This year has been a bumper season for the slow-breeding endangered native parrots, with 46 eggs hatching and 36 chicks surviving.
Working in shifts around the clock, Doc staff have been raising 11 chicks in a building in Esk St which did not thrive with their mothers.
At the beginning of last month Doc put some of the older chicks at the facility on display. Ms Futter said since then more than 4000 school groups and members of the public had visited.
‘‘It’s been very popular, and some people have travelled to be here, which is amazing. [Last] weekend a lady flew from Sydney to Invercargill just to see them.’’
Because of the birds’ popularity, public viewing had been extended to this Saturday and Sunday and June 18 and 19, Ms Futter said.
Tickets are available through the Invercargill iSITE, Gala St, at $2 per person.
Six chicks had already returned to their homes on Whenua Hou (Codfish Island), Foveaux Strait, or Anchor Island, Fiordland, Ms Futter said.
The rest of the chicks would return home after June 19, she said.
On Friday, conservation minister Maggie Barry visited the facility, getting the opportunity to hold a large kakapo chick before accompanying that chick and another home to Whenua Hou.
Holding the chick was ‘‘amazing’’, she said.
‘‘It’s like holding a piece of history.’’