If you've spent more than five minutes online this month, you've likely either played Wordle or seen people sharing the results of their games. At this moment, that 6x5 grid of tiles seems virtually inescapable. 

For those who have somehow entirely avoided the game up to this point, here's the gist: Wordle is a word-guessing puzzle that gives you six tries to guess a five-letter mystery word using the process of elimination. Correct letters placed in the correct tiles are marked green, and correct letters in the wrong tiles are yellow. Completely wrong letters are grayed out. On each attempt, reshuffle and replace accordingly. Sounds simple, right? It can be—and yet, it can also be surpringly difficult! Either way, Wordle is a whole heap of fun, and each day a new word provides a fresh challenge. You can learn more about Wordle's creator and the game's backstory here

Perhaps unsurprisingly, Wordle and its popularity have already inspired a slew of spinoffs. In fact, there's now one for the four-letter banding codes, or alpha codes, researchers use as shorthand for species' names—and it just so happened to be designed by Audubon's very own graphic designer Alex Tomlinson. Launched this week, BRDL has received rave reviews on Audubon Slack and Bird Twitter, so try your hand below to see if you can deduce which banding code is the mystery code of the day. If you're like most people and don't know your banding codes by heart, here's a full list. You can also find a quick tutorial on how they work below. 

Once you know your North American codes and start acing BRDL on the daily, it might be time for a new challenge. In that case, we suggest looking across the pond; BRDL itself has already been modified by Rob Robinson of the British Trust for Ornithology to feature the five-letter British banding codes. His version is called "A Ringing BRDL," a reference to the British use of ring instead of band. So file that one away with boot, and lift, and bumbershoot, and all those other wonderful Britishisms. 

How does Alex feel about BRDL's speedy success and its very own spinoff? "It is so surreal!" he told me over Slack. "I had no idea such a niche thing would be so popular!" 

Source: brdl.alex.gd

How Do the BRDL Banding Codes Work? 

In North America, banding codes can be either four or six letters. There are actually multiple sets of four-letter codes, but we won't get into all that here. Let's just say that the world of banding codes is nuanced and delightfully pedantic, so you should definitely read more about it when you have a moment. (For folks in the know and worried about those notorious "collisions," Alex plans to avoid them for now.) The key point to remember for BRDL is that the codes used are from the government's official Bird Banding Laboratory and they depend on a specific set of rules, as outlined below. 

 
Toggle to see full names

When the name is one word, the code is simply the first four letters.

BOBOlink
OSPRey
GYRFalcon

When the name is two words, which is frequently the case in the bird world, the code features the first two letters of each word. 

Mourning Dove
Great Egret
Common Nighthawk

With three words, things get a little trickier. Here, the code consists of the first letter from each of the first two words, and the first two letters of the third. 

Great Blue HEron
Clay-Colored SParrow

However, when a hyphen is at the end of a three-word name, as seen below, then you use the first two letters from the first name and the first letter from each of the second names

FLorida Scrub-Jay

Finally, when the name is four words, the code is the first letter of each one regardless of hyphens. 

Eastern Whip-Poor-Will
Gray-Crowned Rosy-Finch
Wedge-Rumped Storm-Petrel

Got all that? Okay, good. Happy BRDLing!  

Graphic: Alex Tomlinson/Audubon.

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