I went to Big Bend NP again in February 2007, and spent two days day-hiking in the State Park near it. While way up in the canyon country I came across a herd of aoudads. I've never seen them in the wild and thought this was pretty neat.
Here is the overview picture. I heard them at the top of the
talus at the base of the cliff in the first red box on the left; after they
realized I had heard them, they began to make their way along the talus to
the right and then displayed their mad aoudad skillz and climbed straight
up the cliff. (see below)
I think there were eight of them
Here they are climbing straight up.
Their fearless leader paused every once in a while to find a good hold, then scampered straight up again. The rest soon followed, sometimes balancing on finger-wide ledges while the others caught up.
The next three pictures are all the same; I put the first one in for a sense of scale. The top one includes the bighorns, but you can barely seem them in the center. The bottome two are zoomed. 
