In the past seven years, the group has co-ordinated 70 volunteers, contractors and more than 100 local landowners to remove 14,327 possums from the area.
Group project manager Dr Ursula Ellenberg said a door-to-door survey, which began in November, of households in the "neck'' of the peninsula - Waverley, Shiel Hill and Vauxhall - had been welcomed.
University of Otago wildlife management master's student Frances Peres visited close to 300 homes and was impressed by people's knowledge of nature and their willingness to help with pest control.
Of those surveyed, 93% were knowledgeable about wildlife in the area, 83% perceived possums as a pest requiring control and more than half would consider having possum traps on their properties.
In addition, 28% of local residents interviewed were already trapping possums on their properties.
"That has come as a great boost for us, to know that our hard work is appreciated and supported,'' Dr Ellenberg said.
That support would be vital as the eradication project moved into its next phase - to prevent a "reinvasion'' of possums from the neck of the peninsula, she said.
From next week, the group would be distributing "chew cards'' for households to place on their trees in order to help identify the presence of possums.
This could then be followed up with trapping, Dr Ellenberg said.
Information sessions will be held early next month, and a trapping workshop on April 21.
"The best time to trap possums is in late autumn through to winter, when they are hungry and looking for food.''
Visiting Larnach Castle this week to draw the prizewinner from among those who took part in the household survey, retiring Portobello Senior Constable Lox Kellas reflected on the success of the biodiversity group.
"I was a member of the Peninsula Community Board when the biodiversity group was first mooted, and it has been great to see it going from strength to strength.
"It is a proactive organisation, which has been of real benefit for the wildlife and to the amount of birdlife on the peninsula.''
The increase in the numbers of piwakawaka (fantails), tui and kereru (wood pigeons) had been remarkable, he said.
Larnach Castle executive director Norcombe Barker agreed, saying the castle garden had also benefited.
"At a wedding we hosted last weekend, there was a fantastic chorus of birds as a backdrop to the ceremony,'' he said.
The winner of the prize of a high tea and garden voucher for two at Larnach Castle was Gillian Crosbie.
