Many birders create shorthand methods for noting bird
species in the field. Others, like John Shipman, create codes as a way of
making data entry into computer databases more efficient. Spokane Audubon is
providing the following coding systems as quick and useful methods of bird
notation for field or computer entry. Please note that we are not arguing to
replace the BBL coding system (the system generally used in bird banding
The following information on Birding Codes is used with
the permission of the author John W. Shipman. His page can be found here:
http://www.nmt.edu/~shipman/z/nom/homepage.html. (Note: All references
made to “the author” are referring to John W. Shipman.)
Bird Banding Lab (BBL or Alpha) Codes
BBL or Alpha codes are 4 letter abbreviations of bird species common
names. They are used by bird banders as shorthand for the common names of
bird species. They are also used by some birders as a quick way to record
their sightings in the field. For a complete list of these codes click here:
The BBL code system: Rules for forming
The USF&W Bird Banding Lab codes were introduced in:
Klimkiewicz, Kathleen, and Chandler S. Robbins.
Standard abbreviations for common names of birds. North American Bird Bander
Codes are formed using these rules:
- If the name consists of only one word, the code is
taken from the initial letters, up to four:
- If there are two words in the name, the code is made
from the first two letters of each word:
AMWI American Wigeon
EAME Eastern Meadowlark
- For three-word names where only the last two words
are hyphenated, the code uses two letters from the first word and one each
from the last two:
EASO Eastern Screech-Owl
WEWP Western Wood-Pewee
- For other names with three words, the code takes one
letter each from the first two words and two from the last word:
RTHA Red-tailed Hawk
WWCR White-winged Crossbill
- For four-word names, the code takes one letter from
BCNH Black-crowned Night-Heron
ASTK American Swallow-tailed Kite
NSWO Northern Saw-whet Owl
A collision is a situation where two or more names would
abbreviate to the same code using these rules.
The Bird Banding Lab decides what code to use in these cases. If one name
is far more common than the other name or names involved, typically the
common species gets to use the name. In most cases (e.g., Lark Bunting and
Lazuli Bunting) when both birds are common, the collision code is not used,
and unambiguous substitutes are provided for both forms.
The BBL code system: Collision problems
The author has written a computer program to analyze the Bird Banding Lab
code system. This program forms the codes according to the
rules, and then produces a report showing all the cases where there were
collisions (two or more names abbreviating to the same code) or for some
other reason the BBL code is not the one expected by the rules.
Collisions involving birds found in the AOU Check-List but
absent from the ABA Checklist have been omitted.
A total of 98 names were involved in collisions. Usually, substitute
codes are given to both forms involved in a collision. When one of
the forms is fairly rare, however, the BBL has allowed the common form to
use the collision code---which I consider a very dangerous practice.
A critique of the Bird Banding Lab code
The banders' code was designed for use in banding. It was never intended
to be a general-purpose code for North American bird records. In the
author's opinion, its use in other sorts of bird records may lead to
Benefits of the BBL code
Applying the principles in the author's discussion of
design goals for bird code systems, the BBL four-letter code is not all
that bad a code system. Because it is produced by applying a few rules to
the English names, it meets the criteria of being easy to learn and easy to
encode. It covers North America and Hawaii, and it is nice and short.
Drawbacks of the BBL code
In many of the design goals, though, the BBL code falls short. For
example, after reading the list of
collisions in the BBL code system, can you honestly say that this system
is easy to learn? There are nearly 100 bird names involved in
Collisions in the BBL system are handled by picking a different,
arbitrary code for one or both of the forms. For example, both Lark Bunting
and Lazuli Bunting abbreviate to code
LABU. Since both birds are common
in the West, they are given codes
But suppose a summer intern records a sighting as
and no one notices until the intern has moved on. If we come along later and
look at the record, we (or a computer program) may detect that it's not a
valid code, but how can we know sure which species was really seen? We might
not be able to reach the observer.
People who take wren data have to remember that there is a three-way
collision for the code
CAWR: Carolina Wren (CARW),
Cactus Wren (CACW),
and Canyon Wren (CANW).
It's probably safe to assume that a Kentucky record for
is a Carolina, but what about a record from New Mexico? In many localities
it could be either Cactus or Canyon.
For this reason, the author feels that it is vital to keep the number of
exceptions to the rules as small as possible. He once entered a point count
survey for the Institute for Bird Populations (which uses the BBL codes) in
which over 20% of the records were not legal BBL codes.
When one of the forms involved is rarely encountered in North America, or
has limited distribution, the commoner form is encoded as usual and an
arbitrary substitute is assigned to the other. This violates the design
principle that people who use the code system should not be required to know
anything about bird distribution.
To avoid such problems, the author's preference is to disallow use of the
collision codes altogether. Then, when someone uses such a code, we will
know that they were unaware of the collision. This allows automatic
detection of encoding errors by computer programs. Having a computer detect
an error takes a lot less time than catching it in proofreading, assuming
you have time to proof it at all.
Codes that the BBL will not define
The Bird Banding Lab defines virtually no codes for forms other than
species and certain races. Banders have no need for a code for "hawk sp.",
because banders will have the bird in hand and be able to key it out to
species. But in databases involving sight records, there is a real need for
Furthermore, a novice observer in Cave Creek Canyon, Arizona, might not
MOQU is not the code for
Montezuma Quail. This is a collision with Mountain Quail, which is more
common nationally than Montezuma Quail. Since the BBL does not define codes
for gamebirds, who will resolve this conflict?
Finally, please see the list of
684 North American bird names and identifiable forms that have no BBL code.
Design goals for bird code systems
Among programmers, good programs or systems are often described as
``robust.'' Such systems should be easy to learn and use, and they should
not tend to confuse users or mangle data. Design of a good encoding system
involves more than just the problem of representing the data. We should
consider human factors as well.
Here are some other qualities of a good code system:
- It should be short, to save keystrokes during
- Encoding should be easy to learn and quick to
- The codes should be meaningful and easy to decode.
Although any code can be translated mechanically by a program, it often
saves time if we can just look at a code and know what it means without
having to look it up.
- It should handle forms other than species---any
category of birds, however precise ("Blue Goose") or vague ("black bird
sp.") the identification.
- It should cope well with the continual changes
in taxonomy and nomenclature.
- It should be usable even by non-experts, so
beginners and even non-birders can use it for data entry.
- Use of a code should not be a significant source
For efficient data entry, we want to be able to bang the records into the
machine quickly (minimizing mistakes, of course). Speed depends on more than
just the keystroke rate. Thinking takes time too---the time it takes to
think of the right code, or look it up if necessary.
A robust system should also be designed so that most errors can be
detected easily, and easily corrected whenever possible. In the author's
opinion, this is an argument against using the shortest possible code.
Longer codes have more redundancy, so it is more likely that a user can
figure out what was meant even if the code has an error in it. As an
example, the English language has a lot of redundancy in it, which is a
robust characteristic. We can oftxn undxrstand a sxntxncx xvxn if it
contains quitx a fxw typos.
How the six-letter bird code system came
The new coding system presented here was invented by the author for use
in preparing a database of Christmas Bird Count (CBC) data. We found that
using the banders' four-letter code to enter data was very frustrating, as
we spent far too much time consulting the list of exceptions.
After some experimentation, we found a six-letter system to be a good
tradeoff. Even though each code takes two extra keystrokes, the number of
special cases went down by an order of magnitude. This greatly reduces
thinking time, making the work flow more smoothly, and significantly
increases the throughput measured in records per hour.
We have used these codes to enter over three million historical CBC
records: all the North American and Hawaiian counts from the 1st CBC, in
1900, through the 90th CBC in 1989 (except for ten years, the 63rd-72nd
counts, which were provided by Dr. Carl Bock's project at the University of
Colorado). As an example, the 89th CBC, with 1523 count circles and about
115,000 records, took less than 50 hours to enter at a keying rate of about
65 words per minute. This translates to a rate of well over 2,000 records
Many refinements in this system were suggested by Greg Butcher and Jim
Lowe of the Cornell Lab of Ornithology. The author greatly appreciates their
Rules for the six-letter bird code system
As with the Bird Banding Lab's four-letter codes, six-letter codes are
derived by abbreviating the name of the bird. Names are not limited to
standard AOU species names. Codes may be based on obsolete names (e.g.,
Short-billed Marsh Wren), subspecies names (Peale's Falcon), color morphs
(Blue Goose), or even vague categories like "raptor" or "Empidonax
- Birds with one-word names are abbreviated by taking
the initial letters of the name:
EMPIDO Empidonax sp.
- For two-word names, take the first three letters of
the first word and the first three letters of the last word. Hyphenated
words are always treated as separate words:
CEDWAX Cedar Waxwing
LARFAL large falcon
- For three-word names, take two letters from the
first word, one from the second, and three from the third:
BABWAR Bay-breasted Warbler
GRPCHI Greater Prairie-Chicken
DABSHE dark-backed shearwater
- For four or more words, take one letter each from
the first three words, then the first three letters of the last word:
GBBGUL Great Black-backed Gull
BCNHER Black-crowned Night-Heron
BTBWAR Black-throated Blue Warbler
- Certain similar color names are abbreviated in
standard ways: green as
GN; gray as
GY; black as
and brown as
BLKPHO Black Phoebe
GRYJAY Gray Jay
GNBHER Green-backed Heron
BNCFLY Brown-crested Flycatcher
Collisions in the six-letter bird code
The author checked the six-letter system for collisions by writing a
computer program that applies the rules mechanically to each name, and then
running the program on a file of all the species names from the current
Only nine two-way collisions were found. There were no three-way
collisions. Here is a list of the collisions and their resolutions. For
safety's sake, both species involved in a collision are given substitute
Wrong Right Name
------ ------ ----
BAROWL BRDOWL Barred Owl
BRNOWL Barn Owl
BLAWAR BKBWAR Blackburnian Warbler
BKPWAR Blackpoll Warbler
BLUGRO BLUGRB Blue Grosbeak
BLUGRS Blue Grouse
BRSPET BRIPET British Storm-Petrel
BARPET Band-rumped Storm-Petrel
BTGWAR BTNWAR Black-throated Green Warbler
BTYWAR Black-throated Gray Warbler
GOCWAR GCHWAR Golden-cheeked Warbler
GCRWAR Golden-crowned Warbler
LESPET LCSPET Leach's Storm-Petrel
LSSPET Least Storm-Petrel
RUTHUM RTHHUM Ruby-throated Hummingbird
RTLHUM Rufous-tailed Hummingbird
SPOSAN SPBSAN Spoonbill Sandpiper
SPTSAN Spotted Sandpiper
Using the six-letter system with names other than standard species names
leads to more collisions. Some involve obsolete names, or forms that have
never been accepted on the standard checklists. These are included to allow
handling of older names and names from rejected or hypothetical records.
Here is the list of all the additional collisions encountered after using
this code system for over ten years of work with CBC and other field records
of all kinds.
BELSPA BLDSPA "Belding's" (Savannah) Sparrow
BLLSPA "Bell's" (Sage) Sparrow
BUFBOO MASBOO "Blue-faced" [=Masked] Booby
BFOBOO Blue-footed Booby
CATHAR CATHAC Catharacta sp.
CATHUS Catharus sp.
COLUMB COLBA Columba sp.
COLBID columbid sp.
COLBIN Columbina sp.
DENDRO DENCYG Dendrocygna sp.
DENICA Dendroica sp.
FRINGI FRINLA Fringilla sp.
FRINID fringillid sp.
FRININ fringilline sp.
HARHAW HRLHAW "Harlan's" (Red-tailed) Hawk
HRSHAW Harris' Hawk
INHMYN COMMYN Indian House [=Common] Myna
HILMYN Indian Hill [=Hill] Myna
PASSER PASR Passer sp.
PASINA Passerina sp.
PASINE passerine sp.
PROCEL PROCID procellariid sp.
PROCIF procellariiform sp.
WILWAR WLSWAR Wilson's Warbler
WLWWAR Willow Warbler
YELLOW YELLEG yellowlegs sp.
YELTHR yellowthroat sp.
Note: Names starting with "Mc" or
"Mac" are treated as one word. Code
MAGWAR would otherwise be a collision between
MacGillivray's and Magnolia warblers.
Bruce Bowman's Six-Letter
Bruce Bowman's Website
The four-letter Bird Banding Lab (BBL - often called Alpha Codes) are
familiar to many birders. However, this code can be very difficult to learn
as there are many exceptions to the rule. Northern Michigan Birding has
adopted Bruce Bowman's code system for use in the sightings database. His
code system is very simple and carries very few exceptions to the rules.
Read the rules of his code system below. We've also created a database for
you to easily familiarize yourself with Bruce Bowman's system.
Bruce's system is applied to species included in the American Birding
Association (ABA) CHECKLIST OF THE BIRDS OF THE CONTINENTAL U.S. AND CANADA
(5TH ED., 1996). Standard abbreviations are based on a six-letter
abbreviation scheme. Specifically, the rules given below must be followed in
constructing a species abbreviation.
"Words" in a species name are those parts of the name separated by spaces
or hyphens. Ex.: "Bay-breasted Warbler" has three words.
* ONE-WORD NAMES Use the first six letters, or use the entire name if it
is less than six letters in length. Ex.: Canvasback = CANVAS, Sora = SORA
* TWO-WORD NAMES Use the first three letters of each word. Ex.: Wilson's
Plover = WILPLO, Fish Crow = FISCRO
* THREE-WORD NAMES Use the first two letters of each word. Ex.: Great
Gray Owl = GRGROW, Broad-tailed Hummingbird = BRTAHU
* FOUR-WORD NAMES Use the first letter of each of the first two words and
the first two letters of each of the last two words. Ex. Black-and-white
Warbler = BAWHWA, Black-crowned Night-Heron = BCNIHE
Because several instances of duplicate abbreviations result when the
above rules are applied to the 917 species names in the American Birding
Association Checklist, special-case abbreviations are necessary for the
species listed below:
SPECIAL CASE ABBREVIATIONS
Barn Owl= BARNOW
Barred Owl= BARROW
Common Redpoll= COREDP
Common Redshank= COREDS
Blackburnian Warbler= BLBUWA
Blackpoll Warbler= BLPOWA
Green-breasted Mango= GNBRMA
Gray-breasted Martin= GYBRMA
Blue Grouse= BLGROU
Blue Grosbeak= BLGROS
Leach's Storm-Petrel= LEACSP
Least Storm-Petrel= LEASSP
Black-throated Gray Warbler= BTGYWA
Black-throated Green Warbler= BTGNWA
Spotted Sandpiper= SPOTSA
Spoonbill Sandpiper= SPOOSA