Western Bluebirds at the Tuolumne River Bluffs

Western Bluebirds (Sialia mexicana) run hot and cold on my walks. Sometimes weeks will pass and I won't see any at all, and then I'll see several of them within a day's time, and in multiple locations. In a matter of weeks I expect that most of them will start moving up into the Sierra Nevada foothills and on into the higher forests.

These individuals were lurking around the area I call the Tuolumne River Bluffs, a future park set on the hills overlooking the Tuolumne River in the edge-of-the-foothills town of Waterford. There are some old trees, oak and walnut, lining the bluffs. I also see the birds fairly often on my college campus, but I've had less time these days to look in on them. The end of the semester is looming; lots of work piling up, and then onto delayed projects at home and office.

A less brightly colored female

Tree Swallows on the Tuolumne River: You See What You Know...

In my usual life as a geologist and professor, I often describe to my students the secret of mineral or fossil hunting: once you've seen something, however difficult to see, you'll start seeing it everywhere. I've spent my entire first year and a half as an amateur birder, and in that time I never saw or noticed the Tree Swallows that live in our area. Barn Swallows, yes. Violet-green Swallows, sure, but never the Tree Swallow (Tachycineta bicolor).

But then we took a walk on Friday evening through the Joe Domecq Wilderness Park on the Tuolumne River, and I saw a pair of unfamiliar swallows in an old snag and got a few pictures. A short while later I discovered it was a Tree Swallow. 

So here it is on Monday, and I take a walk down to the Tuolumne River bluffs at the future park in Waterford, and there is another Tree Swallow in an old snag, hunkered down in the heavy winds. It was kind enough to let me get a couple of close-ups before wandering off. 

Tree Swallows range all the way from Central America to northern Alaska, and are more tolerant of cold temperatures than other swallow species (when their preferred food of bugs aren't available, they'll switch to plants). They arrive from their migrations sooner than the others, and with global warming, they have been nesting nine days earlier than they used to. Sibley's guide suggests that they are year-round residents in the Great Valley. So why haven't I seen them until now?

Western Kingbird on the bluffs above the Tuolumne River

I wandered out to the future river park in Waterford today, and saw my first Western Kingbird of the season. They spend their winters in Central America and migrate north to breed across the western United States. I saw quite a few of them last year, so I've been watching for their return.

The Kingbirds are in the flycatcher family, and like to spend time in open fields with high perches. They'll dive down to capture bugs on the fly. They are very territorial during the breeding season, sometimes chasing away much larger birds like Kestrels and Hawks.

From its appearance here, it looked like it was about to chase me off! Or yawning...