Physical Sciences and Mathematics Commons^™

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 …

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.

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 …

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 …

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 …

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 …

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 …

"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 …

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 …

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), …

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, …

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.

Mechanical Mouse Lure For Brown Treesnakes, Alexandria C. Lindberg, John A. Shivik, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

The importance of prey movement for stimulating feeding behavior of Brown Treesnakes was tested by using a mechanical mouse model in combination with and without prey odor. Prey movement was found to be important in stimulating brown treesnake feeding behavior. Prey movement combined with prey odor was not significantly different than prey movement alone. In the development of simple artificial lures based on the stimulus of live mice, visual lures lacking movement are likely to be ineffective. Lures that combine a visual moving stimulus with prey odor are likely to be the most effective artificial lure for trapping brown treesnakes.

Digestibility, Nitrogen Excretion, And Mean Retention Time By North American Porcupines (Erethizon Dorsatum) Consuming Natural Forages, Laura A. Felicetti, Lisa A. Shipley, Gary W. Witmer, Charles T. Robbins

United States Department of Agriculture Wildlife Services: Staff Publications

North American porcupines (Erethizon dorsatum) subsist predominantly on low-protein, high-fiber, high-tannin diets. Therefore, we measured the porcupine's ability to digest dry matter, fiber, and protein by conducting digestion trials on eight natural forages and one pelleted ration varying in concentration of fiber, nitrogen, and tannins. On these diets, dry matter intake ranged from 5 to 234 g/kg ^0.75/d and dry matter digestibility ranged from 62% to 96%. Porcupines digested highly lignified fiber better than many large hindgut fermenters and ruminants. The porcupine's ability to digest fiber may be explained, in part, by their lengthy mean retention time …

Lethal Control Of Piscivorous Birds At Aquaculture Facilities In The Northeast United States: Effects On Populations, Bradley F. Blackwell, Richard A. Dolbeer, Laura A. Tyson

United States Department of Agriculture Wildlife Services: Staff Publications

Predation by piscivorous birds is considered a substantial threat to the aquaculture industry. However, lethal control of birds at aquaculture facilities has raised concerns about the effects on the distribution and abundance of populations of the species killed. We examined the relationship between numbers of piscivorous birds reported killed under U.S. Fish and Wildlife Service (USFWS) permits at aquaculture facilities in New York, New Jersey, and Pennsylvania and species population trends within the respective states. The USFWS issued 26 permits to 9 facilities from 1985 through September 1997. Eight species appeared on permits, but only six species were reported killed: …

Changes In Coyote Activity Patterns Due To Reduced Exposure To Human Persecution, Ann M. Kitchen, Eric M. Gese, Edward R. Schauster

United States Department of Agriculture Wildlife Services: Staff Publications

Activity patterns in animals are influenced by a number of factors, including the animal's physiological adaptations, prey availability and distribution, and disturbances caused by predators and humans. We compared coyote (Canis latrans) activity patterns estimated using radio-tracking locations between 1983 and 1988 with those documented between 1996 and 1997 on the Pinon Canyon Maneuver Site, in southeastern Colorado. We tested the hypothesis that changes in the type of disturbance experienced by coyotes would result in changes in their activity patterns. Disturbance experienced by the coyote population studied during 1983-1988, included >50 years of intense exploitation (shooting and trapping by ranchers) …

Seasonal Variability In Brown Tree Snake (Boiga Irregularis) Response To Lures, John A. Shivik, William G. Wright, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

In continuing investigations of brown tree snake, Boiga irregularis, attraction to carrion odor, we hypothesized that the attractiveness of live or dead and visually apparent or concealed lures varies seasonally. We determined that lure condition (live or dead mouse lures) and sensory cues (visually apparent or concealed lure) interact among wet and dry seasons. Concealed carrion lures were more effective during the dry season than the wet season, but the effectiveness of live mouse lures showed less seasonal variability. We identified weather variables that covary with observed seasonal trends in capture rates and investigated the influence of recent feeding …

Wildlife Strikes: A Growing And Costly Problem For Civil Aviation In The Usa, Sandra Wright, Richard Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife strikes, defined as aircraft collisions with birds or other animals, are a serious safety and economic concern in the USA and elsewhere. Liability issues related to wildlife strikes are also growing for airports and aircraft operators. In this paper, we will give examples of some significant strikes, show trends in wildlife strikes, explain why the strike problem is an increasing concern and discuss what actions can be taken to reduce and prevent strikes.