Spring Arrivals Continue: Western Wood-Pewee on the Tuolumne River

The parade continues. The pattern is the same: a few days will pass, and I won't see any new birds on the Tuolumne River, and I'll start thinking that I've missed some of my favorites. Then I'll turn a corner on the Tuolumne Parkway Trail, and there will be another spring arrival. On Thursday, the new kid on the block was a Western Wood-Pewee (Contopus sordidulus). It simply landed on a branch about twenty feet in front of me, and we stared at each other for maybe two minutes, and then it took off. I've seen them here in previous years, as early as the first of May. I think they may be passing through because I haven't seen any during the summers, but in the fall they returned again for a few weeks on their way south to Central America.

The Fall Migrants are Arriving: Western Wood-Pewee on the Tuolumne River

It's still August, but there's the hint of a slight chill early in the morning, and some of the fall migrations are just getting started. On today's walk on the Tuolumne River, the sighting was of a juvenile Western Wood-Pewee (Contopus sordidulus). It seemed as curious about me as I was of it as it hopped around on bushes only 30 feet or so away.

The young bird has a long road ahead, as it will be migrating to South America. According to eBird, the Eastern and Western species of Wood-Pewee are definitely distinct genetically, but aside from their calls they are pretty much identical in appearance. They don't intermingle much in the areas where their ranges overlap in the north, but no one knows if they do so in their southern winter homes. And they don't sing much in the winter!

Another New Bird (for me) on the Tuolumne River: A Western Wood-Pewee

I was kind of excited to add two birds to my Tuolumne River Parkway Trail list this week. The first, and most exotic, was the Forster's Terns that I was able to get pictures of (finally). On the same day I saw the first tern, I also saw a bird that acted just like a Black Phoebe, chasing insects from a prominent perch and flying back. But it wasn't black. I realized eventually that I had come across a Western Wood Pewee (Contopus sordidulus). It isn't entirely unusual to see them here in the valley, but they are more common in hilly or mountainous terrain. They are also a summer migrant, and they've been seen at just four localities in our county thus far this year (according to eBird).

I have seen Pewees before, but in a far different and unusual place: Ash Meadows National Wildlife Refuge, an oasis in the barren desert east of Death Valley National Park. They range across all the western states and Alaska as well as Central America and the northernmost part of South America. Their range ends across a north-south line in the Great Plains, a line that coincides with the western edge of the range of the Eastern Wood Pewee. The birds are pretty much identical aside from their songs, but according to eBird there is little evidence that the two species interbreed. This leads to an interesting mystery: they migrate south for the winter, but no one is sure about where they go. The birds don't sing often in winter, and are thus pretty much indistinguishable in their winter habitat. Wherever it may be.

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.