I would strongly disagree with the earlier characterization of the
difficulty of finding Colima Warblers at Big Bend. It really does NOT
take a 10-hour, up before dawn hike, at least from my experiences. I
found them easily in a single, afternoon hike up from the "The Basin"
Campground to Laguna Meadow. And I was primarily photographing plants,
not intensively birding. The old Lane Guide to the Rio Grande Valley"
has a good discussion of the trails. Going up to La Laguna first is
the easiest hike to Boot Springs. I didn't do the loop, as I found the
plants I was looking for at Laguna, and just turned around after that
because my time was limited. I saw a small group of Colimas about 2/3
of the way to Laguna Meadows, on 18 August! At this time of year, the
Chisos Mts are BEAUTIFUL, lush green and full of wildflowers,
following a good "monsoon" season. The warblers were still singing
then, somewhat surprisingly. Perhaps a second nesting. The hike is
steep but not grueling by Cascades standards. I did NOT find Lucifer
Hummingbird, but I loved the entire area -- it really deserves
National Park standards & is much more like being in the Mexican
Sierras than, say, the Rocky Mts. Everyone that loves nature should
make a visit to Big Bend some time. April is good, but often very dry,
August-September the vegetation is at its most lovely. Seeing the
gorgeous Salvia regla in full bloom alone makes the trip worth while!