White Wagtail
Although this bird does not fit into the usual water birds category, it does hang out around water, and doesn't fit in as a perching bird. It walks on the ground, pecking at insects in or near water, and wags its tail up and down. This is a very rare bird in this area--it normally migrates and breeds in Asia and Alaska. Based on its markings, it is likely an immature bird whose internal GPS malfunctioned by a long ways. He was photographed at Prado Regional Park in Chino Hills, CA.