Skip to main content

Gutierrez, R J

Mitochondrial DNA control region sequences of spotted owls (Strix occidentalis) allowed us to investigate gene flow, genetic structure, and biogeographic relationships among these forest-dwelling birds of western North America. Estimates of gene flow based on genetic partitioning and the phylogeography of haplotypes indicate substantial dispersal within three long-recognized subspecies. However, patterns of individual phyletic relationships indicate a historical absence of gene flow among the subspecies, which are essentially monophyletic. The pattern of haplotype coalescence enabled us to identify the approximate timing and direction of a recent episode of gene flow from the Sierra Nevada to the northern coastal...
We conducted a survey of spotted owl (Strix occidentalis) ectoparasite richness by examining live and museum specimens of the three subspecies of spotted owl. Seven ectoparasite species from five arthropod orders were collected. A tick (Dermacentor occidentalis), a mite (Euschoengastia sp.), and a flea (Opisodasys vesperalis) were collected, but were presumed to be accidental strays from prey. Strigiphilus lice were found on all the subspecies of spotted owl, while the louse Kurodaia magna was only collected from the northern spotted owl (S. o. caurina). The hippoboscid fly Icosta americana was found on the California spotted owl (S. o. occidentalis); this species had previously been well documented in the northern...
The Mexican spotted owl (Strix occidentalis lucida) is a threatened subspecies whose recovery depends, in part, on both an understanding of its habitat requirements and the protection of its habitat. Therefore, we evaluated habitat composition and configuration around owl sites in the Tularosa Mountains, New Mexico, using a vegetation map derived from Landsat Thematic Mapper (TM) digital imagery and digital elevation models. Owls occupied sites with more mature mixed-conifer and mature pine and less pinyon-juniper than random sites. No difference existed in the amount of young forest between owl and random sites. After correcting for the area of the vegetation classes within owl territories, no difference existed...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.