ENVIRONMENTAL SOURCES OF VARIATION OF BIGHORN SHEEP PHYSIOLOGIC VALUES

Physiologic values were obtained from 220 bighorn sheep (Ovis canudensis) from diverse parts of their range and under diverse environmental conditions. Evaluating and testing the sources of variation narrowed the main effects under this experimental design and model to subspecies, captive or wild, condition, excitability, habitat, subspecies X captive, and excitability X captive classes. Application of physiologic values to bighorn management was demonstrated with blood urea nitrogen (BUN) values reflecting protein intake, glucose and rectal temperature reflecting excitability, and packed cell volume (PCV) reflecting condition. Less significant effects and relationships were discllssed, and the potential of different sources of variation under different conditions was assessed. Many ecologic studies of ruminants have dealt primarily with the behavior of the animal, its seasonal movements, its food habits, and its effect on the range. Few studies have considered the physiology of nondomestic ruminants. Since the health and condition of the animal are directly related to the condition of the environment, certain physiologic parameters of the animal may be of value-in assessing the quality, and changes in quality, of the environment. The bighorn sheep was selected as the ruminant for which to develop basic physiologic data. Woolf and Kradel ( 1970 ) have reported physiologic data for captive bighorns.

Franzmann and Thorne (1970) and Franzmann (1971) have reported values for captive and wild bighorn sheep, and these values were utilized in the current study. The objectives of the present study were to develop base line physiologic data on bighom sheep and to determine what lDirect financial assistance for this study was from the Idaho Cooperative Wildlife Research Unit, Project WU-77; the Idaho Fish and Game Department; a National Defense and Education Act Fellowship; a National Wildlife Federation Fellowship; and the University of Idaho College of Forestry, Wildlife, and Range Sciences. 2Present address: Kenai Moose Research Center, Soldatna, Alaska. 924 parameters, if any, are applicable to the ecology and management of bighorns. I am grateful to Drs. K. E. Hungerford F. W. Frank, M. G. Hornocker, and E. W. Tisdale, University of Idaho, for their guidance and review of the manuscript.

I thank D. Hebert, University of British Columbia, for cooperation in sampling sheep from his project; Dr. E. T. Thorne research veterinarian with the Wyoming Game and Fish Department, whose cooperation and assistance were utilized throughout the study; E. Lacey, Manager of the Okanagan Game Farm, Penticton, British Columbia, for his cooperation; Dr. J. R. Gorham, Director, Endoparasite lector Pioneering Research Laboratorya Agriculture Research Service, Pullman, Washington, who provided laboratory facilities and assistance; and Dr. D. Ol. Everson and Celia Chang, University of Idaho, who assisted with the statistical analysis. Agencies and organizations that cooperated and with which many persons were involved were Banff National Park; British Golumbia Fish and Game Branch; Canadian Wildlife Service; Idaho Fish and Game Department; Montana Fish and Game Department; Utah Division of Fish and Game Department of Natural Resources; \07ashington Department of Game; and Wyoming Game and Fish Commission.

This content downloaded from 157.55.39.255 on Wed, 25 May 2016 05:44:25 UTC All use subject to http://about.jstor.org/terms PHYSIOLOGIC VALUES OF SHEEP * Franzmann 925 dition, excitability, and rectal temperature. Age was determined by using counts of horn segments (Geist 1966) and sequence of tooth eruption ( Taber 1963 ) . Mieighing with a spring scale was accomplished by supporting the sheep with ropes, slings, or crates. Evaluation of condition was based on the utilization of the principles of Robinson’s ( 1960 ) 10-point system for whitetailed deer ( Odocoileus virginxanus ) and applying them to bighorn sheep. Classification of individual excitability was based on heart rate, respiratory rate, and physical struggle prior to and during examination. A scale from 1 ( none ) to 5 ( highly excited ) was used. Properly immobilized sheep and captive sheep accustomed to being handled were generally classified as 1 (none) or 2 ( slight ), with heart beats up to 75 per minute and respirations up to 25 per minute. Sheep with heart beats from 76 to 100 per minute and respirations from 25 to 35 per minute were generally classified as 3 (moderate). Sheep with heart beats from 101 to 125 per minute and respirations from 35 to 45 per minute were generally classified as 4 (excited), and those above these limits were classified as 5 ( highly excited ) . Rectal temperature was obtained with a 5-inch mercury bulb theImometer that was periodically checked with a laboratory standard. Each captured sheep was bled from the jugular vein with an 18 gauge l-inch needle on a 20-ml disposable syringe. Blood was slowly drawn into the syringe to prevent mechanical damage, and a drop of blood was placed on a microscope slide and a smear prepared ( C;oles 1967:44 49 ) . Blood from the syringe was placed into a 15-ml blood vial and a 3-ml blood specimen tube with an anticoagulant, ethylenediaminetetraacetic acid ( EDTA ) .