I have always been a big fan of Thayer's Birding Software. Thayer Birding has released two interesting new editions of their software: Version 4.5 (For Widows XP, Vista, Widows 7 and Mac OSX 10.4 to 10.7) and Gold version 5.5 (for Windows XP, Vista, and Windows 7--BUT NOT FOR THE MAC, unless you run a Windows emulation program in your Mac.) Thayer provides free updates for birders who already own version 4.0 and Gold 5.0. Those of us with older versions need to purchase new DVDs.
This software is an incredibly robust tool for learning the birds of North America. When I taught ornithology, my students bought these DVDs in place of a normal textbook. Although the prices of these products seem expensive, most college textbooks cost more! In any case, the DVDs come with an imbedded 785-page copy of The Birder's Handbook. While perhaps not replacing a traditional ornithology text, this handbook, linked to individual species accounts, provides extensive bird biology.
There are many improvements among the various editions of these DVDs. You can check out the many features of these DVDs at Thayer Birding Software. The one that inspired this review, however, is the inclusion of over 600 photos of bird eggs and nests. This feature makes this resource all the more valuable for birders. Briefly, the Gold edition now contains 970 species and 3,431 photos. There are 719 bird songs and 552 video clips. (Compare this to 702 species, 2,501 photos and 655 songs in version 3.9). In addition to more video clips, version 4.5 adds 53 new species from previous editions.