Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16785
Fire clay
Seven companies mined fire clay in four states during 2003. From 1984 to 1992, production declined to 383 kt (422,000 st) from a high of 1.04 Mt (1.14 million st) as markets for clay-based refractories declined. Since 1992, production levels have been erratic, ranging from 383 kt (422,000 st) in 1992 and 2001 to 583 kt (642,000 st) in 1995. Production in 2003, based on preliminary data, was estima
Authors
R.L. Virta
Mineral resource of the month: rare earths
As if classified as a top-secret project, the rare earths have been shrouded in secrecy. The principal ore mineral of the group, bastnäsite, rarely appears in the leading mineralogy texts. The long names of the rare-earth elements and some unusual arrangements of letters, many Scandinavian in origin, may have intimidated even those skilled in phonics. Somewhat obscurely labeled, the rare earths ar
Authors
James B. Hedrick
Gemstones
Part of the 2003 industrial minerals review. Supply and demand data for gemstones are provided. Industry developments and the outlook for 2004 are discussed.
Authors
D.W. Olson
Industrial garnet
Supply and demand data for industrial garnet are provided. Topics discussed are production, consumption, prices, foreign trade, and the outlook for 2004.
Authors
D.W. Olson
Demographic estimation methods for plants with dormancy
Demographic studies in plants appear simple because unlike animals, plants do not run away. Plant individuals can be marked with, e.g., plastic tags, but often the coordinates of an individual may be sufficient to identify it. Vascular plants in temperate latitudes have a pronounced seasonal life–cycle, so most plant demographers survey their study plots once a year often during or shortly after f
Authors
M. Kery, K.B. Gregg
Atlantic Flyway review: Region IV - Fall 2003: Patuxent powerline right-of-way (390-0764)
The station was operated on fewer days than usual in 2003, opening a bit later, closing a week early, and missing several good days in September through mid-October, when the manager/lead bander was conducting research on migrating birds in Lower Delmarva. As a result, capture totals for many species are not comparable to other years, and totals for several species, including House Wren, Northern
Authors
Deanna K. Dawson
Coping with unobservable and mis-classified states in capture-recapture studies
Multistate mark-recapture methods provide an excellent conceptual framework for considering estimation in studies of marked animals. Traditional methods include the assumptions that (1) each state an animal occupies is observable, and (2) state is assigned correctly at each point in time. Failure of either of these assumptions can lead to biased estimates of demographic parameters. I review des
Authors
W. L. Kendall
Atlantic Flyway review: Region IV - Fall 2003
We welcome the Eden Mill station in northeastern Maryland to Region IV this year. With three stations reporting their worst year ever, we really need to be refreshed. After a cool and wet July, August was hot and wet in the east. Temperatures in September remained close to normal, but thanks to tropical storms Henri (6-8 Sep) and Isabel (18 Sep), rainfall was excessive in the Chesapeake Bay states
Authors
Chandler S. Robbins
Large-scale habitat associations of four desert anurans in Big Bend National Park, Texas
We used night driving to examine large scale habitat associations of four common desert anurans in Big Bend National Park, Texas. We examined association of soil types and vegetation communities with abundance of Couch's Spadefoots (Scaphiopus couchii), Red-spotted Toads (Bufo punctatus), Texas Toads (Bufo speciosus), and Western Green Toads (Bufo debilis). All four species were disproportionately
Authors
Gage H. Dayton, R.E. Jung, Sam Droege
Changes in lagoonal marsh morphology at selected northeastern Atlantic coast sites of significance to migratory waterbirds
Five lagoonal salt marsh areas, ranging from 220 ha to 3,670 ha, were selected from Cape Cod, Massachusetts to the southern DelMarVa peninsula, Virginia, USA to examine the degree to which Spartina marsh area and microhabitats had changed from the early or mid- 1900s to recent periods. We chose areas based on their importance to migratory bird populations, agency concerns about marsh loss and sea-
Authors
R.M. Erwin, G.M. Sanders, D.J. Prosser
Zinc toxicosis in a free-flying trumpeter swan (Cygnus buccinator)
A trumpeter swan (Cygnus buccinator) was observed near it mill pond in Picher, Oklahoma. USA. It became weakened and emaciated after about 1 mo, was captured with little resistance, and taken into captivity for medical care. Serum chemistry results were consistent with hepatic, renal, and muscular damage. Serum zinc concentration was elevated at 11.2 parts per million (ppm). The swan was treat
Authors
J. W. Carpenter, G.A. Andrews, W. N. Beyer
Extraordinary size and survival of American black duck, Anas rubripes, broods
Two female American black duck, Anas rubripes, were initially observed during June 1982 with 20 Class Ib or 18-22 Class Ia-b ducklings in two wetlands in Hancock County, Cherryfield, Maine. Fifteen of 20 ducklings (75%) in one brood and 16 of 18-22 ducklings (72-89%) in the other brood survived to fledge. These large broods probably resulted from post-hatch brood amalgamation.
Authors
J. R. Longcore, D.G. McAuley