The effects of fire and mechanical fuel treatments on wildlife in the mixed-conifer forest of the Sierra Nevada

Research was conducted on wildlife at Blodgett Forest Research Station, located near Georgetown, California. Twelve mixed-conifer stands were selected randomly from a set of available stands. Each stand was assigned to 4 treatment groups: controls, prescribed fire only, mechanical only, and mechanical plus fire combined. For bird and mammal species, species-specific abundance was monitored through time. Avian nest survival and foraging behavior were also documented.; For avian abundance, 3 species had significant treatment effects. The American Robin (Turdus migratorius) increased within mechanical plus fire treatments from pre- to post-treatment. Two species, the Golden-crowned Kinglet (Regulus satrapa) and Hammond's Flycatcher ( Empidonax hammondii) had significant disturbance effects. Kinglets declined from pre- to post-treatment within all treated stands relative to controls, whereas Hammond's Flycatchers increased relative to controls.; For avian foraging, all 9 species examined exhibited significant selectively for certain tree species within pre- or post-treatment periods. Four species exhibited a significant positive shift to California black oak from pre- to post-treatment periods in both burned and unburned stands. For most species, selectivity was generally consistent with previously published work within similar forest types.; For avian nest survival, 7 models incorporating treatment and other factors were tested (concealment, presence or absence within a group selection patch, nest placement, nest stage, temporal factors, treatment group, and Brown-headed Cowbird (Molothrus ater) parasitism), and all but 1 of these models were the most important for at least one species. The Cassin's Vireo (Vireo cassinii) was the only species analyzed that was parasitized by the Brown-headed Cowbird, and parasitism rates increased across all treatments from 2001-2004.; Finally, small mammal abundance was measured during 1 pre- (2001) and 1 post-treatment period (2003) for 4 species. Only the deer mouse ( Peromyscus maniculatus) exhibited a potential treatment effect. Abundance increased from pre- to post-treatment in the fire only and mechanical plus fire treatments, and decreased within the control and mechanical only treatments. For the other 3 species, the California ground squirrel (Spermophilus beecheyi), long-eared chipmunk (Tamias quadrimaculatus), and brush mouse (Peromyscus boylii), year was a significant factor, and all 3 species increased in abundance from pre to-post treatment.