Wild Side: Birding misidentifications

Are you stringing yourself along?

Matt Pelikan a few years ago on a Christmas bird count. In addition to binoculars, self-awareness is something every birder should carry into the field. —Katherine Scott

Birders really want to get it right: Correct identification is the central challenge of birding, and especially with less common birds, reports shape our understanding of avian status and distribution. Errors distort the picture.

But we don’t always get full-on, short-range views like the pictures in a field guide. We often know less than we think we do. And our minds can play tricks on us. Here are three common reasons for birding screwups.

The first, and the only one that in my view reflects poorly on the observer, is misidentification as a result of wishful thinking. Finding rarities is fun, and discovering verifiable rarities leads to stature in the birding world. Very few birders actually fabricate sightings of rarities; the birding world relies heavily on the honor system (though photos and verification by others are always welcome!). But the desire to find unusual birds can pull you subtly off track.

The wrong turn comes when the observer notices something that doesn’t look quite right about what initially appeared to be a common species: It’s too large or small, the color is off, an expected field mark isn’t obvious. That puts the idea into your head that maybe what you’re looking at is not the common, expected bird. And from there, under the power of wishful thinking, you begin selectively emphasizing details that support your optimistic ID and ignoring details that don’t fit the pattern you’re trying to create. Before you know it, you’ve talked yourself into a blunder.

The British, with their expansive, colorful jargon for birding, call this “stringing,” as in “stringing yourself along.” Once you establish a reputation as a stringer — and just one high-profile instance can do it — it’s a very hard reputation to shed. So it’s important to recognize the stringing impulse when it appears: When something looks a bit off, the right response is to ask how the aberration can still fit with the most likely choice, rather than jumping to the conclusion that you have a rarity. Rule out the common choices before contemplating the rare ones.

More benign errors often come from imperfect knowledge, and these can take a multitude of forms. As you’d expect, beginners or birders in regions they’re not familiar with are most at risk for this type of blunder. But even veteran birders can overlook a possibility.

Consider the case of purple finches and house finches on the Vineyard. Closely related, males of both species are both streaky brown birds with reddish color on the head and chest. The extent and shade of red, though, differs, as do the structure and vocalizations of the two species. They’re not hard to tell apart.

But what if you don’t know that two species fit the general description? Some older field guides for the Eastern United States don’t include the house finch. If you’re using such a guide, and a finch-like bird with red on the head turns up at the feeder, calling it a purple finch makes perfect sense. But 95 times out of hundred, you’re wrong; house finches are common feeder birds year-round on the Vineyard, while purple finches are uncommon, irregular visitors.

With experience, you learn the relative abundance of house and purple finches, and you learn how the species differ. But meanwhile, a healthy percentage of purple finch reports on the Vineyard prove to be bungled house finch sightings.

Finally, errors can stem from imperfect data: Distant views, obstructed views, views through rain or fog, or very brief glimpses can leave a convincing but wholly erroneous impression in the mind even of a veteran birder. For example, I’ve momentarily mistaken a great black-backed gull for a mature bald eagle. Despite the dramatic differences between these two species, a gull circling at very long range is simply a bird with dark wings and a white head and tail as it banks on the far side of its circle. As the bird swings through other portions of its loop, no details may be visible at all, so you’re left with intermittent glimpses that point toward a totally wrong conclusion.

Completely eliminating error from your observations is impossible; indeed, observers who think they never make mistakes increase their chances of blundering. And inexperienced observers come up with some real shockers (I recall fielding a report of a sandhill crane — the reporting observer was “100% certain” — that proved to be somebody’s guinea hen). No wonder birders are a skeptical bunch!

Experience helps (though there is no shortcut to acquiring it). But ultimately, the best defense against errors is humility. Whatever level you’re at as an observer, keep in mind the pressure you put on your own mind, the possibility of gaps in your knowledge, and the limitations of what you see and hear. There’s nothing wrong with saying you’re not quite sure.