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Pocket gopher biology, behavior, damage, and control are discussed extensively in this paper, with emphasis on Thomomys spp. found in California and elsewhere in the western states. Habitat modification by use of herbicides to reduce forbs, which are preferred by gophers, has been demonstrated to be effective on Forest Service rangelands. Limitations of burrow flooding or burrow fumigation are discussed. Exclusion techniques are described as most useful in home and garden situations. Gopher control is most effectively done by poisoning and/or trapping, both of which are discussed in detail, as are types of traps commonly used. Effective poisons are Compound 1080 and strychnine, if correctly formulated and applied. The recently developed mechanical gopher bait applicator implement, the burrow-builder, is discussed. Pertinent references are provided.

Biology, damage, management, and control of rabbits (genus Sylvilagus) and hares (genus Lepus) in California are described. This paper places emphasis on control of the common jackrabbit, Lepus californicus, as it is the most significant of the rabbit and hare species in California and the western states in terms of damage and the need for control. Exclusion methods are discussed, including rabbit-proof fences as well as individual plant and tree protectors. A summary of repellents used against hares and rabbits is provided, as well as precautions for their use. They typically provide only temporary effectiveness. A recipe for a strychnine-based poison wash for trees, which has found to be of use as a repellent, is provided. Use of toxic baits to control rabbits and hares is described, with appropriate precautions. Bait formulation and application are discussed in some detail, with use of strychnine as the active ingredient. Recipes are provided for formulating both prebait and toxic baits; the primary ingredient can be barley, oats, root vegetables (carrot, sweet potato, or parsnip), fruit (green pears or cull apples), dry alfalfa leaves, or grain heads using barley or milo.

This paper focuses on managing wildlife damage in forest environments, with emphasis on the use of vertebrate pesticides in the western United States. Types of forest damage caused by vertebrates fall into the categories of seed destruction, foliage clipping and browsing, and root and bark injuries. Consumption of natural seedfall or following direct-seeding applications for reforestation varies with tree species as well as with vertebrate seed predators, which include both rodents and birds. With Douglas-fir, deer mice (Peromyscus spp.) are cause the greatest losses. For Ponderosa pine, deer mice, chipmunks, and ground squirrels are primarily responsible for seed loss. Seeding in black walnut is primarily impacted by gray squirrels and the eastern fox squirrel. Success with rodenticide treatments in advance of seed applications were only effective for short periods, as rodent populations rebounded quickly. Current efforts are relying on various seed coatings that provide greater efficacy. Clipping by small rodents is a particular problem with newly emerged seedlings; existing seedlings are also damaged by snowshoe hares and mountain beaver in the Pacific Coast states. Contact repellents have been effective but may need to be re-applied periodically. Browsing damage to existing conifer stands is caused primarily by deer and elk, and there is no general solution for this problem. Root injury to seedling and small saplings is most frequently caused by pocket gophers. A variety of animals may cause bark injuries: meadow mice (Microtus spp.) can seriously damage seedlings, while bark damage to both young and also mature trees can be caused by porcupine, woodrats, rabbits, squirrels, and pocket gophers. Bear damage to bark is usually seen on mature trees. Seed treatment formulations using endrin as the active ingredient are described, as are a foliar repellent treatment using TMTD, and the manufacture and use of salt blocks containing strychnine for porcupine control. Pertinent literature citations are provided.

This paper updates a 1964 review of vertebrate pest problems and control techniques used in the Republic of South Africa. Appreciable progress has occurred within the past few years, with assistance provided by the U.S. Fish and Wildlife Service. Methods for controlling damage caused by the major predators, the black-backed jackal and the Cape baboon, are described. For jackals, useful techniques include hunting with packs of hounds, use of traps, and use of toxicants, including the coyote getter. Successful lures to attract jackals to coyote getters are described. Baboons, which are gregarious and form troops numbering from a dozen to over 100 individuals, cause extensive damage to vineyards, orchards, and vegetable crops, and at times kill lambs and young goats. Destruction of the baboon’s major predator, the leopard, is blamed for recent rapid increases in baboon populations. Successful use of the toxicants thallium sulphate, Compound 1080, and Telodrin against baboons are described. Damage and control practices associated with the dassie (hyrax) and dune mole are discussed. Introduced American gray squirrels, while limited in distribution, are known to have become firmly established and are a major predator of the nests of songbirds, as well as damaging pine plantations and orchards. Feeding habits of the cape vulture, which normally eats carrion, have changed and these birds are now periodically killing lamb and ewes, especially those in poor condition, perhaps due to food scarcity.

This paper provides an in-depth understanding of the concept of biological control (biocontrol). In doing so, it interprets important biological principles of control methodology, and it intercalates these discussions with analysis of the biological backlashes and other ecological interactions that may be created whenever vertebrate “pests” are control by biological means. The concept “balance of nature” is explained, noting that only in the most remote area is human impact on the environment not present. The term “biological control” is defined as an attempt to reduce the population density of a pest species (e.g., increase mortality, reduce natality, or cause significant emigration) either by increasing predation, changing habitat conditions, introducing or stimulating epizootics, or by use of antifertility agents. The dynamics of vertebrate population are examined in detail. Detail discussion in provided on predators (both native and introduced), habitat modification, diseases, and chemosterilants, in regard to both mammals and birds. The greatest likelihood for effective application of biological control of existing pestiferous vertebrate populations is by means of integrated control (i.e., where biological control is done concomitantly with an initial population reduction by some conventional control method). An extensive literature review is provided.

This paper provides a detailed analysis of bird damage assessments to detect crop loss in corn. Measurement criteria, methods of loss calculation, and rate of sampling are discussed. In planning a strategy to measure crop loss, one needs to take into account distribution of damage as well as variation in measurement.

Capitalizing on research directed toward oral contraceptives for humans, a wide variety of compounds are now under study for their practical value in inhibiting rodent reproduction to suppress detrimental populations. This paper discusses the specifications of ideal rodent chemosterilants and the advantages of chemosterilants over other methods of control and compares the potential values of chemosterilants acting on females, males, and both sexes. Specific situations are detailed where chemosterilants will be most valuable in rodent control, together with proposed methods of application. Chemosterilants are not expected to become a panacea for control, but since they are based on sound biological principles they should be a safe and effective approach to regulation of rodent populations.

Poison baits are extensively used for commensal rodent control; considerable folklore exists regarding the use of additives to induce rodents to come to and eat poison baits. This paper describes a rational evaluation of attractants and the influence of different odours in inducing Rattus norvegicus to feed at given locations. The influence of certain repellents was also examined. Tests consisted of attempts to induce rats to feed at non-preferred sites or to repel them from preferred sites. Place preference was the dominant factor in feeding by rats, and odours failed to Influence feeding activity significantly.

While the problem of anticoagulant resistance in commensal rodents has been well-documented from certain areas of northern Europe in recent years, this paper describes its first known occurrence in North America in 1971. Over a rural area of about 5 square miles in Johnson County, North Carolina, it was noted that attempts to control Norway rats using typical warfarin rodenticide bait were increasingly ineffective. Diphacinone was alternated with warfarin with no success. On one farm, 200 lbs of bait had been used in bait boxes in a single month. Laboratory trials on rats captured at this location demonstrated resistance. It was concluded that at this location, intensive use of anticoagulants (mostly warfarin) over a decade, in the absence of adequate sanitation and building maintenance, provided the selective agent to develop resistant populations. This likely will be repeated elsewhere in the U.S.

Federal Urban Rat Control Program grants were awarded to cities in different areas of the United States. Severe problems of rat infestations have been detected in many of the cities by the Environmental Health Service. Approximately 20% of 3.8 million people in the project areas were occupying homes infested with rats. Control operations are now in effect in all cities, and the living conditions of the people have been substantially improved. An increase in interest in rodent control also is evident in countries outside of the United States. The Technical Development Laboratories of the National Communicable Disease Center are participating in the World Health Organization program of research on new rodenticides. The evaluation program involves five steps which carry a candidate toxicant from laboratory phase through field testing. Acceptability and suitable concentrations of both acute and accumulative rodenticides are determined. Observations are made on the hazard of the compound to pets and to other nontarget vertebrates. Laboratory and field studies have been completed on a new, promising stabilized scilliroside glycoside which has given excellent control of the Norway rat in 16 out of 19 premises. Another new coded compound has shown a unique specificity for roof rats as compared to Norway rats. Although anticoagulant resistant rat populations have occurred in several countries in Europe, as yet no evidence has been noted of such resistance in rats in the United States. (Note: This paper was originally presented at the 4th Vertebrate Pest Conference in 1970.)

This paper is submitted in an effort to acquaint the personnel of allied State agencies with related laws which control the public and private possession of live exotic and native wild animals. The need for this common knowledge of related laws by agencies with law enforcement responsibility is readily apparent when the annual number and related problems from imported or resident wild animals in California are examined. In addition to resident wild animal populations, millions of fish and thousands of mammals, birds, and reptiles enter California each year through the utilization of most methods of transportation. Most of these imported animals are exotic species from foreign lands which cannot be readily identified and pose various degrees of potential and actual threat to native wildlife, agriculture, and public health if they are introduced into the wilds of this State. For the purpose of this report, a general picture of imported exotic animals is presented in an introduction, and specific animals with related laws are treated individually under the headings of current laws and future regulations.

Taste enhancers and olfactory attractants are needed to improve bait acceptance for rodent control, but most methods for evaluating preference for taste and odor stimuli are not suitable for screening large numbers of such compounds. This paper describes two automated preference testers designed for this purpose. The taste preference apparatus is based on the principle of the brief-exposure, foods-together technique, whereby the animal briefly samples each food alone, in alternate sequence, before the two foods are presented together, in alternate positions. The odor preference tester is based on an open-field maze, whereby the test animal samples each of four odor sources before preference behavior is recorded. Both devices are fully automated (in both operation and data recording), are free of position bias, and produce preference determinations in relatively little time; neither requires special training of test animals. The design, operation, and application of each apparatus in rodent control is discussed and illustrated.

Development of predictive formulae or qualitative statements about the probable outcome of control campaigns entails knowledge of bait quality and distribution, behaviour, vagaries of weather at the time of the control campaign, and other factors which govern the probability that the target animals will accept bait. This paper collates experience in recognising, estimating and using some of these variables for predicting the outcome of large-scale poisoning, and discusses possible approaches to the solution of some hard-core problems.

Measurement of palatability and rodent acceptance of oral baits is a controversial subject. Particularly with anticoagulants, effectiveness requires the bait be consumed by the target species, and this is of increasing interest to the industry as well as to regulatory agencies. This paper explores the role of sex of the test animal, the significance of difference between assay methods, and the number of observations during an assay. Factors affecting bait palatability are discussed, including the toxicant, formulation and mixing methods, and shelf life.

The results of testing dry anticoagulant baits at the Animal Biology Laboratory are evaluated in this paper. Overall, 14,940 rats were committed to these tests resulting in a mortality rate of 91.8 percent. The five chemicals tested and their mean mortality per test are: Diphacinone (93.5 percent), Pival (87.5 percent), Warfarin (93.9 percent), Prolin (91.2 percent), and Fumarin (92.8 percent). The data indicates that 77.4 percent of the tests conducted resulted in a mortality of 90 percent or greater, but only 11.9 percent of them resulted in acceptance of 33 percent or greater and mortality of 90 percent or greater.

The paper reviews social interactions in small rodents in which pheromones have been reported to play a part. Some of the chemical messengers involved may have a potential use in control of rodent pests. Research in this field should be encouraged, because alternatives to the current control methods are highly desirable.

Pocket gophers (Thomomys talpoides) in environmental systems adapted readily to laboratory conditions. The laboratory equipment is described in this paper. Results are reported, including data on food consumption as it varies with the activity patterns of the gopher and the variation between individual gophers. One gopher used an average of 52 g of food per day for a 131-day period, but during an extremely active 17-day period, the gopher consumed approximately its own weight in food each day (75 g). The experimental setup is described for food location experiments and results indicate that gophers locate their food primarily by odor. Test animals react very quickly (in seconds or minutes) to odor stimuli if the gopher's food cache is depleted and the animal is hungry.

The manner in which an experiment is conducted determines the inferences that can be made from the results of the analysis of the experiment. This paper emphasizes the critical need in pest-damage control (PDC) experiments for a detailed planning process (i.e., the design of experiments) by exampling improper designs that prohibit a researcher from making valid inferences about his hypotheses of interest. Emphasis is placed on identification of experimental units, determination of restrictions on the randomization procedure, and specification of treatment forms of pest control materials. A list of some specific actions to strengthen PDC experiments is given.

A review of the literature reveals that over 60 chemicals have been used for the capture of wild animals, but only 30 of the most widely used chemicals are discussed in the present paper. For practical considerations these chemicals can be classified as being either (1) neuromuscular blocking agents, or (2) central nervous system (CNS) depressants. Some common neuromuscular blocking agents are d-tubocurarine, gallamine, succinylcholine, and nicotine. M99 and its derivatives, phencyclidine, and xylazine are some of the more commonly used CNS depressants. Neuromuscular blocking agents have a relatively rapid onset and short duration of action but they do not possess sedative, analgesic, or anesthetic properties. CNS depressants do produce desirable sedative, analgesic, and anesthetic effects, and frequently a combination of CNS depressants results in more desirable immobilization characteristics.

The University of California, Davis, starling research program was broadened in 1976 to encompass agricultural pest birds in general. Under new direction there were a number of applied problems studied. The effects of feeding cattle only between 1600 hours and 0800 hours on cattle weight gain was studied with results indicating slower weight gains and lower meat quality when compared to cattle fed ad lib. Feed component selection by starlings (Sturnus vulgaris) was also studied finding that a starling selected diet contains a higher percentage of the high protein components than present in a commercially prepared dairy feed ration fed to them. References are given to papers on a damage assessment technique for grapes, a field test of methiocarb as an avian repellent to protect figs, and a field test using Avitrol treated seed to control house finches (Carpodacus mexicanus). An overview of continuing research activities and a status report on the bird damage specialist position is discussed.

In addition to welcoming Conference participants, the author expresses his philosophy of the need for vertebrate pest control activities. Too few people understand that a highly stable animal-plant-soil equilibrium exists where man has not markedly altered the environment. In temperate regions, the balance of nature in natural habitats is little affected even when a large number of individuals of any one or several species of vertebrates are removed by man. The naturally evolved species that are present have acquired great resilience to offset various climatic and other catastrophes. In contrast, the type of habitat modification done by homeowners, farmers, and the like nearly always causes some vertebrates to become pests. Some conservationists, through protectionist zeal founded on ignorance of the population dynamics of vertebrates in altered environments, indirectly force many farmers to practice an undesirable form of biological control of vertebrate pests--clean farming. The farmers cannot afford to keep hedge rows and riparian vegetation because they will foster serious pest problems unless some other control is practiced. At this Conference the speakers will illustrate how they are seeking the most ecologically desirable protection of mankind's food, fiber, and other resources, including wildlife in general. All of the papers will shed light on the role that vertebrate pest control is playing in managing modified environments in perpetuity in a healthy manner.

Tests were conducted using 0.05% warfarin baits which were put into polietilinized paper bags with corn oil as attractants, in order to control cotton rats (Sigmodon hispidus major) through-out 4,000 ha. of crops in the Sinaloa State. Both the effectiveness of the warfarin bait and the security and efficiency of the handling of the polietilinized paper bags was demonstrated. Furthermore, the tests showed that there were economic advantages in using the warfarin baits instead of the zinc phosphide baits; to the extent of a 46.67% saving in the control expenses.

Since VACOR® was first introduced to the market as a fast-acting rodenticide in 1975, it has been sold successfully throughout the United States. The VACOR line is sold over-the-counter as a ready-to-use bait for rats and mice. The DLP-787™ rodenticide line was introduced to the market for sale to professional users only. This line includes both bait and mouse tracking products. It has been well accepted by professional users even though DLP-787 is offered only as ready-to-use products. New products of the same type will be available for commercial introduction in 1978. This paper discusses the successful market entry of VACOR and DLP-787, their field use against commensal rodents, and the new products now on the horizon.

This paper describes the development of a biological technique that successfully controls conifer seed damage by the deer mouse. Eleven experiments have been conducted on three study areas at the University of British Columbia Research Forest, Maple Ridge, B.C. Populations of deer mice have been monitored in all experiments with data from 56,000 trap nights. The technique involves a mixture of conifer seed (Douglas fir) with sunflower seed and oats which is uniformly distributed on logged areas in the late winter-early spring. Survival of conifer seed with these alternate foods was excellent, compared with control Douglas fir by itself, for an 8-week period during this time of year. Populations of seed-eating birds and chipmunks are not present on clearcut areas from late October to early April. In addition, deer mice are at their lowest density during the spring. Thus, the use of alternate foods with Douglas fir seed in a direct-seeding operation at the appropriate time of year will result in successful regeneration of cutover forest lands.

This paper examines and evaluates the use of strychnine baits and cyanide guns for coyote (Canis latrans) control by livestock producers in Alberta. Livestock predation occurred almost exclusively during spring, summer, and fall; livestock predation was negligible during winter. In contrast, use of toxicants was negligible in spring, distributed rather evenly through the summer and fall, and most intense in mid-winter. Forty-eight percent of the producers set toxicants in response to predation, and 1/2 of these apparently resolved their predator problems. Fifty-five percent of the producers set toxicants for preventive control, predominantly during October-February when the effectiveness of control was probably negligible or at least minimal. Overall, the program may be less than 30% effective. The producer-training program must be re-examined in an effort to make coyote control more effective. Preventative control with toxicants, where necessary, should be conducted immediately prior to the whelping season or no more than a month in advance of anticipated livestock losses. Changes in livestock management must be emphasized.

Thirteen-lined ground squirrels (Spermophilus tridecemlineatus) and other small rodents damage corn (Zea mays) stands by digging and consuming planted seeds and young seedlings, particularly in reduced-tillage fields. The use of reduced-tillage systems such as ecofarming provides greater dryland crop yields, conserves moisture, reduces soil erosion, and provides suitable habitat for ground-nesting birds. The habitat available in these fields also allows various species of rodents to thrive. Reduced-tillage farming is expected to increase markedly in the years ahead; thus, rodent problems will increase as well. Seed repellents offer a promising and cost-effective method of controlling rodent damage to planted corn in some areas. This paper reviews repellents for this use and describes repellency studies currently in progress with the compounds methiocarb [3,5-dimethyl-4-(methylthio) phenol methylcarbamate] and thiram (tetramethylthiuram disulfide).

Reducing a pigeon population to a tolerable or minimal impact level is a subject about which one can find much antiquated and impractical information. Most technical literature reports on the biology of pigeons and associated disease factors. The intention of this paper is to describe the practical application of large-scale pigeon population reduction programs that have been at least 90% effective in 45 out of 46 cases over the past four years. Human relations, exclusion, trapping, toxic perches and Avitrol are discussed.

This paper updates control operations in Modoc County, in northeastern California, for the Oregon or Belding ground squirrel, Spermophilus beldingi oregonus. With the increase of sprinkler irrigation and continual improvement in farming methods, we are giving the ground squirrel a better environment: the squirrels have more food and moisture, and their juvenile survival rate appears to have continued to increase. As in earlier years, we still have problems with bait-shyness or poor bait acceptance. It is now virtually impossible to obtain adequate acceptance of grain baits, forcing us to use “green” baits. Dandelion is the bait that is best accepted by the squirrel, but it is hard to obtain at the right time and in sufficient quantities. Cabbage is the next best green bait, and it is practical and economical to use. In 1972, we started treating fields using 1080-treated cabbage, and treatments resulted in 95% to 99% squirrel control. For efficiency, aircraft broadcasting has become the common method of application. This baiting program is quite effective, but it is not the cure-all. We still have several unresolved problems. We have fields in which squirrel control is so effective we can skip two or three years before retreating; however, other fields must be treated annually. In some cases, squirrels move in from nearby areas. Some problems with bait acceptance continue.

The ecology of plague relies on the intermixing (commingling) of animal hosts and their ectoparasites. There has been a noticeable increase in commingling of rats and ground squirrels in Southern California in recent years. This paper discusses this phenomenon in Los Angeles and Orange Counties, where it occurs, how it results from man's activities, and the ecology of varying locations. The role of fleas as vectors of plague and the intermixing of fleas between hosts are discussed. Action to reduce the incidence of commingling and the threat of plague to the urban society is addressed.

Damage to homes and buildings caused by woodpeckers is a widespread and locally severe problem in vertebrate pest control. This paper describes the distribution, characteristics, and impacts of woodpecker damage as determined by questionnaires, interviews, and published accounts. Woodpecker damage results from territorial behavior, feeding, or nesting activity. Some plywood and cedar are especially vulnerable. Average loss per incident is about $300, although some cases result in much greater losses. Disturbance and aggravation are also important factors. Abatement measures include scare devices, structural modification, chemical treatment of the siding, and shooting or trapping (with a permit). Success is variable. Recommendations to reduce the problem include a public awareness program, continued abatement research, a change in plywood production or installation procedures, and a reduction in the effort required to obtain a permit for lethal control.

Compound 1080 (sodium monofluoroacetate) is a uniquely selective predacide for controlling coyotes, compared to other predacides. In addition to discussing the biological aspects of 1080, the reasons for the current emotional-political status of 1080 are also reviewed because the biological rationale concerning 1080 has been largely determined by a conspiracy orchestrated in 1972 by an individual of the Council on Environmental Quality but assisted by others from the U.S. Department of the Interior and the Environmental Protection Agency. Many of the distortions about 1080 can also be traced to environmental organizations which still use 1080 as an issue which they can be "anti" in order to solicit funds from the public. This paper is an attempt to clarify the true biological facts about 1080 and to expose the political conspiracies against 1080 by government and environmental organizations.

This paper reports on work carried out in a variety of sites and installations that have required active gull control. The methods used are a result of observations by a variety of researchers and attest to the effectiveness of a behavioral control technique with the use of thin steel spring wire or monofilament fishing line.

This paper reviews toxicological research involving fluorocitrate, the toxic metabolite of sodium monofluoroacetate (fluoroacetate), which is the active ingredient in the pesticide Compound 1080. Many toxicological studies have been done with fluoroacetate and the results obtained are actually due to the fluorocitrate because it has been definitely proved that, from a biochemical perspective, fluoroacetate is not toxic but fluorocitrate is. The classical explanation of the toxic action of fluorocitrate is that it inhibits the enzyme aconitase in the tricarboxylic acid cycle. Deactivation of aconitase results in decreased energy production by cells and ultimately death of the organism. However, the more recent explanation of fluorocitrate's mode of action is that it binds with mitochondrial protein which prevents transport of citrate and its utilization by cells for energy production. Metabolism studies indicate that only small amounts, perhaps less than 3%, of fluorocitrate is formed from fluoroacetate. From the limited number of acute and chronic studies conducted with fluorocitrate it does not appear to be as potent as fluoroacetate by either the oral or parenteral routes of administration. This decreased level of toxicity is thought to be due to the larger molecular weight of fluorocitrate which would not be as readily absorbed by tissues. Central nervous system toxic manifestations (i.e., tremors, convulsions) are characteristic in many animals poisoned with fluoroacetate. Fluorocitrate administered directly into the brain was found to be 100 times more toxic than fluoroacetate. The accumulation of citrate in organs is characteristic of fluorocitrate poisoning; from a quantitative point of view the liver is less affected than the brain, heart, kidney, or spleen. Fluorocitrate causes extensive kidney damage, but the testes are most sensitive to sublethal doses. Testicular damage may be either reversible or irreversible, depending upon the dose. Several plants have the ability to metabolize both fluoroacetate and fluorocitrate from either inorganic or atmospheric fluoride.

It is said that there are 400 species of mammals in China and 150 species of them are rodents, of which 25-30 species of rodents are usually considered serious pests. Large amounts of grassland, forests, and agricultural crops are destroyed or seriously damaged every year. There is no accurate estimation of the total loss. The first acute rodenticides used for rodent control were white arsenic and yellow phosphorus. These have now been replaced by more suitable chemicals. Acute rodenticides have had a relatively long history of use in China and have played a very important role in rodent pest control. But, at the moment, some of them are becoming a subject of heated dispute and the target of public criticism. Therefore, people follow with interest the development of debate and pay close attention to the future and destiny of acute rodenticides. In this paper, I briefly look back at the history of acute rodenticides used in China and evaluate their achievements and errors.

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 to eight pen tests on coyotes or dogs were conducted with each compound. NaCN was tested on both coyotes and dogs. Except for one coyote that survived a dose of CaCN, each test animal died after pulling an M-44 and receiving a full charge of ejected toxicant. Average lapsed times from pull to first observed symptoms were 31 seconds for NaCN, 34 seconds for KCN, 63 seconds for CaCN, and 2 minutes for methomyl. Both NaCN and methomyl were lethal in all pen tests, yet coyote recovery rates (carcasses found/coyote pulls) in the field were 80% for NaCN and only 24% for methomyl. This difference was attributed to the faster action of NaCN. KCN and CaCN were not field-tested, but results from captive coyotes indicate that KCN would be about as effective as NaCN and CaCN would be less effective. None of the three alternate compounds offers enough advantage over NaCN to warrant the expense of registration, since NaCN is already registered.

"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 muskrats (Ondatra zibethica (L.)), which were introduced or escaped into the Sacramento Valley--hence locally feral--are the state's number one furbearer. Except for these species, the other feral mammals are, for the most part, much less desirable.

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 and develop effective surveillance and control measures against plague in a north-central New Mexico plague focus.

Plagues of the house mouse (Mus musculus) occur at irregular intervals throughout the agricultural regions of south-eastern Australia. This paper discusses these phenomena in terms of their impact on agricultural production, previous attempts to reduce damage and levels of infestation, and associated environmental implications. Consideration is also given to the accurate prediction of mouse plagues and the control strategies which need to be in place if effective management is to become a reality.

We are living in a day of change. Environmental awareness is a part of our everyday life in a way unprecedented in history. The courts, in their infinite wisdom, have initiated the joint and several liability (deep pocket) rules that make everyone at risk in almost all situations. Bird management programs, by their very nature, are extremely sensitive. Any project, if not evaluated, planned, carried out, and documented properly can result in adverse regulatory agency action, bad publicity, and even fines or lawsuits. Proper photographic documentation can play a vital part in helping to provide the necessary records to help prevent problems and/or defend yourself in case of lawsuit or regulatory action. In the preparation of this paper, we surveyed state pesticide lead agencies, state Department of Conservation (Fish and Wildlife) agencies, some U.S. Fish and Wildlife Law Enforcement personnel, and several individuals to get their reaction to and their comments about this concept of supplemental recordkeeping. Of those responding, a majority thought the concept of supplemental photographic recordkeeping would be an asset to individuals and organizations conducting bird management projects.

Assessments of the palatability of rodenticide baits are usually conducted in the laboratory but little is known of the value of such tests as determinants of the potential performance of formulations in the field. Field bait acceptance tests conducted earlier were either unduly time-consuming or failed to take account of aspects of rodent behavior in relation to baiting regimes which make the interpretation of results difficult. This paper describes a novel, cost effective technique for assessing the palatability of baits in the field and the use of the new method to compare the acceptance of three commercial formulations, containing either difenacoum or brodifacoum, with that of an EPA approved challenge diet. No statistically significant differences were found in the acceptance of the three baits and the challenge diet at three farmsteads harboring infestations of Rattus norvegicus. Similar results were obtained in equivalent laboratory choice tests conducted following an established protocol. A comparison of results from the two environments bestows confidence both in the practical value of the laboratory test method and in the likely performance of the baits when used for rodent control operations. Wider possible uses of the field test methodology are discussed.

This paper summarizes Animal Damage Control (ADC) program records relating to M-44 use during Fiscal Years 1976-86. During these years, M-44s were used in 14 western states to take 103,255 animals, including 92,843 coyotes, 5,544 other target canids, and 4,868 nontarget animals. More animals were taken in Texas than in all other states combined. Program-wide during FY 1977-81, M-44 effort averaged approximately 5,600 unit years annually and 1.2 target animals were recovered per M-44 year. M-44s accounted for 12.3 percent of all coyotes taken by the ADC program during FY 1976-86. The coyote take by M-44s doubled from FY 1981 through 1986. In FY 1986, more coyotes were taken by M-44s than by any other method in Texas, New Mexico, and Nebraska. Program-wide in that year, aerial hunting ranked first, the leghold trap second, and the M-44 third in numbers of coyotes taken. The M-44 has increased in importance since its reregistration in 1971, but the coyote lake by M-44 has not approached the peak reached in 1971.

In this paper I present a discussion of current Environmental Protection Agency (EPA) policy on ensuring compliance with the Good Laboratory Practice (GLP) regulations as applied to health effects studies submitted to the EPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The EPA has recently proposed extending these regulations to essentially all studies submitted to the Office of Pesticide Programs (OPP) in support of a request for a new registration or in response to data requirements issued under Section 3(c) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The potential impact of these proposed regulations as they may apply to vertebrate pesticide efficacy testing is presented and discussed.

The pesticide controversy is much more complicated than simply a disagreement over facts and risk estimates between the "experts" and the "fearful." It is a battle over ideology as much as one over information. This paper discusses the notion of "educating the public" about pesticides, establishing realistic expectations of efforts by industry and academia, and notes some of the limitations, and potential involvement, of scientists as "translators" in dealing with this controversy.

A survey of Extension Wildlife Specialists in the U.S. provided a basis for estimating the magnitude of urban wildlife damage and control in this country. Response to the 9-question mail questionnaire was good (76 percent) following the single mailing to all Extension Wildlife Specialists or people in similar positions listed in the national directory. The majority of questions were answered based upon the experiences and best estimates of these specialists for the interval October 1986-September 1987. Specialists had difficulty providing estimates of damage and costs of prevention and control; 57 percent were not able to provide any data on these topics. Several of the questions dealt with attitudes of people requesting urban wildlife information and/or assistance and wide ranges of responses were received to most of these questions. Most people (78 percent) appeared willing to implement prevention/control measures recommended by these specialists, more than half (61 percent) wanted the animal handled/removed by someone else, and only about 40 percent wanted the damage stopped regardless of cost. Also, slightly over half (55 percent) of clientele represented did not want the offending animal harmed in any way. These results were highly variable from state to state. Several differences were noted in overall responses regarding urban wildlife species. Requests for information were received most frequently for bats and snakes, but both of these groups of animals ranked very low in terms of actual damage reported. The most frequently mentioned groups of animals causing damage in urban areas were roosting birds (including pigeons, starlings, and sparrows), woodpeckers (especially flickers), tree squirrels, bats, and moles. In terms of actual dollar values of damage done, white-tailed deer and pocket gophers apparently caused the most estimated damage. Due to these differences, it is necessary to know which criteria are being used to make an assessment of the relative importance of animal damage control problems. Techniques for controlling urban wildlife damage, such as exclusion, live-trapping, repellents, and poisons, are compared and discussed in some detail in this paper. As urbanization occurs across the nation, concerns about urban wildlife damage will continue; in most cases, we can and will live among these creatures.

The snowshoe hare (Lepus americanus), several species of voles (Microtus spp.), the northern pocket gopher (Thomomys talpoides), and the red squirrel (Tamiasciurus hudsonicus) cause serious damage to forest plantations and stands (and voles and pocket gophers in tree fruit orchards) by their feeding activities. Certain synthetic predator odors are reviewed which have produced significant avoidance responses in these pest species and reduced damage to crop trees on an experimental basis. In addition, the specific study reported in this paper was designed to assess the influence of predator odors on population density and survival of montane vole (M. montanus) populations in natural grassland habitat. Vole populations declined significantly in three consecutive winters on an area (and also on a replicated area in the third winter) treated with predator odors. These declines were caused by significantly lower survival in the treatment than control populations. Concurrent feeding damage to young apple trees was significantly reduced on the treatment area. We suggest that the predator odors may have attracted additional predators to the study area thereby increasing predation, as well as perhaps inducing behavioral-physiological stress in the vole populations. This technique could be implemented in forest plantations and tree fruit orchards as a means to disrupt resident vole populations and protect crop trees from damage.

In 1986, the U.S. Environmental Protection Agency (EPA) initiated an effort to comply more fully with the Endangered Species Act. This effort became their "Endangered Species Protection Program.'' The possibility of such a program was forecast in 1982 when Donald A. Spencer gave a presentation to the Tenth Vertebrate Pest Conference on "Vertebrate Pest Management and Changing Times." This paper focuses on current plans for implementing the EPA's Endangered Species Protection Program as it relates to the USDA Forest Service. It analyzes the potential effects this program will have on the agency, using the pocket gopher (Thomomys spp.), strychnine, and the grizzly bear (Ursus arctos horribilis) as examples of an affected pest, pesticide, and predator.

Lamb predation in Patagonia, Argentina, is considered by ranchers as the cause of one of their greatest losses and limits sheep production. Patagonian red fox (Dusicyon culpaeus) is the main predator and the magnitude of the problem reflects its distribution and abundance. Since 1979, the Bariloche Experimental Station of the Instituto Nacional de Technologia Agropecuaria (INTA) has performed 8 studies, totaling 1,717 lamb necropsies, with the purpose of determining the relative importance of predation and other causes of lamb mortality. This paper analyzes the causes of lamb mortality, with special reference to red fox and carnivorous bird predation. Red fox predation pattern is also discussed, based on the analysis of 157 cases of red fox kills.

In India, as in other countries, problems associated with locally overabundant wildlife species have emerged as important management issues for reason of some species losing their natural habitat but adapting themselves to the man-altered habitats. Consequently, there is a clash with the interests of local people. Crop-raiding by locally overabundant wild populations of nilgai and blackbuck in Haryana is one such problem analyzed in this paper. Nilgai causes extensive damage to agricultural crops; among these, gram, wheat seedlings and moong are the most preferred ones. Blackbuck nibble mainly on young shoots of various cereal and pulse crops and the damage is much less than caused by nilgai. Possible management strategies such as culling, fencing in nilgai and black buck (enclosures or corrals), and fencing agricultural areas to minimize the problem are suggested. Chain-link fencing of a sizable Reserved Forest (RF) patch, where the animals seek daytime shelter, combined with other local protective methods in the cultivated areas of Nahar hold promise of reducing the pest animal populations. The experiment is likely to establish one approach for dealing with the specific problem in Haryana. This paper discusses agricultural crop-raiding by locally overabundant populations of nilgai (Boselaphus tragocamelus) and blackbuck (Antilope cervicapra) in several districts of Haryana and the possible management strategies that can limit or reduce the conflict. Based on these strategies, a management experiment is being conducted in one of the districts, namely, Nahar, and its results are presented in this paper.

This paper will discuss strides taken to limit or eliminate use of the leghold trap and will explore recent trends in the animal rights movement's attack on fur and traps. A current legislative effort in Ohio, which seeks to protect wearers of fur and other animal products, as well as retailers, will be examined. Finally, the outlook as to what the future holds for the anti-trap debate and what we must do as responsible conservationists is discussed.

Constant developments in technology, both materials and methods, allow smaller and smaller animals to be radio-tracked for longer periods of time than was previously possible. Developments in electronic component miniaturization and battery chemistry are primarily responsible for this advancement. Approximately 30 years of field-use of radiotelemetry techniques have led to innovative procedures and uses of materials for the application of transmitters to animals. New technology such as satellite telemetry and recapture collars are only in their infancy and are not, at this time, appropriate for use in vertebrate pest research. Sophistication in receiving systems also allows more accurate and more complete data to be collected. This paper is not intended to be a review of telemetry devices on the cutting-edge of technology or non-field-proven developmental systems, but rather presents an overview of currently available, on-the-market technology appropriate for use by vertebrate pest researchers. As it is a review paper, not a research paper, it does not strictly follow the standard research paper format.