Archives For Mangere Island

DOC Ranger Tansy BlissBy Chatham Islands Ranger, Tansy Bliss

It all began on a sunny Sunday afternoon, when I was chatting to another DOC Ranger, Shelly Sidley, who had just put the Chatham Island team through their paces with health and safety training.

When I mentioned the endemic Chatham Islands coxella weevil Hadramphus spinipennis, surprisingly, she responded with an interested look and then a follow up comment of, “I know just the person who would love to help you with monitoring it.”

Chatham Islands coxella weevil

Chatham Islands coxella weevil

A year later, I am on Mangere Island  with Mark Anderson — a secondary teacher of science and biology at Marlborough Boys’ College.

We’re systematically searching 455 soft speargrass plants (Aciphylla dieffenbachii) for the large, flightless Chatham Islands coxella weevil, last studied in 1996 by Katrin Schöps.

Speargrass on the coast.

Speargrass

In 2011, Mark, under a Royal Society of New Zealand teacher’s fellowship, undertook the first comprehensive study of the ngaio weevil on Stephens Island.

As his enthusiasm for weevils and monitoring had not diminished, Mark volunteered his practical skills, knowledge and time to help on Mangere.

Mark Anderson searching for weevils.

Mark searching for weevils on a speargrass flowerhead

During the 10 days of intensive work on Mangere Island, we revisited all the original sites where weevils had been found in the mid-1990s and systematically surveyed thirteen 25 mquadrants at night, recording how many weevils we saw and where we found them.

A weevil after heavy rain.

A weevil after heavy rain

The results were impressive. We discovered:

Soft speargrass plants with as many as nine weevils quietly munching away on leaf stems or feeding on the high protein male and female flower heads.

Weevil aggregations of up to seven weevils piggy backing each other.

Numerous weevil pairs perhaps mating.

Lone weevils, metres away from any speargrass plants, plodding across iceplant or carex.

Weevils hiding in the grass, playing dead during the day.

Weevils out in the pouring rain all glistening and dark with the moisture.

Weevils mating on speargrass

Weevils mating on speargrass

We even found weevils in the middle of Robin Bush, some 300 metres away from any speargrass plant.

As we concluded our work, confirming good numbers of weevils still present on the island, we were thankful to Shelly Sidley who made it all possible.

By Juzah Zammit-Ross

A long history of restoration

Mangere Island in the Chatham’s provides an important predator-free refuge to many rare and endemic invertebrates, birds and plants. Restoration first started on the island in the 1970’s with the Wildlife Service planting akeake shelterbelts in Douglas Basin and on the Top Plateau in an effort to expand the habitat available to black robins. Since the early 1990’s tens of thousands of akeake have been planted on the island thanks to the Tuanui and Moffet families and planting contractors.

Mangere plantings 1981

Plantings in Douglas Basin in 1981. Photo: Dave Crouchley

Diversification

As part of the ongoing restoration I led a team of seven people in a week of planting on the island in June.  Although the weather was a bit on the miserable side (gale force winds, very cold and hail most days), we kept warm carrying the heavy bags of plants from the boat landing up to the planting area in the basin.  We managed to plant 1850 plants under the emerging canopy, adding diversity amongst older plantings many of which are self seeding and spreading naturally in the basin.

Mangere and Douglas Basin

Looking over Mangere’s Douglas Basin towards Little Mangere

Local produce

The species planted this trip included Chatham Island nikau, kawakawa, hoho (Pseudopanax chathamica), ngaio, mahoe, ribbonwood and matipo. All the plants were eco-sourced, meaning the seeds were collected locally from Mangere, Pitt and South East Islands and were grown in the DOC nursery at Te One before being transported to Mangere and planted.

Tree planting

Filling in the gaps

But wait, there’s more…

As well as planting, we also cleared tracks, checked rat bait stations, ran rodent tracking tunnels and collected seed for future plantings. We also had the opportunity to visit Robin Bush to view the black robins and walk up to the summit  to enjoy the spectacular views of Mangere, Little Mangere and Pitt Island. Next year will be the last year of akeake planting on the island however diversification plantings will carry on for the next ten years as part of the long-term ecological restoration of Mangere Island.

Mangere planting team

Mangere Island winter planting team 2012: Pete Lusk, Nadia Thomas, Ryan Jones, Juzah Zammit-Ross, Mike Van Velzen, Colin Bishop and Denny Prendeville