Biodiversity research and conservation hinge on accurate and consistent species definitions, especially when those species definitions can be different across taxonomies and time. Traditionally, a species is defined by a specific version of the taxonomy, and a scientific name. However, taxonomies and taxon concepts change as we learn more about species behavior and evolutionary history. While billions of records exist attributed to a taxonomic name and are being used in research and conservation, the concept behind the name may be different from dataset to dataset depending on the originating taxonomy. Our work focuses on birds and we manage the Clements Checklist of Birds of the World, which presents a global taxonomy of 10,514 species. This checklist provides the scientific and English name of each species, a taxonomic hierarchy, and a description of the worldwide range of each species and subspecies. Here we describe how taxon-based assets are managed through the use of unique taxonomic concept identifiers, how the identifiers are managed within a dynamic taxonomy and finally, how those identifiers are applied in various projects to consolidate unrelated assets. We use these identifiers to uniquely define a taxonomic concept and the real-world populations that the concept represents. Traditional taxonomic information, such as scientific names, common names, higher order assignments and relationships between species and subspecies is layered on these ids using the Clements checklist. While these ids are represented by scientific names defined by the current Clements checklist, the id persists across taxonomies and versions, as long as the real-world populations represented are unchanged. Every species based asset (observations, data visualizations, multimedia, life history articles and specimens) is assigned a unique taxon concept id and as the taxonomy is revised, the taxon ids of assets remain largely unchanged. In some cases, taxonomic revisions will require changes to the taxon id of the asset, for example, where further refinement of the taxon can be determined (such as an elevation of allopatric subspecies to species). We manage an ever-growing set of assets, 350 million observations, over 1 million images and 1000s of articles that are tracked and managed through yearly taxonomy updates allowing us to accurately represent these assets and the taxa they represent.  Researchers and conservationists combine these various datasets, without understanding the taxonomic intricacies themselves, and species account projects like Birds of North America and even Wikipedia can automatically integrate these resources into scientifically accurate species monographs.
