Record Details
Greater sage-grouse movements and habitat use during winter in central Oregon
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Greater sage-grouse movements and habitat use during winter in central Oregon |
| Names |
Bruce, Jennifer R.
(creator) Robinson, W. Douglas (advisor) |
| Date Issued | 2008-06-04 (iso8601) |
| Note | Graduation date: 2009 |
| Abstract | Greater sage-grouse (Centrocercus urophasianus), a sagebrush obligate species, has contracted in extent by nearly half its original distribution. This is primarily due to habitat loss and degradation over the past 150 years. During winter, sage-grouse depend completely on sagebrush habitat for food and cover, yet sage-grouse winter ecology has been poorly studied in the past. We studied greater sage-grouse winter habitat use and movement in central Oregon by tracking 22 radio-collared sage-grouse (7 female, 15 male) from January through mid March 2007 to record specific characteristics of sagebrush used and patterns of movement for each sex during winter. We quantified winter habitat characteristics such as canopy height and topography at each sage-grouse location, estimated winter distances moved using weekly to biweekly point locations, and compared this information between males and females. The sage-grouse we studied moved extensively across the landscape in central Oregon, using approximately 1,480 km2 during winter. Sagebrush canopy height in sites used by sage-grouse varied from 0.25 to 0.75 m, with females tending to use sites with taller sagebrush plants and less total foliar cover than sites used by males. The difference in foliar cover between sexes was related to a seasonal change in habitat use; four females found in low sagebrush in January and early February stopped using it after 15 Feb 2007. Also by this date, most male sage-grouse had stopped using big sagebrush as they migrated to lekking areas. During our study there was half as much snow cover on average, which may explain why sage-grouse mortality rates were low. Managers interested in preserving sage-grouse populations should provide large areas (thousands of square km) of habitat that contain heterogeneous sagebrush habitat, specifically with both low and big sagebrush so that food and cover are available for greater sage-grouse during winter. |
| Genre | Thesis |
| Topic | Greater sage-grouse |
| Identifier | http://hdl.handle.net/1957/9176 |
