PDF
Ecology of Greater Sage-Grouse in South-Central Owyhee County, Idaho Item Info
- Title:
- Ecology of Greater Sage-Grouse in South-Central Owyhee County, Idaho
- Creator:
- Wik, Paul A.
- Date Created (ISO Standard):
- 2002
- Description:
- Thesis (M.S., Wildlife Resources) -- University of Idaho, December 2002. Major professor: Reese, Kerry P.
- Abstract:
- Breeding populations of greater sage-grouse (Centrocercus urophasianus) have been reduced 17- 47%, which is thought to be a result of over-exploitation, habitat loss, and habitat degradation. The seasonal habitats, movements, and survival of sage-grouse populations in southwest Idaho were poorly understood, and this lack of information hindered planning efforts of the United States Air Force (U.S.A.F.), which received approval for training sites to be constructed in Owyhee County beginning in 1999. This research was designed to help assess potential effects in sage-grouse from these activities. My primary objectives were to assess whether sage-grouse were affected by the construction of U.S.A.F. Enhanced Training in Idaho (ETI) sites and obtain baseline ecological data on the population and habitats. Male and female sage-grouse were captured and fitted with necklace-style radio transmitters in 1999, 2000, and 2001 to determine survival, movements, and success from nests and broods. Annual survival rates for males were 0.54 (n = 14, 1999/2000, September 1999- August 2000) and 0.61 (n = 17, 2000/2001, i.e. September 2000- August 2001), with seasonal survival rates ranging from 0.76- 1.00 for all seasons (Seasons were: Sept- Nov, Dec- Feb, Mar- May, and June- Aug) and years. Adult female sage grouse annual survival rates were 0.58 (n = 21, 1999/2000) and 0.42 (n = 38, 2000/2001). Sub-adults (10 weeks of age to 15 months) survival rates were 0.22 (n = 16, 1999/2000) and 0.55 (n = 18, 2000/2001). Seasonal rates ranged from 0.74- 1.00 for adults and from 0.40- 1.00 for sub-adults. Nest success was 43% (9 of 21, 2000) and 50% (8 of 16, 2001) with an average first clutch size of 6.5 ± 0.27 (95% C.l.). In 2000, 20% of the hens that lost their first nest renested (2 of 10) and no estimates of renesting could be obtained for 2001. Nests were placed under taller shrubs (P ~ 0.001) with greater shrub cover (P ~ 0.001), taller grass (P ~ 0.001), and greater cover provided by grass (P = 0.003) than randomly available. Brood-rearing success was low in 2000 (38%) and increased in 2001 (83% ), but production from both years (0.43 and 0.66 chicks/hen in 2000 and 2001, respectively for flush counts at 7 weeks) was well below the 2.25 chicks/hen thought necessary to maintain a stable or increasing population. Hens with broods used taller (P = 0.025) shrubs with greater grass cover (P = 0.004) than was randomly available. In 2000, hens with broods used the same habitat through the brood-rearing period, whereas in 2001, hens switched habitats at the end of June. In 2001, 5 forbs were identified to occur more frequently in habitats used by broods in the early brood-rearing season (4- 5 weeks posthatch), and 4 forbs were identified to occur more frequently at brood sites in the late brood-rearing period. Most birds moved south to southwest from spring to summer range. Males tended to use higher elevation habitats during the summer and females used the upland shrubs and agricultural fields centered around the community of Riddle, Idaho. Females moved an average of 1.7 ± 0.42 km (95% C.l.) from lek of capture to nest, with renests averaging 790 m (240- 1300m) from the first nest. Mean distance moved from spring range to summer range for males was 23.9 ± 2.13 km (95% C.l., ages combined) and 17.0 ± 1.44 km (95% C.l., ages combined) for females. Males moved farther than females (P = 0.027) to reach their summer range. Decay rates of sage grouse intestinal droppings were examined to determine whether they could be used as a sampling tool for detecting changes in habitat use. Droppings were placed in 3 habitats (A. t. wyomingensis, A. arbuscula, and Agropyron cristatum) in groups of piles and singles. Single droppings decayed at a similar rate (P = . 0.702) among the 3 habitats, but piles decayed slower (P = 0.051) in the A. arbuscula habitat than the other 2 habitats during 734 days of exposure. Using dropping counts for detecting changes in sage grouse use is viable with count intervals 1 year. Insufficient data had been collected to determine whether any effects from the construction of the U.S.A.F. sites occurred. Additional data will be collected on dropping counts placed around 4 Enhanced Training in Idaho (ETI) sites constructed by the U.S.A.F. during 1999-2001 to continue assessing this issue.
- Subjects:
- sage-grouse
- Original Format:
- text
- Type:
- Text
- Format:
- application/pdf
- Language:
- eng
U of I Digital Collections contain unique digitized and born digital archival materials in a variety of formats. The Library is committed to ensuring our resources are accessible to all users. Please contact us if you need support accessing or using this archived content.
Contact us about this record Library HelpAttribution
- Citation:
- "Ecology of Greater Sage-Grouse in South-Central Owyhee County, Idaho", Institutional Repository Collection, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/ir/items/ir0010.html
Rights
- Rights:
- In Copyright - Educational Use Permitted. For more information, please contact University of Idaho Library Special Collections and Archives Department at libspec@uidaho.edu.
- Standardized Rights:
- http://rightsstatements.org/vocab/InC-EDU/1.0/