Whale Island Kiwi Project A Whakatane Kiwi Trust, Kiwi project
Moutohora Kiwi Information
Prepared by Tansy Bliss, Department of Conservation.
Moutohora (Whale Island) is part the Whakatane Kiwi Project which aims to have kiwi thrive and prosper in the Whakatane District.
The main Whakatane Kiwi Project is based in and around Ohope Scenic Reserve. Eggs are harvested from resident adult birds, then hatched and reared in captivity at Kiwi Encounter, Rainbow Springs through a programme known as Operation Nest Egg. This dramatically increases chick survival from less than 5% in the wild to over 95% in captivity. Juvenile birds over 1kg in weight are then released back into appropriate areas in the Whakatane District. Moutohora is one of those areas.
As dogs, cats, traps, and vehicles all pose significant threats to kiwi at most mainland sites, it is essential to establish a backup population of North Island Brown Kiwi in a safe location. Moutohora being predator free with restricted access status of a wildlife refuge, is ideal. Once a secure breeding population that is genetically robust is established on Moutohora, some birds can then be harvested to help rejuvenate kiwi populations on the main land.
About the birds
Fourteen young kiwi, approximately 6 months old, sourced from the Whakatane Kiwi Project’s Operation Nest Egg Programme have been released on Moutohora since 2001. A total of 13 birds now live on the island, 4 of those released in 2006 and 1 so far in 2007.
(Photo of taking Koma up to saddle for release.)
Who and when
2001-Manaia, female, later paired with Tua, male released in 2003
2001- Humbumble, female later paired with Tumanako, male released in 2003
2003- Hookie, female who fell off a cliff and died as a young bird.
2003- Awhi, female who paired with Morena, male also released in 2003
2005- Maraea, female sub-adult
2005- Obi, male sub-adult
2006- Aria, female sub-adult
2006- Poi, male sub-adult
2006- Tauwhare, male sub-adult from Waiotahi to increase genetic diversity
2006- Pirihira, female sub-adult
2007- Koma, male juvenile from Waiotahi
When released each bird carries a unique micro chip inserted under one wing for future identification. In addition, each bird is fitted with a radio transmitter carried on the upper part of its leg. This allows the bird to be tracked and its movements and status to be checked by the Whakatane Kiwi Project team each time they visit the island.
(Photo of monitoring)
As the young birds are actively growing for at least the first year after release, the harness carrying the transmitter needs to be changed every few months so it does not get too tight and cause sores on the bird’s legs. Each time the birds are caught, they are weighed and have their bills measured to help assess growth rates.
For the adult birds that have finished growing, they only need to be caught once a year when the transmitter battery runs out.
(Photos x 3: Pirihira in Burrow, Pirihira after health check, Tauwhare having health check)
Breeding or not.
By checking the bird’s locations it is usually possible to work out if the birds have paired and are ready for breeding. To date there are three known breeding pairs on the island.
à Mania and Tua,
à Humbumble and Tumanako,
à Awhi and Morena.
Only the two younger pairs still carry their radio transmitters. In 2006 the males were fitted with a new ‘nesting transmitter’ which can detect whether the bird has settled on a nest by monitoring any change from normal activity levels.
In the 2006/07 breeding season which runs from June to March, both pairs established nests which were left to hatch naturally in the wild, as there are no predators on the island. The male bird does all the incubation while the female protects the territory and regains her weight after laying two eggs per clutch, each weighing as much as 500g or 25% of her body weight. If she is in good condition she may lay a second clutch, effectively laying her complete body weight in a season.
Unfortunately in early November Tumanako got off the nest after 68 days, approximately 10 short of completing incubation. Neither eggs found later in the abandoned nest were viable. An autopsy will reveal whether the eggs were fertile and had started developing.
(Photo of abandoned nest with eggs)
Morena at the eastern end of the island left his nest after 85 days, after the first egg should have hatched. However on examination, one broken egg was found congealed in the leaf litter and an immature dead chick discovered squashed up in one corner of the nest. It is probable that this chick had difficulty hatching.
(Photo of nest in bracken)
Morena has since gone on to incubate another nest and any chicks should hatch late March.
Challenges for the kiwi and staff alike
The kiwi are well distributed all over the island and in very different terrain and vegetation. Water is not abundant and most of the kiwi’s requirements must come from their food.
Humbumble and Tumanako are the beach and swamp birds and mainly feed in the rich damp areas of the swamp on the Western side of the island.
(Photo of probe holes in mud).
They forage out across the sand-dunes and their tracks can be seen winding up and down after a night of activity.
(Photo of footprints in sand)
They prefer to rest up in the thick reeds and rushes and have a series of passageways and tunnels connecting their favourite places in the swamp.
(Photo: Monitoring in swamp)
Awhi and Morena have the old kumera terraces as their preferred terrain over on the eastern side of the island. Here thick fern coats the ground under rapidly regenerating pohutukawa trees. A maze of Grey-faced Petrel burrows exist just below the surface and dense mats of pig fern provide safe spots for the kiwi to roost.
Aria and Obi have chosen the steep slopes below the summit as their locations, with Obi showing a preference for tall fern thickets. Aria has proved difficult to locate, concealing herself behind a thick wall of Unga Unga.
Maraea, Tauwhare and Pirihira are usually on the steep slopes of Pa Hill and recently Maraea, was located in a tight rock crevice with a 100m sheer drop to the sea on one side!
(Photo of view from Maraea’s burrow)
Manaia, Tua and Poi have dropped their transmitters and their preferred locations are not known at present.
The island has an estimated holding capacity of 12 pairs of kiwi and birds from the mainland will continue to be introduced until this target is reached, with emphasis being on establishing genetic diversity within the small population. Once successful breeding has been confirmed, the transmitters will be removed from the birds and they will be allowed to breed naturally until the population density is suitable for harvest. Call count surveys conducted each year will detect the increase in kiwi numbers.
Web page sponsored by Phil van Dusschoten, Whale Island Tours A Trustee for the Whakatane Kiwi Trust