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The Cascades Ecoregion (Omernik, 1987; U.S. Environmental Protection Agency, 1997) covers approximately 46,787 km2 (18,064 mi2) in Washington, Oregon, and California (fig. 1). The main body of the ecoregion extends from Snoqualmie Pass, Washington, in the north, to Hayden Mountain, near State Highway 66 in southern Oregon. Also included in...

The Central California Valley Ecoregion, which covers approximately 45,983 km2 (17,754 mi2), is an elongated basin extending approximately 650 km north to south through central California (fig. 1) (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The ecoregion is surrounded entirely by the Southern and Central California Chaparral and Oak Woodlands...

This chapter has been modified from original material published in Soulard (2006), entitled “Land-cover trends of the Central Basin and Range Ecoregion” (U.S. Geological Survey Scientific Investigations Report 2006–5288). The Central Basin and Range Ecoregion (Omernik, 1987; U.S. Environmental Protection Agency, 1997) encompasses approximately 343,169 km² (132,498 mi2) of land...

Habitat suitability (HS) maps are widely used tools in wildlife science and establish a link between wildlife populations and landscape pattern. Although HS maps spatially depict the distribution of optimal resources for a species, they do not reveal the population size a landscape is capable of supporting--information that is often...

Spatial patterns of marine predator communities are influenced to varying degrees by prey distribution and environmental gradients. We examined physical and biological attributes of an estuarine fjord with strong glacier influence to determine the factors that most influence the structure of predator and prey communities. Our results suggest that some...

Tundra swans (Cygnus columbianus) are broadly distributed in North America, use a wide variety of habitats, and exhibit diverse migration strategies. We investigated patterns of hematozoa infection in three populations of tundra swans that breed in Alaska using satellite tracking to infer host movement and molecular techniques to assess the...

The catastrophic breakup of the Larsen B Ice Shelf in the Weddell Sea in 2002 paints a vivid portrait of the effects of glacier-climate interactions. This event, along with other unexpected episodes of rapid mass loss from marine-terminating glaciers (i.e., tidewater glaciers, outlet glaciers, ice streams, ice shelves) sparked intensified...

Sex allocation theory predicts that parents should favor offspring of the sex that provides the greatest fitness return. Despite growing evidence suggesting that vertebrates are able to overcome the constraint of chromosomal sex determination, the general pattern remains equivocal, indicating a need for experimental investigations. We used an experimental feeding...

We present the results of a reconnaissance investigation of unusual debris mass-movement features on permafrost slopes that pose a potential infrastructure hazard in the south-central Brooks Range, Alaska. For the purpose of this paper, we describe these features as frozen debris-lobes. We focus on the characterisation of frozen debris-lobes as...

1. The Argos System is used worldwide to satellite-track free-ranging animals, but location errors can range from tens of metres to hundreds of kilometres. Low-quality locations (Argos classes A, 0, B and Z) dominate animal tracking data. Standard-quality animal tracking locations (Argos classes 3, 2 and 1) have larger errors...

The Wasatch and Uinta Mountains Ecoregion covers approximately 44,176 km2 (17, 057 mi2) (fig. 1) (Omernik, 1987; U.S. Environmental Protection Agency, 1997). With the exception of a small part of the ecoregion extending into southern Wyoming and southern Idaho, the vast majority of the ecoregion is located along the eastern...

This chapter has been modified from original material published in Soulard and others (2007), entitled “Land-cover trends of the Southern California Mountains ecoregion” (U.S. Geological Survey Scientific Investigations Report 2007–5235). The Southern California Mountains Ecoregion (Omernik, 1987; U.S. Environmental Protection Agency, 1997) encompasses approximately 17,871 km² (6,900 mi²) of land...

Somatic cell nuclear transfer offers the possibility of preserving endangered species including the black-footed cat, which is threatened with extinction. The effectiveness and efficiency of somatic cell nuclear transfer (SCNT) depends on a variety of factors, but 'inappropriate epigenetic reprogramming of the transplanted nucleus is the primary cause of the...

The Eastern Cascades Slopes and Foothills Ecoregion (Omernik, 1987; U.S. Environmental Protection Agency, 1997) covers approximately 57,329 km² (22,135 mi²) in the states of Washington, Oregon, and California (fig. 1). The ecoregion is bounded on the east by the Columbia Plateau, Blue Mountains, and Northern Basin and Range Ecoregions; on...

As the name suggests, the Arizona/New Mexico Mountains Ecoregion includes much of the mountainous regions of these two states, plus a very small part in the Guadalupe Mountains of northwestern Texas. Several isolated areas of higher terrain in Arizona and New Mexico are also included in the ecoregion, which occupies...

Characterization of vertebrate chemo-orientation strategies over long distances is difficult because it is often not feasible to conduct highly controlled hypothesis-based experiments in natural environments. To overcome the challenge, we couple in-stream behavioral observations of female sea lampreys (Petromyzon marinus) orienting to plumes of a synthesized mating pheromone, 7a,12a,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS),...

The Northern Basin and Range Ecoregion (Omernik, 1987; U.S. Environmental Protection Agency, 1997) is located in eastern Oregon (58.7 percent), northern Nevada (20.6 percent), southwestern Idaho (14.8 percent), and northeastern California (5.9 percent), encompassing the northern extent of the hydrographic Great Basin (Grayson, 1993). The ecoregion, which covers approximately 110,039...

The Southern and Central California Chaparral and Oak Woodlands Ecoregion, which covers approximately 102,110 km2 (39,425 mi2), is characterized by a Mediterranean climate with cool, moist winters and hot, dry summers (Omernik, 1987; U.S. Environmental Protection Agency, 1997). Natural vegetation includes chaparral (for example, manzanita, Arctostaphylos spp.) and oak (Quercus...

With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope...

Methylmercury chloride and seleno-L-methionine were injected separately or in combinations into mallard eggs (Anas platyrhynchos), and embryo mortality and teratogenic effects (deformities) were modeled using a logistic regression model. Methylmercury was injected at doses that resulted in concentrations of 0, 0.2, 0.4, 0.8, and 1.6 µg/g Hg in the...

The thermal output from the Yellowstone magma chamber can be estimated from the Cl flux in the major rivers in Yellowstone National Park; and by utilizing continuous discharge and electrical conductivity measurements the Cl flux can be calculated. The relationship between electrical conductivity and concentrations of Cl and other geothermal...

Analyses of organic-rich mudstones from wells that penetrated the Upper Jurassic Kimmeridge Clay Formation, offshore United Kingdom, were performed to evaluate the nature of both organic and inorganic rock constituents and their relation to porosity in this world-class source rock. The formation is at varying levels of thermal maturity, ranging...

No abstract available....

The Wyoming Basin Ecoregion (Omernik 1987; U.S. Environmental Protection Agency, 1999) covers approximately 128,914 km2 (49,774 mi2) in Wyoming and parts of northwestern Colorado, northeastern Utah, southeastern Idaho, and southern Montana (fig. 1). The ecoregion is bounded on the east by the Northwestern Great Plains Ecoregion; on the south and...

The Middle Rockies Ecoregion—characterized by steep, high-elevation mountain ranges and intermountain valleys—is a disjunct ecoregion composed of three distinct geographic areas: the Greater Yellowstone area in northwest Wyoming, southwest Montana, and eastern Idaho; the Bighorn Mountains in north-central Wyoming and south-central Montana; and the Black Hills in western South Dakota...