Figure 1 from: Lepage D, Vaidya G, Guralnick R (2014) Avibase – a database system for managing and organizing taxonomic concepts. ZooKeys 420: 117-135. https://doi.org/10.3897/zookeys.420.7089

Figure 1 - Simplified schema of Avibase primary tables, The Avibase ID table is the central element of Avibase, to which all other concepts are related, and which aims to represent all distinct taxonomic concepts ever published for birds. Published taxonomic concepts (species and subspecies, as well as subspecies groups in some cases), along with their scientific and common names as recognized in the publication, are each mapped to a single Avibase ID. A table of parent-child relationships is used to describe relationships between different Avibase IDs. Because all taxonomic concepts are congruent with Avibase IDs, relationships among taxonomic concepts themselves are not needed. Biological properties (geographic range, life-history, etc.) are linked directly to Avibase ID, as are synonyms, a table that partly overlaps with the names used by taxonomic concepts, but that can also extend to vernacular names in multiple languages. Name concepts, which relate to names attached to original type specimens, are a property of taxonomic concepts, and can themselves be linked to ITIS Taxonomic Serial Number (TSN) identifiers