BNA Online provides comprehensive life histories for each of the 716+ species of birds breeding in the USA (including Hawaii) and Canada.
Here is a sample article about the Belted Kingfisher.
The Encyclopedia of Life Sciences (ELS) features more than 4,000 specially commissioned and peer-reviewed articles on a broad range of biology related topics. This is an encyclopedia with in-depth, scholarly coverage of major concepts in the life sciences.
Here is a sample entry from the ELS written by EEB professor Peter R. Grant (go to the entry and open the PDF). In each ELS article, you will find the "References" and "Further Reading" sections helpful for developing your knowledge of the article topic.
Includes The McGraw-Hill Encyclopedia of Science & Technology 10th edition, McGraw-Hill Yearbooks of Science & Technology, McGraw-Hill Dictionary of Scientific and Technical Terms, and the Hutchinson Dictionary of Scientific Biography.
Here is a sample article from AccessScience on Island Biogeography
This guide presents extensive data on the habitats and ecosystems of more than 1,200 species identified as endangered or threatened by the U.S. Fish and Wildlife service. Arranged taxonomically, entries include introductory information with an image of the species; a summary section detailing information on each species; a concluding summary of recovery efforts; and a bibliography of contacts for further information.