These are slightly different photos than the ones on Magnolia Blog.
Kiskadee's nesting in Cactus. Bill Stilson was curious about the nesting material. Since I see blue and orange strings I would guess it be packing cord as well as grasses.
Great Kiskadees are a treat for bird watchers who visit south Texas—and the birds won’t keep you waiting. They’re boisterous in both attitude and color: a black bandit’s mask, a yellow belly, and flashes of warm reddish-brown when they fly. Kiskadees sit out in the open and attract attention with incessant kis-ka-dee calls and sallying flights. Despite their small U.S. range, this is one of the most widespread flycatchers in the Western Hemisphere.