This manual provides electric utilities with practical information about recommended practices and policies to help reduce animal-caused outages on transmission lines, in substations, on overhead distribution lines and in underground distribution systems.


Power quality is a major issue for electric utilities. Sensitive electronic equipment and computers are a part of daily life, and consumers are increasingly outspoken about service interruptions. Many utilities find that consumer complaints are not only the result of prolonged or repeated outages, but also the result of frequent "blinks" or recloser operations. In many cases, these outages and recloser operations are the result of animal contacts somewhere on the system. Various steps should be considered when planning programs to reduce animal-caused outages. The first and most important is collecting accurate and specific outage data. The next step is to learn about the animals responsible for the outages, which will help explain why some animal deterrents work and others do not. Such information also may help utilities foresee problems and take corrective action before an outage occurs.

Next, commercial deterrents, design alternatives, material properties, and economics should be examined carefully. Once the deterrent and method have been selected, a utility can develop an efficient and economical plan of action. To help with planning and maintenance, the manual outlines two step-by-step procedures, one to use when planning new construction before an outage occurs, and one to use for existing construction after an outage occurs. Every effort has been made to include in the manual the widest range of information on the animals most often involved in outages, the deterrents that are available and how well they work, and the policies and practices that have been used successfully. Installation tips are also provided because improperly installing devices can lead to additional problems.


Three recommendations are made consistently throughout the manual. They are the three most effective things all utilities can do to reduce or eliminate animal-caused outages.

  • Implement an aggressive right-of-way clearing and tree-trimming program.

  • Maintain a regularly scheduled inspection program.

  • Become familiar with the animals in the area. It is impossible to effectively and economically reduce or eliminate animal-caused outages without knowing something about the animals that are causing the problem. Different animals cause different types of outages that require different solutions.

Further, the manual is divided into easy-to-find segments that outline the problem, the plan, the animals, the solutions, solving problems on existing equipment, preventing problems in new construction, remedies, design modifications, and a summary table that shows recommended and non-recommended solutions for various animals.


NRECA's Guide to Reducing Animal Caused Outages is a comprehensive animal management guide for electric co-ops. The first half of the guide is dedicated to identifying the behavior of the animals most likely to cause disruptions on your system. It is by knowing and understanding their behavior that one can more easily defend against their tactics. The second part of the manual outlines the specific actions that can be taken to prevent animals from coming in contact with parts of the system. The guide provides reviews of devices currently on the market that can be installed to on your system. The guide also offers advice on design new construction as well as design modification that can be adopted in order to minimize animal contacts.


Management, engineers, field crews


Animal-caused outages, the animals, the solutions, solving problems, preventing problems, deterrents, distribution, Engineering, operations, animals, outages, raptor, squirrel