Ideally, observations of organisms are identified by the observer with a taxonomic concept, consisting of the taxonomic name and the reference defining that name. However, systems that manage observational data must be able to accommodate imprecision or uncertainty in concepts since observers are not always able to classify an organism as a single, well-established species (or subspecies) taxonomic concept. There are several instances in which indefinite concepts are required. First, an observer may identify an organism as a hybrid of two species. Second, imperfect observation conditions (e.g., limited visibility), limited experience, or other factors might limit an observer to classifying an organism only as a member of some subset of concepts, where the subset has meaning to field observers, but may not be circumscribed by a academically established taxonomic concept. Finally, similar factors might lead an observer to identify an organism only to a genus or higher taxonomic rank. The first two cases may lead managers of observation systems to informally become taxonomists, since they must create concepts to accommodate the observations they hold and which do not fall into a well-established taxonomic concept. This presentation shows how uncertainty and imprecision in taxonomic identity are handled by the Bird Monitoring Data Exchange standard used by the Avian Knowledge Network (AKN, www.avianknowledge.net) and the TDWG Taxonomic Concept Transfer Schema standard.

Analysis of 29 million avian observation records from eBird (www.ebird.org) and the Avian Knowledge Network shows that uncertain and imprecise taxonomic concepts represent 5% (eBird) 18% (AKN) of the concepts in these systems. However, observations labeled with uncertain or imprecise concepts represent only 0.05% (eBird) and 1% (AKN) of the observations held in those systems.