Spanish sparrow
There has been much debate on the origins and taxonomic status of the Italian sparrow, especially given its possible hybrid origin. Some have classified it as a subspecies of the house sparrow, a subspecies of the Spanish sparrow, or as a separate species, a treatment followed if only for convenience by authorities such as the "Handbook of the Birds of the World". A DNA analysis by Glenn-Peter Sætre and colleagues published in 2011 indicated an origin of the Italian sparrow through hybridisation between the Spanish and house sparrows, and Sætre and colleagues argued that given its origins and the limited extent of hybridisation, the treatment as a distinct species was supported.