The Breeding Bird Survey system works on the assumption that the birder running each route is familiar with all the bird species that may be encountered.

That's the key word: "familiar."

Which is not synonymous with "know."

I can figure out most of the birds I come across on the two routes I run every June. Suspect most true birders would consider my routes to be fairly easy. Not a lot of diversity.

So today, while running my second and last route, at stop 46, I get not one, but two birds I cannot identify. Sitting in two adjacent boxelder trees, singing responses back and forth to each other. But clearly separate species.

Can't even see the first bird, in the left tree, but as I'm driving off to stop #47 (You have to finish these routes on time... there's no time to go through the field guides and song tapes to identify these unknowns. I know. I've tried.), I catch a glimpse of the bird on the right.

A blue bird (no, not a bluebird, but a blue bird). With wing bars.

Just exactly like the unidentified bird I had on stop 42.

So, when I finish the route, and have given the sisters their much awaited running break and water break, we head back.

To stop 46.

And they're still there. The blue bird has moved across the road into the willows and birches along the creek, but it's the same bird, same song.

And quickly identified, now. Not that many blue birds in North America, particularly in this part. And with a white belly and rusty brown breast.

A Lazuli bunting.

Which means the unknown on stop 42 was also a Lazuli. So far, so good. Two down, one to go.

I hop out and start wandering amongst the old boxelders. My unknown is singing up a storm, but it takes me a while to finally spot it.

And spot it. And spot it. Over and over again.

I have no idea what the frick this thing is. A plain, plain brown bird, with no eye ring, no eye line, no cheek patch, no wing bars, no malar streak, no nothing. Just a plain brown bird, slightly lighter underneath than it is any place else.

And noisy. Lots of loud song coming from such a small bird. And it and the Lazuli are still answering each other.

A drab little bird, except for the tail. Looks exactly like a wren tail, with lots of fine barring. Although it holds it down and out, instead of flipping it up like a wren. That should be easy to find in the book.

It isn't.

Only things in there with wren's tails are, well, wrens.

But this bird doesn't hold its tail up like a wren. And it stretches out on the branch like a vireo, not all hunched up like a wren.

So, back into the trees I go. Camera in hand. Leaving the sisters in the truck. (Did this once before, years ago, on this very same spot. Wandering about trying to identify an unknown bird. When I finally got back to the rig, I found a rattlesnake had decided to take shelter from the midday heat in the truck's shadow. Right there at the driver's door.)

Heelers don't get out at this stop anymore. But this time I leave it running, with the air on. Was only 61^o when we ended the route, but it's a lot warmer now.

Even got video of the little brown dinosaur singing, so I could compare the song to the tapes. But I didn't need it. Figured it out from one of the photos.

And here it is.

It's a wren.

Yup, a house wren.

Matches the photo in Stokes and Stokes, and their description:

"Our dullest-colored wren, with no prominent field marks."

Okey-doke. We're three miles from the nearest house, but that's what this thing is. No more unknowns, and a new species for this route (to go along with the rock wrens and canyon wrens, both of which I have seen on stop 46).

Learn something every day.