DUNCANVILLE, TEXAS — I don’t put a lot of stock in claims about the size of birds. There are two reasons for this: I’ve screwed up too often (”Ooo, kestrel … or … ahh … Barn Swallow.”) and I’ve seen others screw up too often (”That’s way to big to be a mockingbird.”). Yes, both examples are true stories. Size can be extraordinarily deceptive, and relying on your impressions can get you in trouble — it certainly has me.

So, when I saw Jim Stevenson’s photo of two Common Loons this evening, I exclaimed out loud. Have a look at the size difference between those birds! The bird on the left is tiny.

The photo prompted much discussion on Texbirds today, and I’m shamelessly collating the high points here, after others did all the research.

A paper published in The Auk in 1921 proposed that Gavia immer elasson be recognized as a subspecies of Gavia immer. “Elasson,” a footnote explained, was from a Greek word meaning “smaller.” Rejecting the name “Common Loon,” the author proposed that these remarkably small loons be called Lesser Black-billed Loons. (Read the full paper: Description of a New Loon.)

The birds’ subspecific status was fairly short-lived, however. Just over 30 years later, a paper in The Condor argued that a wide range of measurements taken from birds all across North America present “a patently impossible distributional pattern” for the alleged elasson and that Gavia immer should again be considered monotypic. (Read the full paper: Status of the Lesser Common Loon.)

And with that, the Lesser Common Loon faded back into relative obscurity. I for one hadn’t heard of it until today.

I’ll be looking at loons a little more carefully from now on, that’s for sure.

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