Record Details
Aspects of mountain goat ecology, Wallowa Mountains, Oregon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Aspects of mountain goat ecology, Wallowa Mountains, Oregon |
| Names |
Vaughan, Michael R.
(creator) |
| Date Issued | 1974-06-07 (iso8601) |
| Note | Graduation date: 1975 |
| Abstract | Twenty- six mountain goats (Oreamnos americanus), located between the Lostine River drainage and the East Fork Wallowa River drainage of the Wallowa Mountains, were monitored from June 1972 through June 1973. The age composition of the population was 76.9 percent adults and 11.5 percent each yearlings and kids. The addition of three kids in 1973 with the absence of any detectable mortality altered the age composition to 79.3 percent adults and 10.3 percent each yearlings and kids. Males comprised 34.6 percent of the population. Mountain goats were dispersed a maximum of 9 airline miles from the point of original release. In summer the population was divided into two female- subadult groups (one each on the Hurricane and Hurwal divides) with males scattered singly or in small groups throughout goat range. Fifty percent of the population occupied the Hurwal Divide during the summer. In winter at least 77 percent of the population merged into a single group on the Hurwal Divide. Within the approximate 3440 km2 study area an intensive use area of 710 km2 was identified and seven habitat types were defined. High elevation habitat types received the greatest use in summer and winter while low elevation types received the greatest use in spring and fall. In relation to the relative percent composition of each type, ridge top received the greatest annual use. Population models designed to hypothetically reconstruct the development of the Wallowa Mountains goat population were used to illustrate that low productivity rather than a high rate of mortality may be responsible for the current tenuous status of the population. A 10-20-10 percent mortality schedule for adults, yearlings, and kids respectively combined with alternate year reproduction by females following 15 years of maximum production (one kid per adult female per year) produced a hypothetical population which closely approximated the real population. Eleven factors were evaluated as potential limiting factors. Insufficient winter range leading to winter nutritional stress and ultimately resulting in in-utero or neonatal losses appeared to be the most likely cause of low mountain goat numbers in the Wallowa Mountains. |
| Genre | Thesis |
| Topic | Rocky Mountain goat |
| Identifier | http://hdl.handle.net/1957/8862 |
