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Overcoming Expectation

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.

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Blake Mathys

Blake Mathys

Blake Mathys completed his Ph.D. at Rutgers in 2010, studying evolution of birds introduced to islands. His field work was in Bermuda, Puerto Rico, Hawaii, and Trinidad, and was complemented by museum research. Prior to graduate school, he worked with Cape Sable Seaside Sparrows in Everglades National Park, as a hawk counter in Washington State, on the Farallon Islands studying Northern Elephant Seals for PRBO Conservation Science, and sampling fish for the Ohio EPA. Blake and his wife Dimitria recently moved to Ohio, where he is an Assistant Professor of Environmental Science at Ohio Dominican University in Columbus. Aside from birds, he maintains a fascination with salamanders, mammals, and anything else with a backbone.
Blake Mathys

Latest posts by Blake Mathys (see all)

  • I could probably write a book…

    There’s the Western Kingbird I spent three hours carefully following so I could get record photos of Scissor-tailed Flycatcher. There’s the Lark Bunting that I, along with several other prominent Oregon Birders (who I won’t out) all got very excited until we moved the car six feet and the white thing in the tree in front of the blackbird moved out of perspective.

    But my best documented mistake was the Cattle Egret which I found and photographed at Brownsmead. Cattle Egret is a good bird on the North Oregon Coast and so I took lots of photos of the small white heron in the that cow pasture. When the slides came back (this was pre-digital), I labeled them as Cattle Egret and filed them. Three weeks later, Harry Nehls found a Little Blue Heron (an even rarer bird) in the same cow pasture. When I pulled out my photos and really examined them…

    Personally, I think the mistakes make for better stories, after I get over the initial embarrassment.

    If you want to see the original photo and subsequent photos of a bird that ended up hanging around for another month go to:

  • Thomas Bayes

    This is an excellent blog post. If only someone could work out a mathematically-sound, coherent way of incorporating prior expectations with observed data to create a single measure of certainty. I’m going to get right on this.

  • As the kids say, lol.

    Well played, Mr Bayes.

  • Ai Wen

    It’s nice to find that the birder community is embracing the Bayesian nerdiness. Well done, Mr. Bayes.

  • Just last week I was aiming my lens at a deer when I caught movement out of the corner of my eye, a bald eagle was jumping off its man-made nest perch over the river and I clicked four frames before he disappeared over the trees.

    I returned home and downloaded my pictures only to find that my eagle had morphed into the shape and color of an osprey. Odd. 😀

  • Orion Weldon

    I followed the link to that you posted in your comment here, and scrolled down to the heron/egret pictures. It sounds like your pride is not in need of consoling, but I thought it worth pointing out that the bird in the first photo IS is in fact a Cattle Egret and not a Little Blue Heron. The second photo is certainly a juvenile Little Blue Heron, but the first is not.
    We can run through many of the subtle details, but just the head shape and bill alone give it away. In the first photo the relatively shorter bill, the lighter outer half of the bill with the suggestion of red/pink at the base, and the raised crown all say Cattle Egret. In the second photo notice the bill is longer and thinner with the chin feathering extending further down the bill. The bill in the second photo is a uniform grey in color and has not attained the fully dark tip.
    I guess this means that you may have a reason to contact the rare birds committee after all. Good luck, and good find!
    Orion Weldon

  • Look closer

  • Thanks for sharing Mike, I appreciate your willingness to admit your mistakes and learn from them. And as we can see from Orion’s response, you can certainly be excused for misidentifying this bird. I looked very closely, and I think I see where the confusion is coming from, at least based on the picture. The length of the bill is not obvious, due to blending in with the fence post behind it. The dark spot toward the end of the bill is not actually at the end. The light tip is a similar color to the fence post behind it, giving the appearance of a shorter bill. Once I realized how long the bill actually is, it made the identification as a Little Blue much more obvious.

  • Part of the reason I chose that photo rather than one of the several that show the bill clearly is that it forces the viewer to look at the whole bird rather than depend on a single field mark. The bill does look short in this photo and that colors the viewer’s expectations (the larger point made by you in this article). We selectively filter out the long, GREEN legs and other features that get one to Little Blue Heron, because we’ve already decided it’s a Cattle Egret based on what we think we’re seeing in the bill.

    Had I looked at the whole bird in the first place rather than making assumption (cow pasture, smallish white heron, etc.) I wouldn’t have made the mistake in the first place.

  • Orion Weldon

    Wow, that certainly got me! Thank you for the correction. And, don’t I feel the the sucker, and the example, but kind of a nice fortuitous example given the article. I totally thought the bill ended at the end of the yellowish section. And, as you said Mike, my eyes glazed right over the longish neck.

    Most of my misidentifications have come not so much from expecting normality, as much as a desire for the rare. While I was first taking ornithology as an undergraduate I came across a peculiar bird while birding on my own time. The bird had all the markings of a White-eyed Vireo, but a completely dark eye. Our required text for the class was the ‘new’ Kaufman Guide that used pictures instead of drawings. ‘My’ bird looked infinitely more like the picture of the Thick-billed Vireo rather than a White-eyed. After double checking in the National Geographic (which only shows White-eyed Vireos with white eyes) I tried to convince my ornithology professor to no avail. She actually didn’t know first year White-eyed Vireos have dark eyes, but she knew enough not to be persuaded. It was only after I bought the Sibley Guide, about a year later, that I realized how wrong I was. It a humbling experience like an anvil on the head.

  • Northen Mockingbird for me. Fairly common in my corner of the world. State Bird of Texas it is.

    At a park close by not long ago I had my experience with expectation. I was ready to see a new bird; so my mind gave me one. Sighted a perched bird, and using my best stealth, approached cautiously. Two or three careful steps; then a glance through the binoculars. Then again, and agin. I got close. Real close. It flew. So did I. Back to my truck and my Sibley field guide. I was ready to make that sighting anything but what it was. Try as I might, I couldn’t make it anything but what it was – a Northern Mockingbird. I was so ready for a new sighting. Alas, it was what it was and was soon back in its territory on its perch, mocking my sighting, as it were.
    At first I was embarrassed. I looked about. Had anyone seen? Should I journal this? Who should I tell? A secret for keeping between the almighty and me?

    But in the end, it became a lesson on expectation and also gave me the opportunity to see my beloved Northern Mockingbird in yet again one of its many guises.

    Good blog post. Fun read.

    Arnie Hauswald
    Houston, Texas
    ABA Member

  • Well, early in my birding life I visited the Salton Sea in southern California with my newly purchased Mexican Field Guide….

    And, I was driving the vehicle for Mike Patterson’s faux Lark Bunting (though I thought it was a Bobolink)…

    There was the time I burst out of the wheelhouse on the boat shouting “Laysan Albatross! Laysan Albatross!” only to have a very close Western Gull fly up. I took comfort in spotting a real Laysan a few hours later…

    Sadly, I’m probably not even aware of my worst misidentifications.

    Last summer I photographed a bird and still didn’t identify it correctly. I blogged about it in: I love to misidentify birds!

  • If this were Facebook, I’d press the “like” button.

  • I think this is a great post. I like how Blake is encouraging us to *understand* the process of bird identification–as opposed to just rattling off a bunch of field marks for tricky loons and Podiceps grebes in transitional plumage.

    And Blake is in good company: Kenn Kaufman’s latest book (“Field Guide to Advanced Birding”), too, is all about understanding bird ID, not just memorizing field marks. I’d heard about this book for a while, and, to some extent, I’d been thinking to myself, “Nice. Another book on bird ID. There are so many of them already. I suppose it will add ever so incrementally to our knowledge of bird ID…”

    Well, I was wrong. Kaufman’s latest book is, in my mind, a real game-changer. The book contains scores of insights I’d never thought of–and I’m not even half-way through. And it’s a pedagogical marvel, a breakthrough even: In my interactions with other birders in the field, I know I’ll be borrowing from so many of Kenn’s ideas and insights. Even if you think you know it all (especially if you think you know it all??), this book is well worth the (actually rather modest) purchase price. Kudos to Kaufman and to the folks at Houghton-Mifflin who have given us a remarkable new birding resource.

    (One last thing. When you go to buy the book, be aware that this is the completely new second “edition.” It’s not really even a new edition. It’s a brand new book by the same old name. If you’re not careful, you could easily wind up with Kenn’s old classic from 20 years ago; for example, both Google and Amazon take you initially to the old book, not the new one. Caveat emptor.)

  • In response to your request: How much time do you have????

  • Norm Jenson

    The corollary is not seeing a bird because you don’t expect it to be there.

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