contain morphological characters, and GenBank (http://www.ncbi.nlm.nih.gov/Genbank/) has DNA sequence characters.

Nomenclatural databases provide information and documentation on the scientific names of organisms. They provide the correct (valid) names for species so users have the appropriate search terms for queries in other databases. Like specimen databases, the number of nomenclature databases for particular groups and areas is increasing, and so is the number of software applications that consolidate or provide access to them. The Catalogue of Life, through its annual checklist, provides minimal information on more than a half-million species; all of that information is integrated with the services of GBIF as part of the Electronic Catalogue of Life Names of Known Organisms. The Universal Biological Indexer and Organizer contains approximately 5 million names; the Taxonomic Search Engine searches all major nomenclators; and the Integrated Taxonomic Information System provides the official taxonomy of living organisms for the United States, Canada, and Mexico. Some specialized databases that include pollinator data are the BioSystematic Database of World Diptera and the Hymenoptera Name Server.

Species databases provide information and documentation on organisms. Unfortunately, a comprehensive database does not yet exist, although ultimately, species databases will be transformed into the envisioned Electronic Encyclopedia of Life (Wilson, 2003). Species databases sort information by attributes, such as the pollinators of a given plant, and they provide summaries about species or links to species web pages.

Literature databases compile published information and they comprise the same sources used generally for the biological sciences. Literature databases range from general commercial compilations, such as Biological Abstracts and the Zoological Record, to specialized research databases, such as AnimalBase, which links digital versions of the early zoological literature to personally maintained, but publicly accessible databases. One example is the Pollination Biology Database, maintained by David Inouye at the University of Maryland.

Conservation-oriented databases exist to track and monitor putatively threatened populations of animals and plants. Among them are the Nature-Serve Explorer and the Heritage Program network; the federal database of species protected by the U.S. Endangered Species Act; and international lists, such as those from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (www.cites.org/) and the World Conservation Union (IUCN; www.redlist.org/). The Heritage Program and NatureServe tracking systems provide a first step in understanding patterns of decline.

Numerous sources of data—including museum collections, naturalists’ observations, and accounts published in peer-reviewed literature—contrib-