Bird Identification: Need help with hummingbirds, 1 by Grasmussen

Grasmussen wrote:
While this tread was being debated, I was chasing both Anna's Hummingbirds and Costa's Hummingbirds through City parks in Gilbert, AZ a suburb of Phoenix, and Yuma, AZ. These locations are a couple hundred miles west and north of Tucson, AZ. However, from what I learned locally, I would expect to find both species in Tucson, at this time.

One distinguishing characteristic is the length of the wings, relative to the tip of the tail. At rest the wing tips of the
Costa's Hummingbird are approximately equal in length to the tip of the tail.

This is a Costa's Hummingbird, photographed in Yuma, AZ Dec. 14, 2009