Tieke / North Island Saddleback - Restoration
(Philesturnus carunculatus rufusater)

Restoration Visitor Experience Facts

Saddleback with Conservation Manager
Raewyn Empson
Photo © Dave Hansford

Current Status

Nov 2004: seven pairs have been found nesting and ten chicks have fledged.
More chicks are due to fledge in December.

The Karori Story

Prior to European colonisation, tieke were widely distributed in the North Island. It is assumed that saddleback would have been naturally found in the Sanctuary valley and that is why they have been restored to the Sanctuary.

Like most of our endemic birds, tieke were highly vulnerable to bush clearance and introduced predators such as rats, cats and mustelids. The loss of saddleback from the valley would probably have started when rats were released, and hastened when the forest was cleared and burned.

The Return of Tieke to Wellington

Hand-netting a saddleback
Photo © Peter Reese

Early in June 2002, two Sanctuary staff and one volunteer travelled north to Tiritiri Matangi Island, where they were joined by Department of Conservation and Auckland Regional Council staff, members of the Supporters of Tiritiri Matangi and volunteers to capture 40 saddleback. The birds were caught over several days using a variety of techniques including mist-nets, hand nets and capture at roost boxes. Once caught, the birds were checked, weighed, sexed, banded and released into an aviary.

On 15 June 2002, the 39 tieke were re-captured, weighed and placed into wooden transfer boxes for their journey to Wellington. They were blessed by representatives of the local iwi, Ngati Paoa, before departure to Wellington. The birds were accompanied on the ferry, van and plane by Sanctuary staff and Ngati Paoa representatives. They were given food and water on arrival at Wellington and kept in their transfer boxes overnight.

Tieke being checked and measured
Photo © Peter Reese

On 16 June 2002, the birds began the final stage of their journey. They were carried through the gates of the Sanctuary to the sound of the karanga (maori call of welcome). A karakia, speeches of welcome and the transfer of the guardianship of the birds from Ngati Paoa to the Wellington Tenths Trust followed. Half the saddleback were carried up the valley to the release sites on the Contract Energy Wilderness Trail in the heart of the valley. Finally, the magic moment - the boxes were opened and the birds flew out into their new home. The remaining tieke were placed in a temporary aviary and were released about a week later, to see if dispersal would be reduced by holding birds in captivity for a short time at the release site.

Several months prior to their release, members of the volunteer Wednesday Work Group were kept busy building roost and nest boxes using the same design used by saddleback on other islands such as Kapiti and Tiritiri Matangi Islands. These were installed at various locations in the valley before the release to provide the birds with familiar roost sites after release. Roost boxes have an opening at the bottom, and are used by the birds to roost in overnight, while nest boxes have an opening at the top, and are usually only used during breeding. There are plentiful natural sites in the valley for birds to roost and nest safely, but the boxes were installed as a precaution to reduce the risk of dispersal and breeding outside the safety of the Sanctuary.

A New Generation

Within months, a number of tieke had paired and established territories, and set about the serious business of generating a new population of Sanctuary-bred saddleback. In mid September 2002, the first chick hatched - the first time on the Mainland for over 100 years. More chicks followed in October.


Saddleback chicks in nest box		Saddleback chick
Photos © John Shorland

In 2003 John Shorland, photographer, Sanctuary member and volunteer joined the monitoring team and photographed chicks in a nest every 2 days to record plumage changes. These photos can be used by staff to estimate age of chicks where the hatch date is unknown, and thus schedule banding of the chicks at the appropriate age before they fledge.

Breeding

2002-2003: First breeding season

Ten pairs established territories. Eight pairs bred successfully (fledged at least one chick) and 68% nests were successful. Twenty-nine chicks fledged.
Of the 55 eggs observed, 69% hatched but only 51% fledged, and fledge rate appears to have been affected by nest location. The most successful nests (100%); were those built in nesting boxes or hollow tree trunks. 75% of nests found in the base of flax bushes were successful. Only 25% of nests located on the ground or in banks were successful, and it appears that chicks hatched in damp or chilly sites were vulnerable once females reduced their time on the nest.

2003-2004: Second breeding season

Fourteen pairs were found; 8 pairs continuing from 2002/03 and 6 new pairs, mostly comprising locally bred birds. To improve fledging rates, some nest boxes were relocated to potentially vulnerable sites chosen by females in the previous breeding season. A case of ‘location, location, location!’
It was decided that if any chicks hatched in a vulnerable nest (i.e., those built on the ground or in a bank) that the nest would be shifted into a nest box. This had been done successfully with one nest the previous season. Three vulnerable nests were shifted during 2003/4 with 100% chicks fledging successfully.
Following these changes, 72% nests were successful and 86% chicks fledged (cf. 74% the year before). However, only 57% of eggs laid hatched, with most unhatched eggs being infertile as in the previous year.

2004-2005: Third breeding season

Seven pairs have been found nesting so far and we hope that other young birds will pair up and breed this season. There appear to be fewer pairs in the Sanctuary than last year with more birds than usual disappearing over the winter. There are a number of factors that could have caused this. Tieke populations are known to fluctuate on offshore islands so we expect that ours will continue to fluctuate in the future as well.

Ten chicks have already fledged (by the end of November 2004) and there are more chicks due to fledge in December. Not all pairs have been successful so far, but there is still plenty of time for them to hatch chicks over the next few months.

The Future

It is not known how many pairs of tieke the Karori Sanctuary could support, but it is unlikely that the population will reach the density of offshore islands such as Tiritiri Matangi. Already some birds have left the valley, and it is expected that as numbers grow and the competition for territories increases, birds will spill over the fence into local gardens and bush reserves.

Outside the sanctuary fence, saddleback will once again face introduced predators such as rats, cats and stoats. Possum and rat control is being undertaken in reserves adjacent to the Sanctuary by Greater Wellington (Wellington Regional Council) staff and in other areas such as Otari-Wilton Bush, and these control programmes will aid tieke survival, but it is unlikely that saddleback will ever successfully breed outside the sanctuary.

More Information

Tieke / North Island Saddleback - Restoration (Philesturnus carunculatus rufusater)