Thesis (M.S.)--Humboldt State University, 2009. / Includes bibliographical references (leaves 48-54). Also available via Humboldt Digital Scholar.

Thesis (M.S.)--Humboldt State University, 2006. / Includes bibliographical references (leaves 46-53). Also available via Humboldt Digital Scholar.

Thesis (M.S.)--Humboldt State University, 2006. / Includes bibliographical references (leaves 72-78). Also available via Humboldt Digital Scholar.

A wildfire burned over 40,000 ha of conifer and mixed conifer-hardwood forest in the Silver Creek drainage of southwestern Oregon in the fall of 1987 allowing me to assess big game use of a large natural burn. I used fecal pellet group counts to estimate habitat use and effects of forest management activities on Roosevelt elk (Cervus elaphus roosevelti) and black-tailed deer (Odocoileus hemionus columbianus) within the Silver Fire Recovery Project Area (SFRPA) of the Siskiyou National Forest. Pellet decay rate and differences in observers' abilities to detect deer and elk pellet groups (interobserver variability) were estimated to test validity of pellet group counts. Pellet group persistence was estimated during a 10-month period. There were no differences in pellet group persistence between elk and deer (P < 0.05). Observers differed in ability to detect elk (F = 2.7; df = 4, 530; P = 0.03) and deer (F = 10.7; df = 4, 883; P < 0.0001) pellet groups. Interobserver variability related to elk pellet groups was low and was attributed to differences in numbers of transects searched by each observer. Two observers detected greater mean numbers of deer pellet groups than did other observers. I counted 775 elk pellet groups and 3,888 deer pellet groups on four study areas within the SFRPA. I analyzed habitat use for two periods: June to mid-October (summer-fall), and mid- October through May (fall-spring). I used stepwise logistic regression to create models predicting categories of habitat use during each period. Management variables were added to the habitat models to estimate effect of management on predicted categories of habitat use. Total overstory canopy cover was negatively related to deer use during both use periods. Distance to road was the only significant management variable affecting deer habitat use during the fall-spring period (P = 0.03). Slash cover had a negative effect on probability of habitat use by deer during the summer-fall period (P = 0.02). Elk use was negatively affected by steep slopes and hardwood canopies during both periods, while grass seeding positively affected elk use during both summer-fall (P = 0.05) and fall-spring (P = 0.03) use periods. Clearcutting had a negative effect on probability of elk use during the fall-spring period (P = 0.04). / Graduation date: 1995

The Roosevelt elk (Cervus elephus roosevelti) is a National Forest management indicator species on the westside of the Cascade mountains, Western Oregon. A Habitat Effectiveness model is used by State and Federal agencies to evaluate elk habitat in the region. Concerns about the model's lack of differentiation between winter and summer ranges in the analyses and assumptions that burning will increase forage quality on winter range prompted this study. I investigated the effect of broadcast burning, plant association, and time since disturbance on the quality of trailing blackberry (Rubus ulna), red huckleberry (Vaccinium parviflorum), willow (Salix spp.), vine maple (Acer circinatum), salal (Gaultheria shallon), and red elderberry (Sambucus racemosa). Crude protein, neutral detergent fiber, acid detergent fiber, acid insoluble ash, lignin, astringency, condensed tannin, and hydrolyzable tannin contents were measured. No significant effects of burning, plant association, or age were observed for crude protein, hydrolyzable tannins, or neutral detergent fiber. Crude protein varied among taxa: trailing blackberry contained 9.65%, and the other taxa ranged from 5.21-7.24%. Neutral detergent fiber was highly variable: trailing blackberry contained 30.90%, and the other taxa ranged from 52.20%-65.06%. Acid detergent fiber content ranged from 44.88%-49.49% for all taxa except trailing blackberry (17.78%). Lignin varied among taxa: trailing blackberry had the lowest content (6.37%) and salal had the highest (30.25%). Lignin content in salal was greater on recently disturbed sites. Astringency ranged from 0.0015 mg protein precipitated per mg plant tissue in vine maple to 0.6737 in trailing blackberry. Salal and willow had intermediate astringencies: elderberry, huckleberry, and vine maple had the lowest. Hydrolyzable tannins were present in all species except red elderberry. Burning and plant association effected astringency and condensed tannin content in trailing blackberry and huckleberry. Samples from burned, very dry and resource-poor sites had higher astringencies than on similar unburned units and non-resource-limiting sites. Condensed tannin contents increased with unit age in salal, huckleberry, and trailing blackberry, possibly accumulating during peak years of re-establishment after disturbance. Vine maple and red huckleberry were the only taxa with positive digestible protein levels. Digestible protein content may be higher in winter forage on less severe sites. Elk forage enhancement in winter range should be evaluated on a site-specific basis. Burning did not promote a detectable increase in quality for these forage taxa, and it decreased the quality of species sensitive to site conditions. / Graduation date: 1991

No studies have evaluated the effects of limited vehicle access on movements, survival and habitat use of Roosevelt elk (Cervus elaphus roosevelti) . We installed twenty gates, restricting motorized vehicle access by the public in seven discrete Road Management Areas (RMAs), comprising 35% of the study area. We radio-tracked 31 cow elk for 13 months in a 38,000 ha area of the Oregon Coast Range. Prior to the installation of the gates, 20 of these elk had been tracked for 14 months, allowing a paired comparison of elk movements and habitat use before and during the limited access period. The percentage of elk home ranges or core areas within the RMAs did not differ between periods, but there was a clear decrease in daily movement of elk during the limited access period. Survival rates increased during the limited access period and declined after the removal of the gates. During the limited access period, there was a significant increase in the use of open, foraging habitats and areas <150 m from roads. We conducted habitat selection analysis on vegetative cover types, distance from roads and distance from water. In general elk use of vegetative cover types was not significantly different from availability (p<0.05). Elk avoided areas <150 m from roads and selected areas >150 m from roads. Elk selected areas <150 m from streams and avoided areas >600 m from streams. Roosevelt elk should benefit from the preferred alternative of the President's forest Plan, which maintains roadless areas near streams. / Graduation date: 1996

Forage availability, diets, distribution, and productivity were compared for Roosevelt elk, Cervus elaphus roosevelti, using improved (i.e. seeded, fertilized, and grazed) and untreated areas of the Oregon Coast Range. Seasonal forage availability was substantially different on 1-year-old improved and untreated clearcuts, but the differences diminished by clearcut age 4 and essentially disappeared by clearcut age 7. Elk diets, as evaluated by fecal analysis, were similar in plant species composition and DAPA concentrations on both areas. There was no significant difference in estimated calf birth weights or survival, or in pregnancy and lactation rates, kidney and metatarsal marrow fat concentrations, or breeding dates of adult cows using improved and untreated areas. Summer and winter calf ratios were similar in 7 of 8 seasons sampled. There was no significant difference in home range or core area size, and distances traveled were similar on both areas in all seasons except winter. Elk exposed to summer sheep grazing were displaced an average of 1211 m (SD = 28 m) for an average of 14 weeks (SD = 5 weeks). Elk using improved areas stayed closer to forage areas in spring, but otherwise there was no significant difference in proximity to forage. Elk from both areas demonstrated preferential use of meadows, and used other forage areas in proportion to their availability. The combined results indicated that the forage improvement practices were ineffective in producing any measurable benefits for elk. / Graduation date: 1994