Environmental Health and Protection Commons^™

Estimating Livestock Losses, Charles Drain

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Most information published by the Texas Agricultural Statistics Service (TASS) is based on data gathered through a system of Sample Surveys. TASS regularly surveys sampled farms and ranches and agricultural businesses m order to make statistical inference (estimates) for a total population. The alternative to using a sample survey would be to make a complete enumeration or count of the entire population. Both cost and timely results favor the survey approach. This discussion is an attempt to explain the concepts and sampling methods TASS employs in conducting basic surveys, for both inventory and death loss data for cattle, sheep and …

Lethal Options For Controlling Coyotes, John W. Dorsett

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Lethal control methods are required to stop coyote depredation or to reduce the coyote population in an area. Various lethal control options are available, including traps, snares, shooting, denning and toxicants. The effectiveness, selectivity, and specificity of each method should be considered before being utilized. Each method requires varying degrees of skill and experience to be made effective. Usually a combination of control methods is most effective in coyote control situations.

Coyotes As Part Of Texas' Fur Trade, Jerry L. Cooke

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

One factor that potentially affects coyote (Canis latrans) abundance is recreational and commercial trapping for harvest of coyote fur. Herein I report how the economic impact of coyote pelts has changed from 1979–1994 for landowners and trappers from the Texas. Pelt values accounted for over 50% of the variability observed during this 15-year period. The future of this economic incentive for managing coyotes is questionable because of the impending ban by the European Union of furs from North America.

The Effects Of Control On Coyote Populations: Another Look, Guy E. Connolly

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Population dynamics models are useful for estimating coyote (Canis latrans) population responses to exploitation w well as to hypothetical birth intervention techniques At least 6 coyote simulation models have been developed over the past 25 years. This paper reviews the model developed by Connolly and Longhurst (1975), and identifies some potential improvements based upon new biological information and modem computing technology. The biological concepts embodied in the Connolly–Longhurst (C–L) model seem as valid In 1995 as they were in 1975. Newer studies have tended to reaffirm rather than revise earlier concepts of coyote population mechanics. One significant shortcoming …

The Coyote's Role In A Rabies Epizootic, Keith A. Clark, Pamela J. Wilson

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

In 1994, the canine rabies epizootic in South Texas was declared a state health emergency; a statewide rabies quarantine was enacted in 1995. Prior to 1988, rabid coyotes (Canis latrans) were reported only infrequently in Texas. In 1988, Stan and Hidalgo Counties, located In extreme South Texas, experienced an epizootic of canine rabies resulting in 11 laboratory-confirmed cases of canine rabies in domestic dogs and 6 cases in coyotes. By 1991, the epizootic had expanded approximately 100 miles north of the US–Mexico border and included 10 counties. During the next 3 % years, 10 additional counties became involved …

Management Of Coyotes For Pronghorn?, S. Kemble Canon

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Coyotes (Canis latrans) and pronghorn (Antilocapra americana) have co-existed for thousands of years, but in today's production-oriented society the Pronghorn may need some help periodically. Although pronghorn numbers have rebounded dramatically since the early 20th century, continued management of this species is necessary and may include management of its primarily predator, the coyote. Pronghorn defense mechanisms offer protection from predators, but the coyote's hunting strategies overcome these mechanisms The Trans-Pecos region of Texas holds the greatest numbers of pronghorn In the state. Ranchers in the Trans-Pecos can use predators, such as rainfall; strategies, such as proper …

Interpreting Physical Evidence Of Coyote Predation, James E. Bowns

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

There are situations where it is necessary to determine the cause of death of livestock, game animals, or other wildlife. Criteria used for recognizing predator kills are well known and scientifically documented. These criteria include the attack, killing and feeding behavior of predators as well as the characteristics of their tracks, droppings, and canine teeth size and spacing. Diagnostic criteria for recognizing coyote (Canis latrans), domestic dog, fox (Urocyon cinereoargenteus, Vulpes vulpes), cougar (Felis concolor) , bobcat (Lynx rufus), bear (Ursus spp ), and eagle (mostly Aquila chrysaetos) predation …

Coyote Interactions With Other Carnivores, Terry L. Blakenship

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Coyotes (Canis latrans) occur sympatrically with several predators throughout their range. Habitat and food resources are similar, although the coyote typically utilizes a wider range of food items. Larger predators generally select larger prey, allowing predators of different sizes to coexist. Coyotes exhibit aggressive actions towards smaller predators, but in most cases they avoid contact with other predator species. Studies indicate that coyotes can exclude 01- displace foxes (Vulpes vulpes, Urocyon spp.), and an inverse relationship exists between abundance of coyotes and foxes. There is evidence suggesting that extensive reduction of coyote populations allows other predator …

Behavior Of Coyotes In Texas, William F. Andelt

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Coyotes (Canis latrans) live in social groups with relatively small territories or as single, non-territorial transients with large home ranges in southern Texas. Coyotes communicate and establish territories through auditory, olfactory, and visual means They consume mammals, fruits, and insects with their diets reflecting difference sin abundance and vulnerability of prey, effects of plant phenology and weather conditions. Coyotes have adapted to human exploration by avoiding humans and their control techniques. Because coyotes habituate to nonlethal control techniques (e.g. frightening devices), I suggest apply frightening devices only when coyotes are a problem. Lethal techniques likely will be most …

Selected Parameters Of The Reproductive Physiology And Endocrinology Of Coyotes, Max S. Amoss Jr., Connie M. Hodges

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

The development of the reproductive system and the dynamics of reproductive hormones were studied in captive male and female coyotes (Canis latrans). Captive male coyotes exhibited incomplete sexual maturation at the first reproductive season (< 12 months of age). Peak serum testosterone levels in 1-year old males were 50% (300 ± 200 vs. 810 ± 300 pg testosterone/ml) and total sperm production was only 10% (57.4 ± 6.6 vs. 558.8 ± 26 x 10⁶ total sperm) of that observed in males older than 1 year. Yearling males were never observed copulating with a female. The sexual maturation of captive female coyotes was less equivocal than their male counterpart's. The pregnancy rate of yearling females was 40% compared to 63% m older females. Average peak serum LH values at the ovulatory surge were 33 ng/ml in yearling …

Alternative Methods Of Predator Control, Crystal A. Wilbanks

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Acceptable solutions to animal damage problems must consider the social and recreational values of wildlife, regulation of population levels, potential hazards of chemical use, human safety and disturbance to biotic communities. The objective should be to reduce harm and economic loss of livestock to an acceptable level. This paper, reviews alternative, i.e. nonlethal, predator management methods. Alternative methods include guard animals, fencing, repellents, frightening devices and perhaps someday, immuno-contraception. The intent of animal damage control should be an integrated pest management approach tailored to fit the individual landowner's needs.

Coyotes In The Southwest: Foreword, Dale Rollins

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Long before the recent clamor over endangered species, predators and their management were controversial. The coyote (Canis latrans) is often at the center of such debates. Cursed by some, revered by others, respected by all, the coyote is an icon of the Southwest.

Historical Perspective On Coyote Control Methods In Texas, Robert L. Phillips, Gary L. Nunley

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

A variety of control methods used over an 80-year period (1915–1995) contributed to the effective and successful coyote (Canis latrans) damage management program that exists in Texas today. Traps, toxicants, shooting, denning, and dogs were important during the early years of the Texas Animal Damage Control Service (TADCS) program. Aerial hunting and snares evolved as important control tools following the ban on strychnine and Compound 1080 in 1972. The livestock protection collar (LPC) has received increased use in recent years and has been useful in resolving difficult depredation problems. ADC policy along with changing state and federal regulations …

The Coyote In Southwestern Folklore, Wyman P. Meinzer

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Perhaps one of the first mentions of the coyote (Canis latrans) by Anglos in early-day journalism was from Mark Twain's notes during his travels through the plains frontier in the early- to mid-19th century. Touring the frontier region before its inevitable subjugation to ranching and farming, Twain wrote of the coyote and its larger more infamous cousin, the wolf(C. lupus), In words which left no doubt to the reader the popular sentiments for such predators of the day. Although derogatory in some respects, Twain did concede respect for C. latrans and made mention of …

The Coyote, Baxter Black

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

I think I can speak for the coyote
With more understanding than most
Especially those who defend him
And live on the New Jersey coast

Audubon's Perspective On Coyotes, Dede Armentrout

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

Audubon has a membership which probably spans all views of coyotes (Canis latrans) Audubon's staff views coyotes as biologically appropriate predators in most of the Southwest. We believe that they can be an asset to a well-managed ranch, but that they can also cause localized depredation which must be answered.

Our members value predators, including coyotes, for their natural role in ecological systems, including their influence on prey species. Many of our members travel broadly and spend money to view wildlife, and consider it a treat to see and hear coyotes.

Disease And Coyotes In Texas, Danny B. Pence

Coyotes in the Southwest: A Compendium of Our Knowledge (Symposium Proceedings, 1995)

The coyote (Canis latrans) population in southern Texas has a recurring group of 3 common helminths and several peripheral species of lesser importance. Although recurrent group analyses have not been applied to other macro- or microparasite communities, there are certain infectious agents with high prevalences that could form recurrent groups, and that are potentially important in tams of impacting host population (i.e. coyote) abundance. While the current rabies epizootic involving coyotes in southern Texas is of public health concern, it probably will not have a major impact on the coyote population. Most likely, the net effect of canine …

Policy Considerations For Contraception In Wildlife Management, Wendy A. Sanborn, Robert H. Schmidt, Herbert C. Freeman

Vertebrate Pest Conference Proceedings: 16th (1994)

Managing wildlife populations by manipulating their birth rates is a promising technology. However, the use of contraceptive technologies will involve the development of new wildlife management policies. We designed and implemented a survey that was intended to gather information on the range of perspectives of concerned publics on contraceptive use in wildlife management. There appears to be considerable confusion and mistrust regarding the application and appropriateness of this new technology. We recommend that promoters of contraception use in wildlife management be careful to explain what this new technology can and cannot do in order to avoid the pitfalls associated with …

The Prospects And Associated Challenges For The Biological Control Of Rodents, Grant R. Singleton

Vertebrate Pest Conference Proceedings: 16th (1994)

Biological control using macro- or micro-parasites is a promising research area for control of rodents. The largest impediment to progress is a dearth of high quality research, under field conditions, on wild rodents and their diseases. A major challenge is to identify a candidate control agent which is sufficiently pathogenic, has a high transmission rate and is target specific. Once this has been done, ecological studies of both the host and the disease agent, and of the epidemiology of transmission, are required. Whether the desired pathogenicity is via increased mortality and/or reduced fertility will depend on the agent and on …

Wild Carnivores As Plague Indicators In California - A Cooperative Interagency Disease Surveillance Program, Charles R. Smith

Vertebrate Pest Conference Proceedings: 16th (1994)

A cooperative interagency program of sampling and testing wild carnivores for plague antibody has been utilized as an important component of an integrated plague surveillance program in California since 1974. The carnivore serology program involves the California Department of Health Services, the U.S. Department of Agriculture, APHIS/Animal Damage Control, the U.S. Department of Health and Human Services, Centers for Disease Control, and various other cooperators. This paper summarizes the results of the testing of wild carnivores, opossums, and feral pigs over the past two decades from 49 of California's 58 counties, and discusses the importance of the program to the …

Ground Squirrel Management In The Angeles National Forest, Robyn K. Spano

Vertebrate Pest Conference Proceedings: 16th (1994)

In 1987 and 1988 there was a sharp rise in epizootics in the ground squirrel (Spermophilus beecheyi) population in the Arroyo Seco District of the Angeles National Forest. In response to these incidents, a proactive rather than a reactive approach was implemented in this area. This was the beginning of a ground squirrel management program in the Angeles National Forest. From 1988 to 1993 the program developed into a joint management program between the United States Department of Agriculture, Forest Service (USFS), Los Angeles County Department of Health Services (DHS), Los Angeles County Agricultural Commissioner's Office-Weights and Measures …

Effects Of Initial Rat Captures On Subsequent Capture Success Of Traps, Mark E. Tobin, Robert T. Sugihara, Richard M. Engeman

Vertebrate Pest Conference Proceedings: 16th (1994)

Trapping records from studies conducted in Hawaiian sugarcane fields were analyzed to determine the effects of rat captures on subsequent capture success of Rattus norvegicus, R. rattus, and R. exulans. Traps that captured rats were subsequently more likely to capture another rat of the same species. We detected no differences in trap responses of males and females, nor did we observe any evidence that capture success of Polynesian rats and roof rats was affected by previous captures of Norway rats. This increased trap success may have been due to residual trap odors, or to greater success of traps …

Activity Patterns Of The Pocket Gopher Pappogeomys Merriami Merriami In A Mexican Rangeland, Desley Whisson, Beatriz Villa-C.

Vertebrate Pest Conference Proceedings: 16th (1994)

Pocket gophers (Pappogeomys meiriami merriami) are a problem in both crops and rangelands of Mexico. In rangelands, damage results from the animals burrowing habits which cause much soil disturbance, and their feeding on rangeland vegetation. Although considered a pest, to date there have been no quantitative studies of the activity and damage caused this species. This study was initiated to document fluctuations in activity of P. m. merriami throughout the year in a Mexican rangeland.

Natural History And Protection Of Burrowing Owls, Clark S. Winchell

Vertebrate Pest Conference Proceedings: 16th (1994)

Burrowing owls (Speotyto cunicularia) were monitored over a four year period at Naval Air Station North Island, a developed area at the north end of San Diego Bay, California. Protection of the nest burrows and a burrow marking program were initiated in 1991. The breeding population increased from 14 to 27 nests after this marking program began. Burrow types and ways to differentiate burrows used by owls from those used by California ground squirrels (Spermophilus beecheyi) are outlined. The importance of burrows and their management is discussed with reference to the natural history of the owl.

Supplemental Bear Feeding Program In Western Washington, Georg J. Ziegltrum

Vertebrate Pest Conference Proceedings: 16th (1994)

Black bear (Ursus americanus) damage to trees is a severe problem in the Pacific Northwest. Significant damage has been observed for many years, especially in highly managed private industrial forests in western Washington. The introduction of intensive silvicultural techniques resulted in higher yields, but may have also made trees more vulnerable to black bear destruction. Early lethal control efforts lost public support and the forest products industry investigated different methods that concentrated on non-lethal management tools. In 1985, the Washington Forest Protection Association introduced supplemental bear feeding as a damage prevention program in high damage areas during the …

Closing Remarks - Sixteenth Vertebrate Pest Conference, Robert M. Timm

Vertebrate Pest Conference Proceedings: 16th (1994)

As Chairperson-elect of the Council, I wish to express my appreciation to all who participated in this 16th Conference. I trust you have enjoyed this conference, as I have, as well as your visit to the Santa Clara Valley. Much information has been presented here, not only in the more than 70 formal presentations, but also in evening sessions, meetings, and informal sharing and interaction. We hope we have provided adequate opportunities for informal networking, as this can be equally valuable as the scheduled papers and presentations.

Rodent Pests In Colombian Agriculture, Danblo Valencia, Donald J. Elias, Jorge A. Ospina

Vertebrate Pest Conference Proceedings: 16th (1994)

The tropical zones of Latin America are sources of a great faunal richness. A significant number of mammals are associated with damage to the agricultural and livestock industries of Colombia. Some studies have indicated that rodents cause serious economic and social damage in the agricultural, livestock, and stored product sectors of the Colombian economy. Evaluations of this damage have been based on three criteria: 1) the characteristics of the damage; 2) the species of rodent involved; and 3) the loss of production at harvest. Cereals and oil-producing crops are most affected as standing crops; in the livestock area, poultry and …

Using Geographic Information Systems For Tracking An Urban Rodent Control Program, Matt Von Wahlde, Bruce A. Colvin

Vertebrate Pest Conference Proceedings: 16th (1994)

Geographic information system technology is being used to help coordinate an urban rodent control program initiated as part of the Central Artery/Tunnel Project in Boston. Databases with neighborhood survey data, surface and subsurface baiting data, sanitation code violations, and public complaints are linked to base mapping, land parcel, and utility graphics. This integrated approach helps Project biologists plan control strategies and evaluate the relatedness of rodent activity to environmental conditions. Spatial querying techniques and the ability to graphically display and map variables, such as bait stations and sanitation deficiencies, help ensure that control resources are effectively targeted and tracked. This …

Zinc Phosphide: Implications Of Optimal Foraging Theory And Particle-Dose Analyses To Efficacy, Acceptance, Bait Shyness, And Non-Target Hazards, Ray T. Sterner

Vertebrate Pest Conference Proceedings: 16th (1994)

The U.S. Department of Agriculture (USDA), Animal Plant and Health Inspection Service (APHIS) maintains six federal registrations for zinc phosphide (Zn3P2); three of these address the control of eight rodent species using steam-rolled oats (SRO) or wheat grains in diverse applications. Optimal foraging theory (OFT) and "particle-dose analysis" (PDA) afford predictions relevant to the efficacy, acceptance, bait shyness, and non-target hazards of these Zn₃P₂ baits. For PDA, numbers of SRO groats or whole wheat grains associated with acute oral median lethal (LD^) or approximate lethal (ALD) doses of Zn3P2 were compared among nine target rodent and eleven …

Registration Requirements For Non-Toxic Natural Products As Animal Damage Control Agents, Stephen A. Schumake

Vertebrate Pest Conference Proceedings: 16th (1994)

Plant extracts, animal glandular secretions and excretions, and natural food flavoring agents are common sources of natural products that can be used in animal damage control applications. Such products can be used either by themselves (e.g., coyote urine as a rodent repellent), or in combination with other control agents (e.g., food odor or flavor enhancer at baiting sites). The Environmental Protection Agency registration requirements are described for a variety of potential applications of natural products including bird and rodent repellents. In some applications, the product chemistry or other data requirements could make the registration process prohibitive due to the cost …