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Full-Text Articles in Physical Sciences and Mathematics

A Changing Approach To Dingo Control In Western Australia, A. W. Hogstrom Mar 1986

A Changing Approach To Dingo Control In Western Australia, A. W. Hogstrom

Vertebrate Pest Conference Proceedings: 12th (1986)

The traditional method of dingo control on sheep properties in Western Australia relied on labor-intensive trapping and baiting. A cost/price squeeze in the rangeland sheep-grazing areas around 1970 forced a revision of these practices. Research was conducted on dingo biology, habitat preference and use, movements, social organization and damage to livestock. The data demonstrated the territorial nature of dingoes, that they usually occur in groups of 2 to 15, that long movements are rare, and that they quickly learn to harass and kill sheep. Aerial baiting trials using factory-manufactured baits and baits prepared from fresh meat demonstrated that an adequate …

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Integrative Models Of Poisoning Vertebrate Pests, J. Hone Mar 1986

Integrative Models Of Poisoning Vertebrate Pests, J. Hone

Vertebrate Pest Conference Proceedings: 12th (1986)

Strategies for the control of vertebrate pest are identified using mathematical models of poisoning. The models integrate aspects of foraging ecology and toxicology in a probabilistic framework. The structure, assumptions and control implications of the models are presented. Variables (control parameters) influencing the probability that a pest animal dies in a poison program are identified and classified according to their degree of operator control. Control strategies suggested by the models are identified, and practical means of applying them are discussed. The models suggest that the probability that an animal dies is a function of 15 to 17 control parameters, of …

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Implications And Management Of Feral Mammals In California, Walter E. Howard, Rex E. Marsh Mar 1986

Implications And Management Of Feral Mammals In California, Walter E. Howard, Rex E. Marsh

Vertebrate Pest Conference Proceedings: 12th (1986)

"Feral" is defined. For each of the principal species of feral mammals in California we note the broad ecological implications they have on the environment and the potential or actual management approaches being followed. The main emphasis of this paper, and all of the slides shown, was on how wild horses and burros, two controversial feral species, are managed in California and in other western states. The feral pig is about to become the number one big game animal in California, and mustrats (Ondatra zibethica (L.)), which were introduced or escaped into the Sacramento Valley—-hence locally feral--are the state's …

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Wildlife Damage In Conservation Tillage Agriculture: A New Challenge, Ron J. Johnson Mar 1986

Wildlife Damage In Conservation Tillage Agriculture: A New Challenge, Ron J. Johnson

Vertebrate Pest Conference Proceedings: 12th (1986)

Conservation-tillage farming systems have changed agriculture and brought new challenges to the wildlife damage field. Associated minor problems may result from the presence of rattlesnakes (Crotalus viridis) or badgers (Taxidea taxus), but sprout-pulling damage by birds has not been reported. Rodents dig and consume newly planted corn. At least 14 small mammal species have been captured in notillage cornfields, some species throughout fields and others primarily at edges. Deer mice (Peromyscus maniculatus) generally have been the most abundant, comprising 71 to 93% of total captures. Small mammal populations in no-tillage fields are generally no …

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A Review Of Brodifacoum Efficacy In The U.S. And Worldwide, Dale E. Kaudeinen, Michael Rampaud Mar 1986

A Review Of Brodifacoum Efficacy In The U.S. And Worldwide, Dale E. Kaudeinen, Michael Rampaud

Vertebrate Pest Conference Proceedings: 12th (1986)

It was just over 10 years ago with the paper by Hadler and Shadbolt (1975) that a series of novel anticoagulants, which included brodifacoum, was announced. Today, after a decade of brodifacoum study and experience, the value of this compound in vertebrate pest management, particularly in rodent control, can scarcely be questioned. In order to most effectively build upon this experience, a thorough review of the literature for the period of 1975 to 1985 was undertaken to also include much unpublished information available to the authors.

Undoubtedly to a greater extent than any other new vertebrate pesticide, brodifacoum has been …

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A Five-Year Evaluation Of The Silvicultural Treatments For The Control Of Squirrel Damage In Taiwan, Pao-Chang Kuo, Yue-Ken Liao Mar 1986

A Five-Year Evaluation Of The Silvicultural Treatments For The Control Of Squirrel Damage In Taiwan, Pao-Chang Kuo, Yue-Ken Liao

Vertebrate Pest Conference Proceedings: 12th (1986)

The Formosan red-bellied tree squirrel (Callosciurus erythraeus. ) is a pest animal that causes serious damage to many conifer plantations in Taiwan. Poisoning has been the major means to control the damage. The feasibility of forestry control through habitat manipulation has been evaluated during the past 5 years. The objective of this study was to investigate the effects of forest-tending operations on the activity and damage by squirrels. Forest-tending conducted included weeding and thinning. Test sites were at three Japanese cedar (Cryptomeria japonica) plantations located in Chitou. The results of this study revealed that squirrel activity in …

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The Mechanical Control Of Bushpig, Potamochoerus Porcus, In Zimbabwe, Michael La Grange Mar 1986

The Mechanical Control Of Bushpig, Potamochoerus Porcus, In Zimbabwe, Michael La Grange

Vertebrate Pest Conference Proceedings: 12th (1986)

Bushpig, Potamocheorus porcus, occurring naturally in the high rainfall areas of Zimbabwe, have become a major threat to maize producers in the country. Traditional means of control including hunting have been unsuccessful in keeping the numbers to a tolerable level owing to the secretive and cunning nature of the animal. The use of poisons has been discouraged because of indiscriminate use and problems of secondary poisoning, so alternative methods of mechanical control were sought. Several methods evolved during experimentation, producing a strategy to control bushpig throughout the year.

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Keynote Address—Changing Times For Animal Damage Control, James O. Lee Jr. Mar 1986

Keynote Address—Changing Times For Animal Damage Control, James O. Lee Jr.

Vertebrate Pest Conference Proceedings: 12th (1986)

Times do change! USDA's Animal and Plant Health Service, or APHIS, is now in the process of taking over the animal damage control program from the U.S. Fish and Wildlife Service. The transfer will be completed by April 1.

This is the opposite of what was happening back in 1939. At that time, a government reorganization plan resulted in the transfer of the Bureau of Biological Survey—-forerunner of Fish and Wildlife Service--from Agriculture to Interior; and with it went the ADC program.

We're pleased to have the ADC program back at Agriculture. We never lost interest in it. While the …

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The Effectiveness Of Strychinie Laced Alfalfa On Pocket Gopher Activity In Diamond Valley, Nevada, Steven R. Lewis, John O'Brien Mar 1986

The Effectiveness Of Strychinie Laced Alfalfa On Pocket Gopher Activity In Diamond Valley, Nevada, Steven R. Lewis, John O'Brien

Vertebrate Pest Conference Proceedings: 12th (1986)

The Townsend pocket gopher, (Thomomys townsendi), poses a serious economic threat to alfalfa production in Diamond Valley, Nevada. Many control methods have been practiced with only limited or seasonal success. Application of strychnine-treated alfalfa hay has been an effective control method; however, the relationship between strychnine concentration and pocket gopher kill has not been examined. This study was conducted to evaluate the effectiveness of three concentrations (0.5%, 1.0% and 1.7%) of strychnine-treated alfalfa hay baits. The three strychnine levels and untreated control were replicated three times on twelve 0.8-ha (2.0-ac) plots. Plots were located on a 6-year-old stand …

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Private Costs Of Predator Control In New Mexico In 1983, Gary A. Littauer, Ronald J. White, David Carroll Hall Mar 1986

Private Costs Of Predator Control In New Mexico In 1983, Gary A. Littauer, Ronald J. White, David Carroll Hall

Vertebrate Pest Conference Proceedings: 12th (1986)

A survey was conducted by the New Mexico Department of Agriculture in early 1984 to determine costs incurred by livestock producers to control predation on livestock during 1983. Out of a sample of 1,848 producers who were sent questionnaires, 706 (38%) usable responses were returned. The respondents reported having about 30% of the peak number of sheep and lambs and 19% of the peak number of range beef cattle and calves, respectively, estimated to have been in New Mexico in 1983. Total cost reported by 306 respondents who had costs, not including donations to the New Mexico cooperative Animal Damage …

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Intoxication Of Domestic And Wild Animals By Anticoagulant Rodenticides — A Synthesis Of Data From The French National Veterinary Antipoison Center, G. Lorgue, K. Nahas, G. Keck, M. Rampaud Mar 1986

Intoxication Of Domestic And Wild Animals By Anticoagulant Rodenticides — A Synthesis Of Data From The French National Veterinary Antipoison Center, G. Lorgue, K. Nahas, G. Keck, M. Rampaud

Vertebrate Pest Conference Proceedings: 12th (1986)

During the period from 1980 to 1985 the laboratory of toxicological analysis associated with the National Veterinary Antipoison Center received 1,343 samples for research of anticoagulant rodenticide (e.g., 14.1% of total samples): 79% concerned animals, 31% baits. Six compounds marketed in France were investigated (warfarin, chlorophacinone, bromadiolone, difenacoum, coumachlore, coumatetralyl). In two-thirds of the samples, none of these substances could be found. Warfarin was by far the most incriminated rodenticide (23.1%), and dogs represented the most affected species (65.7%). However, its occurrence decreases regularly. The other compounds were found with a very low frequency (1 to 3%). In 70% of …

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Barn Owls And Industry: Problems And Solutions, Lee R. Martin Mar 1986

Barn Owls And Industry: Problems And Solutions, Lee R. Martin

Vertebrate Pest Conference Proceedings: 12th (1986)

Three methods were explored to eliminate damage caused by owl pellets and fecal droppings: exclusion; trapping; and sound deterrents including abstract sound, biosonic sound, and high frequency sound.

Initial successful results of various types of sound diminished with time to the point that owls adapted and ignored all sound repellents within a short period. Exclusion techniques were ineffective as owls would find ways around, through or between any non-permanent structure blocking entry through warehouse openings. Live-trapping and relocating owls was the only effective technique tested in this experimental program. Three trap methods were found effective, but trap success diminished with …

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Specifications For Wire Mesh Fences To Exclude The European Wild Rabbit From Crops, I. Gordon Mckillop, Harry W. Pepper, Charles J. Wilson Mar 1986

Specifications For Wire Mesh Fences To Exclude The European Wild Rabbit From Crops, I. Gordon Mckillop, Harry W. Pepper, Charles J. Wilson

Vertebrate Pest Conference Proceedings: 12th (1986)

The sizes of hexagonal and rectangular meshes needed to exclude all age classes of rabbits(Oryctolagus cuniculus) were 31 mm and 50 x 25 mm, respectively. In an enclosure, fences 0.75 m high excluded >90% of adult rabbits, a similar percentage to that obtained using the commonly accepted height of 0.9 m. In a subsequent field experiment using fences with a mesh size of 31 mm and heights of 0.9 m and 0.75 m, the numbers of rabbits seen on protected fields were reduced by about 80% for each height and therefore the 0.75-m-high fence was more cost-effective.

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An Integrated Approach To Bubonic Plague Control In A Southwestern Plague Focus, Curtis E. Montman, Allan M. Barnes, Gary O. Maupin Mar 1986

An Integrated Approach To Bubonic Plague Control In A Southwestern Plague Focus, Curtis E. Montman, Allan M. Barnes, Gary O. Maupin

Vertebrate Pest Conference Proceedings: 12th (1986)

Plague is widespread among rodents and their fleas in the western United States, but most human cases occur in several definable, ecologically unique, and geographically limited high risk areas in the Southwest and Pacific Coast states. Control strategies to prevent human cases in high risk areas must vary from one epizootic focus to another, depending on such basic ecological factors as rodent/flea species involved; their distribution, abundance, seasonality, and relationship with the plague organism; climatic factors that affect transmission; the lifestyles of human residents; and others. This paper briefly summarizes preliminary results of a long-term program to define human risk …

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New Potential Diagnostic Methods For Identifying Anticoagulant Rodenticide Poisoning In Dogs And Other Nontarget Animals, Michael E. Mount Mar 1986

New Potential Diagnostic Methods For Identifying Anticoagulant Rodenticide Poisoning In Dogs And Other Nontarget Animals, Michael E. Mount

Vertebrate Pest Conference Proceedings: 12th (1986)

Analytical methods for anticoagulants are complex and encumbered with highly sophisticated instrumentation for determination of anticoagulant concentrations. This greatly limits the application of anticoagulant measurement in biological samples as a diagnostic criteria to determine anticoagulant rodenticide poisoning. In the field of veterinary medicine, clinical laboratory measurements of the coagulation status in viable patients have been used historically as the means to make a diagnosis of anticoagulant poisoning. Nontarget animals (companion animals, e.g., dogs and cats; livestock; or wildlife), which are found dead in the context of an anticoagulant application area, are a tremendous diagnostic challenge in spite of postmortem evidence …

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The Complexities At The Interface Among Domestic/Wild Rodents, Fleas, Pets, And Man In Urban Plague Ecology In Los Angeles, County, California, Bernard C. Nelson, Minoo B. Madon, Arthur Tilzer Mar 1986

The Complexities At The Interface Among Domestic/Wild Rodents, Fleas, Pets, And Man In Urban Plague Ecology In Los Angeles, County, California, Bernard C. Nelson, Minoo B. Madon, Arthur Tilzer

Vertebrate Pest Conference Proceedings: 12th (1986)

Bubonic plague was first found in Los Angeles County in 1908. The largest epidemic of pneumonic plague in the United States occurred in the county in 1924, and the last cases of plague associated with domestic rodents in the United States occurred here in 1925. Sporadic plague activity was recorded from 1925 to 1975. Since 1975, plague has been found annually and is now endemic in the San Gabriel Mountains and the interface, that area where suburban encroachment intermingles with wilderness areas along the southern edge of these mountains. Within these two areas, plague is amplified and is a risk …

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Current Changes To Vertebrate Pest Management In New Zealand, Peter C. Nelson Mar 1986

Current Changes To Vertebrate Pest Management In New Zealand, Peter C. Nelson

Vertebrate Pest Conference Proceedings: 12th (1986)

Vertebrate pest control in New Zealand is changing as a result of a reduction in state funding. Monetary assistance for control programs is being withdrawn at $0.8 million per year and currently is $5.4 million. This reduction affects several parts of the organization and the Agricultural Pests Destruction Council has initiated various programs to rationalize control. The major effect of reducing assistance is that the landowners have to contribute more money. The necessity of blanket control of rabbits is now questioned and two investigations are underway to determine the extent of the areas where rabbit control is required and demonstrate …

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An Approach To The Design Of Target-Specific Vertebrate Pest Control Systems, Peter H. O'Brien Mar 1986

An Approach To The Design Of Target-Specific Vertebrate Pest Control Systems, Peter H. O'Brien

Vertebrate Pest Conference Proceedings: 12th (1986)

Vertebrate pest control has the dual objectives of maximizing efficacy and minimizing nontarget hazard. The task in design is to make these objectives complementary, rather than mutually exclusive. Historically, vertebrate pest control has emphasized target control as a single objective, with nontarget impact a subsequent, secondary consideration. This sequence necessarily constrains the capacity of the design process to minimize nontarget impact.

I describe a framework for the design of vertebrate pest control which is based on comparative evaluation of the socioecology of target and potential nontarget species. Using this approach, control systems are designed which focus on and exploit identified …

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Protection With Vexar Cylinders From Damage By Meadow Voles Of Tree And Shrub Seedlings In Northeastern Alberta, Ronald W. Pauls Mar 1986

Protection With Vexar Cylinders From Damage By Meadow Voles Of Tree And Shrub Seedlings In Northeastern Alberta, Ronald W. Pauls

Vertebrate Pest Conference Proceedings: 12th (1986)

Vast areas of land will require reclamation and reforestation following oil sands development in northeastern Alberta. Greenhouse-grown tree and shrub seedlings used in reforestation may be clipped or girdled by meadow voles, especially during periods of high population density. The impact of partial girdling, the most common form of damage, varies among species. Reduced survival rates in seedlings girdled over as little as 50% of their circumference and reduced growth rates in seedlings girdled over as little as 25% of their circumference, have been noted. Plastic mesh cylinders (tradename Vexar) have proven effective in preventing seedling damage and durable in …

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The Status Of Bromadiolone In The United States, Richard M. Poche Mar 1986

The Status Of Bromadiolone In The United States, Richard M. Poche

Vertebrate Pest Conference Proceedings: 12th (1986)

The anticoagulant rodenticide bromadiolone is used throughout the U.S. under a number of trade names. An expanded research program is underway within Chempar to examine the use of bromadiolone in commensal and field rodent control. Data are presented herein on the toxicology, metabolism, secondary hazards, efficacy, and formulation developments with bromadiolone. A new Maki 0.001% liquid bait is being tested and excellent control results obtained against Norway rats (Rattus norvegicus), roof rats (R. rattus), and house mice (Mus musculus). New Maki paraffin blocks containing 50 ppm bromadiolone have been developed and are soon to …

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Bait Preference Field Study Of The California Ground Squirrel, Brenda D. Protopapas, A. Charles Crabb Mar 1986

Bait Preference Field Study Of The California Ground Squirrel, Brenda D. Protopapas, A. Charles Crabb

Vertebrate Pest Conference Proceedings: 12th (1986)

A bait preference field study of the California ground squirrel (Spermophilus beecheyi beecheyi) was performed involving the comparison of the following untreated bait formulations fed ad lib.: oat groats, Ramik Green, and ZP Rodent Ag Bait. The study was performed on rangeland at California Polytechnic State University, San Luis Obispo, California, from March 11, 1984, to September 15, 1984.

Poor bait quality problems occurred in the early period of the study (March 11 to May 17), resulting in poor acceptance of both Ramik and Ag Bait. A descriptive analysis of this period is discussed. The statistical analysis of …

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Approaches To Small-Holder Rodent Control, C. G. J. Richards Mar 1986

Approaches To Small-Holder Rodent Control, C. G. J. Richards

Vertebrate Pest Conference Proceedings: 12th (1986)

Rodents are now recognized as one of the most important pests damaging crops in countries as far apart as Indonesia, Tanzania and Venezuela (Benigno and Sanchez 1984, Taylor 1984, Williams and Vega 1984). Damage to crops such as rice may be devastating during periodic upsurges in rodent numbers, with yields often reduced by 50% or more. It is being increasingly recognized, however, that continual chronic losses, which commonly occur over very large areas, are economically more significant (Buckle et al. 1985), resulting in yield losses in the range of 5 to 10% of national crops every year in many countries …

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Comparison Of Fumigant Gases Used For Rabbit Control In Great Britain, John Ross Mar 1986

Comparison Of Fumigant Gases Used For Rabbit Control In Great Britain, John Ross

Vertebrate Pest Conference Proceedings: 12th (1986)

The two most commonly used fumigant formulations, one generating hydrogen cyanide (HCN) and the other phosphine (PH3), were compared in paired field trials using the spoon-gassing technique. The two formulations were equally effective in reducing rabbit numbers seen in spotlight counts. The PH3 generating formulation was more convenient and slightly cheaper to use. Safety and humaneness aspects of the two formulations are discussed and alternative formulations (generating HCN and PH3) are considered. The potential usefulness (for rabbit control) of some other fumigant gases is briefly reviewed.

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Agriculture And Forestry Rodent Problems And Control In Italy, Luciano A. Santini Mar 1986

Agriculture And Forestry Rodent Problems And Control In Italy, Luciano A. Santini

Vertebrate Pest Conference Proceedings: 12th (1986)

Rodent pest problems and their control in Italy are reviewed. Two rats, Rattus norvegicus and Rattus rattus, and the field mouse, Apodemus sylvaticus, are often important pests both in rural and forestry areas. Other species, such as voles, Microtus arvalis and Microtus (Pitymys) savii, in orchards and in horticulture, and Sciurus vulgaris and Myoxus (Glis) glis in forestry, sometimes represent serious problems. For each species the kind of damage and control is recorded, and additional considerations are supplied to the public and private organizations responsible for rodent control.

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Laboratory Efficacy Studies With Strychnine Baits On Pigeons, Edward F. Schafer Jr., Mary L. Eschen Mar 1986

Laboratory Efficacy Studies With Strychnine Baits On Pigeons, Edward F. Schafer Jr., Mary L. Eschen

Vertebrate Pest Conference Proceedings: 12th (1986)

Pigeons held under a fall and spring photoperiod-temperature regime consumed a maximum of 16.9 to 21.4 kernels of whole corn per hour with an average ranging from 7.6 to 12.4 kernels per hour. Peak consumption occurred during the first and/or next to last hour of the day with a secondary, but smaller, peak around noon. Corn consumption ranged from 91 to 112 kernels/bird/day and approximated daily consumption equal to 10% of an average bird's mass.

The acute oral LD50 of strychnine alkaloid to pigeons was estimated to be 7.73 mg/kg (95% Confidence Interval of 6.75 to 8.85). The LD90 was …

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Rodent Control In East Africa, William R. Smythe Mar 1986

Rodent Control In East Africa, William R. Smythe

Vertebrate Pest Conference Proceedings: 12th (1986)

The nations of East Africa consist of Ethiopia, Somalia, Kenya, Uganda, Tanzania, Malawi, Mozambique and Zimbabwe. They encompass a widely varied topography, from coral strands to snow-capped mountains, rain forests to deserts, and tropical to temperate. In all these areas where soil and rainfall patterns permit, agricultural crops are grown. For the most part farming is of a subsistence nature being small single family plots. These farms make up to 90% of the farming in most of the East African nations. There are large farms in Kenya and Zimbabwe generally confined to the temperate uplands. Elsewhere there are large government …

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Trends Of Predator Losses Of Sheep And Lambs From 1940 Through 1985, Clair E. Terrill Mar 1986

Trends Of Predator Losses Of Sheep And Lambs From 1940 Through 1985, Clair E. Terrill

Vertebrate Pest Conference Proceedings: 12th (1986)

Mortality of sheep and lambs from all causes and from predator losses from 1940 through 1985 for the United States is presented including economic aspects. Lamb losses from all causes were 9% of the lamb crop in 1940 and were generally higher thereafter and reached a peak in 1978 of 14%. Losses of sheep 1 year old and older from all causes were 7.5% in 1940 remained somewhat higher through the '60s and then declined to a low of 5.2% in 1985. Calculation of predator losses were based on an upward trend of lamb losses relative to sheep losses with …

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An Economic Threshold Model For House Mouse Damage To Insulation, Robert M. Timm, Daryl D. Fisher Mar 1986

An Economic Threshold Model For House Mouse Damage To Insulation, Robert M. Timm, Daryl D. Fisher

Vertebrate Pest Conference Proceedings: 12th (1986)

Commensal rodents have become increasingly troublesome and damaging pests in insulated structures. Modern poultry and livestock confinement buildings in the Midwest often have insulated walls and ceilings. These buildings usually provide an optimum habitat for rats and mice; the rodents gnaw, tunnel through, and nest in the insulation, decreasing its insulative value. Such structures are known to be heavily damaged within a matter of months when commensal rodents have access to wall spaces and attics.

We have developed an economic threshold model to help livestock producers or building managers decide when to conduct house mouse (Mus musculus) control …

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Approaches To Coot Management In California, Valerie Van Way Mar 1986

Approaches To Coot Management In California, Valerie Van Way

Vertebrate Pest Conference Proceedings: 12th (1986)

Coot depredations have been documented in California since 1886, and shooting has been relied on as the principal means of mitigating damage. Immobilizing agents continue to offer promise as useful nonlethal tools for population reduction programs. Exploration of the use of tribromoethanol in coot capture is described, and the potential for other bird management techniques is discussed.

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Predator Damage Control: 1980 To 1986, Dale A. Wade Mar 1986

Predator Damage Control: 1980 To 1986, Dale A. Wade

Vertebrate Pest Conference Proceedings: 12th (1986)

This discussion is an update from Wade (1980) which summarized executive and other decisions relating to cancellation of the predacides in 1972. This review continues that summary of major events from January 1980 to the present. Major political factors, predator damage control, and research findings during this period are briefly discussed. A chronology of administrative and judicial decisions and related events is appended (Appendix A).

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