Kakapo Update

1997




Fifty kakapo are known to survive - nineteen females and thirty one males. All have been relocated since 1975 to off-shore islands in order to protect them from introduced mammalian predators - no natural population is known to remain. Twenty six birds (16 males and 10 females) are on Codfish Island; two males on an island off southern Stewart Island; eight (4 males and 4 females) on Maud Island; and fourteen (9 males and 5 females) are on Little Barrier Island. No adult mortality is known to have occurred during the last three years.

Several birds were moved from Little Barrier Island (LBI) during the winter. "Arab" and "Barnard" (presumed mates of "Heather" and "Wendy", who produced infertile clutches in 1995) have traditionally hogged the much-prized Summit track and bowl systems (t&bs) on Little Barrier, systems usually visited by the females in a breeding year. They were exiled to an island off southern Stewart Island to sit out the breeding season, contemplating their suspected infertility. Though Arab and Barnard have not been confirmed as infertile, the Kakapo Scientific and Technical Advisory Committee concurred with the Kakapo Management Group decision to remove them for this season. The birds' fertility will be assessed over the next two booming seasons, after which a decision will be made on how best to use them.

"Flossie" and "Richard Henry" were shifted from LBI to Maud Island since they had proved to be unmanageable on the much larger and more rugged Little Barrier.

Richard Henry has settled in his former home-range (he was on Maud from 1975 to 1982) and has continued to accept supplementary foods. His tarsus diameter has continued to increase very slowly throughout the 22 years since his removal from Fiordland and he has yet again outgrown his special-issue, male-kakapo leg band. If in fact this is typical then tarsus diameter may serve as an index of age in kakapo!

The object in transferring Flossie to Maud was to bring her into the management programme - to enable her to be more closely monitored and to be supplementary-fed. Within a month of her arrival she had learned to lift the lid of her food hopper and to eat the various foods on offer.

Also on Maud Island, five-year-old "Hoki" (the only captive kakapo and only female to hatch and survive since 1981), has been encouraged to leave her pen in order to socialise with the seven free-living kakapo on Maud - and to mate when she is ready. She has a stoat-proof, modified cat flap door to facilitate her comings and goings, as well as an artificial roost/nest chamber. So far, she has explored some hundreds of metres beyond her pen - including the garden around Brian and Debbie Patton's house, and within 100m of Comalco Lodge. She now feeds from her feeding station within her pen most nights but generally roosts outside by day. Her activities and well-being are of course being closely monitored.

Many kakapo transmitter mortality switches have failed in recent months, requiring unscheduled replacement - and disturbance to birds.

BREEDING:
No breeding occurred on any of the islands during the 1996 season. However, booming has now begun on both Little Barrier and Codfish Islands - so hopes of breeding occurring this year are high!

Little Barrier: By mid-January 1997 seven t&bs were being tended and at least four males were booming. The male Ox appears to have taken over the prime summit t&bs (previously occupied by Barnard) and Dobbie to have occupied the Woodpile system (formerly occupied by Arab).

Maud: The activity noted at t&bs in October and November seems to have tapered off, though on one occasion in late December a male was heard booming.

Codfish: At least ten t&bs were active and nine males were booming by mid-January, and several females had indulged in "walkabouts" beyond their home-ranges - behaviour believed to be linked to courtship and breeding.

Alison Ballance of the Natural History Unit, TVNZ is at present remotely monitoring and filming the nightly activity of the male Lionel at his t&bs. As during last booming season Alison is hopeful of seeing and filming for the first time mating and associated behaviour. According to Alison, Lionel's booming and visual displays are more intense this year than last.

INCREASED PRODUCTIVITY:
Rats: Because kiore rats are present on two of the three kakapo islands and are a major cause of chick mortality it is essential we are able to quickly and safely control them near nests. Field trials we carried out on LBI during 1996 indicate that these rats just love white chocolate, preferring it to natural foods available during Autumn. Also, that they are most reluctant to enter the traditional (enclosed) poison-bait stations we have used previously. By incorporating chocolate into a toxic bait and redesigning our bait stations we have increased many-fold the "bait take" by rats, as well as virtually eliminating the risks to kakapo and other non-target animals. Hopefully, the heavy loss of kakapo chicks to rats will now be a thing of the past!

Disaster management: Special heat pads have been developed to maintain incubation/brooding temperatures in nests, should the female not return. This gives a buffer of several hours. Standard Operating Procedures for disaster management of nests have been developed. These cover reporting, communications, decisions, equipment operation, and safety.

Loggers: With the upgrade and increased number of loggers we can now manage nests from an earlier stage. If a female is logged at a track and bowl system, her precise location will be fixed daily by triangulation; if she has not moved for a specified number of days she will be checked visually to determine whether or not she has a nest. Loggers will also reduce the effort required for monitoring males during the booming season through provision of data about which males are visiting track and bowl systems.

A SUCCESSFUL RESEARCH SEASON
The summer season is only just under way, but we have already finished a highly successful research season, thanks to Comalco's generous sponsorship - a sponsorship which is to continue for the next six years! Significant progress is already being made towards achieving the goals outlined in the Kakapo Recovery Plan, and with this continued sponsorship, we look forward to even greater results.

SAMPLING PROGRAMME:
During their normal transmitter change (mainly during July - August), 45 kakapo were caught and a blood sample and cloacal and choanal swab taken from each. There were three main objectives for this sampling programme:

Genetic analysis: We want to know the degree of relatedness of all our birds and to be able to identify individuals from moulted feathers. Blood samples have therefore been sent to Massey University, for DNA analyses and with the help of Drs David Lambert and Bruce Robertson of Massey's Department of Ecology a DNA programme has been set up.

Health norms: We aim to establish biological norms in kakapo through determination of normal levels of various blood components, as well as micro-organisms and parasites. Swabs, blood and faecal samples from all birds have been analysed. Kakapo were found to be remarkably free from pathogens. A paper will be prepared by late March for publication and for distribution to veterinarians associated with the kakapo programme.

During sampling we found that Fuschia (a female on Maud Island) had a low-grade bacterial infection. We treated her with doxycycline (an antibiotic used previously on kakapo); another sample taken three weeks later showed that she had recovered. Ken (a male on Codfish Island) was also found to have a low-grade infection caused by a partially healed wing injury dating from 1995, but as he is not currently taking supplementary foods we have been unable to treat him so effectively.

Energy expenditure: The technique known as "doubly-labelled water" was used to measure energy expenditure in a sample of twenty kakapo from all three islands. Professor David Bryant of Stirling University (Scotland) is analysing the results, which should be available early in the new year. Preliminary results indicate that non-breeding kakapo have an exceptionally low field energy expenditure.

ADDITIONAL RESEARCH:

Kakapo sperm: Daryl Eason is developing means for collecting and assessing kakapo sperm. With the anticipated intense booming season this year we hope to at least master sperm collection techniques.

Diet and nutrition: Faeces are being collected on a regular basis from specific females, which are also being tracked at night to see what and where they are eating. The aim of this exercise is to spot any change in diet that might be associated with - and perhaps trigger - breeding.

We have also negotiated the return from the United States of faecal material collected by a Cornell University researcher on Stewart Island during the 1981 breeding season (that is, from the last successful breeding season - of the last natural kakapo population!) Identification of plant material from this unique sample of droppings would seem to offer the only means we now have of determining the natural diet fed to kakapo chicks.

Hormone therapy: Last year, Massey and Agresearch scientists instigated research aimed at inducing breeding in birds - initially using mallards - by administering gonadotrophin releasing hormone. We are following this research closely since inducing non-productive females to breed, and inducing those that already do to breed more often are key programme goals.

Scent and hearing: Julie Hagelin (University of New Mexico, USA) has been investigating scent discrimination, using field trials on Maud Island and autopsy of museum specimens. It had appeared that kakapo had little or no sense of smell, but a trial involving Richard Henry (the last Fiordland bird) and Hoki (the only captive kakapo) showed that they could find foods using what we assume to be smell. Examination of museum material showed that the species olfactory lobes are unexpectedly large. Also, the large size of kakapo ear apertures suggest that they have acute, perhaps directional, hearing - an attribute likely to be enhanced by the birds' owl-like facial discs.

Plant phenology: Dr Bill Lee (Landcare Research) is designing a plant phenology monitoring programme for us. We have for some years been monitoring rimu fruiting on Codfish: A heavy crop is developing at present and should be available to the birds from late March/early April. In 1992 - the last time that rimu there fruited heavily - kakapo breeding failed when the crop aborted just prior to ripening. Although a significant amount of fruit has fallen in recent months, the crop that remains is a heavy one.

 New
Zealand Department Of Conservation - Te Papa Atawhai Information provided by
Don Merton
Senior Technical Officer
Kakapo Management Group
Department of Conservation
PO Box 10 420
WELLINGTON, NZ.



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