Friday, August 7, 2015

Western Wood-pewee at China Ranch Near Death Valley

Continuing our review of a long summer of bird sightings, we make a stop at China Ranch east of Death Valley National Park. I got a good look at a Western Wood-pewee (Contopus sordidulus) for the first time, and oddly enough saw it at three different locations over the next two days.
The Western Wood-pewee is a common bird across (surprise!) western America, and is very similar to the Eastern Wood-pewee, which is common across (surprise!) eastern America. There is very little range overlap, and they apparently don't interbreed, so it is interesting that they are practically indistinguishable (mainly differences in their songs). I guess they have no trouble telling each other apart. Both species migrate through Central America to South America for the winter.
The Wood-pewee is in the flycatcher family along with the Phoebes, and that describes their activity pretty well. They perch on a branch or fence, and suddenly fly out and capture flying insects.

But what were they doing out in the barren deserts east of Death Valley National Park?
Yeah, I want to know too...
China Ranch is a unique geologic environment in one of the driest places in North America. During the ice ages, a pluvial lake, Tecopa Lake, filled with water and spilled over into the adjacent drainage, which was Lake Manly in Death Valley. At some point, the outlet was eroded and the sediments that had filled Tecopa were exposed and eroded into a barren badlands landscape. But here and there, the downcutting gulleys intersected with the groundwater table. This resulted in permanent springs.
China Ranch is one of those spring complexes where water flows all year. It is a magnet for wildlife from miles around, and more than 200 species of birds have been sighted there. Water draws people as well. The region has been occupied for as many as 10,000-12,000 years. China Ranch itself was established only in the late 1800s. It is a working date ranch today, and an occasional stand-in for places like Afghanistan in Hollywood movies. The green of the riparian vegetation is in stark contrast to the barren white cliffs made of rock formed in long-gone lakes and swamps.

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