Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Nebraska - Lincoln

Boiga irregularis

Articles 1 - 24 of 24

Full-Text Articles in Physical Sciences and Mathematics

Limitations Of Invasive Snake Control Tools In The Context Of A New Invasion On An Island With Abundant Prey, Shane R. Siers, Melia G. Nafus, Jereid E. Calaor, Rachel M. Volsteadt, Matthew S. Grassi, Megan Volsteadt, Aaron F. Collins, Patrick D. Barnhart, Logan T. Huse, Amy A. Yackel Adams, Diane L. Vice Jan 2024

Limitations Of Invasive Snake Control Tools In The Context Of A New Invasion On An Island With Abundant Prey, Shane R. Siers, Melia G. Nafus, Jereid E. Calaor, Rachel M. Volsteadt, Matthew S. Grassi, Megan Volsteadt, Aaron F. Collins, Patrick D. Barnhart, Logan T. Huse, Amy A. Yackel Adams, Diane L. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

In October 2020, a new population of invasive brown treesnakes (Boiga irregularis) was discovered on the 33-ha Cocos Island, 2.5 km off the south coast of Guam, United States. Cocos Island is a unique conservation resource, providing refuge for many lizards and birds, including endangered species, which were extirpated from mainland Guam by invasive predators including brown treesnakes. We sought to evaluate the usefulness of toxic baiting with acetaminophen-treated carrion baits and cage trapping, common tools for the control of brown treesnakes on mainland Guam, as potential eradication tools on Cocos Island. We evaluated multiple bait types and …

Go to article

Optimal R&D Investment In The Management Of Invasive Species, William Haden Chomphosy, Dale T. Manning, Stephanie A. Shwiff, Stephan Weiler May 2023

Optimal R&D Investment In The Management Of Invasive Species, William Haden Chomphosy, Dale T. Manning, Stephanie A. Shwiff, Stephan Weiler

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive alien species (IAS) threaten world biodiversity, ecosystem services, and economic welfare. While existing literature has characterized the optimal control of an established IAS, it has not considered how research and development (R&D) into new removal methods or technologies can affect management decisions and costs over time. R&D can lower the costs of control in a management plan and creates an intertemporal trade-off between quick but costly control and gradual but cheaper removal over time. In this paper, we develop and solve a continuous time dynamic optimization model to study how investment in R&D influences the optimal control of an …

Go to article

Predation Thresholds For Reintroduction Of Native Avifauna Following Suppression Of Invasive Brown Treesnakes On Guam, Robert M. Mcelderry, Eben H. Paxton, Andre V. Nguyen, Shane R. Siers Jan 2022

Predation Thresholds For Reintroduction Of Native Avifauna Following Suppression Of Invasive Brown Treesnakes On Guam, Robert M. Mcelderry, Eben H. Paxton, Andre V. Nguyen, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The brown treesnake (BTS) (Boiga irregularis) invasion on Guåhan (in English, Guam) led to the extirpation of nearly all native forest birds. In recent years, methods have been developed to reduce BTS abundance on a landscape scale. To help assess the prospects for the successful reintroduction of native birds to Guåhan following BTS suppression, we modeled bird population persistence based on their life history characteristics and relative sensitivity to BTS predation. We constructed individual-based models and simulated BTS predation in hypothetical founding populations for each of seven candidate bird species. We represented BTS predation risk in two steps: …

Go to article

Adaptation Of An Artificial Bait To An Automated Aerial Delivery System For Landscape-Scale Brown Treesnake Suppression, Rafael A. Garcia, Thomas W. Mcauliffe, Lorelie P. Bumanlag, Shane R. Siers, Bruce A. Kimball Oct 2021

Adaptation Of An Artificial Bait To An Automated Aerial Delivery System For Landscape-Scale Brown Treesnake Suppression, Rafael A. Garcia, Thomas W. Mcauliffe, Lorelie P. Bumanlag, Shane R. Siers, Bruce A. Kimball

United States Department of Agriculture Wildlife Services: Staff Publications

Dead neonatal mice are currently used as bait for delivery of toxin to invasive brown treesnakes (Boiga irregularis) on Guam; once deployed in the field the mice are highly attractive to the snakes but only for about four days. An artificial bait containing a mixture of fats mimicking those in skin of the mice is also highly attractive to the snakes and remains attractive 2–3 times longer. The artificial bait, however, costs more than the mice, and is more difficult to attach to the capsules of a novel aerial bait delivery system. This paper describes a reformulation of the bait …

Go to article

Brown Treesnake Mortality After Aerial Application Of Toxic Baits, Scott M. Goetz, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Amanda R. Bryant, Robert N. Reed, Shane R. Siers May 2021

Brown Treesnake Mortality After Aerial Application Of Toxic Baits, Scott M. Goetz, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Amanda R. Bryant, Robert N. Reed, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

Quantitative evaluation of control tools for managing invasive species is necessary to assess overall effectiveness and individual variation in treatment susceptibility. Invasive brown treesnakes (Boiga irregularis) on Guam have caused severe ecological and economic effects, pose a risk of accidental introduction to other islands, and are the greatest impediment to the reestablishment of extirpated native fauna. An aerial delivery system for rodent‐based toxic baits can reduce brown treesnake abundance and heterogeneity among individuals may influence bait attraction or toxicant susceptibility. Previous baiting trials have either been simulated aerial treatments or relied on slightly different bait capsule compositions and the results …

Go to article

Allometric Regression Of Snake Body Length From Head Image Measurements, Shane R. Siers Jan 2021

Allometric Regression Of Snake Body Length From Head Image Measurements, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

As in many fields of wildlife research and management, camera devices and photogrammetry have become an integral part of the toolkit for exploring otherwise‐unseen aspects of the biology, behavior, and control of the invasive brown treesnake (Boiga irregularis) on Guam. Because brown treesnakes are cryptic and nocturnal, and nearly all aspects of their ecology are influenced by snake size, methods are needed to estimate snake size from images captured by infrared wildlife cameras. Unfortunately, it is difficult to capture images of an entire snake’s length at a controlled distance from a simple camera setup. Here, I describe the …

Go to article

Evaluating Airsoft Electric Guns For Control Of Invasive Brown Treesnakes, Adam J. Knox, Björn Lardner, Amy Yackel Adams, Robert N. Reed Aug 2020

Evaluating Airsoft Electric Guns For Control Of Invasive Brown Treesnakes, Adam J. Knox, Björn Lardner, Amy Yackel Adams, Robert N. Reed

United States Geological Survey: Staff Publications

Firearms are often used in lethal control of invasive vertebrates, but safety and regulatory aspects limit the circumstances under which they can be used. During August 2016 at the Brown Treesnake Project laboratory on Guam, we evaluated hobby‐grade Airsoft Electric Guns (AEGs; a lower powered, less‐hazardous, and less‐regulated alternative to firearms) for capture and control of small animals, with specific emphasis on invasive brown treesnakes (Boiga irregularis). Tests of AEGs differing in power with ammunition (plastic pellets) masses ranging from 0.20 to 0.39 g, fired at gelatin blocks from distances of 4, 8, and 12 m, showed that …

Go to article

Photographic Validation Of Target Versus Nontarget Take Of Brown Treesnake Baits, Shane R. Siers, Aaron B. Shiels, Cynthia G. Payne, Francinem M. Chlarson, Craig S. Clark, Stephen M. Mosher May 2020

Photographic Validation Of Target Versus Nontarget Take Of Brown Treesnake Baits, Shane R. Siers, Aaron B. Shiels, Cynthia G. Payne, Francinem M. Chlarson, Craig S. Clark, Stephen M. Mosher

United States Department of Agriculture Wildlife Services: Staff Publications

Use of toxic baits or other tools for managing nuisance species must ensure that the species of interest is adequately targeted while exposure to nontarget species is minimized. Nontarget takes of acetaminophen‐laced baits for control of invasive brown treesnakes (Boiga irregularis) on Guam may put those animals at risk of lethal intoxication and render the bait unavailable to the intended target species. We used wildlife cameras to identify species removing toxic and nontoxic baits from brown treesnake bait stations designed to exclude nontarget taxa in 2015 and 2016. Throughout various sites and habitat types, and balanced by season (wet vs. …

Go to article

Automated Aerial Baiting For Invasive Brown Treesnake Control: System Overview And Program Status, Shane R. Siers, John D. Eisemann, William C. Pitt, Larry Clark, Scott M. Goetz, Robert J. Gosnell, Aaron F. Collins, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Michael C. Messaros, William G.N. Coon Jan 2020

Automated Aerial Baiting For Invasive Brown Treesnake Control: System Overview And Program Status, Shane R. Siers, John D. Eisemann, William C. Pitt, Larry Clark, Scott M. Goetz, Robert J. Gosnell, Aaron F. Collins, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Michael C. Messaros, William G.N. Coon

Vertebrate Pest Conference Proceedings: 29th (2020)

The economically and ecologically catastrophic introduction of invasive brown treesnakes to the Pacific Island of Guam has long served as a cautionary tale about the dangers of invasive species and the seeming impossibility of their management on a landscape scale. USDA Wildlife Services and federal and private partners have engineered a system for the automated manufacture and aerial delivery of toxic baits for landscape-scale suppression of brown treesnakes in large and remote forest plots. The helicopter-borne dispensing module can launch four bait cartridges per second, and a single payload of 3,600 cartridges can treat 30 ha of forest at 120 …

Go to article

Climate Matching As A Tool For Predicting Potential North American Spread Of Brown Treesnakes, Gordon H. Rodda, Robert N. Reed, Catherine S. Jarnevich Aug 2007

Climate Matching As A Tool For Predicting Potential North American Spread Of Brown Treesnakes, Gordon H. Rodda, Robert N. Reed, Catherine S. Jarnevich

Managing Vertebrate Invasive Species

Climate matching identifies extralimital destinations that could be colonized by a potential invasive species on the basis of similarity to climates found in the species’ native range. Climate is a proxy for the factors that determine whether a population will reproduce enough to offset mortality. Previous climate matching models (e.g., Genetic Algorithm for Rule-set Prediction [GARP]) for brown treesnakes (Boiga irregularis) were unsatisfactory, perhaps because the models failed to allow different combinations of climate attributes to influence a species’ range limits in different parts of the range. Therefore, we explored the climate space described by bivariate parameters of …

Go to article

Can Temperature Be Used As A Tool For Limiting Brown Treesnake Invasion Via Transportation Pathways?, Michelle T. Christy, Julie A. Savidge, Richard Bischof, Gordon H. Rodda Aug 2007

Can Temperature Be Used As A Tool For Limiting Brown Treesnake Invasion Via Transportation Pathways?, Michelle T. Christy, Julie A. Savidge, Richard Bischof, Gordon H. Rodda

Managing Vertebrate Invasive Species

The use of extreme temperatures is one of the few chemical residue-free techniques available for control of pest species and has proven fast and effective in a variety of applications. We determined the upper and lower lethal temperatures for the brown treesnake. We also investigated whether gender, size, body condition and exposure time influenced survival at temperature extremes. Elevating snake core temperatures to 40°C and 41°C for one hour resulted in 99% mortality within seven days (40°C) and 100% mortality within one hour of exposure (41°C). Mortality decreased sharply to 51% for a one hour exposure to 39°C. Shorter, heavier …

Go to article

Spotting Cryptic Animals In The Dark: What Light Properties Should A Good Headlamp Have?, Bjorn Lardner, Julie A. Savidge, Gordon H. Rodda Aug 2007

Spotting Cryptic Animals In The Dark: What Light Properties Should A Good Headlamp Have?, Bjorn Lardner, Julie A. Savidge, Gordon H. Rodda

Managing Vertebrate Invasive Species

Relying on headlamp illumination for visual detection of cryptic nocturnal animals may present a challenge. To test how search light properties affect brown treesnake (Boiga irregularis) detection rate, we assigned eight biologists to search for dead snakes placed in roadside vegetation. Each person conducted 4 searches using lamps with varying properties: weak versus strong light, crossed by narrow versus wide beam. On each occasion, 100 snakes were placed randomly along the roadside transect. The mean number spotted per transect search was 13.5. Using an information theoretic approach, sequential order of transect runs was the only confounding variable included …

Go to article

Are Vultures Birds, And Do Snakes Have Venom, Because Of Macro- And Microscavenger Conflict?, John A. Shivik Oct 2006

Are Vultures Birds, And Do Snakes Have Venom, Because Of Macro- And Microscavenger Conflict?, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

I outline models that describe vertebrate and microbial competition for carrion resources and help explain the resultant morphologies observed in extant vertebrate scavengers. Odors from microbial decomposition signal the presence of a carcass to vertebrate scavengers. Therefore, microbes must consume carcasses rapidly or evolve toxic defenses to protect themselves and their resource from their vertebrate competitors. Similarly, macroscavengers must evolve traits that allow rapid detection of carcasses or develop chemical defenses against microbial toxins. My modeling suggests that the most efficient macroscavenger adaptations increase the probability of carcass detection, which explains why highly vagile species, such as vultures, are the …

Go to article

Potential Flotation Devices For Aerial Delivery Of Baits To Brown Treesnakes, Peter J. Savarie, Kenneth L. Tope Feb 2004

Potential Flotation Devices For Aerial Delivery Of Baits To Brown Treesnakes, Peter J. Savarie, Kenneth L. Tope

United States Department of Agriculture Wildlife Services: Staff Publications

Brown treesnakes are exotic invasive predators that have extirpated native forest birds and caused drastic reductions of lizards on Guam. Operational management control methods to contain the snake on Guam include the use of live traps, hand capture from fences, and canine detection. Live traps are also used to depopulate small forest plots. Toxicants offer an additional means for reducing snake populations on small plots. Polyvinyl chloride (PVC) plastic pipe bait stations containing dead neonatal mice (DNM) treated with 80 mg acetaminophen are placed about 1.5 m above the ground in vegetation to reduce exposure to terrestrial scavengers such as …

Go to article

Sustained Evaluation Of The Effectiveness Of Detector Dogs For Locating Brown Tree Snakes In Cargo Outbound From Guam, Richard M. Engeman, Daniel S. Vice, Darryl York, Kenneth S. Gruver Jul 2002

Sustained Evaluation Of The Effectiveness Of Detector Dogs For Locating Brown Tree Snakes In Cargo Outbound From Guam, Richard M. Engeman, Daniel S. Vice, Darryl York, Kenneth S. Gruver

United States Department of Agriculture Wildlife Services: Staff Publications

The accidental introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island's native terrestrial vertebrates, has created a health hazard to infants and children, and has resulted in economic losses. The high brown tree snake population densities on Guam, the species' adaptations for successful dispersal, and Guam's position as a focal point for commercial and military cargo shipments have created a high level of concern that brown tree snakes could spread from Guam to colonize other vulnerable locations. Cargo inspections using teams of handlers and their detector dogs …

Go to article

Aerosolized Essential Oils And Individual Natural Product Compounds As Brown Treesnake Repellents , Larry Clark, John Shivik Jun 2002

Aerosolized Essential Oils And Individual Natural Product Compounds As Brown Treesnake Repellents , Larry Clark, John Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Chemical irritants useful as repellents for brown treesnakes (Boiga irregularis) were identified. Exposure to various compounds produced a range of intensities for locomotory behavior in snakes. Essential oils comprised of 10 g liter -1 solutions of cedarwood, cinnamon, sage, juniper berry, lavender and rosemary each were potent snake irritants. Brown treesnakes exposed to a 2-s burst of aerosol of these oils exhibited prolonged, violent undirected locomotory behavior. In contrast, exposure to a 10 g liter-1 concentration of ginger oil aerosol caused snakes to locomote, but in a deliberate, directed manner. We also tested specific compounds, all derivative …

Go to article

Importance Of Bacterial Decomposition And Carrion Substrate To Foraging Brown Treesnakes, S.M. Jojola-Elverum, J.A. Shivik, L. Clark Jun 2001

Importance Of Bacterial Decomposition And Carrion Substrate To Foraging Brown Treesnakes, S.M. Jojola-Elverum, J.A. Shivik, L. Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Brown treesnakes are an invasive species to the island of Guam that have caused extensive ecological and economic damage. Efforts to control the snake population have included trapping using live mouse lures, but for logistical and economic reasons a synthetic lure is needed. When searching for live food, brown treesnakes use both visual and odor cues. However, when searching for carrion, odor cues are sufficient. Attempts to develop synthetic lures based on chemical reconstruction of the complex carrion odor have not succeeded. We provide evidence that a microbial–substrate interaction is important for bait take by brown treesnakes. Microbial cultures taken …

Go to article

Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark Apr 2001

Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Because the brown treesnake (Boiga irregularis) has virtually extirpated the avifauna on Guam and is a threat to other Pacific islands, the development of alternative and efficient control methods is required. Therefore, we performed a large-scale field experiment to determine whether the acetaminophen baits we developed could be used to reduce population levels of brown treesnakes on Guam. Toxic baits were made by inserting 80 mg of acetaminophen into dead neonatal mice, and these mouse baits were used to treat plots. Reference plots were baited with unadulterated baits. We used mark-recapture methods to estimate snake abundance on plots …

Go to article

Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark Mar 2001

Use Of Acetaminophen For Large-Scale Control Of Brown Treesnakes, Peter J. Savarie, John A. Shivik, Gary C. White, Jerome C. Hurley, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Because the brown treesnake (Boiga irregularis) has virtually extirpated the avifauna on Guam and is a threat to other Pacific islands, the development of alternative and efficient control methods is required. Therefore, we performed a large-scale field experiment to determine whether the acetaminophen baits we developed could be used to reduce population levels of brown treesnakes on Guam. Toxic baits were made by inserting 80 mg of acetaminophen into dead neonatal mice, and these mouse baits were used to treat plots. Reference plots were baited with unadulterated baits. We used mark-recapture methods to estimate snake abundance on plots …

Go to article

Objectives And Integrated Approaches For The Control Of Brown Tree Snakes, Richard M. Engeman, Daniel S. Vice Mar 2001

Objectives And Integrated Approaches For The Control Of Brown Tree Snakes, Richard M. Engeman, Daniel S. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

The inadvertent introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island’s native terrestrial vertebrates, has presented a health hazard to small children, and also has produced an economic problem. Management of brown tree snakes is aimed at a number of objectives, the foremost of which has been to deter its dispersal through Guam’s cargo traffic to other locations. Another objective is to reclaim areas on Guam for reintroduction of native wildlife. A related objective is the protection of small sensitive sites on Guam from brown tree snake …

Go to article

A Direct Comparison Of Trapping And Spotlight Searches For Capturing Brown Tree Snakes On Guam, Richard M. Engeman, D.S. Vice Mar 2001

A Direct Comparison Of Trapping And Spotlight Searches For Capturing Brown Tree Snakes On Guam, Richard M. Engeman, D.S. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

Brown Tree Snake populations on Guam are controlled in the vicinities of cargo staging and transport areas to prevent their dispersal from Guam, and their populations are controlled in areas where endangered species are to be reintroduced. Trapping and night-time spotlight searches of fences are the two primary Brown Tree Snake population reduction methods used on Guam. We conducted a three month study comparing Brown Tree Snake captures by spotlighting fences to captures by trapping. Traps were placed either on the edge of the forest paralleling the fences, or they were hung on the fences. Applications of each capture method …

Go to article

Standardizing The Evaluation Of Brown Tree Snake Trap Designs, Richard M. Engeman, Daniel S. Vice Jan 2000

Standardizing The Evaluation Of Brown Tree Snake Trap Designs, Richard M. Engeman, Daniel S. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

The introduced brown tree snake has had devastating impacts on the native vertebrate fauna of Guam. Trapping is the primary means by which brown tree snakes are removed, either in support of reintroduction of endangered species or to deter their movement from Guam in cargo. Traps used to control brown tree snake populations have been continually evolving since the 1980s. Before general operational implementation of a new design, the efficacy of new trap developments must be demonstrated. In this paper we combine the current knowledge about brown tree snake control objectives and practicalities, the information gained from a variety of …

Go to article

Managing Island Biotas: Brown Treesnake Control Using Barrier Technology, Gad Perry, Earl W. Campbell Iii, Gordon H. Rodda, Thomas H. Fritts Apr 1998

Managing Island Biotas: Brown Treesnake Control Using Barrier Technology, Gad Perry, Earl W. Campbell Iii, Gordon H. Rodda, Thomas H. Fritts

United States Department of Agriculture Wildlife Services: Staff Publications

The brown treesnake (Boiga irregularis), accidentally introduced to the previously snake-free U.S. island of Guam after World War 11, decimated the island's naive wildlife. Today, it periodically stows away on craft going to other islands where the ecological damage may be repeated. Barriers offer an effective tool for keeping the snakes out of areas from which they can disperse off-island, as well as sites identified as critical for the protection of human health, conduct of economic activity, or conservation of endangered species. The authors have developed a variety of barrier designs which repulse at least 95% of snake …

Go to article

Trapping Strategies For Deterring The Spread Of Brown Tree Snakes From Guam, Richard M. Engeman, Michael A. Linnell Apr 1998

Trapping Strategies For Deterring The Spread Of Brown Tree Snakes From Guam, Richard M. Engeman, Michael A. Linnell

United States Department of Agriculture Wildlife Services: Staff Publications

The accidental introduction of the Brown Tree Snake Boiga Irregularis to Guam has resulted in the extirpation of most of the island's native terrestrial vertebrates, has presented a health hazard to infants and children, and also has produced an economic problem. Prevention of its dispersal through Guam's cargo traffic to other Pacific islands has became a high environmental priority. Trapping around ports and other cargo staging areas is central to an integrated pest management program designed to deter dispersal of the species. In this study, perimeter trapping of forested plots characteristic of those found in port areas was found 19 …

Go to article