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Bird name abbreviations (Alpha codes)

2:31 pm

Hi all. As long as we are posting tips for eBird and listserv best practices to start off the year, I thought I would mention some issues with alpha codes (short for alphabetical codes), the abbreviations for common names that have become fairly popular. They are popular for obvious reasons – they are fairly intuitive to construct and they save a lot of typing. The problem is that most people don’t seem to realize how common code conflicts are. One of the most common errors is with Canada Goose. The code is not CAGO, like most people think, because Cackling Goose would share the same code, creating confusion. When these conflicts happen, the usual solution is to remove a letter from the word they have in common and add the next letter from the unique word in their names. So in this situation Canada Goose becomes CANG and Cackling Goose becomes CACG.

Some of the most counterintuitive codes come with two of our warblers. The names for Black-throated Green and Black-throated Gray Warbler differ by only two letters. In this case, the way to resolve the conflict is to add the LAST letter from the unique word in their names, so you get BTNW and BTYW. If you didn’t already know about these code exceptions, I doubt you would recognize the birds those codes apply to, which highlights one of the problems with using these codes when communicating with a broad audience.

In these examples so far, the code conflicts have occurred with taxonomically related species, but some of the most unexpected conflicts come with unrelated species. For example, Brandt’s Cormorant can’t use the code BRCO because that would be the same as Bronzed Cowbird, so they become BRAC and BROC. Even more confusing is a code change resulting from the most recent taxonomic update: Northern Goshawk was changed to American Goshawk, which creates a code conflict with American Goldfinch. It probably wouldn’t have occurred to most people that American Goldfinch is abbreviated AGOL in order to avoid confusion with American Goshawk, which is AGOS. 

There are two things I would encourage all of you to do if you want to take advantage of these abbreviations. The first is to completely spell out the common name the first time it appears in any descriptions in your eBird checklists or your posts to the listserv, and only then use the correct abbreviation afterward. After all, not everyone uses these codes. The second thing would be to make sure you are using the correct abbreviation by downloading the complete list from the Institute for Bird Populations website here: Links to the complete lists of codes are in the upper right. Brace yourself, because most people also don’t realize that the codes apply to species from the Caribbean and Central America as well. I would also recommend reading this brief blog post from Peter Pyle, which explains the origins of the alpha codes:
If learning all of these codes and code exceptions seems too tedious and time consuming, that’s because it is for most people. If you are one of those people, I would strongly encourage you to skip the codes and spend your time improving your skills in describing the birds you see. But maybe that’s a topic for another post.
Happy new year, 
Bruce Rideout
La Mesa