Meaning of swan-upping

swan-up•ping

Pronunciation: (swon'up"ing), [key]
— n. Brit.
  1. the taking up of young swans to mark them with nicks on the beak for identification.
  2. an annual expedition for this purpose on the Thames.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.