Project bringing back the birds

Exciting . . . Demonstrating a non-toxic "chew card", which helps to pinpoint the presence of possums in the Larnach Castle garden are (from left) Otago Peninsula Biodiversity Trust project manager Dr Ursula Ellenberg, University of Otago Masters Student in Wildlife Management Frances Perez, Larnach Castle executive director Norcombe Barker, and OPBT treasurer Laurie White. PHOTO: BRENDA HARWOOD

The laser focus of the Otago Peninsula Biodiversity Group (OPBG) on the eradication of possums is paying off, with 13,500 of the pests killed in the past six years.

Group project manager Dr Ursula Ellenberg is thrilled at the achievement, which is due to the tireless work of 70 volunteers, contractors and more than 100 local landowners.

“The work that has been done over the past six years has been fantastic,” Dr Ellenberg said.

“We have made huge progress on eradicating possums on the Otago Peninsula – there are still hot spots, but numbers are very low in many places.”

Founded in 2008 by a group of concerned landowners, the group began its possum-control work in 2011, focusing on the outer peninsula – from Taiaroa Head to Macandrew Bay.

Group treasurer Laurie White said this had resulted in a noticeable recovery in the peninsula’s biodiversity, with regrowth of native bush and the return of many bird species.

“We are seeing trends that nature is starting to bounce back – people are seeing more tuis, bellbirds and kereru,” Mr White said. “They are also finding that their roses have more flowers and there is more fruit on their trees.”

Larnach Castle executive director Norcombe Barker, a long-standing supporter of biodiversity efforts on the peninsula, has been delighted to hear tui returning to the castle garden, New Zealand’s only privately owned Garden of International Significance.

“The drop in possum numbers is definitely having benefits for natives such as rata and pohutukawa in the garden,” Mr Barker said.

With things looking up on Otago Peninsula, the OPBG is moving into a new phase of the project – to prevent a “reinvasion” of possums from the more densely populated “neck ” of the peninsula.

In the next couple of weeks, University of Otago master’s student in wildlife management Frances Perez is surveying 300 households in the Waverley, Shiel Hill and Vauxhall areas to gauge people’s attitudes to conservation and pest control.

Ms Perez has already spoken with about 50 people, and has been delighted with the response.

“People are very welcoming and are interested in what we are doing.”

As part of the survey, households are being asked if they would be willing to place “chew cards” on their trees in autumn to help identify the presence of possums.

“We already have some fantastic allies in local residents, who are great guardians of the land,” Dr Ellenberg said.

“So now we are looking for more community support towards our goal of a pest-free peninsula.”

Larnach Castle, which recently gave $1000 towards the group’s work, is supporting the survey by offering a prize in a draw for people who take part. The prize is a high tea and garden voucher for two.


As part of its community survey, the Otago Peninsula Biodiversity Group will ask homeowners if they are willing to place “chew cards” on their trees in autumn.

Chew cards are a safe method of detecting mammalian pests, mainly possums but also stoats, rats, mice and hedgehogs.

The non-toxic cards identify the animals through the tooth impressions they leave as they chew on the tasty cards, which contain a possum favourite, peanut butter.

The cards are nailed to tree trunks, about 30cm above the ground, and are left for seven days.

Possums leave a distinctive tearing chew pattern, meaning their presence can be easily detected.

The OPBG will then be able to follow up with trapping, which is most successful in winter when the possums are hungry.