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Geology topics

Gregory J. Smith

Publications and source records attributed to Gregory J. Smith.

9 recordsLinked to original sources
USGS2019

Mammut pacificus sp. nov., a newly recognized species of mastodon from the Pleistocene of western North America

A new species of mastodon from the Pleistocene of western North America, Mammut pacificus sp. nov. is herein recognized, with specimens identified throughout California and from two localities in southern Idaho. This new taxon differs from the contemporaneous M. americanum in having narrower teeth, most prominently in M3/m3, as well as six sacral vertebrae, femur with a proportionally greater mid-shaft diameter, and no mandibular tusks at any growth stage. All known Pleistocene Mammut remains from California are consistent with our diagnosis of M. pacificus , which indicates that M. americanum was not present in California.

PeerJ↗
USGS2013

The U.S. Geological Survey Bird Banding Laboratory: an integrated scientific program supporting research and conservation of North American birds

The U.S. Geological Survey (USGS) Bird Banding Laboratory (BBL) was established in 1920 after ratification of the Migratory Bird Treaty Act with the United Kingdom in 1918. During World War II, the BBL was moved from Washington, D.C., to what is now the USGS Patuxent Wildlife Research Center (PWRC). The BBL issues permits and bands to permittees to band birds, records bird band recoveries or encounters primarily through telephone and Internet reporting, and manages more than 72 million banding records and more than 4.5 million records of encounters using state-of-the-art technologies. Moreover, the BBL also issues bands and manages banding and encounter data for the Canadian Bird Banding Office (BBO). Each year approximately 1 million bands are shipped from the BBL to banders in the United States and Canada, and nearly 100,000 encounter reports are entered into the BBL systems. Banding data are essential for regulatory programs, especially migratory waterfowl harvest regulations. The USGS BBL works closely with the U.S. Fish and Wildlife Service (USFWS) to develop regulations for the capture, handling, banding, and marking of birds. These regulations are published in the Code of Federal Regulations (CFR). In 2006, the BBL and the USFWS Division of Migratory Bird Management (DMBM) began a comprehensive revision of the banding regulations. The bird banding community has three major constituencies: Federal and State agency personnel involved in the management and conservation of bird populations that include the Flyway Councils, ornithological research scientists, and avocational banders. With increased demand for banding activities and relatively constant funding, a Federal Advisory Committee (Committee) was chartered and reviewed the BBL program in 2005. The final report of the Committee included six major goals and 58 specific recommendations, 47 of which have been addressed by the BBL. Specifically, the Committee recommended the BBL continue to support science, conservation, and management of birds through the use of banding and banding data and that the BBL be managed by the USGS and located at the USGS Patuxent Wildlife Research Center (PWRC) in Laurel, Maryland. Recommendations that have not been implemented include those already addressed by other organizations, as well as lower priority, such as developing a BBL business plan. The comprehensive review and recommendations of the Committee, the response of the BBL to address the Committee’s recommendations, and other improvements to its operations have positioned the BBL to provide a high level of service to the banding community. As new technologies are developed and incorporated into BBL operations, further efficiencies are expected to enable the BBL to continue to meet emerging scientific needs.

Open-File Report↗
USGS2006

Wetland researchers on the hurricane front lines

Close proximity to the Gulf Coast and its expansive wetland ecosystem made Lafayette, Louisiana, a perfect site for the U.S. Geological Survey National Wetlands Research Center. This location also put the center at the edge of the hurricane impact zones. In the days following the storms, researchers became rescuers and scientists saved lives.

Louisiana↗
USGS2005

Using radar to understand migratory birds and their habitats: Critical needs for the Gulf of Mexico

Nearly all Neotropical migratory landbird species of the eastern United States as well as many western species use Louisiana and the northern Gulf of Mexico coast during their transcontinental migrations each spring and fall. Radar has determined that hundreds of millions of birds make the nocturnal crossing of the Gulf of Mexico resulting in daily flights of as many as 2.5 million individuals stopping in Louisiana to feed and rest. These migration landings are so spectacular that the term “fallout” has been coined to describe the concentrations of birds arriving on the coast.

Fact Sheet↗
USGS2005

Migratory bird pathways and the Gulf of Mexico: Importance of Louisiana's coast

Because of its geographic position, Louisiana plays an important role in the hemispheric-scale phenomenon known as the Nearctic-Neotropical bird migration system. Each year millions of landbirds migrate across or near to the coast of the Gulf of Mexico. Birds migrate in large, broad fronts that sometimes exceed 2 million individuals, and there is an advantage for them to take a direct north-south route (the shortest distance). During migration seasons, nearly all of the migratory landbird species of the eastern United States, as well as many western species, use the coastal plains of the western gulf. Spring migrants arrive with depleted energy reserves and depend on Louisiana's coastal habitats to provide food and cover after long gulf crossings. Fall migrants depend on Louisiana’s coastal habitats for food to store fat reserves just prior to gulf crossings in autumn. Mortality during the migratory period can be high. Recent research on the black-throated blue warbler ( Dendroica caerulescens ) indicates that more than 85% of the annual mortality for the species occurs during migration. Migrants en route tend to concentrate in habitats adjacent to ecological barriers; DOI land managers need to identify key coastal landscape features that are important to these birds. Because of the vastness of the North American continent, it is nearly impossible to delineate movement patterns and migration pathways by using traditional ground-based surveys.

Fact Sheet↗
USGS2005

Depicting coastal Louisiana land loss

The Coastal Louisiana Land Loss map depicts historical (1932-2000) changes of land to water and water to land, as well as projected changes (2000-2050). Projections are based on the assumption of no future restoration.

Fact Sheet↗
USGS1989

Selenium accumulation by raccoons exposed to irrigation drainwater at Kesterson National Wildlife Refuge, California, 1986

In February–March 1986, eight raccoons ( Procyon lotor ) were collected at Kesterson Reservoir (Merced Co., California), which had received selenium-contaminated irrigation drainwater, and four raccoons were collected at the nearby Volta Wildlife Area, which had not. Selenium concentrations in Kesterson raccoons averaged 19.9 ppm (μg/g dry wt) in liver, 28.3 ppm (dry wt) in hair, 21.6 ppm (dry wt) in feces, and 2.61 ppm (wet wt) in blood and exceeded Volta concentrations by 12, 30, 21, and 10 times, respectively. Selenium concentrations in livers of Kesterson raccoons were less than those in five of nine other mammal species sampled in 1984. Selenium concentrations in hair provided the strongest statistical separation between study areas. Hemoglobin levels in two Kesterson raccoons equalled levels reported in rats with selenium-induced anemia, but the raccoons showed no illness. Amyloidosis in one Kesterson raccoon may have been selenium-induced. Our data indicate that raccoon births peaked about 2 months later than was previously reported. Based on our sample of 12 raccoons, we found no evidence that contamination by irrigation drainwater had negative effects on raccoons inhabiting Kesterson.

California↗
USGS1986

Cholinesterase activity in black-crowned night-herons exposed to fenthion-treated water

Fenthion, ( 0,0 -Dimethyl 0 -[3-methyl-4-(methylthio)phenyl] phosphorothioate), a widely used mosquito control agent, has caused wildlife mortality. To simulate a shallow wetland environment, an exposure chamber was used containing water treated with fenthion at 1 and 10 times the field application rate of 112 g active ingredient (AI)/ ha. This system permitted an evaluation of exposure routes and the effects of fenthion in a representative species of wading bird, the black-crowned night-heron ( Nycticorax nycticorax ). The results suggested that herons received only a dermal exposure, and that their brain acetylcholinesterase activity was not significantly inhibited. In contrast, however, plasma butyrylcholinesterase activity was inhibited, suggesting the herons were exposed to the insecticide. The application rates and types of exposures were not life-threatening in this species.

Archives of Environmental Contamination and Toxico↗