We made a May 18th run up to the migrant traps of the northwest Mojave and southern Kern County recently. It was probably a bit early for such a trip, but there wasn’t much going on down in Orange County. And you never know what you will find up there. We left at an ungodly hour and arrived at Butterbredt Spring, the Audubon California Kern River Preserve, shortly after dawn. It wasn’t a great day for it: the wind was whipping at a steady 25 mph. But even on the road in from Jawbone Canyon, we could see lots of birds on the move. Despite the blow, Wilson’s Warblers, Swainson’s Thrushes and flycatchers were crossing the road in droves. They stayed low to the ground, contour flying out over the open desert hills.
The preserve itself was simply alive with birds. We saw 5 species of warbler, 9 species of flycatcher and assorted passerines, like Lazuli Buntings and Black-headed Grosbeaks. One great thing about a morning like this is the chance to study difficult species like the (Empidonax) flycatchers. It’s always nice to have a chance to compare and contrast this difficult group in terms of their structural differences. We recorded five species of Empids that day, with Pacific-slope and Willow Flycatchers being the most common. A few Hammond’s, Dusky and Gray Flycatchers put in an appearance as well. We also had great looks at Olive-sided Flycatchers and Western Wood-Pewees (photo) together. Watching these similar species side-by-side at close range made their structural differences much easier to see. Listening to them talk, particularly the two commonest Empid species, was also a pleasure.
From Butterbredt Spring, we drove to the next migrant trap: Central Park in California City. Like Butterbredt, this site offers water and trees to birds migrating over the desert. Thus, it draws rare birds in frequently. Disturbingly, we found the main entrance gate to the park closed and locked, but we knew that by driving around to the back side, we’d still be able to walk in among the ponds.
The presence of cattail-lined ponds meant that we added quite a few common birds to our day list, but most of the migrants were the same, with the exception of a Plumbeous Vireo that was difficult to get good views of. A small colony of Yellow-headed Blackbirds, which breed on the site, provided us our flashiest birds. This male kept displaying and singing his distinctive raspy song. No great beauty that song, but what a handsome guy!
Our last migrant trap destination on the day was the resort at Galileo Hill. Once again, flycatchers dominated all other birds here, especially the common Empids and Western Wood-Pewees. Swainson’s Thrushes were everywhere, looking incongruous hopping about on the lawns like robins. Legions of Wilson’s Warblers graced the spot too. But a careful search among the ponds revealed a few new things. At least half a dozen Spotted Sandpipers cavorted around the various water features.
Perhaps the biggest surprise birds were a pair of Fox Sparrows, comprising two different sub-species. A Thick-billed Fox Sparrow, with a nicely contrasting gray head, rusty back and of course, that great honking bill, showed up first. Later, we found a smaller-billed individual that proved to be a Sooty Fox Sparrow, showing much more rust color overall, and almost no contrast between the head, nape and upper parts. This Acorn Woodpecker (photo) seemed out of place here, in a location with no oaks!
The other pleasant surprise wasn’t avian. Groundskeepers alerted us to the presence of a young Pacific gopher snake (Pituophis catenifer). This snake measured about 3 feet long, and quite beautifully marked, but rather ill-tempered. It struck multiple times and bloodied one hand, taking quite a while to calm down after I picked it up to get a look at it. This snake seemed considerably paler and more washed out in color than the individuals we see on the coastal plain. An adaptation to desert life, perhaps? I soon released it into thicker scrub away from the lawns of the resort, where it might have come to grief at the hands of some of the resort guests. It was very happy to be let go!