Environmental Health and Protection Commons^™

Water Quality Study Of Lake Mead, Dale A. Hoffman, Paul R. Tramutt, Frank C. Heller, Bureau Of Reclamation

Publications (WR)

This report presents Lake Mead Water quality data obtained from 1964 to 1966. The effect of filling Lake Powell on the water quality of Lake Mead is evaluated. General limnological principles and the present limnology of Lake Mead are discussed. Lake Mead has a warm monomictic annual temperature cycle characterized by summer stratification, fall overturn leading into a continuous circulation throughout the winter; temperatures never fall below 39 deg F (4 deg C). During stratification, lower dissolved oxygen values were recorded in the thermocline than in the epilimnion and hypolimnion. Mineral content increases from the upper to the lower end …

Closing Remarks - Third Vertebrate Pest Conference, Richard H. Dana

Proceedings of the 3rd Vertebrate Pest Conference (1967)

The record of this meeting will stand as a tribute to all of those who participated in the Third Vertebrate Pest Conference. It should remind them for years to come of their worthwhile contributions.

Proceedings: Third Vertebrate Pest Conference -- Frontmatter & Contents

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Sponsored by the California Vertebrate Pest Technical Committee

Maynard W. Cummings - Chairman

Richard H. Dana - Vice Chairman

Rex E. Marsh - Secretary-Treasurer

GENERAL CHAIRMAN OF CONFERENCE - Maynard W. Cummings, Assistant State Director, Agricultural Extension Service, University of California, Davis, California. VICE-CHAIRMAN OF CONFERENCE - Richard H. Dana, Vertebrate Pest Control Specialist, California Department of Agriculture, Sacramento, California. PROGRAM CHAIRMAN - Charles C. Siebe, Vertebrate Pest Control Specialist, California Department of Agriculture, Sacramento, California. PUBLICITY CHAIRMAN - Rex E. Marsh, Associate Specialist, Department of Animal Physiology, University of California, Davis, California. ARRANGEMENTS CHAIRMAN - Jerry P. Clark, Agricultural …

The Current Status Of Wild Animal Rabies In California, George L. Humphrey

Proceedings of the 3rd Vertebrate Pest Conference (1967)

During the 15-years 1952-1966, a total of 3504 cases of animal rabies were reported in California, an average of over 230 cases annually (Table 1). Of these 3504 cases, 2255 or nearly 65 percent were reported in wildlife species. An estimate sometimes used is that for every reported or recognized case of wild animal rabies, 10 cases probably occurred without recognition. Using the foregoing "rule-of-thumb", it can be hypothesized that during the 15-years 1952-1966, an estimated 22,600 or more cases of wildlife rabies occurred in California. The addition of the over 1200 cases of rabies reported in domestic animals during …

The Current Status Of Plague In California, Keith F. Murray

Proceedings of the 3rd Vertebrate Pest Conference (1967)

At the first Vertebrate Pest Control Conference in 1964, I traced the history of plague control in California and outlined a revised approach, based on newer concepts of plague ecology. In our state of relative ignorance, this required a number of unproved assumptions about plague occurrence in California that verged on crystal ball gazing. These were principally that (1) plague persists in relatively resistant rodent species in certain favorable locations, (2) ground squirrels and chipmunks experience periodic epizootics, but are not permanent reservoirs, (3) plague "foci" of the past were merely sites of conspicuous epizootics, they did not necessarily correspond …

Role Of The Agricultural Extension Service In Vertebrate Pest Control, Marvin D. Davis

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Frankly, I often wonder what our role is in vertebrate pest control. It seems to me that we in A.E.S, are frequently treading in the "twilight zone" of pest control. This is because of the wide diversity of problems which arise within an area such as I represent. I feel it is most significant that our county was invited to cover the role of A.E.S. in vertebrate pest control and discuss the tremendous variations and considerations necessary to serve an urban/semi-urban to rural county. Those of you familiar with San Mateo County readily recognize the potential problems due to population …

Winter Starling Control In Idaho, Nevada, And Oregon, Homer S. Ford

Proceedings of the 3rd Vertebrate Pest Conference (1967)

This paper is intended to bring you up-to-date on the progress of various winter starling control projects conducted by our Bureau on feedlots in Idaho, Nevada, and Oregon. This report briefly covers the field work accomplished since that reported by the late Mr. H. Nelson Elliott in his paper delivered to the second meeting of your conference held in Anaheim, California, in March 1964. Prior to the winter of 1960-61 we experienced a tremendous build-up of starling populations in feedlot situations throughout the Pacific Northwest. The expanding livestock feeding industry was receiving great economic losses from starlings eating livestock feed …

Measuring Bird Damage To Corn, John T. Linehan

Proceedings of the 3rd Vertebrate Pest Conference (1967)

When corn is damaged by birds, kernels are eaten or "milked" and the affected ears are left with fewer intact kernels. The resulting damage, or loss, can be expressed in terms of the number, weight, volume, or value of the kernels that were removed or pecked. Assessment of loss thus frequently entails measuring, counting, or estimating from evidence of kernels lost. Estimates of loss resulting from the activity of birds should express the difference in value between a crop grown under the conditions that prevail and the value under the hypothetical condition of no adverse bird activity. To offset the …

Control Of Nuisance Pests In Suburbia, Howard A. Merrill

Proceedings of the 3rd Vertebrate Pest Conference (1967)

To a rancher or high-rise apartment dweller, problems with vertebrate pests in suburbia may seem insignificant. But when one stops to consider that last year over 2 million acres of farmland were converted into urban and industrial use, then it takes a different perspective. Some mammals are protected—game animals and fur bearers are usually protected by Fish and Game Departments. Cottontail rabbits, deer, and tree squirrels are examples of game animals, and muskrats, foxes, badgers, and raccoons are examples of fur bearers. In California a number of birds and mammals have no protection; these are English sparrows, American or black-billed …

Aircraft As A Means Of Baiting Ground Squirrels, Rex E. Marsh

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Aircraft might soon become an important tool for baiting ground squirrels (Citellus beecheyi beecheyi and C. b. fisheri) on California rangeland. Until recently, almost all squirrel control has been conducted by the hand-baiting method, with grain bait scattered from horseback in spoon-size amounts near squirrel burrows. Ground squirrels are considered a major pest of rangeland in many parts of the West. They not only compete with livestock for forage but also are responsible for substantial losses to cereal and other crops. The magnitude of the problem is exemplified by the fact that, in California alone, over 6,000,000 gross acres of …

Good Practice In Vertebrate Pest Control, Philip J. Spear

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Good practice in pest control is a responsibility of several elements in our democratic, free-enterprise society. Most notably, these are: (1) the general public, (2) responsible government agencies and (3) industry. Before I comment about the responsibilities of each of these three groups, let me tell you about the work of structural pest control operators and their interests in vertebrate pest control. The pest control industry which I discussed in detail at the Second Vertebrate Pest Control Conference (1) continues to grow and expand its fields of activity. At the present time, it is our estimate (2) that 26,700 persons …

Review Of Animal Repellents, Jack F. Welch

Proceedings of the 3rd Vertebrate Pest Conference (1967)

A review of the literature on this subject reveals there is considerable confusion regarding the meaning of the word "repellent" as it relates to animal control. Some people make a liberal interpretation and include any material or device that will alter the pattern of activity of an animal through response to sight, sound, taste, odor, or touch. Although such an interpretation may be valid, for this paper I would like to confine my discussion to "chemical repellents" -- materials that, when applied to seeds, plants, or other materials being damaged by animals, will reduce depredation through taste, odor, or possibly …

Rats, Bombs, And Paradise - The Story At Eniwetok, William B. Jackson

Proceedings of the 3rd Vertebrate Pest Conference (1967)

At Eniwetok Atoll in the Marshall Islands, rats have been involved in an intriguing story. Polynesian rats were probably the only rodents present until after World War 11 when roof rats were brought in along with supplies and equipment for the atomic test program in the late 40's or early 50's. Some islets of the atoll, originally covered with coconut plantations, were denuded by heat, shock, and tidal waves following the detonation of devices. Initially radiation levels were high, but radioactive decay and dilution reduced the radiation hazard, and today the background radiation is well within the safe range. Many …

Animal Control - Progress, Problems And Professionalism, Robert M. Sutton Jr.

Proceedings of the 3rd Vertebrate Pest Conference (1967)

I want to take some liberty with my title as it is rather general. Specifically, I want to discuss some matters of mutual concern, and I will touch lightly upon our Division's activities and the status of our reorganization and redirection. In so doing, I do not propose to rehash the several talks that have been previously given and the papers written on what's new in animal control. Rather, I shall use this opportunity to examine a few problems that confront our Division, and in many cases, that confront everyone concerned with vertebrate pest control. We are now, in a …

Blackbird Behavior, Gordon W. Boudreau

Proceedings of the 3rd Vertebrate Pest Conference (1967)

A knowledge and understanding of a bird's habits and behavior patterns is prerequisite to any intelligent approach toward solving problems created by that species. This also applies to associated species commonly observed with it. Since my subject today is blackbirds I will confine my observations to species in this group, particularly red-winged blackbirds. The Red-Winged Blackbird, (Agelaius phoeniceus) is numerically and economically the most important. Several sub-species or races are recognized and in California the most important of these is the Bi-colored Blackbird, (A. p. californica). The ranges of subspecies commonly overlap, particularly in the Southeast, and field identification is …

Starling Control In Livestock Feeding Areas, Richard R. West, Jerome F. Besser, John W. Degrazio

Proceedings of the 3rd Vertebrate Pest Conference (1967)

The Denver Wildlife Research Center has been investigating methods to combat starling (Sturnus vulgaris) problems at livestock feeding areas since 1960. A variety of chemicals, baits, and methods of bait placement have been tested. This paper summarizes these investigations.

CHEMICALS TESTED About 500 chemicals have been screened for toxic and stupefacient effects on starlings. Although several chemicals have been found that immobilize starlings in the laboratory, they have been largely ineffective in the field; most starlings regurgitate the treated baits, and seldom have substantial numbers been affected. Of the toxicants screened, four compounds, TEPP, DRC-632, DRC-1327, and DRC-1339, have shown …

Opening Remarks - Third Vertebrate Pest Conference, Maynard W. Cummings

Proceedings of the 3rd Vertebrate Pest Conference (1967)

To open this Third Vertebrate Pest Conference is a real privilege. It is a pleasure to welcome all of you in attendance, and I know there are others who would like to be meeting with us, but, for one reason or another cannot be. However, we can serve them by taking back the results of discussion and by making available the printed transactions of what is said here. It has been the interest and demand for the proceedings of the two previous conferen- ces which, along with personal contacts many of you have with the sponsoring committee, have gauged the …

Problems In County-Wide Rodent Control Programming, Loring White

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Vertebrate pest control is recognized and sanctioned as a legitimate function of county government in California, not only by statute but also by a century of tradition. This is an anomaly. Ordinarily, regulatory agricultural pest control programs are part of our plant quarantine system, undertaken against newly introduced pests or those which are not of common occurrence. Programs against vertebrate pests, on the other hand, are carried on where the species involved are common, usually are abundant and often are indigenous. The reason for this lies buried in a bit of history that is very pertinent to my subject.

Epizootic Ecology In The Training Program Of The Vector-Borne Disease Section, Harold E. Stark

Proceedings of the 3rd Vertebrate Pest Conference (1967)

To fulfill the primary objective of the Vector-Borne Disease Section of NCDC to reduce the incidence of vector-borne diseases - a series of courses on vertebrates and arthropods and their role as reservoirs, vectors, and disease-causing agents is presented. Literature is prepared and a museum is maintained. One of these courses, Epizootic Ecology, illustrates some of the aspects dealt with in these courses. Definitions and concepts are presented followed by a brief review of principles of epidemiology and ecology. Specific examples constitute the bulk of the course. One of these, tularemia, is especially useful for the purposes of this course …

The Summer European Starling Problem In Tulare County, William R. Clark

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Summer starlings (Sturnus vulgaris) are known to have caused damage to the agricultural industry of Tulare County since 1960. At this time the first confirmed appreciable damage to grapes occurred. Since that year the threat has grown considerably as populations have increased. Annual monetary losses have fluctuated but damage has increased steadily and many losses are going unreported or unevaluated by the growers. Known total monetary losses in Tulare County have reached over $28,500.00 in a single summer and the unknown or unrealized losses would probably double this figure. The diversity of crops damaged has mounted steadily, as anticipated, and …

Winter Starling Control With Drc-1339, Paul E. Levingston

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Several years ago starling problems in cattle feed lots exploded to economic proportions. In 1964 one northern California feed lot operator reported a loss of $1,000 per day during the winter months. This resulted from daily activity of over a million starlings. Along with consuming and contaminating large amounts of cattle feed, the birds disturbed the cattle and prevented regular feeding habits. This reduced weight gains drastically. To combat what had become a state-wide problem, in 1962 a cooperative program between the California Department of Agriculture, the county agricultural commissioners, the United States Bureau of Sport Fisheries and Wildlife, and …

Blackbirds - Depredation, Research And Control In Ohio And The Midwest, Thomas M. Stockdale

Proceedings of the 3rd Vertebrate Pest Conference (1967)

The earliest settlers in Ohio and the Midwest suffered losses to birds. First it was animal losses to birds of prey, then crop losses to passenger pigeons. Today it is blackbirds! In 1900, F. E. L. Beal conducted an analysis of the digestive tracts of blackbirds collected in the Midwest and found that the preferred food in the summer months was soft seeds. A similar study which I conducted on redwinged blackbirds in 1959 showed that 90% of their diet was composed of soft seeds, primarily milk and dough stage corn during the late summer and early fall. Presently we …

The Status And Use Of Gophacide, Voit B. Richens

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Toxicants have been widely used for several decades to reduce numbers of problem animals. The utility of these substances, however, has been limited by hazards to other animals and man, inadequate effectiveness against the target species, and restrictions on use. The ecological complexity of most habitats in which animal control is undertaken requires utilization of new poisons that are less hazardous, more effective, and more specific. Gophacide1, Bayer 38819, 0_, 0-bis(p-chlorophenyl) acetimidoylphosphoramidothioate, is generally favorable in these respects. Tests with Gophacide were initiated at the Denver Wildlife Research Center in late 1961; and more recently, this chemical has also been …

Biotelemetry — Its Use In Vertebrate Control Studies, Wendell E. Dodge

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Accurate evaluation of rodent control techniques has always been a laborious undertaking. It generally involves tedious pre- and post-treatment censusing by trapping, marking, track counts, reduction of activity, etc., and results, at best, must necessarily contain a significant amount of speculation by the investigator. The biologist conducting such studies has been constantly harassed by uncontrollable parameters such as trap response, immigration, emigration, predation, disease, and many others. Thus, there has been a pressing need of a more definitive technique for evaluating rodent control trials. During the last decade, a new tool called biotelemetry has become available to the wildlife biologist. …

Rodent Problems On Private Forest Lands In Northwestern California, Jarrold B. Cone

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Rodents damage is important to forest management and is adequately described in the literature (Kverno, 1964; Hooven, 1958, 1959; Lawrence, 1958; Isaac, 1943; Kangur, 1954; Tevis, 1956a). It is not the intent of this paper to reiterate the types of damage or the rodents involved; the reader who is interested in this topic is particularly directed to the work of Lawrence, Kverno, and Hartwell (1361). This paper is concerned with the major forest rodent control efforts currently being employed in northwestern California. It will describe the background of literature and investigation from which present practices evolved, the implications that these …

Federal Wildlife Importation Regulations: The Why And Wherefore, Joseph P. Linduska

Proceedings of the 3rd Vertebrate Pest Conference (1967)

This is a hasty and in many ways superficial review of the motivations that started us in the business of importing new, strange, beautiful, and hopefully useful wildlife. It is a capsuled account of the high cost of ill-advised introductions and of near misses that were avoided thanks to a few individuals who viewed such transplants with skepticism and even alarm. And I have touched also on the highlights of the legislative base from which we now operate in efforts to safeguard agriculture and other values from ravages of exotic wildlife; wildlife that may succeed too well with us and …

Blackbird Damage Control With Chemical Frightening Agents, Paul P. Woronecki, Joseph L. Guarino, John W. De Grazio

Proceedings of the 3rd Vertebrate Pest Conference (1967)

Birds involved in damage or nuisance situations also have beneficial qualities, and most species are protected by State and Federal laws. Programs designed to alleviate bird problems, particularly those involving blackbirds, should first seek to discourage the birds from using problem areas and not to eliminate populations by direct reductional control. Habitat manipulation and mechanical frightening devices are useful techniques for discouraging bird activity, but certain chemical frightening agents have distinct advantages in some situations. We have found these agents particularly effective when used to control blackbird damage. Chemical frightening agents can be divided into two groups, the lethal and …

Biological Control Of Vertebrate Pests, Walter E. Howard

Proceedings of the 3rd Vertebrate Pest Conference (1967)

This paper briefly introduces the subject of vertebrate pest control, integrates and interprets some important ecological principles of control methodology, and intercalates these discussions with analysis of the biological backlashes and other ecological interactions that may be created whenever troublesome species of vertebrates are controlled by biological means. Insight in this area must be deepened if we are to fulfill our primary objective of learning how to manage a healthy environment in perpetuity. One important merit of biocontrol is that most people accept carefully planned ecological dislocations in nature more readily than they do the repugnant and hazardous aspects of …

Birds And Airports, Erwin W. Pearson

Proceedings of the 3rd Vertebrate Pest Conference (1967)

For all practical purposes, research in this country on the problem of bird hazards to aircraft began in 1960 with the crash of an Electra turboprop that carried 62 people to their deaths and was attributed to ingestion of starlings into the engines. In this paper I intend to review the problem and present some of the answers found by investigators in this country and, to lesser extent, abroad. The discussion will be roughly divided into two parts: 1) what: causes the problem, when, and where; and 2) what has been and is being done at airfields to reduce it. …

Population Control Of Herring Gulls By The Embryocide, Sudan Black*, David K. Wetherbee

Proceedings of the 3rd Vertebrate Pest Conference (1967)

The purpose of this experiment was to test the application of a biochemical method proposed to control the hatching of herring gull (Larus argentatus) eggs in a wild population. Sophistication was considered in terms of practicality, effectiveness, selectivity, economy, humaneness, remote application and hazards to and in the environment. The herring gull, which at the turn of the century was unknown as a breeding bird in northeastern United States, now nests abundantly along the Atlantic coast as far south as Virginia. Its phenomenal increase in numbers has resulted in conflicts with several human interests, including competition with other desirable nesting …