National Wildlife Research Center Research Articles

Binding Affinity, Selectivity, and Pharmacokinetics of the Oxytocin Receptor Antagonist L-368,899 in the Coyote (Canis latrans).

L-368,899 is a selective small-molecule oxytocin receptor (OXTR) antagonist originally developed in the 1990s to prevent preterm labor. Although its utility for that purpose was limited, L-368,899 is now one of the most commonly used drugs in animal research for the selective blockade of neural OXTR after peripheral delivery. A growing number of rodent and primate studies have used L-368,899 to evaluate whether certain behaviors are oxytocin dependent. These studies have improved our understanding of oxytocin's function in the brains of rodents and monkeys, but very little work has been done in other mammals, and only a single paper in macaques has provided any evidence that L-368,899 can be detected in the CNS after peripheral delivery. The current study sought to extend those findings in a novel species: coyotes ( Canis latrans ). Coyotes are ubiquitous North American canids that form long-term monogamous pair-bonds. Although monogamy is rare in rodents and primates, all wild canid species studied to date exhibit social monogamy. Coyotes are therefore an excellent model organism for the study of oxytocin and social bonds. Our goal was to determine whether L-368,899 is a viable candidate for future use in behavioral studies in coyotes. We used captive coyotes at the USDA National Wildlife Research Center's Predator Research Facility to evaluate the pharmacokinetics of L-368,899 in blood and CSF during a 90-min time course after intramuscular injection. We then characterized the binding affinity and selectivity of L-368,899 to coyote OXTR and the structurally similar vasopressin 1a receptor. We found that L-368,899 peaked in CSF at 15 to 30 min after intramuscular injection and slowly accumulated in blood. L-368,899 was 40 times more selective for OXTR than vasopressin 1a receptors and bound to the coyote OXTR with an affinity of 12 nM. These features of L-368,899 support its utility in future studies to probe the oxytocin system of coyotes.

Low secondary risks for captive coyotes from a sodium nitrite toxic bait for invasive wild pigs

ABSTRACTAn 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 bait showed signs of SN intoxication. Second, we conducted chemical analysis of residual SN in the coyotes for evidence of SN passing from pigs to coyotes. Last, we conducted an acute oral toxicity test (LD50) with SN for coyotes by feeding them meatballs containing capsules of SN. We found no evidence that captive coyotes experienced SN intoxication from consuming on carcasses that had been freshly poisoned with SN, despite consuming = 1.6 kg of tissues/coyote within 24 hours. None of the captive coyotes consumed digestive tracts or stomach contents from poisoned carcasses, which contained the highest levels of residual SN. Chemical analysis indicated that only ≤34.14 mg/kg of residual SN were passed from the tissues of the pigs into the coyotes, confirming that SN does not bioaccumulate. All coyotes quickly vomited various doses of SN during the LD50 test and fully recovered, suggesting a natural defense against secondary poisoning from SN. Testing with captive coyotes indicates that the risks of secondary poisoning for free‐ranging coyotes are likely low, although field‐testing should be used to confirm. © 2019 The Wildlife Society.

Spatial dynamics of transmission and persistence of African swine fever in wild boar populations: insight for control

Spatial dynamics of transmission and persistence of African swine fever in wild boar populations: insight for control

Commentary Setting Research Priorities at Wildlife Services’ National Wildlife Research Center

<em>Commentary</em> Setting Research Priorities at Wildlife Services’ National Wildlife Research Center

Modifying M-44s to reduce risk of activation by swift fox

M-44s are spring-powered sodium cyanide ejectors commonly used in the United States to manage livestock depredation by coyotes (Canis latrans). While highly selective for canids, improvements could reduce risk to nontarget canids, especially State-Endangered or -Threatened canids such as the swift fox (Vulpes velox). In 2012–2013, we tested M-44s set at modified heights to determine whether height modifications reduced risk to swift foxes without reducing activation rates by coyotes. We presented captive coyotes housed at the USDA National Wildlife Research Center's Predator Research Facility, Millville, Utah, USA, with M-44s at various test heights to determine a height that would still ensure activation and then M-44s set at 15-cm height were placed in pens with captive swift foxes at the Cochrane Ecological Institute, near Cochrane, Alberta, Canada, to evaluate their ability to activate M-44s. M-44s were next set in the field as 31 matched pairs within North Dakota, USA. For each matched pair, 1 was set at standard height, where the body of the device was entirely below ground level and only the mouth piece was above ground, and 1 at a modified height, where the top of the mouth pieces was set 15–18 cm above ground level. Camera traps were used to monitor wildlife activity at M-44s. Despite equivalent visitation rates based on camera-trap data, only one modified M-44 was activated by a coyote, whereas 19 M-44s set at standard height were activated by coyotes. No swift foxes were observed during field trials, but red foxes (V. vulpes) were observed at 2 sets and did not activate the M-44s. Modifying the height of M-44s appears to reduce activation risk for nontarget canids, but also reduces the rate of activation by coyotes. Thus, height modifications to M-44s may not be practical or efficient in areas with little or no risk to nontarget canids because of compromised coyote activation rates, but should be considered as an option to enable use of M-44s for coyote management in areas where M-44s are not currently used because nontarget, small canids may co-occur. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

New host/parasite record for very rare chewing louse Cuculotogaster arabicus (Clay, 1938) (Phthiraptera: Ischnocera) on endemic mountain partridges of Arabian Peninsula.

The endemic avifauna of Arabia is unique and characteristic through the whole region. Little is known about these birds and their ectoparasites. The Arabian partridge Alectoris melanocephala (Rüppell, 1835) and Philby's partridge Alectoris philbyi Lowe, 1934 are two endemic species which are distributed through the Sarawat Mountains in Saudi Arabia and Yemen. Captive breeding population of these birds were examined for chewing lice at the National Wildlife Research Center (NWRC) near Ta'if. Only one rare species oflouse, Cuculotogaster arabicus (Clay 1938), was found to infest these birds. The occurrence of such species is considered a first record of the genus Cuculotogaster from Saudi Arabia, and the association of C. arabicus with Philby's partridge is considered a new host/parasite association. The clear diagnostic characters, high definition photos, and drawing of male genitalia are available through this paper.

The USDA APHIS WS Unified Model for Estimating DRC-1339 Bait Application Take Estimates as Effected by French Fry Bait Size

DRC-1339 (CPTH, 3-chloro-p-tolouidine) is an avicide registered to reduce local populations of selected bird species at feedlots, dairies, and staging areas near rice fields, and to prevent livestock depredation. Additionally, two registrations are specifically for controlling gulls and pigeons. U.S. Department of Agriculture Wildlife Services personnel historically have used a variety of methods to estimate take, including counting carcasses and quantifying reduction in bird activity. Because this avicide is slow-acting and birds usually succumb away from the bait site, carcass recovery provides poor estimates of take. Because of natural variability in bird numbers and activity, quantifying reductions in bird activity is also a poor gauge of efficacy. Scientists at the U.S. Department of Agriculture APHIS Wildlife Services National Wildlife Research Center developed and continue to adapt and refine a model using a bioenergetics approach to estimate consumption and the resulting mortality from DRC-1339 bait consumption. The model estimates take for the major baits used under the feedlot and staging area labels for European starlings, blackbirds, brown-headed cowbirds, and common grackles. Consumption of homogeneous baits (rice, cracked corn, fat pellets) has been well characterized, and take (i.e., mortality) is accurately predicted in the model. However, predictions of take when french fries were used as a bait for controlling starlings at feedlots in Washington State were less accurate. Thus, we modified the model to capture the feeding behavior of birds using this highly heterogeneous bait by removing the dependence on bait mass and simplifying the calculation of dose ingested. The modified model calculates dose directly from the amount of DRC-1339 per calorie consumed instead of from the DRC-1339 concentration per bait consumed. In this paper, we compare estimates of take based on french fry bait mass distributions and caloric contents determined for five different french fry bait types.

The Efficacy of OvoControl® (0.5% nicarbazin) in the Management of Feral Pigeons (Columba livia)

Author(s): Wolf, Erick; MacDonald, Alexander | Abstract: In a joint program, Innolytics and the USDA National Wildlife Research Center collaborated in the development of nicarbazin as an avian contraceptive, initially for resident Canada geese and subsequently for feral pigeons. Unfortunately, the introduction of the original goose product, OvoControl G, in 2005, was a commercial failure. Political and social barriers as well as goose reproductive biology effectively thwarted attempts to establish the new technology with any meaningful market success. The introduction of the pigeon contraceptive has been less difficult and the new technology continues to gather momentum. Nevertheless, given the focus on instant results and gratification, contraceptive technology for birds – which works over time – continues to be challenging, and broad market acceptance remains elusive. Especially for short-lived and rapidly reproducing species, however, the market continues to replace outdated or ineffective techniques with the safer and more effective contraceptive tools.

Vaccines for feline contraception: GonaCon GnRH-hemocyanin conjugate immunocontraceptive.

GonaCon™ is the trade name of a GnRH-hemocyanin conjugate immunocontraceptive vaccine formulation shown to prevent reproduction and inhibit production of sex hormones in numerous mammalian species for extended durations. GonaCon is currently registered with the US Environmental Protection Agency (EPA) for contraception of female white-tailed deer, and GonaCon™-Equine for female wild horses and burros. Multiple formulations of this GnRH-hemocyanin conjugate immunocontraceptive vaccine have been developed at the National Wildlife Research Center in the United States. Three studies employing an early generation vaccine formulation indicated its potential for multi-year contraception of female cats (median duration of effect in excess of 39.7 months). The contraceptive effect for male cats was less predictable and of shorter duration (median duration of effect 14 months). Since these initial feline studies there have been formulation composition changes, and further investigation of the safety, efficacy and duration of this contraceptive vaccine for cats is warranted. Individual country regulations will determine if GonaCon could be registered for unowned, free-roaming and/or pet cats.

Forecasting the spread of raccoon rabies using a purpose-specific group decision- making process

Abstract : The Centers for Disease Control (CDC) and USDA Wildlife Services (WS) have been involved in an oral rabies vaccination (ORV) program for raccoons ( Procyon lotor ) that has slowed the westward spread of raccoon rabies. The objective of this study was to forecast the spread of the disease if an ORV zone was not maintained. A group decision-making process was designed to address the forecasting problem and was implemented using a group of 15 experts and 4 support personnel at a meeting at the USDA National Wildlife Research Center. Ten expansion regions were constructed that described the spread of disease at 2-year intervals. This forecast may provide for more accurate cost-benefit analysis of the ORV barrier. Key words : forecast, human–wildlife conflict, oral rabies vaccination, Procyon lotor , raccoon, rabies, United States, zoonotic disease Worldwide, >55,000 people are estimated to die from rabies each year (World Health Organization 2013). Most of these deaths occur in Africa and Asia where canine rabies virus variants have not been controlled (World Health Organization 2004). However, in the United States, canine rabies virus variant transmission has been eliminated, and wildlife are now the primary reservoir of rabies. In 2010, wildlife accounted for approximately 92% of all reported rabid animals in the United States (Blanton et al. 2011). The raccoon (

Potential Use of Perennial Sunflower to Reduce Blackbird Damage to Sunflower

Wildlife Conservation Sunflower Plots (WCSP) have shown potential to reduce blackbird (Icteridae) damage in commercial sunflower. Also known as lure, decoy, or trap crops, WCSP are strategically placed food plots that provide an easily available and proximate food source that entices blackbirds away from valuable commercial crops. By providing an alternative food source, WCSP reduce direct damage to commercial fields, while also lowering indirect costs that producers incur attempting to prevent blackbird damage. However, cost inefficiencies have deterred widespread use of WCSP. Cost-benefit ratios of using WCSP would be greatly improved if a perennial sunflower were used instead of the annual types currently available. Perennial sunflower would reduce seed cost and planting cost, and perhaps lower opportunity costs, if able to thrive on poorer quality soils. In the near-term, scientists are focused on producing a perennial sunflower sufficiently productive to replace annual WCSP plantings. In 2013, scientists from the University of Minnesota, USDA-Agricultural Research Service, and USDA Wildlife Services National Wildlife Research Center evaluated a test plot of an open-pollinated variety of perennial sunflower resulting from genetic crossing of a domesticated annual species (Helianthus annuus) and a perennial wild species (H. tuberosus). Here, we report on results from the 2013 field test and discuss the outlook for development of perennial sunflower, which would help lessen damage to commercial sunflower when used in WCSP; provide a pesticide-free food source for beneficial insects, such as honey bees; help stabilize highly erodible lands near wetlands; and provide year-round habitat for wildlife. Lastly, we provide an initial strategy for using perennial sunflower to reduce blackbird damage in commercial sunflower.

TWENTY YEARS OF IMMUNOCONTRACEPTIVE RESEARCH: LESSONS LEARNED

The National Wildlife Research Center (NWRC) began immunocontraception vaccine research by testing porcine zona pellucida (PZP) on white-tailed deer (Odocoileus virginianus). Early PZP research demonstrated that PZP induced infertility; however, increased length of the rut was observed in PZP-treated deer. An alternative vaccine using a keyhole limpet hemocyanin-gonadotropin-releasing hormone (KLH-GnRH) conjugate formulated with modified Freund's adjuvant was developed at NWRC. Suppression of GnRH has reduced reproduction in both sexes but is most effective in females. This vaccine was effective in preventing contraception in female deer for several years after a prime and boost. Due to adverse side effects of Freund's adjuvant, NWRC developed a new adjuvant called AdjuVac, a mineral oil/surfactant adjuvant with the addition of Mycobacterium avium as an immunostimulant. The price of KLH prompted a search for a more economical hemocyanin carrier protein for the GnRH peptide. Blue protein, derived from the mollusk Concholepas concholepas, proved to be a successful option. Formulation improvements resulted in a vaccine that can be effective as a single injection for multiple years, now called GonaCon. GonaCon is registered with the Environmental Protection Agency (EPA) for use in white-tailed deer in urban/suburban areas and for wild horses (Equus caballus) and burros (Equus asinus). Future GonaCon applications may include reducing reproduction to manage populations of other wildlife species, such as prairie dogs (Cynomys ludovicianus) in urban areas and suppressing reproduction to reduce the spread of venereal diseases such as brucellosis. Research is being conducted to develop a GnRH vaccine used in combination with the rabies vaccine to control population growth in free-roaming dogs, with the secondary effect of managing the spread of rabies. The EPA would regulate all these uses. Research is also ongoing on a GnRH vaccine to delay the onset of adrenocortical disease in pet ferrets (Mustela putorius), a use regulated by the United States Department of Agriculture.

THE USE OF CONTRACEPTION AS A DISEASE MANAGEMENT TOOL IN WILDLIFE

Contraception offers potential as a tool for managing certain diseases in wildlife, most notably venereally transmitted diseases or diseases transmitted at parturition. Brucellosis is an excellent example of an infectious disease present in wild populations that could potentially be managed through immunocontraception. Previous studies in bison (Bison bison) suggest that a single injection of GonaCon (National Wildlife Research Center, U.S. Department of Agriculture/Animal and Plant Health Inspection Service/Wildlife Services, Fort Collins, Colorado 80521, USA) results in 3 or more yr of infertility. Ongoing studies will determine if the use of GonaCon in bison decreases shedding of Brucella abortus from infected animals and will better define the duration of infertility following a single injection

THE POLITICAL AND SOCIAL BARRIERS FOR CONTRACEPTION IN PEST BIRDS: A CASE STUDY OF OVOCONTROL® (NICARBAZIN)

In a joint program, Innolytics and the U.S. Department of Agriculture/Animal and Plant Health Inspection Service National Wildlife Research Center collaborated in the development of nicarbazin as an avian contraceptive, initially for resident Canada geese and subsequently for feral pigeons. Unfortunately, the introduction of the original goose product in 2005 was a commercial failure. Political and social barriers effectively thwarted attempts to establish the new technology with any meaningful market success. Although the market adoption of the pigeon contraceptive has been less difficult, the product still encounters significant social and political obstacles and opposition. Given the focus on instant results and gratification, the introduction of contraceptive technology for birds has been challenging and broad market acceptance remains elusive. Nevertheless, especially for short-lived and rapidly reproducing species, customers continue to replace outdated or ineffective techniques with the safer and more effective contraceptive tool.

Anthropogenic and physiologically induced stress responses in captive coyotes

Repeated stressful events can negatively impact overall health by continuous stimulation of the hypothalamic–pituitary–adrenal axis, which leads to depletion of glucose stores and suppression of immune and reproductive function. The influence of Stressors on survivability is particularly salient for coyote (Canis latrans) populations, because understanding how coyotes cope with Stressors may provide relevant context on coyote adaptation to urbanized ecosystems. Our objectives were to physiologically validate fecal glucocorticoid metabolite (FGM) analysis in coyotes by performing an adrenocorticotropic hormone (ACTH) challenge in 12 captive individuals (6 treatment and 6 control) housed at the United States Department of Agriculture National Wildlife Research Center Predator Research Facility in Millville, Utah; to quantify potential changes in FGM output due to diurnal variation and sex; and to determine the effects of 2 anthropogenic events (placement of a novel cooling fan and state holiday celebrations) on the coyotes' stress responses (via FGM production). Results demonstrated that in response to the ACTH injection, treatment animals (3 males and 3 females) displayed FGM concentration peaks ≥ 5-fold (range: 5- to 30-fold) above their preinjection means approximately 8 h after injection, which was a greater (P = 0.037) response than control animals. FGM output was lowest for morning fecal samples compared with midday (P = 0.001) and evening (P <; 0.001) samples. Within the evening period, FGM output for male samples tended to be higher (P = 0.056) than for female samples, although not significant. The anthropogenic events elicited FGM concentration peaks ≥ 5-fold above pre-event means for several of the study animals occurring approximately 12 and 9 h later, respectively. This study is the 1st to physiologically validate the measurement of stress physiology using FGM analysis in coyotes and demonstrate the impact of anthropogenic events on their stress response. Furthermore, this work provides a foundation for future studies of FGMs, stress, and anthropogenic effects in wild and captive systems.

Dispatches

Dispatches

Laboratory efficacy of an anthraquinone-based repellent for reducing bird damage to ripening corn

Wildlife repellents provide a non-lethal alternative for managing agricultural impacts associated with wildlife depredation. To evaluate a potential bird repellent for ripening corn, we conducted a feeding experiment at the United States Department of Agriculture, National Wildlife Research Center with 66 red-winged blackbirds (Agelaius phoeniceus). Using a two-choice experimental design we tested the efficacy of Avipel repellent (a.i. 50% 9,10-anthraquinone) on ripening sweet corn. Red-winged blackbirds consumed an average of 8.6%±0.9% of kernels from untreated ears and 5.3%±1.1% from ears treated with anthraquinone. The interaction between anthraquinone concentration and corn treatment suggests a positive concentration-response for red-winged blackbirds. Odds ratio analysis suggests red-winged blackbirds were 1.4 times more likely to damage untreated sweet corn compared to treated sweet corn. These results suggest efficacy of anthraquinone-based products as red-wing blackbird repellents for ripening corn. Moreover, exposure to anthraquinone-based repellents may reduce consumption of a food matrix that receives little to no direct anthraquinone exposure. Supplemental research is recommended to evaluate anthraquinone-based repellents under field conditions, including the establishment of a chemical tolerance for food and feed use.

Seabird diet indicates changing Arctic marine communities in eastern Canada

Seabird diet indicates changing Arctic marine communities in eastern Canada J. F. Provencher*, A. J. Gaston, P. D. O’Hara, H. G. Gilchrist Department of Biology, University of Victoria, Victoria, British Columbia V8W 3N5, Canada Science and Technology Branch, National Wildlife Research Centre, Carleton University, Ottawa, Ontario K1A 0H3, Canada Canadian Wildlife Service, Sidney, British Columbia V8L 4B2, Canada

Environmental variation and the demography and diet of thick-billed murres

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 454:237-249 (2012) - DOI: https://doi.org/10.3354/meps09589 Environmental variation and the demography and diet of thick-billed murres Paul A. Smith*, Anthony J. Gaston Environment Canada − National Wildlife Research Centre, Ottawa, Ontario K1A 0H3, Canada *Email: paul_smith@smitheco.ca ABSTRACT: Conditions in arctic marine environments are changing rapidly, and understanding the link between environmental and demographic parameters could help to predict the consequences of future change for arctic seabirds. Over 20 yr (1988 to 2007), we studied colony attendance, adult survival and reproductive success of thick-billed murres, as well as the departure masses and diets of their chicks at Coats Island, Nunavut, Canada (62.95° N, 82.00° W). We evaluated how each parameter responded to climatic conditions near the colony during the breeding season, and in the winter range during the non-breeding period (delineated using geolocation). We used the Arctic Oscillation (AO) and North Atlantic Oscillation indices, as well as local variables to describe ice, oceanographic and weather conditions. We demonstrate that adult survival varied little among years but was higher after winters with lower AO indices, more ice in the south-western part of the winter range in spring, and cooler sea surface temperatures (SST). By comparison, interannual variation in breeding parameters (breeding success, chick mass and diet) was pronounced and responded to SST and ice conditions near the colony. Counts of birds attending the colony, influenced heavily by pre-breeders, were most strongly related to the conditions that influenced adult survival; counts were positively related to ice concentration in the south-west of the winter range. Relationships between climatic conditions and demographic parameters were often lagged, suggesting effects mediated through the food web. The trend towards higher SST and less ice in the vicinity of the colony has not yet reduced reproductive success. However, a significant, ongoing decline in the rate of energy delivery to nestlings suggests that a critical threshold may eventually be crossed. KEY WORDS: Demography · Survival · Reproduction · Climate · Thick-billed murre · Uria lomvia Full text in pdf format Supplementary material PreviousNextCite this article as: Smith PA, Gaston AJ (2012) Environmental variation and the demography and diet of thick-billed murres. Mar Ecol Prog Ser 454:237-249. https://doi.org/10.3354/meps09589 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 454. Online publication date: May 21, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.

Rats! Foiled Again: A History of Rodent Control Methods Development at the National Wildlife Research Center

The National Wildlife Research Center (NWRC) and its predecessor laboratories have a long history of developing ma- terials 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. Consid- erable research has also been conducted on developing methods of managing rodents in underdeveloped countries. Recent efforts by NWRC have focused on development of tools for managing invasive rodents in conservation areas such as island ecosystems and development of alternative, nonlethal control methods.