Townsend's warblers singing

In the Presidio, Townsend's warblers began singing their full breeding song last Thursday. My coworker Diony and I noticed that they had not been singing Wednesday, nor any day before -- no, it was Thursday that they began singing. And, it isn't as if the Townsend's warblers are all concentrated in one location in the Presidio. They are nearly ubiquitous: in the coniferous and mixed tree plantations, in stands of willow with the yellow-rumped warblers and ruby-crowned kinglets, and even in isolated cypress trees surrounded by low-growing vegetation.  That day, I observed them singing in three very distinct and separate places, one well out of earshot from the next. I posted this observation to our local Yahoo group SFBirds, which local birders use to communicate with one another, and others had observed the same or similar.

With all the mysteries of nature that exist, I thought it was pretty cool to capture this event. Did a new wave of migrants arrive the previous night? Did the hormones of all the local wintering birds suddenly spike? One of my SF birding mentors Matt Zlatunich once used the phrase "they are all responding to the same cues".  Matt and I had been observing a mixed-species flock of migratory songbirds with very different plumages, life histories, and final destinations northward. I like this phrase because, to me, it means yes, we humans can observe birds' presence and some of their behavior; but a combination of many, many things that we may not know have brought them in front of us for viewing: the position of the stars in the sky; the precise length of day; barometric pressure; wind patterns; pollen in the air; stream flows; the sound of the surf below as they fly in darkness, thousands of feet above the ground.

I probably could have noticed the onset in Townsend's warbler song in previous years, had I been more in tune to it. The strange thing for me is that I'm not doing anything different(ly?) this year than any prior year. Maybe it was just that I happened to use my bike to get around that day, so heard more birds; and that a fifth year in the field here has just added to my own knowledge base enough that I reached a new point. I'm grateful that Diony was there to confirm what I think I was hearing. There are many things in nature that one learns to wonder about. The more you learn, the more you realize how much more there is to learn. As many photos as I do take, on various cameras and now on my smartphone, so much of the experience of being outdoors is a flash-in-the-pan observation that can't be recorded or shared, just experienced.

Townsend's warblers will soon migrate northward to Oregon and Alaska to find mates and raise the next generation. Then, next fall, again they will return to two specific regions -- a thin strip of Pacific coast from Oregon south to Baja California, and another, distinct region ranging from southeast Arizona through central Mexico and into Central America.

I don't have a powerful enough lens for a great photo of a Townsend's warbler to share. (See the link above.) Perhaps it's time I got one. But, here's a picture I took of a small group of birders at Battery East in the Presidio, on participants in my monthly bird walk there. We were sort of hamming it up, staring into the thick fog. It had been one of those mornings that began miserable and became glorious as the sun "burned off" the fog.

Presidio Park Stewards birding the bluffs, October 2011.