Next / Previous / Contents / Shipman's homepage

3.3. The taxonomic dimension: what kind of bird?

To represent what kind of birds we see, we're fortunate to have the American Ornithological Union's Check-list of North American Birds as a standard for the classification of birds.

However, the AOU Check-List is not a static entity. Every two years a new revision appears, and every few revisions a new major edition appears. At this writing, the Seventh Edition is the base checklist, with supplements through the Forty-Seventh Supplement adding later corrections. The author has built a complete infrastructure for tracking all these versions; it is described in A system for representing bird taxonomy. The fundamental item used from this system is the six-letter bird code, such as VERFLY for Vermilion Flycatcher or BRWHAW for Broad-winged Hawk.

Fundamentally, we prefer to assign each sighting to a biological taxon in the AOU's classification. Most sightings are identified to species, but we may use larger or smaller taxa. For example, what in English we call “falcon sp.” (falcon species) can be assigned to family Falconidae. In another case we might see a well-marked race such as Audubon's Warbler, which is a form of the species Yellow-rumped Warbler. The six-letter codes in the nomenclatural base system allow for assignment to any level: these examples would be encoded as FALCON and AUDWAR respectively.

Two additional wrinkles complicate the process of assigning sightings to taxa: