Cassin's Kingbird

The outer rim on the Cassin's showes very slight color and is located closer to the inside of the tail, than it is on the western.

Oh many thanks guys for the ID and explanation about differences between both species :)

I believe that this is a Western because of the lack of a pale lore. The white rim is also seen on Westerns.

The Cassin's kingbird and the western kingbird may appear to be very similar, but the western kingbird has a slight white line around the rim of the tail, and the cassin's kingbird doesn't, if you go into deep detail you may also slight differences as well.

But that is the main one.

My best guess is Western Kingbird Tyrannus verticalis http://www.allaboutbirds.org/guide/weste...