Publications

Few ecologists would dispute that exposure to high levels of ultraviolet-B radiation (UV-B) is detrimental to organisms. It is well established that UV-B has been a critical factor shaping the physiology (Blum et al. 1949, Hansson 2000), behavior (Pennington and Emlet 1986, van de Mortel and Buttemer 1998), and distribution (Williamson et al. 2001, Leavitt et al. 2003) of many aquatic...

Patterns of debris-flow occurrence were investigated in 125 headwater basins in the Oregon Coast Range. Time since the previous debris-flows was established using dendrochronology, and recurrence interval estimates ranged from 98 to 357 years. Tributary basins with larger drainage areas had a greater abundance of potential landslide source areas and a greater frequency of scouring events...

Island-wide surveys for the endangered Mariana subspecies of the Common Moorhen (Gallinula chloropus guami) were conducted on Guam and the Commonwealth of the Northern Mariana Islands from May through September 2001. Based on these counts, the total adult moorhen population is estimated to be 287, with 154, 41, 2, and 90 adult moorhens on Saipan, Tinian, Rota, and Guam, respectively...

Many of todays agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38° incidence angle (8-m resolution) to map the distribution of winter shorebird

Video recording of prey deliveries to nests is a new technique for collecting data on raptor diet, but no thorough comparison of results from traditional methods based on collections of prey remains and pellets has been undertaken. We compared data from these 3 methods to determine relative merits of different methods for assessing raptor diet as part of a study of the breeding-season...

Introduction In the past two decades, scientists around the world have increasingly noted losses of amphibian populations. Many of these declines have occurred in protected areas like national parks, where the causes mostly remain mysterious. However, in multipleuse landscapes, resource managers frequently face more obvious conservation problems and must make decisions that will affect...

Twenty-four juvenile Steller's Sea Eagles Haliaeetus pelagicus were tracked via satellite from natal areas in Magadan, Kabarovsk, Amur, Sakhalin and Kamchatka. Nestling dispersal occurred between 9 September and 6 December (n = 24), mostly 14 September-21 October, and did not differ among regions or years. Most eagles made stopovers of 4-28 days during migration. Migration occurred 9...

No abstract available.

Birds of Oregon is the first complete reference work on Oregon's birds to be published since Gabrielson and Jewett's landmark book in 1940. This comprehensive volume includes individual accounts of the approximately 500 species now known to occur in Oregon (about 150 more than in 1940), including detailed accounts of the 353 species that regularly occur and briefer accounts of another...

This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most...

No abstract available.

Riparian forests contribute to the diversity and function of both terrestrial and aquatic ecosystems. To assess some of these contributions, we compared tree composition, stand complexity, and temporal patterns of tree mortality on permanent plots in seven mature and old-growth stands representing upland forests and forests along low- and mid-order streams in the Western Cascade Range of...