On a barbed-wire fence is a great place to look for these yellow flycatchers typically in grass covered fields. They will tend to stay consistently low to the ground while they search out flying insects. There are several other large yellow flycatchers of North America which can be hard to tell apart from a distance, but if you look carefully, there are tell tail signs, like the color of the birds head, the size of the beak and of course the voice. This was at Hereford Ranch in the southeast corner of Wyoming.