Organisers said several hundred people had attended the Orokonui Ecosanctuary’s "Odyssey" event, in the Meridian Mall, between 10am and 2pm.
"It was a celebration of everything we love about living in the wildlife capital of New Zealand," ecosanctuary ambassador Kahu Mackenzie said.
"We had many people visiting us who had not been to the ecosanctuary," she added.
"I just feel overjoyed it was such a success," she said.
She was also grateful the science festival team had enabled the event to happen.
It had been "an absolutely incredible against-the-odds" outcome and an amazing achievement to run even a scaled-back "nano-festival", despite the earlier disruption of the Covid-19 lockdown, she said.
Festival organisers said the Dunedin City Council biodiversity team had provided about 100 trees which had been given to participants yesterday, and Ribbonwood Nurseries had loaned a mass of saplings and more mature trees which were displayed during the event.
Festival organisers said it had been one of the most popular of a series of child and youth-oriented events held at the mall this week.
The festival ends tomorrow.