TOSSI works in partnership with the Auckland Council to maximise the success of the Tāwharanui Open Sanctuary.
Our major projects are:
Revegetation and restoration of coastal forest and wetlands. TOSSI grows and plants up to 20,000 trees, shrubs and other plants each year to revegetate key areas of the Park.
Preserving the largely pest-free status of Tāwharanui through assisting Auckland Council with pest trapping and baiting, surveillance, maintaining the pest-proof fence, monitoring programs and observing sensitive wildlife.
Assisting with the reintroduction of native species to the sanctuary and monitoring their survival and breeding.
Monitoring NZ dotterel and variable oystercatcher during the breeding season.
Education and advocacy in schools, the local community and the media.
Revegetation of natural plant communities is critical to the future of the open sanctuary. Our aim is to take land that has been cleared and farmed for decades and make it habitat for native animals.
We plan to have a total of around 350 hectares of forests and wetlands through protecting and enhancing remnant forest, replanting, natural regeneration and re-instating natural water flows. This is a long-term project that will take the next 25-50 years.
Our goal is to create a representative range of natural communities that would have been originally present including coastal forest, dunelands, cliff, rocky and sandy shore communities and saline and freshwater wetlands. Most of this area has already been retired from grazing and fenced off.
Restoration will create links with existing forest areas and provide a diverse range of habitats. It is also an important focus for TOSSI activities in one of the largest revegetation programs to be undertaken on the Auckland mainland.
Natural regeneration takes a long time in retired pasture and much of the restoration involves planting new plants – lots of them. To achieve this TOSSI operates its own nursery at Tawharanui that produces 20,000 plants each year. Our nursery volunteers collect seed from local plants, germinate them and grow all the plants we require for our revegetation program.
The planting program is planned years in advance and is conducted according to site-specific revegetation plans developed by the Auckland Council. Each site is planted with a particular range and number of native plant species.
Every year TOSSI and the Auckland Council conduct a number of planting days during winter. Hundreds of people help out – you can too.
Kiwi chicks have hatched at Tāwharanui, the ōi, bellbird and kākā have returned to breed and pāteke, tūī, saddleback, whitehead and many other birds are thriving in this remarkable sanctuary. Why? In a nutshell, it’s because of the absence of rats, stoats, cats and other introduced predators.
The open sanctuary became effectively pest-free following the completion of a 2.5km “Xcluder” pest-proof fence and an extensive pest eradication program (including two helicopter bait drops) in 2004. Feral cats, possums, Norway and ship rats, weasels, stoats and ferrets were removed from the park and ongoing measures are aimed at the eradication of mice, rabbits and hedgehogs.
Maintaining the pest-free status of the open sanctuary is the number one priority for TOSSI and the Auckland Council. While the 2.5 km pest-proof fence is impregnable there is still risk of incursion. Being an “open sanctuary” means that people are free to come and go and there is always the chance that they may (unknowingly) bring rats or other pests with them in camping gear or in their vehicles or boats. The fence is also open at each coast and, despite the elaborate koru-shaped fence-ends and the many traps set around these, rats and cats occasionally get around these barriers. TOSSI volunteers check the full length of the fence regularly for any damage or possible breeches.
The Auckland Council has established a comprehensive network of trap and bait stations throughout the open sanctuary and in adjoining ‘buffer’ areas to control pest invasions. These are checked and re-baited regularly by Auckland Council staff and TOSSI volunteers. If rats or other pests are detected then a major response plan is activated with more frequent checks, increased trapping and other pest detection methods employed.
Some rats and possums have been found inside the fence especially in late summer when food is scarce and the pests are roaming more widely. So far we have successfully controlled these outbreaks: a major achievement in itself.
The most exciting part of any restoration project is the successful re-introduction of missing species. However, translocation of flora and fauna is high risk/high return.
Natural plant and animal communities of the Auckland mainland are heavily depleted as a result of habitat clearing and plant and animal pests. Many iconic New Zealand birds such as kiwi, pāteke, kākāriki, rifleman, pōpokotea, hihi, tīeke and kōkako are locally extinct. Many other species are still present but in low numbers.
A major objective of the Tāwharanui Open Sanctuary is to restore these key components of Auckland’s ecosystems either through active translocation programs or by managing habitats to allow for species to re-colonise areas that were previously hostile.
At Tāwharanui we are fortunate to have had success with both translocations and self-reintroductions.
TOSSI members play a vital role in many aspects of species translocation. We assist in gaining funding for these programs, help catch birds at the source population, assist in releasing birds and manage or assist with on-going monitoring of the released birds.
Further translocations of threatened species are being considered but will depend upon an assessment of the habitat available at Tāwharanui and whether Auckland Council and TOSSI have the resources to manage these programs. Translocation programs are expensive and time consuming and generous sponsors are critical to their success.
Tāwharanui is a wonderful place to see birds.
Coastal cliffs, open beaches, rocky shores, wetlands, forests and open pasture are all used by birds for feeding or breeding habitat. Removal of mammalian predators and the gradual recovery and restoration of forests and wetlands means that more birds are now living at Tāwharanui.
Over the past 30 years, over 90 species have been recorded in and around the park or just offshore. While some species, such as New Zealand dotterel and shining cuckoo, are present in certain seasons, many others can be seen year round.
Monitoring bird populations within the Park is an important way of learning about the Tāwharanui landscape. TOSSI and the Auckland Council monitor all the bird species that are released into the park using radio tracking, direct observation, and nighttime calls (for kiwi). We can tell where the takahe are, whether the kiwi are producing chicks (they are!), whether pāteke are staying in the park (mostly), and how many breeding pairs of robins there are in the Park each year.
We also monitor shore birds such as New Zealand dotterel and variable oystercatcher to check on their breeding success from year to year. NZ dotterels are found on sandy beaches and estuaries and were once common in New Zealand but there are now only about 1,700 birds left. Much of this decline is due to habitat loss and predators such as cats, dogs and stoats, so their response to the creation of the open sanctuary is worth watching.
“Birds of Tāwharanui” produced by TOSSI and printed by ARC provides a checklist of birds you may see in the park. Take this checklist out with you when you next go to Tāwharanui. Download list as pdf now >>