The blue waters of many Iowa lakes are dotted with thousands of big white birds. The migrating American white pelicans are massing in several places, including one favorite spot — Saylorville Lake, north of Des Moines. Kami Rankin, spokeswoman for the Polk County Conservation Board, says these are surprisingly large creatures.The pelicans weigh in around 17 pounds and have a wingspan between eight and ten feet. For more information, surf to “www.conservationboard.org”.