Numerous laboratory studies with at least 12 species of rodents have reported that exposure of females to strange males results in pregnancy disruption or infanticide. The proximate causes and ultimate benefits of these behaviors have been proposed from an evolutionary perspective. To determine if exposure to strange males or females...
Riparian areas in the arid western United States are critical ecosystems that have been severely degraded by a variety of land and water uses over the last 100 years. In this study, the composition and structure of floodplain vegetation along the Lower Owens River in eastern California was quantitatively described...
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...
The North Pacific humpback whale (Megaptera novaeangliae) population has been increasing at an average annual rate of ~6% since the early 1990s. In northern Southeast Alaska alone, there are now more whales than estimated for the entire North Pacific several decades ago. An understanding of how this growing population is...
The federally threatened northern spotted owl (Strix occidentalis caurina) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted...
Fire severity is hypothesized as an important driver of bird responses to wildfire. For those species that typically respond negatively to increasing severity, Accessibility of high-severity burned forest may be dependent on the proximity of unburned or low-severity burned forest to meet all of the needs of breeding bird species...
Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential...
Shrews previously recognized as Sorex monticolus were classified
into two species (one with 14 subspecies, the other monotypic) on
the basis of a morphometric analysis of 3610 individuals from
throughout their range. Sorex m. neomexicanus has been recognized
previously as a subspecies of Sorex monticolus but is recognized
herein as...
This dissertation focuses on the predator-prey relationship between two species of avian predators, Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus), and one of their important prey types, juvenile salmonids (Oncorhynchus spp.), in the Columbia River estuary of Oregon and Washington states during the period 1998 – 2007. I...