Birds of America Online

Comprehensive life histories of all birds breeding in the U.S. and Canada.

The Complete Works of Charles Darwin

Includes the complete publications, many handwritten manuscripts, and supplementary texts.

Encyclopedia of Earth

A new electronic reference about the Earth, its natural environments, and their interaction with society. The Encyclopedia is a free, fully searchable collection of articles written by scholars, professionals, educators, and experts who collaborate and review each other's work.

Flora of North America

Information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico.

National Wildlife Health Center

Provides scientific and technical support, and disseminates information to "promote science-based decisions affecting wildlife and ecosystem health." The site has links to disease information, research being conducted by the center, center publications, public outreach, related resources, and information about the center.

Science Nation

Science Nation is an online magazine that each week looks at discoveries and researchers that will change our lives.