Population Biology Commons^™

A Model For The Prediction Of Antimicrobial Resistance In Escherichia Coli Based On A Comparative Evaluation Of Fatty Acid Profiles, Randal S. Stahl, Bledar Bisha, Sebabrata Mahapatra, Jeffrey C. Chandler

USDA Wildlife Services: Staff Publications

Antimicrobial resistance is a threat to agricultural production and public health. In this proof-of-concept study, we investigated predicting antimicrobial sensitive/resistant (S/R) phenotypes and host sources of Escherichia coli (n = 128) based on differential fatty acid abundance. Myristic (14:0), pentadecanoic acid (15:0), palmitic (16:0), elaidic (18:19) and steric acid (18:0) were significantly different (α = 0.05) using a two-way ANOVA for predicting nalidixic acid, ciprofloxacin, aztreonam, cefatoxime, and ceftazidime S/R phenotypes. Additionally, analyses of palmitoleic (16:1), palmitic acid (16:0), methyl palmitate (i-17:0), and cis-9,10-methyleneoctadecanoic acid (19:0Δ) showed these markers were significantly different (α = 0.05) between isolates obtained from cattle …

Male Burmese Pythons Follow Female Scent Trails And Show Sex-Specific Behaviors, Shannon A. Richard, Eric A. Tillman, John S. Humphrey, Michael L. Avery, M. Rockwell Parker

USDA Wildlife Services: Staff Publications

Animals communicate with potential mates using species-specific signals, and pheromones are powerful sexual signals that modify conspecific behavior to facilitate mate location. Among the vertebrates, snakes are especially adept in mate searching via chemical trailing, which is particularly relevant given that many snake species are invasive outside their native ranges. Chemical signals used in mate choice are, thus, potentially valuable tools for management of invasive snake species. The Burmese python (Python bivittatus) is an invasive snake in the Florida Everglades where it is negatively impacting native fauna. In this study, we sought to: (i) determine if males can follow conspecific …

Variation In Host Home Range Size Decreases Rabies Vaccination Effectiveness By Increasing The Spatial Spread Of Rabies Virus, Katherine M. Mcclure, Amy T. Gilbert, Richard B. Chipman, Erin E. Rees, Kim M. Pepin

USDA Wildlife Services: Staff Publications

1. Animal movement influences the spatial spread of directly transmitted wildlife disease through host-host contact structure. Wildlife disease hosts vary in home range- associated foraging and social behaviours, which may increase the spread and intensity of disease outbreaks. The consequences of variation in host home range movement and space use on wildlife disease dynamics are poorly understood, but could help to predict disease spread and determine more effective disease management strategies.
2. We developed a spatially explicit individual-based model to examine the effect of spatiotemporal variation in host home range size on the spatial spread rate, persistence and incidence of rabies virus …

Designation Of A Neotype For Oeneis Melissa (Fabricius, 1775) And A Lectotype For Oeneis Polixenes (Fabricius, 1775) (Lepidoptera: Nymphalidae: Satyrinae), Crispin S. Guppy

The Taxonomic Report of the International Lepidoptera Survey

The Oeneis melissa (Fabricius, 1775) “neotype” designations of Lukhtanov and Eitschberger (2000; 2001) do not meet several critical requirements of the ICZN and are therefore invalid. In addition, the locality data is too vague to be taxonomically useful, their “neotype” specimen is a specimen of the taxon generally known as O. melissa semplei, and acceptance of their specimen as neotype would change the meaning of the taxon Oeneis melissa. Hence, I reject their neotype designation. A neotype Oeneis melissa (Fabricius, 1775) is designated from Nain, Labrador with careful consideration of the Articles of the International Code of Zoological …

Food Habits Of Coyotes (Canis Latrans) In The Valles Caldera National Preserve, New Mexico, Suzanne J. Gifford, Eric M. Gese, Robert R. Parmenter

USDA Wildlife Services: Staff Publications

Wildlife managers needed to understand coyote (Canis latrans) ecology in order to develop management plans on the nascent Valles Caldera National Preserve in northern New Mexico. Managers concerned about low elk (Cervus elaphus) recruitment had observed an increase in sightings of coyotes and observations of coyote predation on elk calves. Our objective was to identify and quantify coyote diet, and assess the temporal variation in coyote diet on the Valles Caldera National Preserve, particularly as related to elk calf consumption. We examined coyote food habits using 1,385 scats analyzed monthly from May 2005 to November 2008. The most frequent taxa …

Impact Of The Human Footprint On Anthropogenic Mortality Of North American Reptiles, Jacob E. Hill, Travis L. Devault, Jerrold L. Belant

USDA Wildlife Services: Staff Publications

Human activities frequently result in reptile mortality, but how direct anthropogenic mortality compares to natural morality has not been thoroughly investigated. There has also been a limited examination of how anthropogenic reptile mortality changes as a function of the human footprint. We conducted a synthesis of causespecific North American reptile mortality studies based on telemetry, documenting 550 mortalities of known cause among 2461 monitored individuals in 57 studies. Overall 78% of mortality was the result of direct natural causes, whereas 22% was directly caused by humans. The single largest source of mortality was predation, accounting for 62% of mortality overall. …

Changes To North American Butterfly Names, Jing Zhang, Qian Cong, Jinhui Shen, Paul A. Opler, Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

We obtained and analyzed whole genome shotgun sequences of all 845 species of butterflies recorded from Canada and the United States. Genome-scale phylogenetic trees constructed from the data reveal several nonmonophyletic genera and suggest improved classification of species included in these genera. Here, these changes are formalized and 2 subgenera are described: Amblyteria Grishin, subgen. n. (type species Goniloba exoteria Herrich-Schäffer, 1869, parent genus Amblyscirtes Scudder, 1872), and Coa Grishin, subgen. n. (type species Hesperia baracoa Lucas, 1857, parent genus Polites Scudder, 1872). Furthermore, we resurrect 3 genera and 2 subgenera from synonymy, change the rank of 6 currently used …

Rabies Surveillance Identifies Potential Risk Corridors And Enables Management Evaluation, Amy J. Davis, Kathleen M. Nelson, Jordana D. Kirby, Ryan M. Wallace, Xiaoyue Ma, Kim M. Pepin, Richard B. Chipman, Amy Gilbert

USDA Wildlife Services: Staff Publications

Intensive efforts are being made to eliminate the raccoon variant of rabies virus (RABV) from the eastern United States and Canada. The United States Department of Agriculture (USDA) Wildlife Services National Rabies Management Program has implemented enhanced rabies surveillance (ERS) to improve case detection across the extent of the raccoon oral rabies vaccination (ORV) management area. We evaluated ERS and public health surveillance data from 2006 to 2017 in three northeastern USA states using a dynamic occupancy modeling approach. Our objectives were to examine potential risk corridors for RABV incursion from the U.S. into Canada, evaluate the effectiveness of ORV …

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

USDA 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

USDA 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 …

Rose-Ringed Parakeets, Page E. Klug, William P. Bukoski, Aaron B. Shiels, Bryan M. Kluever, Shane R. Siers

Wildlife Damage Management Technical Series

Rose-ringed parakeets (Psittacula krameri; hereafter RRPA; Figure 1) are an invasive species in the United States, present in Alabama, Louisiana, Texas, and Virginia, and with established populations in California, Florida, and Hawaii. They are also the most successful species of invasive parakeet, worldwide. RRPA can cause significant damage to agriculture, including grains, oilseeds, fruits, and ornamental plants. Large flocks of RRPA roost near human infrastructure resulting in concerns about human health and safety (e.g., collisions with aircraft, disease transmission, feces accumulation, and noise complaints). The population growth and spread of RRPA is of conservation concern given the potential impact on …

Demographics Of A Painted Turtle (Chrysemys Picta) Population Responding To Drought In The Nebraska Sandhills, Allyson Beard

Honors Theses

A large portion of herpetofauna species are declining as a result of anthropogenic influences such as habitat destruction and climate change, and turtles are no exception. Studying demographics of turtle populations in a wide variety of settings could help establish a baseline for future species management because demographics such as survival and movement are essential to understanding the ecology of a species. We conducted a long-term mark-recapture study on painted turtles (Chrysemys picta) in a permanent pond in the Nebraska Sandhills to exam population size, survival, and movement of an aquatic turtle as drought conditions changed in a …

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

USDA 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 …

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

USDA 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 …

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

USDA 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. …

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 …

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

USDA 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 …

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

USDA 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 …

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

USDA 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

USDA 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 …

Information Resources For Animal Control And Wildlife Damage Management, Stephen M. Vantassel, Michael W. Fall, Serge Lariviére

Wildlife Damage Management Technical Series

A bumper sticker reads, “If you think education is expensive, you oughta try ignorance.” That statement could not be truer in regard to wildlife damage management. Being willing to learn is a critical attitude for everyone involved in wildlife damage management. Since wildlife damage management intersects so many other disciplines, no single person can be an expert in all of them. In addition, the arrival of an invasive species, changes in building practices (e.g., egress windows, ridge vents), or the implementation of new regulations can confound traditional practices and require new control methods. Thus, it is important to provide a …

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

USDA 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 …

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

USDA 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 …

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

USDA Wildlife Services: Staff Publications

Functional responses describe how changing resource availability affects con- sumer 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 avail- ability. We linked heterogeneous movement …

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

USDA 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

USDA 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

USDA 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 …

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

USDA 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

USDA 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 …