(Crimson-collard Grosbeak & Varied Bunting)
While scanning one big fig tree next to the reservoir's edge I spotted a bird that I surely wouldn't have seen had I not been intentionally searching among the tree's shadows. For, this bird was well camouflaged, looking black as the blackest shadows, and mottled with a dark red. There deep inside the tree the hints of red-on-black could have been sun-speckles on bark or dead leaves. However, the silhouette was unmistakable.
It was a fairly large, chunky bird with a massive, fig- crunching beak, -- a male Crimson-collared Grosbeak, a species endemic to northeastern Mexico, but sometimes accidental in southern Texas. You can see one at http://www.texasbirds.org/tbrc/ccgros.htm.
The birds in those pictures are well lit and in the open, very different from what I saw. I saw a skulking, black bird who could have been splattered with blood. He was mysterious and retiring, and when he saw me he quickly vanished into heavy cover.
Not far away in another dense, deeply shadowed tree I saw practically the same thing -- same shape, same thick beak, same black-with-curdled-blood coloring, same skulking-in-shadows -- except that this bird was much smaller, obviously a different species. For a moment my mind went blank, trying to figure out how the grosbeak could manifest himself in such a miniature version.
Finally I realized I was seeing a Varied Bunting. There's a pretty picture of one singing at http://www.oiseaux.net/photos/manuel.grosselet/varied.bunting.1.html
Varied Buntings are mainly dark blue, but in deep shadows they look all black with only hints of dark red mottling showing.
The red-on-black-or-dark-blue combination seems to provide good camouflage for chunky birds who perch sedately as they chew on fruits and seeds.