| genetic structure, introgression, and a narrow hybrid zone between northern and california spotted owls (strix occidentalis). | the northern spotted owl (strix occidentalis caurina) is a threatened subspecies and the california spotted owl (strix occidentalis occidentalis) is a subspecies of special concern in the western united states. concern for their continued viability has arisen because of habitat loss caused by timber harvesting. the taxonomic status of the northern subspecies has been the subject of continuing controversy. we investigated the phylogeographical and population genetic structure of northern and cali ... | 2005 | 15773939 |
| using topography to meet wildlife and fuels treatment objectives in fire-suppressed landscapes. | past forest management practices, fire suppression, and climate change are increasing the need to actively manage california sierra nevada forests for multiple environmental amenities. here we present a relatively low-cost, repeatable method for spatially parsing the landscape to help the u.s. forest service manage for different forest and fuel conditions to meet multiple goals relating to sensitive species, fuels reduction, forest products, water, carbon storage, and ecosystem restoration. usin ... | 2010 | 20872142 |
| occupancy estimation and modeling with multiple states and state uncertainty. | the distribution of a species over space is of central interest in ecology, but species occurrence does not provide all of the information needed to characterize either the well-being of a population or the suitability of occupied habitat. recent methodological development has focused on drawing inferences about species occurrence in the face of imperfect detection. here we extend those methods by characterizing occupied locations by some additional state variable (e.g., as producing young or no ... | 2007 | 17601132 |
| sources of variability in spotted owl population growth rate: testing predictions using long-term mark-recapture data. | for long-lived iteroparous vertebrates that annually produce few young, life history theory predicts that reproductive output (r) and juvenile survival should influence temporal variation in population growth rate (lambda) more than adult survival does. we examined this general prediction using 15 years of mark-recapture data from a population of california spotted owls (strix occidentalis occidentalis). we found that survival of individuals > or =1 year old (phi) exhibited much less temporal va ... | 2007 | 17160689 |
| relation between occupancy and abundance for a territorial species, the california spotted owl. | land and resource managers often use detection-nondetection surveys to monitor the populations of species that may be affected by factors such as habitat alteration, climate change, and biological invasions. relative to mark-recapture studies, using detection-nondetection surveys is more cost-effective, and recent advances in statistical analyses allow the incorporation of detection probability, covariates, and multiple seasons. we examined the efficacy of using detection-nondetection data (rela ... | 2013 | 23678946 |
| a quantitative evaluation of the conservation umbrella of spotted owl management areas in the sierra nevada. | whether by design or default, single species management often serves as an umbrella for species with similar habitat requirements. in recent decades the focus of national forest management in the sierra nevada of california has shifted towards increasing closed canopy mature forest conditions through the protection of areas occupied by the california spotted owl (strix occidentalis occidentalis). to evaluate the implications of these habitat changes and the potential umbrella resulting from a sy ... | 2015 | 25905920 |