Publications

We examined effects of fire on golden eagle (Aquila chrysaetos) territory occupancy and reproductive success in southwestern Idaho because wildfires since 1980 have resulted in large-scale losses of shrub habitat in the Snake River Plain. Success (percentage of pairs that raised young) at burned territories declined after major fires (P = 0.004). Pairs in burned areas that could expand...

Tree-ring chronologies for mountain hemlock (Tsuga mertensiana) were used to reconstruct the water level of Crater Lake, a high-elevation lake in the southern Cascade Range of Oregon. Reconstructions indicate that lake level since the late 1980s has been lower than at any point in the last 300 years except the early 1930s to mid 1940s. Lake level was consistently higher during the Little...

The American Kestrel(Falco sparverius) is a sexually dichromatic falcon that exhibits considerable individual plumage variability. For example, the anterior extent of the black dorsal barring in juvenile males has been used throughout North America as one of several aging criteria, but recent data demonstrate that the variability among individual Southeastern American Kestrels(E S...

Lack of information concerning predatory interactions between Ambystoma gracile and Ambystoma macrodactylum (long-toed salamander) larvae, as well as potential cannibalism within A. gracile populations, prompted us to conduct a field experiment to investigate the potential for this inter- and intraspecific predation. This field experiment was conducted at a lake in Mount Rainier National...

A synoptic inventory of physical and chemical properties and plankton assemblages of 27 mountain lakes was conducted at Mount Rainier National Park in 1988. From 1990–1993, die opportunity was presented to resurvey six of these lakes to determine inter-annual change within die set of characteristics surveyed in 1988. If changes were evident, a second objective was to provide guidance to...

No abstract available.

Many applied and theoretical investigations require information on how productivity varies in time and space (Temple and Wiens 1989. DeSante 1995). Examples include studies of habitat quality, population trends, life-history tactics, and metapopulation dynamics. From a demographic perspective, productivity is the number of young counted at a given time of year, produced per adult (e.g...

Tailed frogs (Ascaphus truei) occur in permanent, cold streams in northwestern North America. Their tadpoles reportedly undergo metamorphosis after 2-4 years. Coastal populations that we examined transformed in 2 yr from the Olympic peninsula in Washington to northern Oregon, but in 1 yr from central Oregon to northern California. One inland site in northern California had a 2-yr period...

The diving behavior of Marbled Murrelets (Brachyramphus marmoratus) was studied using telemetry along the Oregon coast during the 1995 and 1996 breeding seasons and examined in relation to predictions from optimal-breathing models. Duration of dives, pauses, dive bouts, time spent under water during dive bouts, and nondiving intervals between successive dive bouts were recorded. Most...

The 13 chapters in this book were selected from the 75 research papers presented at the Fourth Biennial Conference of Research on the Colorado Plateau. The theme of this meeting centered around research, inventory, and monitoring on lands over the Colorado Plateau, with a focus on the newly created BLM Grand Staircase-Escalante National Monument. The conference, held on 15-18 September...

No abstract available.

We studied a nesting population of Prairie Falcons (Falco mexicanus) in the Snake River Birds of Prey National Conservation Area (NCA) from 1974-1997 to identify factors that influence abundance and reproduction. Our sampling period included two major droughts and associated crashes in Townsend's ground squirrel (Spermophilus townsendii) populations. The number of Prairie Falcon pairs...