Physical Sciences and Mathematics Commons^™

Development Of Sarcocystis Falcatula In Its Intermediate Host, The Brown-Headed Cowbird (Molothrus Ater), Shannon L. Luznar, Michael L. Avery, John B. Dame, Robert J. Mackay, Ellis C. Greiner

United States Department of Agriculture Wildlife Services: Staff Publications

Sporocysts of Sarcocystis falcatula obtained from experimentally infected Virginia opossums (Didelphis virginiana) were inoculated orally to 60 wild-caught Brown-headed Cowbirds (Molothrus ater). Another 30 Brown-headed Cowbirds were not challenged and served as uninfected controls. Two inoculated and one control cowbird were necropsied every 2 weeks and the pectoral and thigh muscles were examined grossly for cyst development. Stained histologic sections of pectoral muscle, thigh muscle, and lung were examined by light microscopy and presence, density, and size of sarcocysts were determined. Sarcocysts were present by 6 weeks post-inoculation (PI) and were still growing at …

Ecotoxicology, Ronald J. Kendall, Todd A. Anderson, Robert J. Baker, Catherine M. Bens, James A. Carr, Louis A. Chiodo, George P. Cobb Iii, Richard L. Dickerson, Kenneth R. Dixon, Lynn T. Frame, Michael J. Hooper, Clyde F. Martin, Scott T. Mcmurry, Reynaldo Patino, Ernest E. Smith, Christopher W. Theodorakis

United States Department of Agriculture Wildlife Services: Staff Publications

The field of environmental toxicology, particularly as related to the area of ecotoxicology, continues to be a rapidly developing discipline of environmental science (Connell and Miller, 1984; Duffus 1980; Guthie and Perry, 1980; Hoffman et al., 1995; Moriarity 1988; Truhaut, 1977). The term ecotoxicology was introduced by Truhaut in 1969 (Truhaut, 1977) and this field is a natural extension of toxicology. It is best defined as the study of the fate and effects of toxic substances on an ecosystem and is based on scientific research employing both field and laboratory methods (Kendall, 1982; Kendall, 1992; and Hoffman et al., 1995). …

Effects Of Sterilization On Territory Fidelity And Maintenance, Pair Bonds, And Survival Rates Of Free-Ranging Coyotes, Cassity Bromley, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

Predation on sheep by coyotes (Canis latrans) is a longstanding problem for sheep producers. Current research suggests that surgical sterilization of coyotes could prove to be an effective method of reducing their depredation rates on domestic sheep by modifying their predatory behavior. However, for sterilization to be a viable management tool, the territorial and affiliative behaviors of pack members would need to remain in place. We tested whether surgically sterilized coyotes maintained pair bonds and territories in the same manner as intact coyotes. We also examined if territory fidelity and survival rates differed between sterile and intact coyotes. …

Dealing With Nuisance And Depredating Black Bears, Gary W. Witmer, Donald G. Whittaker

United States Department of Agriculture Wildlife Services: Staff Publications

Black bears (Ursus americanus) are a valued resource in North America but pose many challenges to resource managers. They may be managed in 1 or more ways, including sustained yield harvests, nuisance animal control, or conservation management. Many black bear populations are stable or increasing, and combine with expanding human populations, increased development, and recreational activities, are leading to an increase in human-bear conflicts. Historically, methods such as relocation, general hunting seasons, or special hunts have been used in an effort to reduce bear density and damage, or to target individual offending animals. Many resource managers now operate …

Monitoring Changes In Feral Swine Abundance And Spatial Distribution, Richard M. Engeman, Bernice Constantin, Mark Nelson, John Woolard, Jean Bourassa

United States Department of Agriculture Wildlife Services: Staff Publications

Swine (Sus scrofa) have been introduced in many places throughout the world, and in many places they adversely affect the environment, economically impact agriculture, and/or harbor diseases transmittable to domestic livestock or humans. An easily applied method to assess their abundance is an important need for their management. To monitor efficacy of a swine control program in Florida, data from passive tracking plots provide an index of feral swine abundance. The same track data coupled with plot locations to numerically describe the spatial pattern of swine activity gave an index of pervasiveness, and a simple rate of interception …

A Review Of The Hazards And Mitigation For Airstrikes From Canada Geese In The Anchorage, Alaska Bowl, Darryl L. York, Richard M. Engeman, John L. Cummings, Corey L. Rossi, David R. Sinnett

United States Department of Agriculture Wildlife Services: Staff Publications

Bird strikes to aircraft are a globally pervasive safety and economic concern. In particular, the Anchorage, Alaska area holds substantial risk for destructive collisions between birds and aircraft. An international airport, a municipal airport, a seaplane base, and a U.S. Air Force base are situated throughout the area. Anchorage also has a burgeoning population of Canada geese (Branta canadensis parvipes), one of the species identified as posing the greatest airstrike hazards. A variety of methods are applied and a variety of research has been conducted to reduce the potential for airstrikes with geese around Anchorage.We review the nature …

Understanding Vole Problems In Direct Seeding — Strategies For Management, Gary W. Witmer, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Crop fields can provide habitat to a variety of wildlife and crop damage can result (Wywialowski 1996, 1998; Conover 1998). Among the vertebrates, damage can occur from numerous species of birds and mammals. Worldwide concern, however, has focused on rodents and a large number of species cause substantial agricultural losses each year (Witmer et al. 1995). After the advent of effective herbicides and "clean farming" practices in North America, however, many rodent problems became insignificant (Hines and Hygnstrom 2000). This is, in large part, because the fields were plowed each year, disrupting burrows and removing ground cover. The fields often …

Understanding Vole Problems In Direct Seeding-Strategies For Management, Gary W. Witmer, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Crop fields can provide habitat to a variety of wildlife and crop damage can result (Wywialowski 1996,1998; Conover 1998). Among the vertebrates, damage can occur from numerous species of birds and mammals. Worldwide concern, however, has focused on rodents and a large number of species cause substantial agriculture losses each year (Witmer et al, 1995). After the advent of effective herbicides and "clean farming" practices in North America, however, many rodent problems became insignificant (Hines and Hygnstrom 2000). This is, in large part, because the fields were plowed each year, disrupting burrows and removing ground cover. The fields often lay …

Progress On Cattail Management To Reduce Blackbird Damage To Sunflower, H. Jeffrey Homan, George M. Linz, Ryan L. Wimberly, Linda B. Penry

United States Department of Agriculture Wildlife Services: Staff Publications

In 1989, the USDA began experimenting with cattail management to reduce sunflower damage caused by blackbirds. Dense stands of cattail, which often hold large numbers of blackbirds in late summer and early fall, were thinned with glyphosate-based herbicide. Based on promising results from initial research, a statewide cattail management program was started by the USDA in 1991.

Habitat Characteristics Around Fall Blackbird Roosts, Mark W. Lutman, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

In the fall, blackbirds form large flocks and roost overnight in cattail marshes. These blackbirds cause millions of dollars in damage to ripening sunflower fields in North Dakota, South Dakota, and Minnesota. By knowing the habitat characteristics around fall blackbird roosts sites, management officials may be able to predict future roost locations and then implement control techniques to help reduce blackbird damage to sunflower fields. We present data on the available habitat around blackbird roosts to determine if there is a relationship between the habitat and fall roost sites.

Impact Of Blackbird Damage To Sunflower Bioenergetic And Economic Models, Brian D. Peer, H. Jeffrey Homan, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

We constructed bioenergetic models to assess the economic impact on sunflower production horn a regional population of blackbirds (Icteridae) consisting of three species: red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and yellow-headed blackbirds (Xanthocephalus xanthocephalus). Values generated from the bioenergetic models were used to perform a cost-benefit analysis to determine efficacy of a proposed avicide baiting program to manage red-winged blackbirds residing in the Central Lowlands and Northern Great Plains regions of North America. The bioenergetic model included metabolic rates, caloric value and moisture content of achenes, and percentage of sunflower in the …

Has An Integrated Pest Management Approach Reduced Blackbird Damage To Sunflower?, George M. Linz, Brian D. Peer, H. Jeffrey Homan, Ryan L. Wimberly, David L. Bergman, William J. Bleier, Linda B. Penry

United States Department of Agriculture Wildlife Services: Staff Publications

Since the mid- 1970s many new and modified damage abatement methods have been used to reduce blackbird damage to ripening sunflower in the northern Great Plains. To assess the overall impact of these techniques, we analyzed the dynamic relationship between breeding blackbird densities and sunflower damage. Breeding density estimates were made at both the regional and county levels, whereas, sunflower damage estimates were made at the county level only. Periodic regional estimates of breeding densities between 1967 and 1998 for red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and yellow-headed blackbirds (Xanthocephalus xanthocephalus) showed …

Local Removal Of Red-Winged Blackbirds: Potential For Blackbird Management?, Richard . S. Sawin, George M. Linz, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

Fall flocks of red-winged blackbirds (Agelaius phoeniceus) are well known for their ability to damage crops such as sunflower (Linz and Hanzel 1997). In response, wildlife managers have considered local population reduction as a strategy for reducing blackbird damage. Male red-winged blackbirds are logistically easier to remove than females because of their conspicuous behavior. However, they exhibit a polygynous breeding system, and male removals may be ineffective if a large population of floaters exists to replace removed birds. We present data from an experimental removal project in two North Dakota townships and discuss the implications for local blackbird …

Avian Use Of Ripening Sunflower Fields, Dionn Schaaf, George M. Linz, William J. Bleier, H. Jeffrey Homan

United States Department of Agriculture Wildlife Services: Staff Publications

In the United States, more than 90% of cultivated sunflower is raised in the northern Great Plains. Cattail marshes in this area provide nesting and roosting sites for red-winged blackbirds, yellow-headed blackbirds, and common grackles. North Dakota's breeding blackbird population was estimated at more than 2.3 million pairs in 1990. Sunflower has become an important part of blackbirds' diet from July-October . In 1999 and 2000, research was conducted on the use of avicide-treated (DRC- 1339, 3-chloro-p-toluidine hydrochloride) rice baits for managing blackbird damage in problem areas. DRC- 1339 was chosen for this purpose because of its high …

Coyote Responses To Changing Jackrabbit Abundance Affect Sheep Predation, L. Charles Stoddart, Richard E. Griffiths, Frederick F. Knowlton

United States Department of Agriculture Wildlife Services: Staff Publications

Domestic sheep ranchers generally perceive abundances of natural prey and coyotes (Canis latrans) as important factors affecting coyote predation rates on sheep. To determine the effect of a changing natural prey base on coyote predation rates, we estimated coyote density and predation rates on ewes and lambs during part of 1 cycle of black-tailed jackrabbit (Lepus californicus) abundance on a 2,300 km² area of the Idaho National Engineering Laboratory in south-central Idaho from 1979–1985. We used 100, 1.6-km scat collection lines and 80, 1.6-km flushing transects to assess coyote and jackrabbit densities, respectively. Ewe and …

Avian Use Of Various Bait Mixtures Offered In Harvested Cornfields During Spring Migration In South Dakota, George M. Linz, H. Jeffrey Homan, Ryan L. Wimberly

United States Department of Agriculture Wildlife Services: Staff Publications

The avicide, DRC-1339, is used to cull populations of spring-migrating blackbirds in eastern South Dakota to reduce damage to ripening sunflower in late summer. We investigated non-target bird hazards associated with using various grain mixtures to attract blackbirds (Icteridae), especially red-winged blackbirds (Agelaius phoeniceus), to avicide-treated bait broadcast in harvested cornfields. During spring 1997 and 1998, we recorded the species and numbers of birds attracted to 0.2-ha plots baited with cracked corn and brown rice, fine-chipped sunflower meats and brown rice (1997 only), and unsupplemented brown rice. Unbaited plots were used as reference sites. In 1997 and 1998, …

Design Of A Laboratory Secondary Hazard Study, David A. Goldade, Peter J. Savarie, Jerome C. Hurley, Stanley A. Gaddis, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

Factors influencing the design and execution of a secondary hazard study are presented using the anticoagulant rodenticide, difethialone, as a model. Frequently, regulatory agencies require a determination of the potential hazard posed to non-target species by the application of pesticides. This hazard can occur through: 1) primary hazard, direct consumption of the bait or formulation containing the pesticide, or 2) secondary hazard, indirect consumption of the pesticide via ingestion of biological matrices such as animals or plants containing pesticide residues. In making this determination, the selection of appropriate test species as well as routes and level of exposure are critical. …

Introduction To Pesticides And Wildlife, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

A pesticide is a substance intended for destroying, repelling or mitigating any animal, microorganism or plant pest. While pesticides are commonly chemical agents, biological or physical agents can also be pesticides. Many people equate the term pesticide with insecticide. However, there are a plethora of pesticides for which insects are not the target pest. Examples include herbicides, fungicides, rodenticides, acaricides, larvacides, etc. Additionally, pesticides are not limited to toxicants, but also include repellents, attractants and growth regulators (1 ) .

Pesticides are nearly ubiquitous in today's world. In agriculture, insecticides, nematicides and herbicides are applied to plants and soil to …

"References" For Carnivore Conservation, John L. Gittleman, Stephan M. Funk, David Macdonald, Robert K. Wayne, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

119-page bibliography of works cited in in CARNIVORE CONSERVATION, edited by John L. Gittleman, Stephan M. Funk, David Macdonald, and Robert K. Wayne, Cambridge University Press, 2001.

Includes approximately 2,000 items.

Experimental Infection Of Nontarget Species Of Rodents And Birds With Brucella Abortus Strain Rb51 Vaccine, Matt C. Januszewski, Steven C. Olsen, Robert G. Mclean, Larry Clark, Jack C. Rhyan

United States Department of Agriculture Wildlife Services: Staff Publications

The Brucella abortus vaccine strain RB51 (SRB51) is being considered for use in the management of brucellosis in wild bison (Bison bison) and elk (Cervus elaphus) populations in the Greater Yellowstone Area (USA). Evaluation of the vaccine’s safety in non-target species was considered necessary prior to field use. Between June 1998 and December 1999, ground squirrels (Spermophilus richardsonii, n=21), deer mice (Peromyscus maniculatus, n=14), prairie voles (Microtus ochrogaster, n=21), and ravens (Corvus corax, n=13) were orally inoculated with SRB51 or physiologic saline. Oral and …

Serological Responses Of Coyotes To Two Commercial Rabies Vaccines, Frederick F. Knowlton, Marianna Roetto, Deborah Briggs

United States Department of Agriculture Wildlife Services: Staff Publications

Between August 1993 and September 1994 we documented serological responses of coyotes (Canis latrans) vaccinated with two commercial rabies vaccines licensed for use in domestic dogs. Serologic responses were documented by testing for rabies virus neutralizing antibodies with the rapid fluorescent focus inhibition test (RFFIT) at 30, 90, 180, 270, and 365 days post-vaccination. All coyotes vaccinated with Imrab 3^® (Rhone-Merieux, Inc.), and 75% of those vaccinated with Dura-Rab 3^® (Immunovet, Inc.) seroconverted, as evidenced by the presence of antirabies antibody titers ≥1:5 in one or more of the five post-vaccination samples. The percent of coyotes …

So You Want To Work With Wolves?, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Growing up with three older sisters was a bit like being raised by wolves. One of their favorite games was called “stop hitting yourself.” To play, I was immobilized, and then with my arms overpowered, I was forced to repeatedly pummel my own noggin while they uttered the name of the game. Watching yourself hit yourself, feeling the pain and humiliation, yet being unable to stop is somewhat like being a federal biologist working with wolves. I’ve learned humility from my experiences but also formed the opinion that if you want to work with wolves, first consider medication; if that …

Non-Target Hazard Assessment Of Using Drc-1339 Avicide To Manage Blackbirds In Sunflower, John D. Eisemann, George M. Linz, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

Terrestrial hazard assessments were conducted for the spring blackbird baiting program to protect sunflower crops. Risk Assessment methodology proposed by the Ecological Committee on FIFRA Risk Assessment Methods (ECOFRAM) and the method currently used by the U.S. Environmental Protection Agency (LD₅₀s/ft²) were compared for their predictive strengths and for the ease of adapting the assessment to site specific conditions. While the ECOFRAM and LD₅₀s/ft² methods identified the same groups of organisms as being at risk, the flexibility of the ECOFRAM methodology allowed more latitude in adapting the assessment to unique behaviors of individual …

Estimation Of Red-Winged Blackbird Mortality From Toxic Bait Application, James F. Glahn, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

Application of slow-acting toxic bait is one method of reducing local populations of depredating blackbirds. Estimating numbers of birds killed in such baiting operations is difficult because affected birds die off-site and are seldom recovered. We conducted bioassays and flight pen studies of red-winged blackbirds (Agelaius phoeniceus) with a slow-acting, toxic brown rice bait to determine whether bird mortality could be predicted accurately using the Poisson and binomial discrete probability distributions. Bioassays confirmed that brown rice treated with 2% (w/w) 2-chloro-p-acetotoluidide was effective as a 1-particle lethal bait for redwings. Within a 0.2-ha flight pen, we offered this …

Ecotoxicological Risks Of Potential Toxicants For Brown Tree Snake Control On Guam, John J. Johnston, Richard E. Mauldin, Peter J. Savarie, Joseph E. Brooks, Thomas M. Primus

United States Department of Agriculture Wildlife Services: Staff Publications

The brown tree snake (Boiga irregularis) is a nocturnal, arboreal, rear-fanged, mildly venomous, colubrid snake which can reach lengths of up to 2.3 m and weigh as much as 2 kg(1). Originally, the species' range included the northern and eastern coasts of Australia, Papua New Guinea and nearby islands (2). It is believed that sometime in the 19501s, that snakes were inadvertently transported from New Guinea to Guam, where they proliferated (3). By the mid-1960’s, marked decreases in Guam's bird life were observed. By the mid-1980’s, snake densities were estimated at 50 to 100/hectare (13,000 to 26,000/sq mile), …

Chlorophacinone Residues In Rangeland Rodents: An Assessment Of The Potential Risk Of Secondary Toxicity To Scavengers, Thomas M. Primus, John D. Eisemann, George H. Matschke, Craig Ramey, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

Field studies were conducted in California to assess efficacy of chlorophacinone-treated steam-rolled oats for controlling rangeland rodents. An objective of these studies was to assess the potential hazards of chlorophacinone residues in rangeland rodent carcasses and livers to mammalian and avian scavengers, especially raptors. Belding's ground squirrels, valley pocket gophers and Microtus spp. carcasses collected during the efficacy studies were analyzed for chlorophacinone residues. The method limit of detection (MLOD) for liver and carcass tissue samples averaged 0.036 μg/g and 0.034 μg/g, respectively. Chlorophacinone residues in Belding's ground squirrel (n=62) liver and carcass tissue ranged from Microtus sp. (n=3) tissue …

Pathology Of Brucellosis In Bison From Yellowstone National Park, Jack C. Rhyan, Thomas Gidlewski, Thomas J. Roffe, Keith Aune, L. Michael Philo, Darla R. Ewalt

United States Department of Agriculture Wildlife Services: Staff Publications

Between February 1995 and June 1999, specimens from seven aborted bison (Bison bison) fetuses or stillborn calves and their placentas, two additional placentas, three dead neonates, one 2-wk-old calf, and 35 juvenile and adult female bison from Yellowstone National Park (USA) were submitted for bacteriologic and histopathologic examination. One adult animal with a retained placenta had recently aborted. Serum samples from the 35 juvenile and adult bison were tested for Brucella spp. antibodies. Twenty-six bison, including the cow with the retained placenta, were seropositive, one was suspect, and eight were seronegative. Brucella abortus biovar 1 was isolated from …

Ornithological Literature, Robert C. Beason

United States Department of Agriculture Wildlife Services: Staff Publications

BABY BIRD PORTRAITS BY GEORGE MIKSCH SUTTON.

COLLINS ILLUSTRATED CHECKLIST: BIRDS OF SOUTHERN AFRICA.

BIRDS OF AFRICA: FROM SEABIRDS TO SEED-EATERS. By Chris and Tilde Stuart.

HARMONY AND CONFLICT IN THE LIVING WORLD. By Alexander F. Skutch.

HOPE IS THE THING WITH FEATHERS. By Christopher Cokinos.

STURKIE’S AVIAN PHYSIOLOGY. Edited by G. Causey Whittow.

STARLINGS AND MYNAS. By Chris Feare and Adrian Craig.

BIRDING IN THE AMERICAN WEST. By Kevin J. Zimmer.

TAKING WING: ARCHAEOPTERYX AND THE EVOLUTION OF BIRD FLIGHT. By Pat Shipman.

A Science-Based Initiative To Manage Double-Crested Cormorant Damage To Southern Aquaculture, James F. Glahn, Mark E. Tobin, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

Aquaculture has expanded rapidly in the Southern United States during the past two decades, especially the cultivation of catfish, crawfish, and bait fish. These fish usually are cultivated on farms with extensive systems of large shallow ponds that are highly susceptible to predation by birds. Double-crested cormorants (Phalacrocorax auritus ), American white pelicans (Pelecanus erythrorhynchos ), wading birds (e.g., Ardea alba, Ardea herodius ), and scaup (Aythya spp. ) are among the birds most frequently implicated. Well-documented problems associated with cormorant predation on catfish farms have coincided with the increase of this industry and the rapid …

Rodent Mining Engineers, Ray Sterner

United States Department of Agriculture Wildlife Services: Staff Publications

Colorado’s seldom-seen pocket gophers are getting some attention from the National Wildlife Research Center. Researchers are attempting to improve management of gophers in agricultural areas. Although the gophers’ tunnel building may damage harvest equipment, their activities enrich soils over time.