Alphabetic (“alpha”) codes are abbreviations of English or scientific bird names that are employed by ornithologists as shorthand. They allow quicker data entry than filling out the full English or scientific name of a species and they can also serve to cross-check other recorded names or numeric data.

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 the United States and Canada. Inconsistencies have occurred in the rules governing the alpha codes of the BBL, however, and the list it maintains does not include most species found in Mexico, Central America, and the Caribbean but not in the United States or Canada.

In 2003, IBP began developing a new set of four-letter (for English common names) and six-letter (for scientific names) species alpha codes to reflect current American Ornithologists' Union (AOU; now American Ornithological Society, AOS) taxonomy and nomenclature in their check-list (AOU 1998) and subsequent supplements (AOU 2000-2016 and AOS 2017-2024). This list includes all species of birds recorded in North America, Mexico, Central America, and the Caribbean region, including records out to 200 miles from shore in most areas. We update this list annually, following publication of each AOU/AOS supplement to their check-list, which usually occurs in July.

We have developed two sets of alpha codes for use by North and Central American and Caribbean ornithologists (for details see Pyle and DeSante 2003). The first set contains four-letter codes, based on English names, broadly following the rules and strategies adopted by the BBL. The second set follows the same basic principles except that it contains six-letter codes based on the scientific names. We hope that this second set will be useful for ornithologists, particularly those in Latin American countries, who prefer using scientific rather than English names.

View or download the latest English and Scientific Alpha Codes for North American Birds by clicking on one of the links at the top right of this page. There are four formats available: three PDF documents (sorted phylogenetically, alphabetically by common name, and alphabetically by scientific name), and a CSV file that can be accessed through several commonly used programs (e.g., Excel, Access, Paradox).

We have created update files containing all of the changes that were made to the Alpha Codes list in a given year; download these lists for 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, and 2024 by clicking on the respective year. Contact Peter Pyle if you would like similar lists dating back to 1999.

If you have any questions about the Alpha Codes or detect any errors, please contact Peter Pyle.