morin, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

Canis latrans (Coyote) has undergone a range expansion in the United States over the last century. As a highly opportunistic species, its home range and habitat use changes with ecological context. Coyotes were first reported in West Virginia in 1950 but were not commonly observed until the 1990s, and there is scant information on Coyotes in the region. We used telemetry data from 8 radiocollared Coyotes in West Virginia to estimate home-range size and third-order habitat selection. Home-range areas (95% utilization distributions; UDs) varied from 5.22 to 27.79 km2 (mean = 12.48 ± 2.61 km2), with highly concentrated use of …

Carrion Availability In Space And Time, Marcos Moleón, Nuria Selva, David M. Bailey, David M. Bailey, Ainara Cortés-Avizanda, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction

Availability of carrion to scavengers is a central issue in carrion ecology and management, and is crucial for understanding the evolution of scavenging behaviour. Compared to live animals, their carcasses are relatively unpredictable in space and time in natural conditions, with a few exceptions (see below, especially Sect. “Carrion Exchange at the Terrestrial-Aquatic Interface”). Carrion is also an ephemeral food resource due to the action of a plethora of consumers, from microorganisms to large vertebrates, as well as to desiccation (i.e., loss of water content; DeVault et al. 2003; Beasley et al. 2012; Barton et al. 2013; Moleón et …

Ecological Functions Of Vertebrate Scavenging, James C. Beasley, Zachary H. Olson, Nuria Selva, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction

The role of vertebrate scavenging in food web dynamics has historically been minimalized and portrayed as the activity of a select group of obligate scavengers (e.g., vultures), with a simplistic linkage between carrion and detritivores in food webs. Research in the last few decades, however, has revealed that the role of carrion in food web dynamics is severely underestimated, highly complex, and pervasive among ecosystems across the globe (DeVault et al. 2003; Selva and Fortuna 2007; Wilson and Wolkovich 2011). Such observations have led to a surge in research interest in scavenging ecology that continues to reveal new information …

Locally Fixed Alleles: A Method To Localize Gene Drive To Island Populations, Jaye Sudweeks, Brandon Hollingsworth, Dimitri V. Blondel, Karl J. Campbell, Sumit Dhole, John D. Eisemann, Owain Edwards, John Godwin, Gregg R. Howald, Kevin P. Oh, Antoinette J. Piaggio, Thomas A.A. Prowse, Joshua V. Ross, J. Royden Saah, Aaron B. Shiels, Paul Q. Thomas, David W. Threadgill, Michael R. Vella, Fred Gould, Alun L. Lloyd

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species pose a major threat to biodiversity on islands. While successes have been achieved using traditional removal methods, such as toxicants aimed at rodents, these approaches have limitations and various off-target effects on island ecosystems. Gene drive technologies designed to eliminate a population provide an alternative approach, but the potential for drive-bearing individuals to escape from the target release area and impact populations elsewhere is a major concern. Here we propose the “Locally Fixed Alleles” approach as a novel means for localizing elimination by a drive to an island population that exhibits significant genetic isolation from neighboring populations. Our …

Comparing Live-Capture Methods For Nutria: Single- Versus Multiple-Capture Cage Traps, Trevor R. Sheffels, Mark D. Sytsma, Jacoby Carter, Jimmy D. Taylor

United States Department of Agriculture Wildlife Services: Staff Publications

Herbivory and burrowing by nutria (Myocastor coypus) cause substantial ecological and economic damage. Trapping is a common, effective practice for reducing nutria damage; however, trapping approaches must continually be adapted to keep pace with evolving animal welfare and ethical issues and to more effectively target pest species of interest. Our objective was to evaluate the efficacy of 2 nonlethal trap types for nutria: single-capture (SCT) and multi-capture (MCT) cage traps. We established 3 MCTs and 3 SCTs at each of 7 sites on a 10,500-ha mixed-use island located 15 km northwest of Portland, Oregon, USA. We pre-baited using carrots, apples, …

Biology And Impacts Of Pacific Island Invasive Species. 15. Psittacula Krameri, The Rose-Ringed Parakeet (Psittaciformes: Psittacidae)1, Aaron B. Shiels, Nicholas P. Kalodimos

United States Department of Agriculture Wildlife Services: Staff Publications

The rose-ringed parakeet (RRP), Psittacula krameri, has become established in at least four Pacific Island countries (Hong Kong China, Japan, New Zealand, U.S.A.), including the Hawaiian islands of Kaua‘i, O‘ahu, and Hawai‘i. Most Pacific islands are at risk of RRP colonization. This species was first introduced to Hong Kong in 1903 and Hawai‘i in the 1930s–1960s, established since 1969 in Japan, and in New Zealand since 2005 where it has repeatedly established after organized removals. The founding birds were imported cage-birds from the pet trade. In native India, RRP are generally found associated with human habitation and are considered a …