having an aftershaft (a small feather at the base of some feathers)

a supplementary feather (usually small) on the underside of the base of the shaft of some feathers in some birds

a supplementary feather (usually small) on the underside of the base of the shaft of some feathers in some birds

a supplementary feather (usually small) on the underside of the base of the shaft of some feathers in some birds