This taxon is Not Recognised as a species by BirdLife International.
Passerella iliaca, P. unalaschcensis, P. schistacea and P. megarhyncha (del Hoyo and Collar 2016) were previously lumped as P. iliaca following AERC TAC (2003); AOU (1998 & supplements); Cramp et al. (1977-1994); Sibley & Monroe (1990, 1993); Stotz et al. (1996).
BirdLife International (2023) Species factsheet: Passerella schistacea. Downloaded from http://datazone.birdlife.org/species/factsheet/passerella-schistacea on 27/09/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 27/09/2023.