Honest, this bird is a Blue-gray Gnatcatcher-but the latter part of the name is pronounced ‘nat-catcher’ with the ‘g’ silent. They are small, slender birds with bluish-gray feathers (yes, the ‘Blue-gray’ part of their name refers to their coloration). They have distinctive white eye rings and quite long blackish tails with white on the outer tail feathers.
They have a distinctive call that is described as ‘pwee’ or pzzz but I think of it as kind of a squeaky sound. You can listen to a variety of their calls on this National Audubon webpage
There are several species of gnatcatchers in North America but the Blue-gray Gnatcatcher is the one found over a large portion of the lower 48 states and just a tiny bit of far southeastern Canada as shown on the range map below.
Gnatcatchers are very active little birds, flitting around leaves and branches of trees and shrubs. They are a challenge to photograph since they rarely stay still for a full second. As they forage for small insects they frequently flick their tails upward, a distinctive behavior for this family of birds.
The other species of gnatcatchers are as follows: Black-capped Gnatcatcher-truly a Mexican species that is a rare vagrant to the southeast Arizona area; Black-tailed Gnatcatcher-a species found in southwestern U.S.; and California Gnatcatcher-found only in southwestern California in the U.S. plus the Baja peninsula of Mexico.