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1986

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Articles 61 - 90 of 104

Full-Text Articles in Environmental Health and Protection

Advances In The Integrated Control Of The European Rabbit In South Australia, John R. W. Burley Mar 1986

Advances In The Integrated Control Of The European Rabbit In South Australia, John R. W. Burley

Vertebrate Pest Conference Proceedings: 12th (1986)

In South Australia, success in control of the European rabbit has been based on an understanding of rabbit biology and behavior.

Drastic population reduction is obtained by use of Compound 1080. This method is much more effective when carried out during midsummer to late autumn. At this time, territorial boundaries are relaxed and the young have been weaned and are feeding aboveground. To ensure that the greatest number of rabbits can receive a lethal dose, it is necessary to pre-feed the population with un-poisoned bait over a period of 8 to 10 days. Oat grain has been chosen as the …


An Urban Roof Rat Control Program In Orange County, California, Gilbert L. Challet Mar 1986

An Urban Roof Rat Control Program In Orange County, California, Gilbert L. Challet

Vertebrate Pest Conference Proceedings: 12th (1986)

A program to control roof rats (Rattus rattus) has been conducted by the Orange County Vector Control District since 1975. Orange County is located in southern California just south of Los Angeles and is composed of 782 square miles of coastal foothills and alluvial plain with a population of 2 million. Urbanization takes up about one-half the total area and it is mainly a semi-desert situation with usually less than 15 inches of rain a year. However, because of the balmy temperature and imported water, vegetation grows rampant. Vegetation is used by the rats as harborage (Algerian ivy, …


Alternate Toxicants For The M-44 Sodium Cyanide Ejector, Guy Connolly, Richard J. Burns, Gary D. Simmons Mar 1986

Alternate Toxicants For The M-44 Sodium Cyanide Ejector, Guy Connolly, Richard J. Burns, Gary D. Simmons

Vertebrate Pest Conference Proceedings: 12th (1986)

The M-44 sodium cyanide (NaCN) ejector is an important tool for coyote damage control. For greatest effectiveness, the ejected NaCN mixture must be a dry powder. NaCN readily absorbs and reacts with moisture to cause solidification or "caking" in M-44 capsules. Because it is difficult to seal the capsules water tight, caking has been a chronic problem ever since NaCN ejectors were introduced over 40 years ago. The toxicity and caking properties of three alternate compounds are reported in this paper.

Comparative toxicity tests were made with M-44 ejectors containing NaCN, potassium cyanide (KCN), calcium cyanide (CaCN), and methomyl. Five …


The House Mouse In Poultry Operations: Pest Significance And A Novel Baiting Strategy For Its Control, Robert M. Corrigan, Ralph E. Williams Mar 1986

The House Mouse In Poultry Operations: Pest Significance And A Novel Baiting Strategy For Its Control, Robert M. Corrigan, Ralph E. Williams

Vertebrate Pest Conference Proceedings: 12th (1986)

Enclosed and insulated commercial poultry buildings provide ideal habitat for supporting unusually large populations of the house mouse (Mus musculus L.). Mice cause damage to various structural and operational components of poultry facilities; thus, they are of economic significance as well as general nuisances. Effective mouse control programs in poultry operations are often difficult, complicated, time consuming and inefficient due to various environmental and operational factors intrinsic to commercial poultry facilities. The significance of the house mouse as an economic pest in poultry operations is discussed via the results of a rodent control survey of 161 commercial poultry operations …


Closing Remarks For The 12th Vertebrate Pest Conference, A. Charles Crabb Mar 1986

Closing Remarks For The 12th Vertebrate Pest Conference, A. Charles Crabb

Vertebrate Pest Conference Proceedings: 12th (1986)

This concludes the 12th Vertebrate Pest Conference. Before going on with my closing remarks, I think we should acknowledge the excellent job done by all of our session chairpersons and speakers. On behalf of the Vertebrate Pest Council I want to thank you for your participation in the conference.


Population Dynamics And Expansion Rates Of Black-Tailed Prairie Dogs, Lyle A. Crosby, Randy Graham Mar 1986

Population Dynamics And Expansion Rates Of Black-Tailed Prairie Dogs, Lyle A. Crosby, Randy Graham

Vertebrate Pest Conference Proceedings: 12th (1986)

The purpose of this review is to describe population dynamics and annual rates of increase of black-tailed prairie dogs (Cynomys ludovicianus) and to determine annual expansion rates of uncontrolled populations. Their reproductive characteristics, including social behavior are examined as they relate to these factors.

In this analysis, the first step is to determine the average number of male and female prairie dogs of breeding age that are present at each burrow system before and after the reproductive cycle. From this determination the total number of prairie dogs is determined, based on the average density of active burrows for …


Pocket Gopher Damage To Conifers In Western Forests: A Historical And Current Perspective On The Problem And Its Control, Glenn A. Crouch Mar 1986

Pocket Gopher Damage To Conifers In Western Forests: A Historical And Current Perspective On The Problem And Its Control, Glenn A. Crouch

Vertebrate Pest Conference Proceedings: 12th (1986)

Pocket gophers (Thomomys spp.) damage or destroy regeneration on hundreds of thousands of acres of forestland in the western United States each year. Despite years of research, poisoning the offending animals—a technique developed around the turn of the century on agricultural land--is still the most prevalent practice for controlling damage on western forests.


Enterprise Budgets: A Tool For Vertebrate Pest Control Decision Making In Developing Countries, Daniel C. Evans Mar 1986

Enterprise Budgets: A Tool For Vertebrate Pest Control Decision Making In Developing Countries, Daniel C. Evans

Vertebrate Pest Conference Proceedings: 12th (1986)

Semi-subsistence farms that predominate in developing countries have more complex goals than the strict profit motives of corporate farms. Small farm management decisions are commonly based on a desire to increase production while avoiding risks and reducing labor demands and operating costs. Enterprise budgets are a valuable tool for understanding diverse farming systems and farmers' decision-making processes. The preparation of enterprise budgets documents production expenses, labor requirements, and specific activities related to pest control, as well as sources of supplies and technical information. By identifying what resources are commonly used and the relative importance of farm labor, the preparation of …


Potential Of Vegetation Management For Ground Squirrel Control, Wendy S. Fitzgerald, Rex E. Marsh Mar 1986

Potential Of Vegetation Management For Ground Squirrel Control, Wendy S. Fitzgerald, Rex E. Marsh

Vertebrate Pest Conference Proceedings: 12th (1986)

Manipulation or alteration of habitat vegetation is used frequently with integrated pest management of certain vertebrate pest species. However, it has been less than satisfactory with ground squirrel species in many situations. Special plantings of tall grasses and broadleaf species were experimentally explored in an effort to make levee habitat less suitable for the California ground squirrel in the Sacramento Valley. The experimental plantings failed to achieve that objective for a variety of apparent or suspected reasons and, in fact, in some grass plots the number of ground squirrels increased over what was present prior to planting. Other problems associated …


Biological Status Of Mountain Lions In California, E. Lee Fitzhugh, W. Paul Gorenzel Mar 1986

Biological Status Of Mountain Lions In California, E. Lee Fitzhugh, W. Paul Gorenzel

Vertebrate Pest Conference Proceedings: 12th (1986)

Mountain lions (Felis concolor) symbolize wilderness. The "wild west," a supreme predator, supreme quarry, destroyer of wildlife (game and nongame), livestock, and "trophy" hunting. They are the epitomy of controversy in California. In this paper we will review the history of management and present legal status of mountain lions in California, the political situation leading to the present status, and some of the biological factors that have been controversial, particularly relating to population status and trends.


Twelfth Vertebrate Pest Conference Frontmatter And Table Of Contents Mar 1986

Twelfth Vertebrate Pest Conference Frontmatter And Table Of Contents

Vertebrate Pest Conference Proceedings: 12th (1986)

Table of Contents


Recent Research On Red Squill As A Rodenticide, Anthony J. Verbiscar, Thomas F. Banagan, Howard Scott Gentry Mar 1986

Recent Research On Red Squill As A Rodenticide, Anthony J. Verbiscar, Thomas F. Banagan, Howard Scott Gentry

Vertebrate Pest Conference Proceedings: 12th (1986)

Red squill has been used in rodent control for several hundred years but in the United States its use has decreased since the 1950s. However, there is now a recognized need for rodenticides with different kinds of toxic activity. Red squill is being investigated as an acute rodenticide and an economic crop for the southwestern states. Clones from a prior USDA collection have been assayed by high-performance liquid chromatography and selections are being propagated in California and Arizona. The major toxicant, scilliroside, is relatively fast acting, causing convulsions and death to rats and mice. This glycoside is also strongly emetic …


Application Of A Benefit:Cost Model To Blackbird Damage Control In Wild Rice, W. Paul Gorenzel, Daniel B. Marcum, Terrell P. Salmon Mar 1986

Application Of A Benefit:Cost Model To Blackbird Damage Control In Wild Rice, W. Paul Gorenzel, Daniel B. Marcum, Terrell P. Salmon

Vertebrate Pest Conference Proceedings: 12th (1986)

From commercial fields near McArthur, California, we collected data on methods for controlling blackbird (Icteridae) damage to wild rice (Zizania aquatica). Using and expanding upon an economic model proposed by Dolbeer (1981), we derived economic comparisons of three control programs employing: 1. methiocarb, 2. shooting and propane exploders, and 3. all methods combined. Shooting and propane exploders used together were the most cost effective with a benefit:cost ratio of 2.16:1. Under the assumptions used in the model, methiocarb was least effective with a benefit:cost ratio of only 0.62:1. We discuss assumptions of the model and using basic initial …


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 …


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 …


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.


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 …


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 …


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.


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 …


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 …


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 …


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 …


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 …


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 …


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.


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.


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 …


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 …


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.