January 1999

Some recent highlights include:

an unexpected breeding event on Pearl Island is proving to be the most significant in recent times! (Codfish Island birds were moved temporarily to Pearl last April to facilitate rat eradication on Codfish). To date five females have produced seven nests (13 eggs) on Pearl. (In addition, a nest of 3 eggs was found on Little Barrier). All eggs are being artificially incubated & the chicks hand-reared at Burwood Bush. Eleven of the 16 eggs appear to be viable - 3 having already hatched. This is the third successive season during which some breeding has occurred;

the first kakapo egg to have been incubated artificially for its full term was hatched at Burwood Bush on 27 February. This event has important implications for future management, and has enabled us to finally confirm the incubation period as approximately 30 days;

confirmation that kakapo are in fact capable of laying a second clutch of eggs within one season: After many years of speculation this question has finally been answered. This exceedingly important discovery may well provide a much-needed means by which to boost productivity;

heavy females (ie of around 2kg body weight before breeding) are not only able to breed, but are capable of renesting if recycled early in the season. The two females that laid second clutches this season were "heavy" at the onset of summer. Previously, no heavy female is known to have bred, and efforts have therefore been made to limit the weight of supplementary-fed females.

the recapture of "Lisa", a female "lost" for 13 years on Little Barrier Island: Lisa was last seen when her transmitter was removed in 1986. She was found in early March this year incubating three viable eggs.

two further females are now known to be capable of producing fertile eggs - thus, 13 (approximately 65%) of the 20 adult females are known to have laid fertile eggs since the rediscovery of females in 1980.

During 1998, 41 kakapo were transferred between islands (see distribution table below). Age is known for 11 birds (approximately 20% of the population) hatched since 1980. The remainder are of unknown age - but greater than 20 years. Overall, subadults now comprise approximately 14% of the population - ie. 7 subadults : 49 adults (2 (approximately 9%) females & 5 (approximately 15%) males are subadult). Seven of the 9 chicks hatched in the last 3 years have been male!

One adult death is known to have occurred in the last year - the male "Ken" died in July 1998 as a result of complications from a transmitter harness injury that occurred in mid-1995. This is the only known adult death in the last 5 years.

With 6 chicks raised in the last two years and just one adult death in the last 5 years the kakapo species is at last showing signs of recovery!

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Little Barrier Island: Five males and one female remain on Little Barrier. The Kakapo Management Group and Kakapo Scientific and Technical Advisory Committee resolved in March 1998 to remove all kakapo from Little Barrier Island (LBI). Over the previous 16 years it had been shown that female kakapo on Little Barrier must be intensively managed in order for them to breed successfully. However, Little Barrier is large (3,000ha) and extremely rugged, and it proved impractical to intensively manage kakapo there. Furthermore, with rat eradication soon to be attempted on LBI, temporary relocation of kakapo would have been necessary.

Three female kakapo ("Wendy", "Heather" & "Jean") were transferred from LBI to Maud Island in May/June 1998. All had free-ranged on Little Barrier since 1982. Two (Wendy & Heather) had received food supplementation since 1989 and all three had bred - Wendy raising one male chick in 1991. Jean had consistently refused food supplementation. During August 1998 one male ("Stumpy") was transferred to Maud and two males ("Luke" & "Merty") were transferred to Nukuwaiata/Inner Chetwode Island along with a male ("Jimmy") from Maud. The fertility/breeding fitness of the latter three males is in question. The remaining five males and one female are to be moved to Codfish and Pearl Islands in mid-1999.

The female ("Lisa") had not been seen since her transmitter was removed in 1986. However, mating sign was found at the summit track and bowl system (court) in early February 1999 indicating that at least one of two "lost" females may still survive. Allan Munn & Murray Willans and their dogs searched likely parts of LBI in late February/early March for any nesting female and in a "needle in the haystack" quest, Allan & his dog found Lisa incubating 3 eggs! Since Lisa had not been trained to take artificial foods, and rats are present on LBI, her viable & well incubated clutch was transferred on 9 March to the Burwood facility for artificial incubation and rearing. A further male & female ("Snark" & "Mike"), not seen since their transmitters failed (9 and 17 years ago respectively) may still survive. No sign of the missing male Snark was found during an intensive search of the LBI arena in late January 1999 when all known males were active there.

At least 16 of the original 22 kakapo released on Little Barrier in 1982 still survive, giving an average annual survival rate greater than 99%.

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Maud Island: Fourteen birds (6 male and 8 female) are on Maud. Three chicks - two male and one female - were raised in 1998. At 24 days, "Sinbad" (the youngest and smallest chick) was removed from the nest for hand-raising at Burwood Bush. He was returned to Maud when 3 months old, held in a large open-topped pen and trained to use a "cat-door". He was released to free-range in late November - the cat-door providing him with exclusive access to supplementary foods within the pen. His parent-raised male sibling ("Gulliver") left his natal home-range in October when approximately 8 months old, and the female ("Kuia"), now approximately 12 months old is still within Flossie's home-range.

This was the first breeding recorded on Maud and indicates that kakapo can adapt to and breed effectively in an alien environment - an exotic pine plantation on a small (309ha), heavily modified island. This, and the successful transmission of genes from the male "Richard Henry", the last known kakapo from the NZ mainland, into the new generation and the survival of all three chicks - including a female - is cause for real optimism.

There has been little arena activity and no breeding on the Maud this season.

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Nukuwaiata/Inner Chetwode Island: Three males are on Nukuwaiata. During August 1998 two males ("Luke" & "Merty") were transferred from LBI to Inner Chetwode/Nukuwaiata along with one male ("Jimmy") from Maud. Fertility of the former two is suspect, and Jimmy has a leg injury which may compromise his ability to mate successfully. The three are to be monitored in order to assess the suitability or otherwise of Nukuwaiata as kakapo habitat since this island has been identified as a contingency for Maud kakapo in any emergency. No arena activity has been seen this season.

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Whenua Hou/Codfish Island: One male is known to remain on Codfish. All 30 transmitterised kakapo were removed from Codfish in April/May 1998 to aleviate any risk from poisoning during an attempt last winter to eradicate rats from the island. Twenty six birds (13 females : 13 males) were transferred to Pearl Island, two males to Anchorage Island and one male ("Ken") to Maud Island in April, and one female ("Nora") to Maud in May. Two pulses of anticoagulant bait were broadcast on Codfish by Southland Conservancy in August. Kakapo are to be returned to Codfish in mid-1999. One non-transmitterised male ("Bonus") could not be located at the time when birds were being moved and he remained on Codfish. He was located in October by Dave Rodda and Mike Anderson and appears unaffected by the poisoning operation.

Twenty five of the original 30 birds released on Codfish Island in the late 1980's - early 1990's are known to survive, including all 10 females, giving an average survival rate in excess of 98% per annum.

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Pearl Island: Twenty six kakapo are currently on Pearl. During April 1998 four males (of dubious fertility) from Pearl (two had been there since August 1996 and two since September 1997) were transferred to Anchorage Island, and twenty six birds from Codfish Island were placed on Pearl in anticipation of an attempt to eradicate rats from Codfish. The latter birds are to be returned to Codfish in mid-1999. Some have received limited food supplementation to ensure they are in good condition for the move back to Codfish Island.

Males on Pearl developed track & bowl systems ("courts")and since early December all ten adult males have been heard booming. Signs found since 3 January indicate that approximately 12 matings have occurred. Five of the 12 adult females have since laid - two of them ("Suzanne" & "Alice") laying a second (one egg) cluch in early March, 4 - 6 weeks after removal of their first clutches! In total, 13 eggs have been laid, 7 (& possibly 8) of which are viable. Because of the high risk of predation by weka and rats, eggs have been removed soon after laying for artificial incubation. Two eggs (Alice's 2nd & 3rd from her first clutch of 3) were viable and were moved from Pearl to the Burwood Bush nursery facility on 24 February. The more advanced of the two hatched on 27 February - the first kakapo egg to have been successfully incubated artificially for its full term! The other egg hatched on cue 3 days later. As an added bonus, this event has enabled us to finally confirm the incubation period as approximately 30 days. Top marks to Daryl Eason & the Pearl Island team for this excellent result. The 2 chicks were sexed from DNA obtained from blood remaining in their egg shells after hatching - both are male!

Never before has laying occurred so soon (9 - 10 months) after birds have been translocated - or over such an extended period (approximately 2months).

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Anchorage Island: Six males, suspected of being infertile or of low fertility are being held here. They will be placed on Pearl Island once Codfish Island birds are returned to Codfish.

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Stewart Island searches: With the discovery in mid-1997 of a "new" female ("Solstice") on Stewart Island the possibility existed that further individuals might persist in the vast scrublands of southern Stewart Island. Two further searches were therefore mounted in this area (15 July - 12 August & 26 August - 9 September 1998), and a possible sighting of a kakapo near the northern end of Mason Bay by a deer stalker was checked out. No kakapo or kakapo sign was found.

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Diet & feeding regime: A new feeding regime simulating more closely the sporadic "masting" cycles of key natural foods was introduced in June 1998. Whereas birds had previously been supplementary fed throughout the year or pulsed on a 12 monthly cycle, the current regime is based on a two yearly cycle with foods being withheld for much of this period. Most Maud birds ceased receiving supplementary foods in June 1998 and will receive no food supplementation until the spring of 1999. Hopefully, a rising plane of nutrition at this time will stimulate breeding in the autumn of the year 2000.

UPDATE ARCHIVE
June 1999  |  January 1999  |  1998  |  1997