• How Do Domestic Herbivores Select Nutritious Diets on Rangelands?

      Howery, Larry D.; Provenza, Fred. D.; Ruyle, George B.; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-12)
      Animal learning has been shown to play a major role in the development of diet selection by domestic herbivores. Dr. Frederick Provenza and his associates at Utah State University have conducted a series of studies over the past 30 years to learn how physiological and behavioral mechanisms govern diet selection. In this paper, we synthesize several key diet selection concepts presented in 4 articles (i.e., Provenza et al. 1992; Provenza 1995, 1996, 1997). Reviewed 12/2014; originally published 05/1998.
    • How Do Domestic Herbivores Select Nutritious Diets on Rangelands?

      Howery, Larry D.; Provenza, Frederick; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998-05)
      Animal learning has been shown to play a major role in the development of diet selection by domestic herbivores. Dr. Frederick Provenza and his associates at Utah State University have conducted a series of experiments over the past 15 years to learn how physiological and behavioral mechanisms govern diet selection. This publication synthesizes several key diet selection concepts presented in four recent articles.
    • Non-Native Invasive Plants of Arizona

      Howery, Larry D.; Northam, Ed; Meyer, Walt; Arnold, Jennifer; Carrillo, Emilio; Egen, Kristen; Hershdorfer, Mary (College of Agriculture, University of Arizona (Tucson, AZ), 2016-12)
      The noxious weed problem in the western United States has been described as, a biological forest fire racing beyond control because no one wants to be fire boss. Indeed, when small weed infestations are left unchecked, they can grow exponentially and spread across the land much like a slow-moving biological wildfire. However, land consumed by fire usually recovers and is often more productive than before the fire occurred. On the other hand, land consumed by noxious weeds may be irreversibly changed and never again reach its full biological potential. Reviewed 12/2016, First Edition Published 2001
    • Non-Native Invasive Plants of Arizona

      Howery, Larry D.; Northam, Ed; Meyer, Walt; Arnold, Jennifer; Carrillo, Emilio; Egen, Kristen; Hershdorfer, Mary; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2009)
      The noxious weed problem in the western United States has been described as, a biological forest fire racing beyond control because no one wants to be fire boss. Indeed, when small weed infestations are left unchecked, they can grow exponentially and spread across the land much like a slow-moving biological wildfire. However, land consumed by fire usually recovers and is often more productive than before the fire occurred. On the other hand, land consumed by noxious weeds may be irreversibly changed and never again reach its full biological potential.
    • Noxious Weeds: A Disaster Looking for a Place to Happen in Arizona!

      Howery, Larry D.; Ruyle, George B. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1996-07)
      Noxious weeds threaten the quality of natural resources on both public and private lands, and will potentially cost Arizonans millions of tax dollars-unless we do something, now. This brochure explains what a noxious weed is and what kind of damages it can cause.
    • Rangeland Herbivores Learn to Forage in a World Where the Only Constant is Change

      Howery, Larry D.; Provenza, Frederick D.; Burritt, Beth; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2010-07)
      When we go to the grocery store it is a fairly easy task to select and purchase nutritious meals. A readily available, predictable food supply is conveniently organized and displayed in the aisles. The nutritional composition of most foods is clearly labeled so you can immediately know what nutrients (and perhaps, toxins) you will be consuming. In contrast, rangeland animals live in a world where nutrients and toxins are constantly changing across space and time. For example, there may be 10s to 100s of plant species growing on a single acre, and each plant can differ widely in the kinds and amounts of nutrients and toxins it offers to free-ranging herbivores. Even at the level of the individual plant, plant parts vary in their concentration of nutrients and toxins; leaves, stems, and flowers, all differ in the kinds and amounts of nutrients and toxins they contain. Nutrient and toxin content of the same plant species can also vary depending on where it grows (in the sun vs. shade, on a wet vs. dry site, on a fertile vs. infertile site, etc.). Mother Nature can also drastically alter foraging environments as a result of natural disasters like floods, fires, or droughts. Wild animals may find themselves in unfamiliar environments during their natural migration patterns. Range and wildlife management practices can also place wild and domestic herbivores in unfamiliar environments via relocation and reintroduction programs or via grazing management practices. Despite all these challenges, rangeland herbivores are remarkably adept at selecting plants that meet their nutritional needs while largely avoiding plants that do not. The fact that animals preferentially select plant species that are more nutritious than what is available, on average, is strong evidence that animals are able to somehow detect nutrient and toxin levels in plants as they change across space and time. In this paper, we examine recent important discoveries that underscore the importance of learning as a critical mechanism which allows rangeland herbivores to survive in a world where the only constant is change (Provenza, 2003; www.behave.net).
    • Rangeland Management Before, During and After Drought

      Howery, Larry D.; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1999-07)
      Rangeland and livestock management in the southwestern U.S. presents many formidable challenges. Environmental regulations, cattle prices, and drought are just a few factors that contribute to the management challenges of the range-livestock industry. Among them, drought may be the least controllable or predictable variable. This publication discusses how to prepare for drought in southwestern U.S. Topics include principles of drought and range-livestock management, management before drought, management during drought and management after drought.
    • Rangeland Management Before, During and After Drought

      Howery, Larry D.; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-12)
      Rangeland and livestock management in the southwestern U.S. presents many formidable challenges. Environmental regulations, cattle prices, and drought are just a few factors that contribute to the management challenges of the range-livestock industry. Among them, drought may be the least controllable or predictable variable. This publication discusses how to prepare for drought in southwestern U.S. Topics include principles of drought and range-livestock management, management before drought, management during drought and management after drought. Reviewed 12/2016 - Originally published 07/1999
    • A Summary of Livestock Grazing Systems Used on Rangelands in the Western United States and Canada

      Howery, Larry D.; Sprinkle, James E.; Bowns, James E. (College of Agriculture, University of Arizona (Tucson, AZ), 2016-12)
      The objectives of this article are to provide an overview of the major grazing systems that have been used on rangelands in the western U. S. and Canada, to summarize the conditions under which they may be applicable, and to highlight examples from the southwestern U. S. when relevant. Revised 12/2014. Originally published 09/2000.
    • A Summary of Livestock Grazing Systems Used on Rangelands in the Western United States and Canada

      Howery, Larry D.; Sprinkle, James E.; Bowns, James E.; Natural Resources & the Environment, School of; Animal Sciences (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2000-09)
      The objectives of this article are to provide an overview of the major grazing systems that have been used on rangelands in the western U. S. and Canada, to summarize the conditions under which they may be applicable, and to highlight examples from the southwestern U. S. when relevant.
    • Using Repeat Color Photography as a Tool to Monitor Rangelands

      Howery, Larry D.; Sundt, Peter C. (College of Agriculture, University of Arizona (Tucson, AZ), 2016-12)
      This article provides an introduction to repeat color photography and explains how it can be used as an important part of a comprehensive rangeland monitoring program. Reviewed 12/2014. Originally published 05/1998.
    • Using Repeat Color Photography as a Tool to Monitor Rangelands

      Howery, Larry D.; Sundt, Peter; Natural Resources & the Environment, School of (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998-05)
      It is important to show people that what you say is true when your critics weren't around 10-15 years ago to see the changes you have seen. A series of photographs taken at the same spot through the years can vividly demonstrate change on the range. This article provides an introduction to repeat color photography and explains how it can be used as an important part of a comprehensive rangeland monitoring program.