A plant native to the Sonoran Desert, the saguaro can live for more than 100 years and a 20' tall one can weigh 2000 pounds! They serve as nesting sites for gila woodpeckers and cactus wrens. Look at the multiple holes puncturing this saguaro's arms and trunk! The resilient cactus forms scar tissue around the holes to protect itself from water loss.
Love birds? Support the Tucson Audubon Society by contributing to their summer matching donation effort. Click here for details: http://www.tucsonaudubon.org/
Tucson has two Saguaro National Parks (east and west) where you can see fabulous specimens.
Here is the link to the National Park Service information which includes maps, hours, everything you need: http://www.nps.gov/sagu/photosmultimedia/photogallery.htm?eid=170356&root_aId=302