The region was renamed nidopallium in 2002 during the Avian Brain Nomenclature Consortium because the prior name, neostriatum, suggested that the region was used for more primitive functions as the neostriatum in mammalian brains is sub-cortical.
In 2002, the region was reclassified as nidopallium through the Avian Brain Nomenclature Consortium's initiative to avoid implying that it performed more fundamental functions, which is indeed the case with the neostriatum in mammalian brains.