Population Changes Within the Gallatin Elk Herd, 1932-65
Peek JM, Lovaas AL, Rouse RA. 1967. Population Changes Within the Gallatin Elk Herd, 1932-65. The Journal of Wildlife Management. 31(2):304-316
A study was made of population changes within the migratory elk herd occupying the Gallatin drainage of southwestern Montana and adjacent Yellowstone National Park, using census, harvest, calf-tagging, and tag recovery records for 1932-65. The general population trend was downward, at about 2 percent per year. Tag recovery rates and average harvest data for three periods from 1940-55 suggested that harvest intensity increased through the years. Life expectancies for both sexes, as derived from tag recovery data, declined during these years. Aging of jaws collected from a 1965 harvest of more than 750 animals, the first heavy harvest in four years, showed little change in the life expectancy of males but an increase in the life expectancy of females over that derived from the tag recovery data. This suggested that when the population increased temporarily, females accounted for the greater share. For harvests of over 700 elk from 1945-65, the data showed a trend toward proportionately fewer bulls and more calves. The general decline in population and age structures of both sexes and the trend towards fewer males seemed largely a result of deteriorating winter forage supplies, resulting from excessive grazing by elk for at least 40 years.
- Type
- Journal Article
- Authors
- Peek, James; Lovaas, Allan; Rouse, Ralph
- Units
- YELL
- Keywords
- Age Distribution, Animal Studies, Banding, Distribution, Ecology, Elk (Cervus elaphus), Feeding, Food, Gallatin River Drainage, Grazing, Mammals, Migration, Monitoring, Mortality, Population, Sex, Tagging