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Full-Text Articles in Life Sciences

Rodents In Agriculture: A Broad Perspective, Gary Witmer Jan 2022

Rodents In Agriculture: A Broad Perspective, Gary Witmer

USDA Wildlife Services: Staff Publications

The largest taxonomic group of mammals is rodents, with over 2200 species known around the world [1]. More recently, it was stated that over 2500 species exist [2]. Many species exist on all continents, with the exception of Antarctica. Rodents have adapted to all ecosystems of the world, including tundra, alpine, temperate forests, grasslands, arid regions, and aquatic systems. They provide many ecosystem functions, including soil aeration and mixing, seed and spore dispersal, vegetation succession, and being an important food source for predatory animals. Some species of rodents are even consumed by people in some parts of the world. Most …


Evaluating The Effects Of Mountain Beaver (Aplodontia Rufa) Management On Conifer Stocking In Western Oregon, Jimmy D. Taylor, Vanessa M. Petro Jan 2021

Evaluating The Effects Of Mountain Beaver (Aplodontia Rufa) Management On Conifer Stocking In Western Oregon, Jimmy D. Taylor, Vanessa M. Petro

USDA Wildlife Services: Staff Publications

Mountain beaver (Aplodontia rufa) is the most primitive rodent species in North America and is endemic to the Pacific Northwest, USA. Within their range, mountain beaver cause more conflict with conifer forest regeneration than any other vertebrate species. Most damage occurs as a result of clipping and browsing new seedlings, which reduces stocking density and delays stand development. An integrated approach using trapping and a registered toxicant (baiting) has been suggested as the most efficacious means to reduce seedling loss during stand initiation. We evaluated this management strategy in intensively managed conifer stands across two mountain ranges in …


Population Increases Of Large Birds In North America Pose Challenges For Aviation Safety, Richard A. Dolbeer Jan 2020

Population Increases Of Large Birds In North America Pose Challenges For Aviation Safety, Richard A. Dolbeer

USDA Wildlife Services: Staff Publications

There is a strong correlation between bird mass and the likelihood of aircraft damage during a bird–aircraft collision. Thus, the U.S. Federal Aviation Administration (FAA) has established airworthiness standards related to bird mass for engines, airframes, and windshields. Most standards use large (1.8 kg) and medium (1.1 kg) birds as benchmarks (the empennage and certain large turbofan engines use a 3.6-kg bird). There are 20 large (≥1.8 kg) and 16 medium (1.1–1.7 kg) bird species in North America with ≥20 strikes reported for civil aircraft (FAA National Wildlife Strike Database), 1990 to 2018. I analyzed the population changes of these …


The Changing Role Of Rodenticides And Their Alternatives In The Management Of Commensal Rodents, Gary Witmer Oct 2019

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

USDA 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 …


Research Priorities For Managing Invasive Wild Pigs In North America, James C. Beasley, Stephen S. Ditchkoff, John J. Mayer, Mark D. Smith, Kurt C. Vercauteren Jan 2018

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

USDA Wildlife Services: Staff Publications

With recent increases in distribution and numbers of feral pigs (Sus scrofa; invasive wild pigs) in North America, there has been a concurrent increase in the ecological and economic effects they have had on native and anthropogenic ecosystems. Despite the amplified interest in invasive wild pig research, there remains a significant knowledge gap regarding their basic biology and ecology, the scope of the damage they cause, and the efficacy of many control strategies. Such information is important to support the successful management of invasive wild pigs throughout North America and other areas. In 2016, members of the National …


Use Of Dogs In The Mediation Of Conservation Conflicts, Kurt C. Vercauteren, Michael J. Lavelle, Jean-Marc Landry, Laurie Marker, Thomas M. Gehring Jan 2014

Use Of Dogs In The Mediation Of Conservation Conflicts, Kurt C. Vercauteren, Michael J. Lavelle, Jean-Marc Landry, Laurie Marker, Thomas M. Gehring

USDA Wildlife Services: Staff Publications

Conflicts between wildlife and humans are of global importance and are increasing. These conflicts may negatively impact wildlife, humans, and other resources, primarily livestock. Human safety and economic well-being can be adversely impacted by depredation of livestock and perpetuation of wildlife-borne diseases in agricultural systems. Conversely, management approaches to mitigate these conflicts may employ primarily lethal control methods that can negatively impact wildlife populations of conservation importance. Dogs, principally livestock protection breeds, have been used for centuries in some cultures to protect livestock from predators. Dogs have also been used for a variety of other conservation-specific practices. Here we provide …


Estimating The Total Economic Impact Of Black Bear Peeling In Western Oregon Using Gis And Remi, Jimmy D. Taylor Ii, Anita Morzillo, Aaron M. Anderson Jan 2014

Estimating The Total Economic Impact Of Black Bear Peeling In Western Oregon Using Gis And Remi, Jimmy D. Taylor Ii, Anita Morzillo, Aaron M. Anderson

USDA Wildlife Services: Staff Publications

In parts of the Pacific Northwest, black bears emerge from winter dens with depleted fat reserves and feed on mature conifers by stripping bark and consuming sugar-rich sapwood. Peeling by bears affects commercial conifers through direct loss of the tree or degraded log quality at stand harvest. Bears generally peel trees from 15-30 years old in intensively managed forests until preferred foods such as fruits and berries are available, and a single bear can peel several trees per day. Dying trees have a signature red canopy and are detected in annual aerial forest health surveys; however, trees that scar over …


Effects Of Local-Scale Removals On Feral Swine Populations In Southern Texas, Johanna Delgado-Acevedo, Randy W. Deyoung, Tyler A. Campbell Jan 2013

Effects Of Local-Scale Removals On Feral Swine Populations In Southern Texas, Johanna Delgado-Acevedo, Randy W. Deyoung, Tyler A. Campbell

USDA Wildlife Services: Staff Publications

Feral swine (Sus scrofa) are one of the most threatening mammalian pest species in North America owing to the damage they cause to natural habitats and agroecosystems, and the risk of disease transmission they pose to wildlife, livestock, and humans. The long-term (> 1 year) effects of lethal control efforts on feral swine populations at local scales are largely unknown. Using a panel of molecular markers, we assessed the effects of lethal control efforts on selected populations of feral swine in southern Texas. We collected tissue samples from two sites during removal campaigns, extracted and amplified DNA, and …


Effectiveness And Target-Specificity Of A Novel Design Of Food Dispenser To Deliver A Toxin To Feral Swine In The United States, Tyler A. Campbell, Justin A. Foster, Michael J. Bodenchuk, John D. Eisemann, Linton Staples, Steven J. Lapidge Jan 2013

Effectiveness And Target-Specificity Of A Novel Design Of Food Dispenser To Deliver A Toxin To Feral Swine In The United States, Tyler A. Campbell, Justin A. Foster, Michael J. Bodenchuk, John D. Eisemann, Linton Staples, Steven J. Lapidge

USDA Wildlife Services: Staff Publications

There are no registered toxins available for use on Feral Swine (Sus scrofa, Linnaeus) in the United States. HOGGONE is a proprietary bait matrix under development in Australia that delivers toxic levels of sodium nitrite to feral swine. However, one challenge is to develop a species-specific oral delivery system to deliver toxins to feral swine in the USA while minimizing non-target wildlife exposure. The HOGHOPPERTM is a lightweight and portable bait delivery system that could overcome this problem. Our objective was to compare non-toxic HOGGONE removal by wildlife that visited HOGHOPPERS during acclimation periods (doors open; free-feeding …


Demonstration Of Avian Control® Bird Repellent (A.I., Methyl Anthranilate) For Managing Blackbird Damage To Ripening Sunflower., George M. Linz, H. Jeffrey Homan Jan 2013

Demonstration Of Avian Control® Bird Repellent (A.I., Methyl Anthranilate) For Managing Blackbird Damage To Ripening Sunflower., George M. Linz, H. Jeffrey Homan

USDA Wildlife Services: Staff Publications

After the reproductive period, blackbirds in the northern Great Plains aggregate in large flocks that feed on ripening crops, especially sunflower. At today’s prices, blackbirds eat about $8–12 million of sunflower annually in northern Great Plains, with most of this damage occurring in North Dakota and South Dakota (Peer et al. 2003). Additional expenditures are incurred by producers trying to protect their crop, including the costs in time, travel, and materials for hazing blackbirds. A chemical feeding repellent would be ideal for protecting sunflower from blackbirds because it would not only cut the amount of losses from foraging but also …


Deer Mice (Peromyscus Spp.) Biology, Damage And Management: A Review, Gary W. Witmer, Rachael S. Moulton Jan 2012

Deer Mice (Peromyscus Spp.) Biology, Damage And Management: A Review, Gary W. Witmer, Rachael S. Moulton

USDA Wildlife Services: Staff Publications

The deer mouse is the most widely distributed and abundant small mammal in North America. They use a wide array of habitats, are very adaptable, and have a high reproductive potential. They play a number of roles in ecosystems, but can cause damage to orchards, forests, agriculture crops, and rangelands primarily through seed and newly-emerged seedling consumption. They also cause damage similar to house mice when they occupy buildings or other structures. Deer mice are important components in disease transmission especially of hantaviruses and Lyme disease. Damage reduction methods generally involve lethal control to reduce numbers using rodenticides and traps. …


Rats! Foiled Again: A History Of Rodent Control Methods Development At The National Wildlife Research Center, Kathleen A. Fagerstone, Michael W. Fall, Gary W. Witmer, William C. Pitt Jan 2012

Rats! Foiled Again: A History Of Rodent Control Methods Development At The National Wildlife Research Center, Kathleen A. Fagerstone, Michael W. Fall, Gary W. Witmer, William C. Pitt

USDA Wildlife Services: Staff Publications

The National Wildlife Research Center (NWRC) and its predecessor laboratories have a long history of developing materials and methods for managing rodents and the damage they cause. The NWRC has been influential in exploring, developing, and maintaining legal uses of many traditional field rodenticides such as strychnine and zinc phosphide. Products have been developed for managing rodents in a variety of locales, and for managing a variety of species, from commensal rodents in urban areas, to pocket gophers and mountain beaver in forests, prairie dogs and ground squirrels on rangelands, and nutria and beaver in wetlands. Considerable research has also …


Deer-Activated Bio-Acoustic Frightening Device Deters White-Tailed Deer, Aaron M. Hildreth, Scott E. Hygnstrom, Kurt C. Vercauteren Jan 2012

Deer-Activated Bio-Acoustic Frightening Device Deters White-Tailed Deer, Aaron M. Hildreth, Scott E. Hygnstrom, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

White-tailed deer damage urban and suburban plantings as well as crops and stored feed. A high public demand exists for non-lethal control methods. Several frightening devices are available for deer and all can be categorized as auditory, visual, tactile, and biological. Several problems exist with frightening devices, including: effectiveness, acclimation, cost, and acceptance. We tested the efficacy of a frightening device that played pre-recorded distress calls of adult female white-tailed deer when activated by an infrared motion sensor. Potential benefits of the device are that deer are less likely to acclimate to animalactivated and infrequently projected calls and that distress …


Voles Damage Seedlings, But Do Deer Mice And House Mice?, Gary W. Witmer, Rachael S. Moulton, Jenna L. Swartz Jan 2012

Voles Damage Seedlings, But Do Deer Mice And House Mice?, Gary W. Witmer, Rachael S. Moulton, Jenna L. Swartz

USDA Wildlife Services: Staff Publications

While it is known that voles will damage seedlings, we do not know the extent to which deer mice and house mice damage seedlings. Knowing this information can assist resource managers in better targeting problem species and implementing appropriate management actions. We planted and monitored ponderosa pine and narrow-leaf cottonwood seedlings in metal stock tanks occupied by deer mice or house mice to assess the potential for damage by these rodents. Both species damaged leaves and stems of cottonwood seedlings, but house mice did more damage. House mouse damage resulted in mortality of over half of the cottonwood seedlings, while …


The Net Benefits Of Controlling Bird And Rodent Pests In Wine Grape And Avocado Production, Aaron M, Anderson, Katy Kirkpatrick, Stephanie A. Shwiff Jan 2012

The Net Benefits Of Controlling Bird And Rodent Pests In Wine Grape And Avocado Production, Aaron M, Anderson, Katy Kirkpatrick, Stephanie A. Shwiff

USDA Wildlife Services: Staff Publications

The objective of this analysis was to estimate the net benefits of controlling bird and rodent pests in California production of wine grapes and avocados. These two crops were chosen because of the expected differences in types and extent of pest damage and methods of pest control used by growers, as well as their importance in California agriculture. A web-based survey was designed to capture grower experiences with current levels of pest damage and their expectations about damage levels without control. Information on the methods of pest control and associated costs was also solicited from growers. We obtained 83 responses …


Management Of Damage By Elk (Cervus Elaphus) In North America: A Review, W. David Walter, Michael J. Lavelle, Justin W. Fischer, Therese L. Johnson, Scott E. Hygnstrom, Kurt C. Vercauteren Jan 2010

Management Of Damage By Elk (Cervus Elaphus) In North America: A Review, W. David Walter, Michael J. Lavelle, Justin W. Fischer, Therese L. Johnson, Scott E. Hygnstrom, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

Abundant populations of elk (Cervus elaphus) are cherished game in many regions of the world and also cause considerable human–wildlife conflicts through depredation on agriculture and specialty crops, lack of regeneration to native ecosystems, collisions with vehicles and transmission of disease between free-ranging and farmed hoofstock. Management of elk varies, depending on current and historical agency objectives, configuration of the landscapes elk occupy, public perception, population density and behaviour of elk. Selection of the method to manage elk often requires knowledge of timing of impacts, duration relief from elk damage is desired, cost-effectiveness of management activities, tolerance of …