Fifteen years of restoration

To celebrate fifteen years of restoration by volunteers in Mangaiti Gully we produced a photo book for all our past and present volunteers. It is hard to imagine what our section of the gully looked like back in 2010. There were no tracks, with honeysuckle, blackberry and grey willow dominating the wet gully floor. Clearing and planting was done section by section. First build a track to gain access, then drill and poison the willows followed by clearing the honeysuckle and blackberry predominately by hand. There was minimal spray used back then. As the tracks were built, they were gradually connected. The public then started to use them at which stage they were upgraded to what they are today. A highly successful public asset for our city.

Juvenile weta

We have been collecting bamboo stakes from the field that are no longer necessary to hold up previous plantings. These will be repainted with coloured tips and reused next planting season. They were being stored in a garage. In the evening when the garage was being inspected to secure it for the night little weta were noticed emerging from some of the bamboo stakes. Seven in total were collected and returned to the gully to carry on their lives. The photo of a weta sitting on a finger shows how small these juvenile weta are. It is interesting to see how long the antennas are. They are out of all proportion to the size of their small bodies.

A snail collection!

See photo. This was taken when servicing one of our rat bait lines. A thrush (or maybe a blackbird) is using the block of wood as a convenient bashing post to break the snail shells to get to the succulent snail inside.

Annual spring tracking tunnel monitoring

We monitor rats across the full 30 hectares of Mangaiti Gully in the spring and autumn to see if our control programme is doing what it is supposed to. Rats are known to be smart. This can lead to rats learning how a programme works and, over time, start to avoid some traps or toxins leading to an increase in the rat population. This is why regular monitoring is important. Thankfully there is no sign of this happening at present. There was only one rat recorded down by Wairere Dive, Hukanui Road end this spring.

Wineberries are a great pioneer species

Wineberry (Aristotelia serrata) is showing clusters of pink flowers in the gully this spring. Wineberry is a good food source for our birds offering them nectar, fruit and seeds. It is a great tree to plant at the very early (pioneer) stage of any restoration planting. They grow large enough to shade out pesky weeds. They seed at an early stage in their life. With the help of bird dispersal, it creates natural seedlings throughout a restoration area.

Black mud fish

In December 2023 our Trust submitted an application to the Department of Conservation (DOC) for the translocation of black mudfish into a blind gully swamp in Mangaiti, Hamilton, New Zealand. This was after identifying the location as an ideal natural mudfish habitat and it being highly probable that mudfish would have occupied this location in the past, before European settler land modification. This is also in line with our Trust’s vision: To manage the gully in such a way that native fauna (birds, fish, bats, reptiles & insects) will re-establish, either naturally or by introduction and for this to be sustainable. In March 2025 this year, a permit was granted. Translocating mudfish has historically, not been that successful so there was reluctance by DOC to translocate them from a known stable habitat. However, the Rotokauri urban subdivision is about to commence where 14 sites of mudfish have been identified. These wetland sites, which in most cases are farm drains, will be modified (drained) during the groundwork. Because our permit specifies that they are to be translocated from “at risk” habitats within Hamilton City, this has, in essence, become a rescue mission of an at-risk, declining, indigenous species through habitat loss. Managing the translocation is not that straight forward, and part of the DOC permit requires three years of monitoring and reporting. We are fortunate to have a retired NIWA marine scientist as one of our volunteers who is being the lead on this project. The following Link https://www.doc.govt.nz/nature/native-animals/freshwater-fish/mudfish/black-mudfish/ will take you to a DOC pdf with extra links explaining all about the unique features of this species. Photo: Waikato Regional Council

Translocating eels

A concern had been raised that successful establishment of mudfish might not succeed if there was heavy predation by eels. Mudfish have evolved alongside both of our long and shortfin eel species. While the eel population in the main Mangaiti stream is quite healthy, from eDNA testing we suspected that the eel population in the swamp we have identified for the mudfish release was low. We have therefore undertaken a fish survey using Fyke netting at 5 sites along the length of the mudfish release area (site Fyke 1-5, Figure 1). After setting the net 6 times (site 2 was sampled twice) the only fish caught were 4 short fin eels (ranging in size from 700 - 813 mm) and 4 very healthy banded kōkopu (145 - 180 mm long). The kōkopu were all released where they were caught, and the eels were transferred into the upstream tributary of the main Kirikiriroa Stream where there was suitable eel habitat.