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Monday, December 31, 2012

Bird Name Shorthand

Smartphones have made getting the word out to the birding community about bird sightings convenient and instantaneous. Like many birdwatchers, I sometimes find that typing out the entire common name of a bird on my phone cumbersome. Thanks to the ornithological community, there are standard, four letter codes that can be used that are easy to figure out.

The following explanation was gleaned from the Carolina Bird Club website. In addition, a webpage with all the shorthand can be found here.

Four-letter bird codes (FLBCs)

Four-letter codes are commonly (and too often incorrectly) used as a short-hand way to write a bird name. Two different sets of codes are in use. The first codes were created by the Bird Banding Laboratory (BBL) for use by bird banders in submitting data; consequently the codes are frequently referred to as “banding codes”. A slightly different set of codes has been published by the Institute for Bird Populations (IBP).

The basic codes were derived from a simple set of rules for reducing a name to four letters. A major problem is that the rules can create “collisions”; cases where two (or more) different names reduce to the same four letters. In these cases, different codes had to be created ad hoc. Unfortunately, if you want to use the codes, you simply must memorize the special cases; there is no way around it. Worse, the BBL and IBP code sets differ in some of these ad hoc codes.

Here is a summary of the basic rules:

1. If the name is one word, the code is the first four letters:

DICK - Dickcissel
SORA - Sora

2. If the name is two unhyphenated words, the code is the first two letters of each word:

MODO - Mourning Dove
AMRO - American Robin

3. If the name is two words, with the last word hyphenated, the code is the first two letters of the first word and the first letter of each part of the hyphenation:

EASO - Eastern Screech-Owl
EAWP - Eastern Wood-Pewee

4. If the name is two words, with the first word hyphenated, or simply three words, the first two letters of the code are the first letter of each of the first two parts of the hyphenation or of each of the first two words, and the second two letters of the code are the first two letters of the last word, or the third part of the hyphenation:

GCFL - Great Crested Flycatcher
GTGR - Great-tailed Grackle
RTHU - Ruby-throated Hummingbird
RTHA - Red-tailed Hawk
CWWI - Chuck-will's-widow

5. If the name has four parts, either separate words or hyphenated parts, the code is the first letter of each part:

BCNH - Black-crowned Night-Heron
NRWS - Northern Rough-winged Swallow

A footnote: The above rules describe how today's BBL codes were generated. I went back and read the 1978 paper by Klimkiewicz and Robbins where the first rules for banding codes were published, and those rules are slightly different. However, nomenclature was quite different then as well. I don't know the source of today's rules.

There are no published rules for resolving collisions in the BBL system, but I have observed the patterns below. First, note that the basic rules for two- or three-word names divide the name into a “first name” and “last name”, or specific name and group name, and the specific name always gets two letters and the group name two letters. Most of the ad hoc cases deviate from this equal division between specific name and group name.

- The most common way of resolving a collision is to take three letters from the specific name and only one letter from the group name. For example, Carolina Wren, Cactus Wren, and Canyon Wren all reduce to CAWR, so unique codes were obtained by taking three letters from the specific name and only the W from Wren: CARW, CACW, and CANW.

- When the above rule still does not provide unique codes, then the code may be made by using only one letter from the specific name and three letters from the group name. For example, Northern Shoveler and Northern Shrike both reduce to NOSH by the basic rules, or NORS by the above rule, so the actual codes are NSHO and NSHR.

- If both of the above rules still fail to create unique codes, another possibility is to use the first and last letters of the specific name instead of the first two letters. Thus, the codes for Barred Owl and Barn Owl are BDOW and BNOW.

- The “last letter” approach is also used in some four-word names. For example, Black-throated Green Warbler is BTNW and Black-throated Gray Warbler is BTYW, using the last letter of the distinguishing word.

- There are some cases that don't fit any of these rules, for example BRNG for Barnacle Goose and BAGO for Barrow's Goldeneye.

When codes collide, usually all of the involved species take ad hoc codes. But in some cases where one species is rare or has a limited distribution, and the other is commoner or more widely distributed, the ad hoc code may be only used for the less common species. This is illustrated by the last example above, where Barrow's Goldeneye keeps the basic code BAGO even though it could be confused with Barnacle Goose, which gets an ad hoc code.

Some specific problems with the BBL codes relate to their primary purpose for banding. For some species, no official code is provided. For example, the BBL does not oversee banding of gallinaceous birds, so it provides no code for them. Also, they tend to retain established codes rather than update them as nomenclature changes. For example, they retain CAGO for Canada Goose even though Cackling Goose is now recognized as a species. And sometimes they provide only specific codes for recognizable forms rather than an over-all code for a species. For example, they have several codes for various forms of Snow Goose, but SNGO is not an official code for the species. The codes from the IBP address these problems.

As you can see, there are many reasons not to use these codes. The foremost reason is that they are a barrier to communication with people who do not know the codes. Another reason is that you are likely to make mistakes, and years later when you refer back to your notes you may find yourself unsure which species you actually meant. Nevertheless, you can't stop people from using the codes so it's best to try to learn them. I suggest that the most appropriate use of the codes is for quick taking of field notes that you will transcribe before you forget what you meant. If you are already a user of the codes, I predict that if you study the table carefully, you will discover at least a couple of species for which you've been using the wrong codes.

The table below lists a sample of codes that are defined for forms that are not species. See the original sources for others.

Blue Greater Snow Goose - BGSG
Lesser Snow Goose (intermediate phase) - SBGI
Lesser Snow Goose (white phase) - LSGO
Greater Snow Goose - GSGO
Lesser Snow Goose (blue phase) - BLGO
Eurasian Green-winged Teal - EGWT
Great White Heron - GWHE
Traill's Flycatcher - TRFL
Gray-cheeked/Bicknell's Thrush - GCBT
Brewster's Warbler - BRWA
Lawrence's Warbler - LAWA
Myrtle Warbler - MYWA
Audubon's Warbler - AUWA
Ipswich Sparrow - IPSP
Sharp-tailed Sparrow - STSP

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