“Rare” is context-dependent. My Collins Bird Guide lists the Dark-eyed Junco as a “rare vagrant,” but that is, of course, because Collins is a bird guide to Europe. Common birds where you don’t expect to find them are exciting. We have our own rarities at the banding station, birds that may be common in the general region but rarely grace our nets; and although no one else would consider them remotely remarkable, we still get excited.
Juncos flock in huge numbers all around the area, but for whatever reason, they do not like the specific patch of riparian land that the banding station monitors. The banding station catches only around five juncos every year, making them rare by our very particular standards.
The “rarity” of these birds is exaggerated by the fact that we volunteers only band a few times each month. The banding station runs three days a week, but any individual bander is out there much less. You could easily miss all the juncos we caught this year if you happened to not be out on those particular days.
The Blue-gray Gnatcatcher is an even rarer visitor to our nets; we caught just one last year, and we have caught one so far this year. A bander who had been at the station for years gasped when she saw him, then tentatively asked if she could be the one to release him.
I had never held one before either. The blue tint to the feathers and the brilliant white eyering are quite beautiful.
Some birds are only rare on close inspection. We get lots of White-crowned Sparrows; they are winter residents here, and we often catch the same birds many times over many years. Usually they are the subspecies gambelii, Gambel’s White-crowned Sparrow.
But occasionally we get the Puget Sound White-crowned Sparrow, pugetensis, instead.
This bird is a juvenile, hence the brown and tan stripes rather than the adult black-and-white of the bird in the previous picture. If you compare the bills, you’ll notice that the pugetensis has a more orange bill, with black only at the tip of the bill rather than more broadly across the top of the bill. Bill color may seem like a small thing, but finding a familiar bird with a small difference can be striking.
And then there are the genuinely odd birds, like this one:
A common species even for us, the Hermit Thrush. But not this Hermit Thrush. Look at the flight feathers on his right wing:
Those feathers should be making a clean, even curve—but the third feather from the end is too short. It isn’t in the middle of growing, or differentiated from the feathers around it in any way; it’s simply too short.
Here is his other wing:
Look closely at the point on the wing, halfway along, where the pointed primary flight feathers give way to the more rounded secondaries. See the one sort of crinkled-looking feather? (The tip of the feather is right by the “7D” on the band size gauge.) See the other feather tip poking out behind it? Those two feathers are occupying the same one spot on the wing. This bird has an extra flight feather.
It’s harder to see on the underside of the wing; the crinkled feather is almost entirely hidden by its duplicate.
This is neat to see, both because it’s unusual and because it is undoubtedly how different bird lineages managed to evolve different numbers of flight feathers. (Well—not exactly how: you would want the feather duplication to be on both wings.)
This thrush is very unusual—but then, even our usual birds are all different in some way. As excited as we get about our rare birds, it’s our regular birds that keep us coming back to the station. Holding your first Blue-gray Gnatcatcher is really cool; holding your 100th Song Sparrow is a different kind of cool.