Publications

No abstract available.

Among studies that have quantified the care of precocial young, few have investigated forms of parental care other than vigilance. During the pre-fledging period, Tundra Swan (Cygnus columbianus columbianus) parents provided simultaneous biparental care by foraging near each other and their cygnets, and cygnets spent more time foraging during bouts in which both parents were foraging nearby than w

No abstract available.

Using molecular-genetic techniques, we determined the gender of 202 Southwestern Willow Flycatcher (Empidonax traillii extimus) nestlings from 95 nests sampled over a five-year period. Overall nestling sex ratio did not vary significantly from 50:50 among years, by clutch order, or by mating strategy (monogamous vs. polygamous pairings). However, we did observe significant differences among the fo

No abstract available.

In the winters of 1998–1999 and 1999–2000, we tracked 67 radio-marked Dunlin (Calidris alpina) throughout the complex agricultural landscape of the Willamette Valley of Oregon. Individual birds were tracked across 8-week sampling periods and indicated a high degree of regional fidelity throughout the three winter sampling periods. Birds exhibited varied degrees of fidelity to specific wetland site

We compared American White Pelican (Pelecanus erythrorhynchos) soaring flight times and altitudes to model-produced estimates of thermal depth and intensity. These data showed that pelican soaring flight was confined to the thermal layer, and that the vertical extent of the soaring flight envelope increased with increases in thermal depth. Pelicans soaring cross-country between foraging and breedi

Terminal restriction fragment length polymorphism (TRF or T-RFLP) analysis and 16S rDNA sequence analysis from clone libraries were used to examine cyanobacterial diversity in three types of predominant soil crusts in an arid grassland. Total DNA was extracted from cyanobacteria-, lichen-, or moss-dominated crusts that represent different successional stages in crust development, and which contrib

In Mount Rainier National Park, the northwestern salamander usually inhabits relatively large and deep lakes and ponds (average size = 0.3 ha; average depth > 2 m) that contain flocculent, organic bottom sediments and abundant coarse wood. Prior to 1970, salmonids were introduced into many of the park's lakes and ponds that were typical habitat of the northwestern salamander. The objective of this

We reviewed the literature to assess status and population trends and to identify mortality factors affecting Golden Eagle populations in the U.S. and Canada. Nesting populations in Alaska and Canada are stable, but some nesting populations in the western U.S. have declined. Small but steady declines in the intermountain West have been associated with shrub loss and declining jackrabbit populatio

Increased exposure to ultraviolet-B (UV-B) radiation has been proposed as a major environmental stressor leading to global amphibian declines. Prior experimental evidence from the U.S. Pacific Northwest (PNW) indicating the acute embryonic sensitivity of at least four amphibian species to UV-B has been central to the literature about amphibian decline. However, these results have not been expanded

Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a starting point, we developed a rapid, qualitative method for asse