Food Habits and Measurements of Hart Mountain Antelope

Abstract

In January, 1950, representatives attending the Four-State Antelope Meeting at Lakeview expressed interest in conducting a comprehensive food habits study. The available literature revealed that stomach analyses had been largely confined to samples collected during the hunting season and information at other periods of the year was inadequate or lacking. The Oregon Game Commission agreed to collect two to three antelope per month. Analyses of stomach contents were to be made by the Food Habits Laboratory of the California Division of Fish and Game. The Hart Mountain Herd was selected for study since it contained the largest number of animals found in any single herd in the state and resides in habitat representative of typical antelope range. Cooperation was extended by the U. S. Fish and Wildlife Service in permitting the collection of animals on the Hart Mountain and Sheldon refuges when necessary. The Nevada Fish and Game Commission also extended authorization for collections south of the Oregon Line. Collections were commenced on May 4, 1950, and terminated on April 19, 1951. A total of 26 stomach samples was analyzed. As far as practical, collections were made at monthly intervals unless weather or other factors interfered. Severe weather prevented access to the winter concentration area in January, 1951 and no animals were collected from December 11, 1950 to February 8, 1951. With the exception of two females taken in December, 1950, all collections were limited to bucks. The Hart Mountain herd summers on or adjacent to the Hart Mountain Antelope Refuge and winters in the vicinity of Sagehen Flat and Big Spring Table southeast of the refuge along the Oregon-Nevada state line. In addition to food habits analyses, field measurements of all specimens were taken. Antelope Food Habits: Table 1 summarizes food habits at monthly intervals. This breakdown is presented for rough comparative purposes only since collections were so few and were not all at the same time of the month. Plant species are listed in the order of their occurrence by total volume. Those species representing traces are not tabulated. Sagebrush, particularly Artemisia tridentata, variety arbuscula, represents the most important yearlong food item on the Hart Mountain range. Sagebrush species make up approximately 61 per cent of the total diet and are represented each month. Ninety-six per cent of the stomachs collected contained some species of sagebrush. Eleven of the 26 stomachs examined contained over ninety per cent sage with three of the 11 containing 100 per cent sage. Various species of Phlox comprised approximately 14 per cent of the total stomach contents and were found in 46 per cent of the samples. Varying percentages of Phlox were utilized during the spring and early summer months of April, May, June and July, followed by utilization again in November and December.