Publications

Fluorspar, this month’s featured mineral resource commodity, has been widely used in steelmaking since the introduction of basic open-hearth furnace technology in the late 19th century. Its uses have grown and changed over the last 100 years, and now fluorspar’s most important markets are fluorochemicals, aluminum refining and steel. M. Michael Miller, Fluorspar Commodity Specialist for the U.S. G

Perlite is found in most homes, workplaces and schools. Most of the white ceiling tiles in offices and classrooms are made primarily of perlite. The soil around potted plants also has small white grains of perlite. Other than in these lightweight construction products and horticultural soil mixes, perlite is used in food processing for filtration and in natural gas processing as a low-temperature

Part of the 2002 industrial minerals review. Statistics on ball clay consumption, production, prices, trade, and trends are presented.

Since domestic sulfur production peaked at nearly 11 million metric tons in 1974, the sulfur industry has undergone dramatic change. In 1974, mined sulfur produced using the Frasch hot water method provided 8 million tons of sulfur, representing 75 percent of total elemental sulfur production. (In the Frasch process, hot water is injected directly into the sulfur-containing mineral strata, melting

A comprehensive monitoring program for colonial waterbirds in North America has never existed. At smaller geographic scales, many states and provinces conduct surveys of colonial waterbird populations. Periodic regional surveys are conducted at varying times during the breeding season using a variety of survey methods, which complicates attempts to estimate population trends for most species. The

Avian conservation science in North America has produced a variety of monitoring programs designed to provide information on population status of birds. Waterfowl surveys provide population estimates for breeding ducks over most of the continent, the North American Breeding Bird Survey (BBS) provides indexes to population change for >400 breeding bird species, and many other surveys exist that ind

This is the third Supplement since publication of the 7th edition of the Check-list of North American Birds (American Ornithologists' Union [AOU] 1998). It summarizes decisions made by the AOU's Committee on Classification and Nomenclature between 1 January 2002 and 31 December 2002.

No abstract available.

Long-term monitoring of estuarine nekton has many practical and ecological benefits but efforts are hampered by a lack of standardized sampling procedures. This study provides a rationale for monitoring nekton in shallow (< 1 m), temperate, estuarine habitats and addresses some important issues that arise when developing monitoring protocols. Sampling in seagrass and salt marsh habitats is emphasi

Management of birds often requires analysis of collections of estimates. We describe a hierarchical modeling approach to the analysis of these data, in which parameters associated with the individual species estimates are treated as random variables, and probability statements are made about the species parameters conditioned on the data. A Markov-Chain Monte Carlo (MCMC) procedure is used to fi

1. Fat reserves are stored energy that may help birds survive periods of harsh winter weather. This hypothesis predicts that annual apparent survival is higher for birds with large fat reserves than for birds with few or no fat reserves in winter. 2. Blackbirds (Turdus merula Linnaeus) were ringed in central Italy from 16 November to 20 February during 1990-2001. Fat scores were recorded for each

Complex surveys often are necessary to estimate occurrence (or distribution), density, and abundance of plants and animals for purposes of re-search and conservation. Most scientists are familiar with simple random sampling, where sample units are selected from a population of interest (sampling frame) with equal probability. However, the goal of ecological surveys often is to make inferences abou