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Disease Incidence Of Demersal Finfishes From The Southern And Western Branches Of The Elizabeth River, Virginia, Randal D. Owen

Biological Sciences Theses & Dissertations

Fishes from the industrialized environs of the Elizabeth River, Virginia were surveyed for external evidence of disease during June through October 1984. A highly significant (p < 0.001) incidence of disease was found in demersal fishes collected by otter trawl from a site in the industrially contaminated Southern Branch compared to a less contaminated Western Branch site. Cataracts, fin erosion and dermal lesions were the most commonly occurring anomalies in the Southern Branch finfish.

Static, solid-phase toxicity tests employing sediment collected from the Southern Branch site resulted in an immediate toxic stress in the spot, Leiostomus xanthurus, which resulted in 100% mortality within 24 hours, compared with no mortalities in control systems. Spot exposed to control, i.e., pollution free, and diluted Southern Branch sediments innoculated with the pathogenic bacterial species, Vibrio anguillarium, developed significant (p ≤ 0.020) cases of fin erosion at a mean total bacterial community density …

Bird Problems In California Pistachio Production, A. Charles Crabb, Terrell P. Salmon, Rex E. Marsh

Vertebrate Pest Conference Proceedings: 12th (1986)

In 1984 studies were initiated to identify the bird species causing damage to pistachio nuts, quantify the losses, and explore possible methods for alleviating bird losses. The first year's field observations were made to identify and determine the level of activity of the various depredating bird species in the orchard. Field samples of nuts were collected to assess the levels of damage occurring in representative orchards. A mail survey of all commercial pistachio growers in California was conducted to determine which bird species growers believed were the cause of nut losses, the extent of damage they have experienced and what, …

Batproofing Structures With Birdnetting Checkvalves, Stephen C. Frantz

Vertebrate Pest Conference Proceedings: 12th (1986)

Denial of re-entry (batproofing) through structural modification is widely accepted as the most effective and ecologically sound method for eliminating commensal bats from structures. Such methods are clearly superior to lethal measures which have only questionable efficacy and may exacerbate bat/human interactions. However, since bats are able to enter small and obscure openings, conventional batproofing of all such openings is often not practical or economical. Further since this work must usually be done after bats have already begun roosting in a structure, the difficulty of high ladder work at night to seal exit holes can be discouraging to homeowners as …

Salmon Poisoning Disease: Research On A Potential Method Of Lethal Control For Coyotes, Jeffrey S. Green, Brad R. Leamaster, William J. Foreyt, Roger A. Woodruff

Vertebrate Pest Conference Proceedings: 12th (1986)

Salmon poisoning disease (SPD) was tested as a potential method of lethal control for coyotes (Canis latrans). Fresh fish containing the agents for SPD was fed to 72 captive adult coyotes. Coho (Oncorhunchus kisutch) and steel head salmon (Salmo gairdneri) from Oregon hatcheries were the principal species of fish used. Coyotes that ate the fish developed observable signs of SPD in a mean of 8 days. The overall rate of mortality was 50%, and death occurred in a mean of 20 days from consuming fish. Coyotes that died from SPD lost a mean of …

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 …

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 …

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 …

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 …

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 …

Rodent Problems Of The West Indies, John O. Williams

Vertebrate Pest Conference Proceedings: 12th (1986)

The commensal rodents as we know them are an introduced species into the West Indies. They came with the first explorers from Europe and the first slaves from Africa and were spread not only in the West Indies but North and South America as well. The first record of attempts at their control was in Barbados in the 1700s when two pence was paid for each rat caught. Active control has been going on in the islands since the 1960s and 1970s with only partial success. The Pan American Health Organization is now assisting many of the governments with their …

Conference Participants

Vertebrate Pest Conference Proceedings: 12th (1986)

The Conference totalled 372 registered attendees. The participants came from 31 states, the District of Columbia, and 13 other countries: Australia, Canada, China, Ethiopia, France, Israel, Italy, Japan, New Zealand, Nigeria, Trinidad, United Kingdom, and Zimbabwe. Students from Sudan and Taiwan were also in attendance. The wide representation from the United States and from countries throughout the world contributed to the success of the Conference by providing a highly diversified group for the exchange of ideas and information.

Opening Remarks—Twelfth Vertebrate Pest Conference, Terrell P. Salmon

Vertebrate Pest Conference Proceedings: 12th (1986)

On behalf of the Vertebrate Pest Council, welcome to the 12th Vertebrate Pest Conference. Every other year since 1962, the Vertebrate Pest Council has sponsored the conference with the primary objective of bringing individuals interested in vertebrate pest control together to discuss problems and solutions of mutual concern. The main objectives of the conference are:
1. To exchange information on vertebrate pest management and related matters.
2. To advance environmentally safe vertebrate pest management methodologies.
3. To build cooperation with public and private agencies in solving vertebrate pest problems.
4. To consider and promote discussion and interaction among agencies and …

The Economic Importance And Control Of Vertebrate Pests Of Graminaceous Crops With Particular Reference To Rice (Oryza Sativa) In Nigeria—A Review, Modupe Akande

Vertebrate Pest Conference Proceedings: 12th (1986)

Graminaceous crops, especially rice (Oryza sativa), have within the last years in Nigeria, surged to be of utmost economic importance, not in improving the economy but in depleting the country of fast foreign exchange. Attempts at improving and massively increasing the production and cultivation of rice (and other graminaceous crops) to meet the enormous demand have proved abortive. This is mainly a result of the ineffective control measures applied against destructive avian pests that sometimes reduce rice plantations to nothing. Much research is still needed to enhance better and effective control strategies.

Anticoagulant Translocation And Plant Residue Studies In Crops, Leonard R. Askham

Vertebrate Pest Conference Proceedings: 12th (1986)

Three types of assessment techniques explore the possible environmental hazards of two anticoagulant compounds currently used for rodent control. In the first, rheological methodologies were used to assess the ability of pelletized baits to withstand precipitation. From these data, objective information was developed to assist agricultural producers to select a proper bait for a specific climatic period. Bioanalytical evaluations of chlorophacinone indicated that the compound decomposes when exposed to ultraviolet light into four nontoxic elements. Hence, if translocation were to occur, the elements—-not the parent compound—-would be the likely candidates. Finally, radioactive (14C) braomdiolone was tested for translocatability. From the …

Eradication And Control Of Feral And Free-Ranging Dogs In The Galapagos Islands, Bruce D. Barnett

Vertebrate Pest Conference Proceedings: 12th (1986)

Islands are notorious for the ease with which the balance of their natural communities can be upset by the introduction of organisms from other areas. Introduced species can establish themselves quickly and successfully at the expense of native flora and fauna because the usual checks to their increase found in their home environments are often absent on islands. Many island organisms are ill-fitted to withstand predation by or competition with introduced organisms. A characteristic of some island species that increases their vulnerability to introduced predators is their relative "fearlessness". As Darwin (1845) prophetically wrote when describing the extraordinary tameness of …

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

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, …

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 …

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

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

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

Vertebrate Pest Conference Proceedings: 12th (1986)

Table of Contents

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

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

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.

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 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

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

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

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.