The Drama of the Four-letter Bird Alpha Codes

The Short Story

After a surprisingly long time, we now have all the birds in Wildlife Rehabilitation MD cataloged with their four-letter alpha codes. Users can now also search for an avian species using the Institute for Bird Populations four-letter alpha codes as well as the species common name.

The Long Story

Bird alpha codes are four-letter codes commonly used by birders and bird banders as abbreviations for bird names. Apparently there is/was drama in the birder’s and bird bander’s community concerning the alpha codes and now 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.

As Stated by the Institute for Bird Populations

“The U.S. Bird Banding Laboratory (BBL) has long used alpha codes in banding data, and these codes have become an integral part of large ornithological programs across Canada and the United States; however, inconsistencies have occurred in the rules governing the alpha codes of the BBL, and their list does not include most species found in Mexico, Central America, and the Caribbean but not in the United States or Canada.

Therefore, a new set of four-letter (for English common names) and six-letter (for scientific names) species alpha codes were developed…”


The Bird Banding Laboratory has acknowledged the species name changes made by The American Ornithologists’ Union (and reflected in the Institute for Bird Populations alpha code list) but has yet to update their alpha code list to reflect the change in species names.

“Taxonomic revisions by the AOU have resulted in many changes in bird classification over the past several decades. The Banding Offices acknowledge these changes and uses the common names assigned by the AOU…”


Because the Institute for Bird Populations maintains an updated list of species and their alpha codes (at the time of this writing and according to the IBP website, maintained through the AOU’s 53rd supplement) we are adopting the IBP’s list of four-letter alpha codes. As of last week, our database of birds has been updated with all the identifiable species alpha codes. The only unidentifiable species we have adopted is Unidentified Bird (UNBI). Users can now search for an avian species using the four-letter alpha codes or the species common name. We will do our best to keep the list of birds and their alpha codes updated, while avoiding the drama.

%d bloggers like this: