Figure 2.

The relationships between the taxonomic entities related to the Vireo solitarius superspecies. Numbers under each name refer to Avibase IDs. The concept for the nominal plumbeus sec. Oberholser, 1974 is therefore distinct from the concept for the nominal subspecies plumbeus when jacksoni is subsumed. It is worth noting however that the recognition or not of jacksoni does not affect the higher related concepts, such as the plumbeus species, any of its other subspecies, or the rest of the Vireo solitarius complex because they are either orthogonal to those alternative arrangements or they completely include both. In the database model (Fig. 1), these trees are maintained with the parent-child relationship table in which each Avibase ID only needs to identify its immediate parent, while other relationships can be calculated programmatically.