FARMINGTON — The keynote speaker for the Great Salt Lake Bird Festival 2011 has been signed.

Bill Thompson III, the editor of “Bird Watcher’s Digest,” and of various books on birds, will appear at the 13th annual festival here, which is now the state’s largest.

Thompson’s family has published the magazine since 1978. He has been an avid bird watcher since the age of 8.

His books include the most recent, “The Young Birder’s Guide to Birds of Eastern North America.” It is part of the Peterson Field Guide series, and included help from Thompson’s daughter Phoebe’s elementary school class.

Festival Chair Neka Roundy said reptiles and butterflies will be added to the ever-growing and evolving festival.

Dates are May 12-May 16. Most of the events are held in Davis County, particularly at the Davis County Events Center in Farmington and Antelope Island.

Birds of the Great Salt Lake and surrounding areas are highlighted. In addition, tours are staged to birding areas. many workshops feature experts in various aspects of birding, along with artists, displays, kids’ events, booths and food.

For more information, visit www.greatsaltlakebirdfest.com or call 801-451-3286.