by Blake Mathys
About a year after I began birding, when I was still very much in the beginner phase, a Red-necked Grebe was reported on a reservoir not far from my undergraduate school. We don't get a lot of Red-necked Grebes in Ohio, and I had never seen one. My friend Tom hadn't seen one either, so he and I decided to drive over to the reservoir to find it. Before too long we found a bird that seemed about the right size, with a long pointed bill. It was drab overall, and we decided that it must be the sought after grebe. We watched it for a while, and then went back to campus.
Later I was looking at bird pictures on the internet, and I came across a bird that looked just like the one we saw at the reservoir, but with a name I didn't recognize. The website said it was a "Great Northern Diver". At the time, I didn't know that "diver" is another name for loon, and that Great Northern Diver and Common Loon are the same species. We quickly sorted out what had happened: Tom and I had gone looking for a Red-necked Grebe, and had forced a Common Loon to fit the description. It became even more entertaining when our birding friend John said he had been at the reservoir at the same time we were there, but hadn't seen us. It was then that we realized we had not only misidentified a bird, but we had gone to the wrong place to do it.
Red-necked Grebe. Or is it? Yes, yes it is.
The preceding somewhat embarrassing story demonstrates the danger of expectation. We had expected to see something, so we forced our observations to fit. This sort of bias isn't unique to beginning birders, and the source of the expectation is not always as obvious as in my example. Often it is as simple as another birder saying "I've got a Coop"; we look at the bird, expecting a Cooper's Hawk and seeing a Cooper's Hawk. If we are paying attention, perhaps something clicks and we realize that the bird is a Sharp-shinned instead. However, it's impossible to know how often things don't click and the bird flies away with the wrong name. Why do we allow ourselves to be tricked by such a simple trap?
The answer is that expectation is a powerful and useful identification tool. Many of our identifications are based on our previous knowledge of geographic range, abundance, and habitat preference. It is much easier to identify birds if we have some idea of what to expect, what is likely to be around. I've noticed it with the beginning birders in my Ornithology classes; we are trying to identify a gull in a marina in New Jersey, and students are making suggestions: Sabine's Gull, Black-tailed Gull, Yellow-footed Gull. I often ask them to take a look at the range maps or read the habitat description.
This knowledge of what to expect helps us narrow down the possibilities: at this time of year, in this habitat, we expect a gull to most likely be a Ring-billed, Herring, or Great Black-backed. But here is the danger; if we try to force our identification to match our expectations, we are going to get identifications wrong sometimes. Black-tailed Gulls can actually show up, and if we miss it (failing to identify it because we didn't "expect" it), we get very upset. The thousands of correctly identified Great Black-backed, Herring, and Ring-billed Gulls will not console us much.
That leads us to the obvious question: What is the answer? How do we use our prior knowledge and expectations to make identifications easier, without biasing ourselves to the point of misidentifying birds? I think the answer is that we have to take a step back and identify our bias before we identify the bird. We have to ask ourselves, "Do I think that this is a Red-necked Grebe because there is supposed to be one here and it is what I want to see, or is it because it actually looks like a Red-necked Grebe?" "Did I just identify that large Accipiter as a Cooper's Hawk because goshawks are rare here, or did I see something that actually made me think it was a Cooper's?" Asking ourselves these questions forces us to evaluate what evidence, if any, we have, and make more informed identifications.
I would love to hear what sort of mistakes you've made because of expectation. This is a non-judging environment, and be assured that everybody makes mistakes. The key is to identify why you made the mistake and learn from it. So have at it, let's hear your misidentifications, see if you can identify the bias or expectation that caused the mistake, and let's all take a step toward avoiding such mistakes in the future.