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Research about Oregon, Washington

Source-linked reports with geographic coverage including Oregon, Washington.

At least 271 records · Page 15Linked to original sources
USGS1987

Evaluation of pitfall trapping in northwestern forests: Trap arrays with drift fences

We operated pitfall arrays with 5-m drift fences at 30 stands in western Oregon and Washington for 180 days. Pitfall arrays had a pronounced removal effect on small mammals (but not on the herpetofauna) during the 1st 60 days of trapping. Conventional short (10-day) trapping periods were only adequate to detect the most common mammals. About 60 days were needed to compile a relatively complete species list (>85% of species captured) at each site. Reptiles were caught almost exclusively in the summer; amphibian captures were correlated with increased precipitation in the fall. Short (2.5-m) drift fences were less effective than the standard length of 5 m. Funnel traps captured few forest vertebrates. Pitfalls captured more insectivorous mammals than did snap traps, but snap traps were more effective for a few cricetid rodents. Pitfall arrays are adaptable to many habitats and can help assess the presence of small vertebrates, such as shrews and amphibians, that are undersampled by other techniques.

Oregon, Washington↗
USGS1984

Effects of heptachlor- and lindane-treated seed on Canada geese

A study of Canada geese (B. canadensis) was conducted in the Pacific Northwest from 1978 through 1981. Lowered reproductive success, mortality of adults, and a population decline of resident western Canada geese (B. c. moffitti) at the Umatilla National Wildlife Refuge (Umatilla NWR) Oregon and Washington [USA] were associated with the use of heptachlor-treated wheat. Analyses of eggs and tissues from dead geese provided strong evidence that heptachlor was responsible for the mortality and decreased production. Residues of heptachlor epoxide (HE) in brains of B. c. moffitti found dead in 1978 and 1979 equalled or exceeded the lethal hazard zone of 8-9 .mu.g/g in experimental passerine birds; HE residues of > 10 .mu.g/g in sample eggs were associated with low nest success. The breeding population of Canada geese at Umatilla decreased from 129 pairs in 1974 to about 100 pairs in 1979. The heptachlor problem was restricted to the Umatilla area; HE residues were low in tissues and eggs collected at other sites in Oregon, Washington and Idaho. In Sept., 1979, the use of heptachlor-treated seed was banned in a 1700-km2 area that encompassed both sides of the Columbia River near Umatilla. Lindane was substituted for heptachlor in the restricted area in 1979, and its use was extended to much of the Columbia Basin in 1981. Concurrently, reproductive success of geese increased, mortality decreased, and the nesting population increased to 170 pairs by 1983. There was no evidence for either biomagnification of lindance residues from treated seed to goose tissues or eggs or for induction of adverse effects by this compound.

Oregon, Washington↗
USGS1983

Sediment deposition in the Columbia and lower Cowlitz rivers, Washington-Oregon, caused by the May 18, 1980, eruption of Mount St. Helens

On May 18, 1980, Mount St. Helens violently erupted, sending billions of cubic yards of mud, ash, rock fragments, and debris down the North and South Forks of the Toutle River, the Cowlitz and Columbia Rivers, and other streams. A total of 35.6 million cubic yards of mudflow material was deposited in the lower Cowlitz (downstream from the Union Pacific Railroad bridge) and Columbia Rivers. The arrival of this material at the Columbia River, during a period of the daily tidal cycle, when the flow was at a minimum or quite probably reversed and flowing upstream resulted in its deposition in an area 7 miles upstream and 2 miles downstream from the junction of the Cowlitz and Columbia Rivers. The thickness of the deposit was at a maximum near Coffin Rock, where a hole 140 feet deep was filled with 90 feet of sediment. Incomplete filling, compaction, and (or) erosion caused a 1Q-foot depression to form in the surface of the newly deposited material at this location. On May 23, 1980, the presence of two scour channels on each side of a tonguelike deposit (delta) of very fine sand and silt indicates that the coarse-grained sediment and water surge on the morning of May 19 initially scoured the lower 0.5 mile of the Cowlitz River bed. A minimum of 0.4 million cubic yard of material was scoured from the Cowlitz River bed and subsequently redeposited in the Columbia River before the 1.3-million-cubic-yard delta was formed.

Oregon, Washington↗
USGS1983

Comparative physiographic diagrams of Mount St. Helens, Washington, and Crater Lake, Oregon

These physiographic diagrams provide a visual comparison of two Cascade Range volcanoes which have had their tops destroyed in different ways -- Mount St. Helens in 1980, Mount Mazama (whose site is now occupied by Crater Lake) about 6,800 years ago. Both volcanoes are viewed from the north from 30 degrees above the horizon, with no vertical exaggeration. The ground area portrayed in each diagram is equal; the south edge of the Mount St. Helens drawing is lower than that of Crater Lake drawing because elevations drop away toward the south, whereas elevations are more constant at the north and south edges of the Crater Lake diagram.

Oregon, Washington↗
USGS1981

Suspected Great Blue Heron population decline after a severe winter in the Columbia Basin

The wintering range of the Great Blue Heron ( Ardea herodias ) extends further north than does that of any other member of the Ciconiiformes in North America. The northern limits of its range extend along the Pacific coast into southeastern Alaska, into Massachusetts on the Atlantic coast, and inland into southern Montana (Palmer 1962). In the northern part of its range, severe winter weather may persist for weeks or months. Little information is available regarding either the response of individual Great Blue Herons to severe winters or the effects of these conditions on populations. In this paper, we report our observations on a small heron population in Oregon and Washington that was exposed to a severe winter.

Oregon, Washington↗
USGS1980

Pollution ecology of breeding great blue herons in the Columbia Basin, Oregon and Washington

Approximately 40 pairs of Great Blue Herons ( Ardea herodias ) formerly nested in trees on or near Blalock Island about 95 km downstream from Richland, Washington, in the Columbia River (Nehls 1972 ). In conjunction with construction of the John Day Lock and Dam and before creating Lake Umatilla in 1968, large trees along the shoreline, including those in the heronry on Blalock Island, were removed except for about six cottonwood trees ( Populus sp.) that were left standing near the south bank of the river (David Lenhart, pers. comm.). As a mitigation procedure, the Umatilla National Wildlife Refuge (Umatilla) was established in 1967. The herons subsequently established a secondary heronry in the six cottonwoods; 20 pairs were present in 1971 (Nehls 1972). The inundated trees died and deteriorated; only two trees with eight nests remained in 1976 (Henny and Kurtz 1978), and we found just two nests in one tree in 1978. With a decrease in traditional nesting sites, the birds nested on islands in big sagebrush ( Artemisia tridentata ), on channel markers in the Columbia River, and on nesting platforms constructed for Canada Geese ( Branta canadensis ). The purpose of this paper is to describe the breeding biology of Great Blue Herons at Umatilla and the McNary Recreation Area (McNary) in 1978 and the relationship of organochlorine residues in eggs to eggshell thickness and reproductive success. The primary reason for conducting this study was to determine if the heptachlor seed treatment that was severely affecting Canada Geese at Umatilla (Blus et al. 1979) was also a hazard to Great Blue Herons. At the same time we also investigated possible effects of other organochlorines on the herons.

Oregon, Washington↗