I can't lay hands on my copy of Faith McNulty's 'The Wooping Crane', but I think this was where Josephine, the wild casualty Whooping Crane who was the last survivor of the Southern non-migratory stock, was kept and eventually reared at least five young over the years with one or more mates from the migratory population. This was before collection of wild eggs for propagation was started. Not sure if Josphine's line persists.
Whooping Cranes were in the UK in at least three collections a hundred or so years ago -- refrences available if anyone is interested.