Tree Swallows on the Tuolumne River

Not all of our spring migrants are orange and yellow. In honor of our graduating students at Modesto Junior College, I offer up a tropical migrant in the school colors of blue and white, the Tree Swallow ITachycineta bicolor). The swallows that I see regularly are nesting in an old sycamore above the Tuolumne River below the Parkway Trail.

The Tree Swallows are long-range migrants, wintering in Mexico and Central America, and breed farther north in the Arctic than any other swallow species. California is one of the few places in North America where they can be seen all year long.

Northern Rough-winged Swallows on the Tuolumne River Parkway Trail

I took my customary stroll on the Tuolumne River Parkway Trail (still not completed!) this afternoon, and wasn't seeing a lot of bird activity, but the river was running clearer than normal, so I found spot where I could watch the water flowing from about 20 feet above. I finally realized that there were several small birds perched on a willow branch above the water. I zoomed in and got some pictures.

The pair of birds were unfamiliar to me, although their extremely long wings suggested that they were swallows of some sort. My best guess is that they are juvenile Tree Swallows (Tachycineta bicolor), but as always I am pretty new at bird identification and would welcome an expert's judgement here [Postscript: Silver Fox is suggesting Northern Rough-winged Swallow (Stelgidopteryx serripennis), and I find it convincing; see comments].

They would occasionally fly out over the water, but the only quarry I saw them catch was a foxtail seed. Here's a short video; they were very cute.

Looking at the World for the First Time: Tree Swallow Chick at Cosumnes River Preserve

I was picking someone up at Sacramento Airport today, which gave me a chance to stop and wander a little at the Cosumnes River Preserve between Stockton and Sacramento.  Maybe this is a bureaucratic nightmare, but the preserve covers 50,000 acres and is managed by not less than seven agencies: The Nature Conservancy, Bureau of Land Management, California Department of Fish & Wildlife, Sacramento County Regional Parks, Department of Water Resources, Ducks Unlimited, and the California State Lands Commission. Their management meetings must be a lot of fun! Still, they've done a good job of protecting a wide swath of river bottomlands, ponds and grasslands along the Cosumnes. I took a three mile loop trail from the visitor center (off Twin Cities Road at I-5) that turned around at the Cosumnes River. There weren't an overwhelming number of birds out and about, but as I followed a trail down to the river I was buzzed by a few Tree Swallows (Tachycineta bicolor). I didn't realize what the ruckus was about until I noticed a nesting box right next to the trail. Something was looking at me. And what a sour face!

I immediately realized the problem and backed off. The Swallows were concerned about their chick (or someone's chick, I couldn't be sure), who was looking out on the world, but wasn't quite ready to emerge from the nest and start exploring. 

It's the quiet season at the preserve as it transitions into the summer and much of the wetlands dry up. The river will be running all year though, so I'll check it out when I can. It's a pleasant place to hang out while waiting for a plane to land.

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?