I’ve been interested in birds since the 1990s and started keeping a life list in 2016. My outdoor time is spent with binoculars around my neck and a field guide in my pocket. When my friends want help identifying some bird they saw, I’m the one they ask. So it’s not surprising that I got upset when eBird wanted proof of the black-capped chickadee I reported. What is surprising is just how much I have learned from this single mistake.

A little context first. I live in Colorado where I see and hear black-capped chickadees daily. I occasionally encounter mountain chickadees in the foothills and mountains, but it is easy to tell the two species apart. However, I was far from home when I saw and heard the chickadee I reported.
In a backyard in northern Maryland in mid-October, I spent half an hour counting birds with my family. I submitted our sightings list to eBird and before the day was out, I was asked for further information about our black-capped chickadee sighting. I was surprised and a little insulted. I had looked carefully at the chickadee I had seen to make sure it didn’t have any of the markers for a Carolina. Besides, my husband and I had both heard it singing. I was certain we had a black-capped. As you already know, I was wrong.
How did I make this mistake? It was a combination of assumptions and ignorance.
First, I was wrong about where we were on the map. The yard was deep in Carolina chickadee territory, not black-capped. Second, the traits I thought marked the difference between the two chickadees were wrong. I hadn’t paid close attention to my field guide which was silly, because these two chickadees look a lot alike. A lot.*
In fact, the two birds look so much alike, they hybridize. I was sixty miles from the boundary between the ranges for the two species, but well within the zone were they are cross-breeding. The one thing I thought proved I had a black-capped chickadee — hearing the familiar calls and song — is not a reliable method of identification when hybrids are present (read about Songs and Calls here).
By the time the experts got back to me about the photo I sent them, I had already realized that the chickadee I had reported was a Caroline, not a black-capped. I could see it was missing the white “hockey stick” on the wing and had a tidy bib edge. The polite regional expert for eBird who helped me learn all this also explained that I couldn’t bird by ear for these species in this location.
The whole experience shook me up. I came away doubting myself and questioning everything I knew about birds. But it was also good. It’s easy to forget that, no matter how long we study, there’s always more to learn.
Standing in the airport shuttle parking lot on my return to Colorado, the first birds we encountered were black-capped chickadees. I dug my binos out of my suitcase to look at them. I could see the white on the wing as described in the field guide, but not the ragged bib edge because they wouldn’t turn to face me. I could see that the difference between these birds and the ones I’d been studying in Maryland for the last two weeks was minimal. There’s a good reason there’s a lot of confusion between Carolina and black-capped chickadees.
Have you ever had a mistake that opened up a whole new world of learning for you?
*The article I used to get a better handle on the differences between black-capped and Carolina chickadees has an error in it (which seems appropriate given the topic of my post.) The “answer” at the bottom of the article is misleading, because the photo of the chickadee in the snow is not reproduced there. Go back to the top of the article for to see it.
Wow, I can see why you got it wrong and how necessary it is to consult a good bird book!
It was an excellent reminder that even common birds can be tricky. I’ll be more careful when I travel now to make sure I know what’s local and what isn’t.
I didn’t even know there was a Carolina chickadee. I know about the chestnut-backed chickadees (which we have here on the west coast) and I know that the black-capped are a more eastern bird, but I didn’t even know about the Carolina. They are so similar, it’s no wonder you were unsure.
I’ve added it to my list of birds I’ll always doubt myself on. Prior to this, the top confusing pair was Cooper’s hawk/sharp-shinned hawk.