The Kākāpō ‘Survivors’ of Stewart Island
Kakapo were 'rediscovered' on Stewart Island in 1977.
The story of the Kākāpō on Stewart Island is perhaps the best-studied example of the decline of a species in modern history. It’s a cautionary tale about how a species that, a little over a century ago, probably numbered half a million individuals — including perhaps three thousand birds on Stewart Island — decreased to just a handful of birds today.
The part of the story we’ll explore today is how the Kākāpō of Stewart Island, which likely numbered a few hundred birds in the late 1970s, plummeted to fifty-one known birds in 1995. However, it is believed that as few as thirty-six unique genetic lineages now make up the modern Kākāpō population.
Stories such as these are important for us to understand because of the intense genetic challenges the Kākāpō faces. In most species, it takes about fifty unrelated individuals to provide the necessary genetic diversity for survival through a population bottleneck. The Stewart Island Kākāpō population has significantly fewer individuals than this. Understanding whether the modern Kākāpō population of 244 individuals can be saved begins with understanding the unique genetic story of these birds.
This is a tale of fighting for survival — the story of the Kākāpō who survived… and the many more who tragically did not.
History of Kākāpō on Stewart Island: 28,000 BC - 1977
Stewart island was once connected to New Zealand's South Island.
Kākāpō have likely inhabited Stewart Island since the last ice age. A limited number of individuals appear to have crossed a land bridge to the island about 30,000 years ago when it was connected to the South Island.
These birds seem to have become isolated from the rest of the Kākāpō population about 10,000 years ago when the ice age ended, and sea levels rose, covering the Foveaux Strait. The island appears to have supported a relatively stable population of perhaps 3,000 to 5,000 birds until the arrival of Europeans. However, it is likely that this population descended from a limited number of founder Kākāpō and suffered some degree of inbreeding throughout its history.
Unlike the mainland, which saw the introduction of mustelids that devastated Kākāpō populations, Stewart Island instead saw the introduction of rats, possums, and cats. The impact of possums on Kākāpō is unknown, but the introduction of rats would have been devastating. Between 1981 and 1999, about a third of all Kākāpō eggs and chicks were predated by rats.
The introduction of feral cats was likely equally devastating. Not all cats kill Kākāpō; it seems to be a learned behaviour by a few opportunistic individuals, which is then largely passed down from mother to kittens. Geneticists have noted a rapid second loss of alleles in the Kākāpō population about ten generations ago (300 years), with a sharp increase in this impact about five generations ago (150 years). This supports the idea that Kākāpō on the island were likely hunted by Māori, possibly with the native Kuri dog, and then experienced significant population declines and fragmentation after the 1840s.
It is notable that there has been a rapid increase in inbreeding since the 1840s, with closely related individuals breeding as genetic diversity rapidly declined across the island. By the 1970s, the Kākāpō population on the island was deeply fragmented. According to hunters, it is believed that only a handful of birds remained in Mawson Bay, Mt Rakeahua, Port Adventure, and the northern parts of the island at this time. However, they were likely at low enough densities to largely avoid detection.
It was in the southern part of the island that Kākāpō remained in sufficient numbers to be detected and studied in the late 1970s. Here, in the vast semi-elevated scrubland of the Tin Range, a population of perhaps 100 to 200 birds was discovered. It seems likely that birds remained here longer than in other areas, possibly due to lower densities of cats or because the area had been modified (burnt) due to human attempts at a mining settlement a century earlier. This altered landscape may have allowed Kākāpō to flourish in ways they had not been able to in other parts of the island.
Kākāpō: A Fiordland Reprieve (1977 - 1979)
The tin range in Stewart island is a low level sub alpine region.
The discovery of Kākāpō offered a reprieve to a species that was at that time considered functionally extinct, with perhaps eighteen males known to exist in Fiordland. It was generally believed that the Kākāpō was facing imminent extinction. The discovery of what was thought to be a breeding population of Kākāpō brought huge excitement.
However, studying these birds proved to be nearly impossible. It was evident that a major breeding season was occurring between 1977 and 1978, with at least 44 male Kākāpō booming on a ridge in the centre of the Tin Range, which sat at about five hundred metres elevation. Yet without the aid of tracking dogs, these birds could not be located outside of breeding seasons when males would boom from their ‘track and bowl systems’ at high elevations for months at a time.
Dogs had been banned after a Wildlife Service dog killed a recently translocated Fiordland Kākāpō named ‘Jill’ in 1977. While the intention behind banning dogs was good, in practical reality, it made it nearly impossible to locate the elusive nocturnal parrots outside of breeding seasons. Hamstrung by limited budgets, the Kākāpō team of the Wildlife Service was almost completely unable to find birds until 1980, when the ban was lifted.
When the ban was finally lifted, researchers were able to locate birds at scale. Over the next eighteen years, approximately 95 Kākāpō were located on Stewart Island. Yet, of these, only sixty-four survived to translocation. Forty-one would actually breed, and approximately thirty-five unique genetic lineages would become represented in the modern Kākāpō population, along with one Fiordland Kākāpō.
The 1979 & 1980 Kākāpō Search
1979 was the first time Juvenile Kakapo were recorded since 1940's.
In an effort to locate Kākāpō on Stewart Island, cage traps were placed across the Tin Range in an area that researchers would eventually call the ‘central study area.’ It was the region of the Tin Range dominated by Arena Ridge and the neighbouring catchments, which had the most Kākāpō sign. To the immediate north, south, east, and west, areas were dubbed ‘outside the main study area,’ and while other areas across Stewart Island were also searched, they were largely deemed to have limited or old Kākāpō sign.
The first two birds to be captured and handled were in mid-1979, but it was a monumental effort to catch them without dogs. It took 314 bait stations to locate the territory of a bird and numerous cage traps to capture him. Eventually, a young juvenile male was captured and dubbed ‘Mawson.’ He was believed to be a product of the 1978 breeding season and, more importantly, proof that females were likely present in the population.
The second bird captured was a large male dubbed ‘Alphonse the Wanderer,’ named for his large territory in the Tin Range. Alphonse was discovered not through tracker dogs but because he was a mature male who maintained a track and bowl system in an area dubbed ‘Arena Ridge.’ Other males had also been present on Arena Ridge, and observations had been attempted in previous seasons, but these efforts had interfered with booming activity, so researchers withdrew. Alphonse was captured in 1979 while tending to his track and bowl system and was fitted with a transmitter.
In 1980, a concentrated effort was made to locate Kākāpō with tracker dogs on the island for the first time. This was critical because it was the first season in which they could legally be used after the ban was lifted. The resulting search provided astounding results. A total of seventeen new birds were located in addition to the two already known. These included four females: Mandy, Maggie, Nora, and Farina, along with thirteen males: CB, Johnny, Strider, Chas Chews, Arab, Jasper, Sass, Idaho, Ted, Ali, Tumbles, Lucky, and Thorin.
Yet the exhilaration of finally finding a breeding population of Kākāpō would rapidly turn to horror. Between 1977 and 1980, 225 cat droppings were found in the research area. A study of these droppings determined that seven contained traces of dead Kākāpō. But were these cats actively killing Kākāpō, or were they opportunistic scavengers feeding on birds that had died from other causes?
The answer soon came in early 1980 when the male Alphonse was found dead. He had been killed and eaten by a cat, which was particularly heartbreaking for Rhys Buckingham (who now heads up the South Island Kōkako search), as he had spent considerable time studying him. In quick succession, Mawson, Farina, Mandy, Strider, Chas Chews, Jasper, and Thorin vanished. In addition to Alphonse, Ted and Ali were found dead, all killed by cats. In total, across just 1980, ten of the nineteen known Stewart Island Kākāpō were lost to cats, representing an alarming fifty percent predation rate annually.
Shifting Stewart Island Kakapo to Maud: 1980 & 81
Maud island is in the Marlborough Sounds. Which is heavily modified habitat a thousand kilometres away from Stewart island.
Urgency was of the utmost importance. While dozens of individuals were involved in the Kakapo searches across the period, four individuals developed a knack for finding Kakapo across the remote and rugged landscapes of Stewart Island. Gary Aburn, Dave Couchley, Alan Munne, and Tony Roxborugh discovered about seventy birds between them. The remaining dozens of wildlife personnel and volunteers over more than eighteen years located just an additional eighteen birds.
In late 1980, the male Arab (named after the legendary Kakapo tracker Gary ‘Arab’ Aburn) was whisked off the island to predator-free Maud in the Marlborough Sounds. Initially, it was planned that a number of birds would follow him, but this largely stalled as it became apparent that Kakapo were about to breed again on Stewart Island. It was decided that Kakapo would not be helped by translocation during a breeding season, so the focus instead shifted to studying Kakapo, attempting to locate new females on nests, and feral cat control.
Only three more birds would follow. The female Maggie, who seemed to be a juvenile likely produced in the 1978 breeding season, had not yet reached sexual maturity. Two newly discovered females, Jean and Dianna, showed no signs of breeding. Tragically, it now seems evident that Dianna had not bred because she lacked the necessary condition to do so. She weighed just 900 grams when translocated and was found dead several months later. The stress of being moved from the cold, wet scrublands of Stewart Island to the warmer, drier Marlborough Sounds proved too much for her.
Of the birds on Maud, Maggie passed away in 2014 when she was killed by a landslide – heartbreaking because she had never bred. However, Arab and Jean both produced chicks. Jean is still alive in 2025.
A Breeding Season and Cat Predation Heartbreak: 1981
Feral cats were killing Kakapo in the central study area.
Back on Stewart Island, the 1981 breeding season was in full swing, and for the first time since the late 1940s, Kakapo chicks were observed being raised in a nest.
The rapid onset of breeding led to dozens of male Kakapo booming across the island, both on Arena Ridge and in other areas outside the central study area. Resources were limited, but nonetheless, five new adult males were discovered: Rangi, Gunter, Glintamber, Lawrence, and Solomon. In addition – and in some respects more importantly – four new females were found: Tobacco Face (named for the brown stains on her face), Bitch (named because she had a habit of biting her handlers), Alice, and Heidi.
The new female Alice and Nora, who had been found in 1980, were both discovered to have bred. Alice bred with the as yet unknown male Buster (who would not be discovered until 1983), producing the male chick Snark. Nora bred with the male Rangi, producing three chicks, two of which survived to fledging: a male, Alder, and a female, Zephyr. Rangi was likely the ‘top’ breeding male on the island at this stage and likely fathered a significant number of chicks across the 1981 and 1978 breeding seasons, including Sarah, Wendy, Merty, Ralph, Zephyr, and Alder. Remarkably, about five percent of all Kakapo ever discovered on Stewart Island were fathered by Rangi. Even more impressive is the fact that many more of his adult chicks were likely killed by cats during this period.
Additionally, a new juvenile male, Lionel, was discovered on Arena Ridge during the breeding season. Likely a subadult from the 1978 breeding season, he was mimicking the mature males around him and attempting to boom. Lionel is fascinating because genetic testing has since suggested he had no close relatives among the Kakapo population but was deeply inbred – essentially the product of closely related individuals breeding together. Unfortunately, he would never breed due to poor-quality sperm, a result of his inbreeding, and his precious (albeit inbred) unique genes were lost forever when he died in 2014.
Yet the addition of three known chicks to the population was offset by a rapid set of frustrating losses.
Handovers between research teams were not particularly efficient, and all three Kakapo chicks were allowed to fledge and disperse without transmitters. While some were recaptured later, the male Alder was never recorded again. Given his location in the central study area and subsequent events, it seems he fell victim to cat predation. Within a short period, more victims followed, with CB, Johnny, Lucky, Tobacco Face, Heidi, and Glintamber discovered dead, having fallen prey to cats. Additionally, the male Lawrence vanished, his body likely lost in the remote thickets of Stewart Island.
Even more disturbingly, several ‘new’, as yet undiscovered Kakapo were found dead across the study area, all slaughtered by cats. In one instance, a bird was so heavily mauled that its gender could not be identified. In one particularly distressing incident, five Kakapo were killed in a matter of days by a single cat moving across a ridge, slaughtering birds from territory to territory.
1982 marked five years since the discovery of Kakapo on Stewart Island. However, instead of a cause for celebration, the results of half a decade of work were grim. Of the nineteen birds discovered in the 1979/80 search, only six were still living: Arab and Maggie on Maud Island, and Idaho, Nora, Tumbles, and Sass in the central study area. Of the additional fifteen birds discovered in the 1981 breeding season, only six were known to still be alive: Rangi, Bitch, Alice, Gunter, and Solomon in the central study area, and Jean on Maud.
In total, thirty-four living birds had been handled, and only twelve were confirmed to be alive. Additionally, seven Kakapo scats were found, and six more dead birds were discovered across the island. This suggests a possible Kakapo mortality rate of more than seventy-five percent over just a handful of years. With such devastating losses, it became clear that even if only a few cats in each area learned how to hunt Kakapo every few years, the species would rapidly vanish.
Cat Control and Little Barrier Island: 1982
Little Barrier island is a remote and rugged island off the Coast of the North island 1300 Kilometres North of Stewart Island.
Cat control had begun out of Port Pegasus to the east of the central study area in 1981, but it was ramped up across the island in response to the devastating impact of cats. A combination of trapping and poisoning was used—trapping outside the central study area, and poisoned meat inside the study area to target cats.
The decision was made that Kakapo inside the central study area would be easier to protect than those outside the area. So the decision was made to search outside Arena Ridge and the surrounding catchments for new birds to translocate to Little Barrier Island in the Hauraki Gulf. The island had recently become free of feral cats and, while it sat outside known Kakapo habitat, it was determined to be the best location for a new offshore Kakapo breeding programme. This was largely due to political and budgetary constraints and eventually proved to be a costly and expensive failure. However, due to this decision, known birds in the study area were left alone, as well as a new male, ‘Gerry,’ who had been discovered in February 1982.
Between April and August, nineteen birds were captured outside the central study area. Eighteen were new birds, and one was the young male Snark: Alice and Buster’s chick from 1981. He was now living six kilometres from his nest, providing valuable insight into just how far young Kakapo can disperse from their nest. Snark and seventeen other new birds were shifted to Little Barrier Island, while one male, Blades, was released. He would promptly vanish for the next decade.
The roll call of Kakapo translocated to Little Barrier Island in 1982 includes the females Flossie, Mike (who was initially mistaken for a male), Heather (later discovered to be the daughter of Flossie and Ben, who had hatched in the 1981 season), Lisa, Bella, Wendy (whose parents are Rangi and Margaret Marie and who likely hatched in 1978), and John Girl (who was also initially mistaken for a male).
Male Kakapo shifted to Little Barrier include Mathew, Rob, Pegasus, Merty (who likely hatched in 1978, whose mother was Lisa, father Rangi, and brother Ralph), Joe (an older chick of Lisa’s possibly from the early 1970s), Luke, Ox, Barnard, and Bill.
Little Barrier was not an environment where Kakapo were able to breed without supplementary feeding. The male Mathew died shortly after his transfer, though no information seems to be public as to how or why. Over the next decade, Rob and Pegasus would die in fights. Snark and Mike would vanish, and John Girl would pass away after the 1991 breeding season—though thankfully not before producing the chick Stumpy with Pegasus.
Despite the setbacks of Little Barrier Island, the transfer itself saved Kakapo that would become critical to the success of the breeding programme. Importantly, twelve of these birds would go on to breed, and more than half of all living Kakapo today trace an ancestor to this group of birds. Perhaps most notable is the female Flossie, who has never produced infertile eggs (more than half of all Kakapo eggs are either infertile or suffer early embryo death) and has twelve living offspring and more than fifty living descendants!
Flossie, Merty, Barnard, Pegasus, John Girl, Heather, Bella, Luke, Ox, Bill, Lisa, and Wendy all have produced chicks. While the male Joe is still living but has never bred. His mother is Lisa, while his father was an unknown male likely killed by a cat. This means he carries unique genes important to incorporate into the population. He does share genetic links to Jimmy or Boss, suggesting they may both be in some way related to his father. Though there are questions about his fertility—he has bred several times but never produced fertile eggs. It may be that, like Lionel, he has a poor sperm count.
A third of all remaining founder birds (birds of unknown age born on Stewart Island) in 2025 came from this group of birds, including Flossie, Heather, Bella, Luke, Lisa, Wendy, and Ox.
Roll Call of Kakapo Losses: 1983
A kakapo captured on Stewart Island in the early 1980's
Back on Stewart Island, things continued to go from bad to worse.
Despite some initial successes in cat control, Kakapo continued to turn up dead. Bitch was found dead, and Idaho vanished. The list of known remaining Kakapo was short—just Rangi, Tumbles, Gunter, Alice, Sass, Nora, Solomon, and Gerry were known to still be living.
It was evident that Kakapo remained in the central study area. While significant track and bowl systems had fallen into disuse, suggesting their owners had been killed, enough remained active to suggest a sizable number of male Kakapo remained. Thus, a second search was commissioned, initially focused on shifting more birds to Little Barrier Island—this time from the central study area.
Yet the search largely discovered only males, including Buster (the father of Snark), Lee, Pierre, Brian, Tramp, Gunner, and Jimmy. Only a single female, a bird dubbed Sue, was found. Due to concerns about an imbalanced sex ratio of birds on Little Barrier, a baffling decision was made to abandon the translocation and leave all Kakapo on the island. A remarkably short-sighted decision given the horrific annual attrition Kakapo were experiencing.
Perhaps there was some degree of optimism that the decrease in the number of Kakapo deaths compared to 1980 and 1981 signalled that the offending cats had been killed. To some extent, this was likely true. Kakapo deaths did decrease in 1982. Equally, however, it was clear that at least one cat remained that was killing Kakapo, and it may have been the abundance of rats following the Rimu mast of 1981 that led to a decrease in predation rather than the effectiveness of the cat control team.
It seems likely that only a handful of cats had learned to kill Kakapo in the 1977–86 period and that they were all related. Killing Kakapo seems to be a learned behaviour amongst cats, likely taught from a mother to her kittens. We know that cats existed with Kakapo on Kapiti Island for more than three decades in the early 20th century before Kakapo vanished in the 1940s, indicating that it’s not a particularly common trait amongst feral cat populations. Yet, as we’ve observed, even only a few cats learning how to kill Kakapo every few years can wipe out healthy populations across a century.
The decision not to shift these birds quickly proved to have devastating consequences. The dominant male Buster, who had fathered Snark in 1981, was discovered dead in 1983. Followed shortly by Brian and Solomon. Most likely, other unknown Kakapo passed away during this period too because limited research was conducted across 1983–1984. As late as 1986, evidence would emerge of cat predation in the central study area.
Limited Funding and Programme Stagnation: 1984 to 1985
A Kakapo on Stewart Island in the mid 1980's.
In 1984, only a single new bird was discovered—a male dubbed 'Bonus' in the remote Deceit Peaks to the west of the study area. He was named 'Bonus' because it was considered a fortunate discovery that any Kakapo remained outside the wider study area at all. Limited funding meant that cat control and surveying the extent of the remaining population were the top priorities. The outcome of this study was worrying—it estimated that only about forty-five birds remained out of the two hundred that had likely been present in 1978.
Only three females were known to remain: Alice, Nora, and Sue. Meanwhile, Rangi, Lee, Tramp, Jimmy, Pierre, Sass, Gunner, Gerry, Tumbles, and Gunter were confirmed to still inhabit the central study area of the Tin Range. Other males were clearly present—their booming calls had been heard—but the resources to track them down were unavailable.
Kakapo bred again in 1985 on Stewart Island. Nora, Sue, and Alice all mated; Nora with Rangi, while Sue and Alice mated with unknown males. Two small chicks hatched but both vanished, seemingly due to rat predation. Even more concerning was the failure of the Rimu crop, which females relied on to feed their chicks. This meant that other chicks on the island likely starved to death.
Underfunding compounded errors. Kakapo teams were small, underfunded, and often composed of volunteers. A recurring issue was inadequate handovers between teams. This was perhaps most evident when a starving juvenile chick was discovered one day near where Alice was feeding. It was assumed that Alice had moved the chick there, and the team mistakenly believed they had rediscovered a missing bird rather than a starving chick that had wandered away from its nest. Even more baffling was the decision to leave the clearly starving chick rather than intervene.
When the team returned days later, they discovered a second chick nearby and realised that these were likely the survivors of a nest that had been predated. Alice had since moved away, and a nest full of kittens was found nearby instead. It is most likely that the mother had been killed, and these two half-grown starving chicks had been far enough away from her at the time that the cat had not identified them. This situation highlighted the fact that in 1985, the feral cat control programme caught more cats than in the previous four years combined.
The decision to leave the two chicks (eventually named Tara and Chubb) to their own devices cost them both their lives. Chubb died shortly afterwards, and while Tara was eventually rescued and shifted to Maud Island for hand-rearing, it was too little too late. Despite initially seeming to recover, she passed away at the end of 1985, simply unable to overcome the effects of the starvation she had experienced as a chick. After her death, examination of her bones revealed significant malnutrition during development.
The loss of Tara was particularly poignant. Only twenty-eight female Kakapo were ever found, and young females hatched in the 1970s and 1980s have played a significant role in the modern Kakapo population due to their fertility. Had Tara survived, the fact that she appeared to be the offspring of two unknown birds would have been a huge boost for the Kakapo breeding programme.
Preparing Whenua Hou / Codfish Island: 1985 - 1987
The Male Kakapo Ralph is still alive in 2025
The dismal results of the 1985 breeding season created a sense of urgency. Evidence of ongoing cat predation and the large number of cats killed in the wake of the breeding season served as a motivating factor to translocate the remaining Kakapo population to offshore islands. As if that weren’t enough, the discovery of Tumbles' old remains in 1986 further emphasised the need for action. He had been dead for a long time, but the likely cause of death was predation by cats, highlighting the ongoing threat.
Additionally, a suitable island habitat for Kakapo had finally become available. Nearby Whenua Hou / Codfish Island, which was large enough to support a breeding population of Kakapo, had been cleared of possums. Furthermore, approximately a thousand weka were removed, as they were believed to steal Kakapo eggs, and cats had never been present on the island.
Efforts began to prepare the birds for relocation to Whenua Hou. During this period, a new female, Margaret-Marie, was discovered. Unbeknownst to researchers at the time, she was the mother of Wendy and Sarah, with none other than Rangi as the father. It is likely they had hatched in 1978, given that Wendy was handled in 1982 and showed no signs of being a juvenile from the 1981 season.
Cat control teams also discovered a second bird, a male named Ralph, when he was accidentally captured in a leg-hold trap in 1986. Fortunately, he was caught only by two toes and was released without harm or incident. It was later discovered that he was another chick of Rangi and Lisa, most likely from the 1978 breeding season. His brother, Merty, was captured in 1982, and like Wendy, showed no signs of being a juvenile. Thankfully, Ralph showed no ill effects from being the only Kakapo ever captured in a leg-hold trap. He is still alive on Codfish Island today, though he has never produced any offspring.
A New Island Sanctuary: 1987 – 1988
Codfish Island / Whenua Hou. It's easy to see how a Kakapo could vanish amongst the bush here.
In August 1987, initial translocations to Whenua Hou / Codfish Island began and continued until March 1988.
The primary focus was to capture previously identified Kakapo. Among the first transferred were Sass and Nora, the last survivors of the nineteen Kakapo discovered in 1979–80—a poignant reminder of how many birds had been lost.
Alongside them, Ralph, Sue, Margaret-Marie, Alice, Rangi, Gunter, Pierre, Tramp, Lee, Gunner, and the young male Lionel were also relocated. Three new birds were found in the central study area: Ben (the father of Heather in 1981), Gumboots, and a new female, Cyndy. Cyndy’s discovery was particularly notable, as she was located in the heart of the study area after a decade of intensive monitoring—highlighting just how elusive Kakapo could be. She was the first bird captured by Alan Munne, who later played a significant role in finding the final Kakapo on Stewart Island.
Limited funding once again led to decisions that would haunt the Kakapo recovery team for years to come. Tracking harnesses were expensive and challenging to maintain, so it was decided to track only females and a limited number of males. As a result, four males were released without transmitters, wearing only metal leg bands. All four promptly vanished. Despite extensive searches over the years, their fate remains unknown. Following an intensive poisoning effort in 1998, when nearly all other known Kakapo were removed from the island, it was assumed that these males had not survived.
In a remarkable turn of events, in 2009, the male Rangi was rediscovered in good health on a remote part of Whenua Hou, booming vigorously. Though he has not bred due to his isolation, he has over thirty descendants from offspring he fathered on Stewart Island. In 2013, another male Kakapo wearing a leg band was briefly sighted but vanished before capture, suggesting that at least one other Stewart Island male may still be alive on Codfish Island. The stories of Rangi and Cyndy underscore the Kakapo’s ability to remain undetected for decades, even in heavily monitored environments. The loss of the other males, representing around 8% of the species’ genetic diversity, remains a heartbreaking consequence of funding limitations.
Of those released with transmitters, Lionel, Gunner, Lee, and Gumboots all lived relatively long lives on Whenua Hou but died between 2005 and 2019 without ever breeding. Evidence suggests Lee may have been related to other Kakapo, possibly as an uncle or grandfather, but their losses highlight how difficult it is for non-dominant males to breed. Some males never pass on their genes, while others, like Lionel, suffer from poor sperm quality, resulting in infertile eggs.
Of the 1987–88 transfers, only Sass, Cyndy, Alice, Ben, Rangi, and Nora have direct representation in the modern Kakapo population. Ben and Rangi have not produced living offspring on Whenua Hou, though they have adult chicks from Stewart Island. Margaret-Marie, Cyndy, Alice, Rangi, and Nora are still alive in 2025.
Removing Kakapo from the Central Study Area: 1989
A Kakapo receives a transmitter on Stewart Island
In 1989, Kakapo males boomed once again, but it is unclear whether breeding occurred. Further north, on Little Barrier Island, there were signs that Kakapo had reached breeding condition, but if females bred on Stewart Island, it went undetected.
Two known males, Bonus and Jimmy, both living outside the central study area, were captured and relocated to Whenua Hou. A concerted effort to locate and transfer the remaining Kakapo in the central study area ensued. Over nine months, eight new males—Ken, Whiskas, Waynebo, Felix, Merv, Basil, Nog, and Boss—were captured and moved. Additionally, three new females—Suzanne, Jane, and Sarah (the daughter of Rangi and Margaret-Marie and sister of Wendy, likely from the 1978 breeding season)—were discovered. This monumental effort, led by Gary Aburn, Alan Munne, and Dave Crouchley, marked the most significant female discoveries since 1982.
These males had a significant impact on the genetics of the modern Kakapo population. Waynebo, Felix, Basil, and Boss each fathered more than ten chicks, collectively contributing to more than a quarter of the current Kakapo population. Whiskas also had a major impact, fathering six chicks in the 2009 season before dying in a fight in 2011. Nog and Merv have also sired offspring. Ken, unfortunately, died from a wing injury in 1998 without breeding, while Jimmy, suffering from an arthritic leg, passed away in 2017, though he may have a distant genetic link to Joe and Boss.
Among the females, Sarah and Suzanne both bred and produced several chicks, with Suzanne still alive today. Jane, an elderly bird with a leg injury that prevented her from breeding, passed away from old age in 2018.
Of the 1989 cohort, Merv, Basil, Nog, Sue, Ralph, and Boss are still alive in 2025, although Ralph has never bred.
The Search for the Last Stewart Island Kakapo: 1990
Gary Aburn and his dog with a Kakapo.
Efforts to locate new Kakapo began to wind down after the 1989 season.
In 1990, Dave Couchly visited Mt Rakahehua, seventeen kilometres to the north, where a study in 1985 had identified two male Kakapo booming and others had been heard in 1981. Only a single bird was located—the male Piripi. He, alongside Gerry from the central study area, was quickly shifted to Maud Island. Gerry would die in 1991 after the Department of Conservation again attempted to keep Kakapo in captivity, a programme they had been repeatedly warned would lead to the death of birds through stress. Piripi would die in a fight with another Kakapo in 2019. Neither ever produced offspring—though fascinatingly, Piripi does appear to share a genetic link to Rangi despite being found seventeen kilometres north of him.
A more concentrated search of the wider tin range during 1990 also located three more birds. The first of these was a stunning surprise: it was none other than Rangi and Nora’s chick, Zephyr, from the 1981 season, who had vanished nine years earlier! Discovering Zephyr was critical to the recovery of Kakapo in the 1990s. Her chick, Hoki, was the first Kakapo chick to be successfully hand-raised, and she would mother half of all Kakapo chicks produced in the following decade. She’s alive today and remains one of the most critical birds in the recovery of her species.
Joy quickly turned to heartbreak with the discovery of two new Kakapo. The new birds, a female named Destiny and a male named Ngwaka, were both located by an overzealous dog named Boss, who mauled both to death before they could be saved. It was a truly tragic set of circumstances that Gary Aburn, his handler, simply never recovered from. A gentle man with a brilliant understanding of animals and the bush, he was so upset by the actions of his dog and the inability to save the two birds that he retired from all Kakapo work.
In some respects, this is the untold story of Stewart Island Kakapo. It wasn’t that no birds remained; it’s that the time and resources to find them simply were not there to search for many more, especially when Gary Aburn retired. He had discovered half of all Stewart Island Kakapo by himself, including sixteen of the twenty-eight females—something truly impressive for a volunteer with no official training.
Without his expertise and knowledge, the search for more Kakapo, especially females, began to flounder. In 1985, based on known sex ratios, it was estimated that a minimum of sixteen female Kakapo and several juvenile females remained on the island. Only fourteen more females were ever found. Had Gary Aburn not retired, it’s not difficult to imagine that more females would have been discovered in the vast bushlands of Stewart Island in the 1990s.
Last-Ditch Search for Kakapo: 1991–92
The Kakapo Male Blades. He has fathered twenty two chicks.
The Kakapo programme was in serious danger of losing the entirety of its funding, and the resources were simply not there to focus on new birds. By 1991, Dave Couchly and Alan Munne were the only remaining experienced members of the team still actively finding new Kakapo. Alan seems to have had limited involvement, while Dave had to split his time between looking for Fiordland birds and his other commitments.
In 1991, Dave returned to Stewart Island and, in a monumental effort, began a three-month search which discovered two new females, Fuschia and Ruth, plus a new male, Smoko. All three were shifted to Whenua Hou and are genetically represented in the modern Kakapo population, though only Ruth is still living. She’s a remarkable bird who has presently raised five chicks (three of whom are still living), despite being blind in one eye!
The 1992 breeding season provided a chance to search for several males suspected to remain but almost impossible to find in non-breeding years. Most important was the male Blades, who was captured in 1982, released, and never seen again. Evidence continued to emerge that a male Kakapo occupied his territory outside the central study area of the tin range, and he was finally captured near the end of the breeding season in 1992, a decade after he was last seen!
Blades was perhaps the most important Kakapo to ever be captured on Stewart Island. He is still living and is by far the most productive male Kakapo in recorded history, with more than twenty two living chicks in 2025. He’s also one of the most well-travelled birds in the programme. Initially transferred to Little Barrier Island in 1992, he was then shifted to Whenua Hou in 1999 and then back to Little Barrier in 2019. In 2025, he’s awaiting transfer for another move back down south!
Significant work was done across the entire study area to locate three more birds. Two males, Rhys and Rewi, and a new female, Sandra, were discovered. Rhys and Rewi were shifted to Mana Island, next to Kapiti, where both quickly died. Again, it seems the lessons of the 1981 transfer were not learned—both males had just come off the back of a demanding breeding season and likely did not have the condition to be transferred, especially a thousand kilometres north to an environment nothing like the region they had just come from. Sandra would breed a single time in the 1990s before passing away from a harness injury in 2012.
Missed Opportunities: 1993 - 1996
A Map of Southern Stewart Island. North is at the top of the map. Mason Bay is to the North of Doughboy Bay, Mt Rakehuea is to the North of Kirklands Hill. Neil Macdonald's Kakapo was likely beyond the Toitoi River. The Lords River is even further east than the Toitoi. Port Adventure is near the coast of the Toitoi. Seal Point is to the South East of the central study area. The Kopeka is River is between the central study area and the Toitoi. Pattersons inlet is South of halfmoon Bay and east of Mt Rakehuea. The ruggedy Mountains are to the North West of the top of the island.
After the 1992 breeding season, efforts to locate new Kakapo on Stewart Island largely stalled due to a lack of resources and experience.
Yet there was strong evidence that some Kakapo probably remained. Booming from Mt Rakehuea in 1981 and 1985 indicated that one or two birds probably remained there. A 1985 search of the Deceit Peaks suggested that a second male was probably inhabiting a track and bowl system near Bonus. Neil Macdonald, a hunter, had observed a Kakapo further east from the study area in 1970, and a 1981 search discovered old Kakapo sign here too.
Harry Vipond was an adamant advocate that Kakapo remained in the Lords River to the east after he’d sighted a bird there thirty years earlier. It’s notable that several hunters I’ve spoken to seem adamant that Harry was ‘hard done by’ and largely ignored in his advocacy of searching the area. I’ve interviewed three separate groups of unconnected hunters who say birds persisted here in numbers, and in the Tikotahia hunting block further north too. But as one of the few places in New Zealand with quality hunting for Whitetail deer, few were interested in advertising that Kakapo were present. This is reinforced by what appears to be a female Kakapo and juvenile chick identified in 1977 (which also appears to have been a rare back-to-back breeding year on Stewart Island, according to author David Butler) in Port Adventure. Ken Sutherland, who provided much of the written accounts of Kakapo in Fiordland (1925–1950), felt that Kakapo were probably present in this area too.
At least three birds were present in Seal Point in the 1950s. While a search in 1985 identified at least five males booming and a staggering thirty-six track and bowl systems, many of these were disused. A dead male Kakapo was found here in 1981, killed by a cat. We know only two birds were ever captured in Seal Creek, indicating that it’s very likely a number of Kakapo remained here post-1992.
Feeding sign was seen in four locations on the left-hand side of the Kopeka River in 1985, despite Kakapo only ever being located on the right-hand side of the river. Additionally, in the same search, a significant amount of Kakapo feeding sign was found further up the headwaters of the Kopeka River, on Kirkland's Hill. However, the other side of Kirkland's Hill was never searched; its elevation would have made it a prime location for Kakapo. Similarly, significant old feeding sign was found on Lee’s Knob to the north in 1984.
In fact, the 1985 search, while limited, seems to have painted a picture of widespread but fragmented Kakapo populations across much of the island—something that’s not often recognised by those telling the story of Stewart Island Kakapo. It’s not that Kakapo were not present across much of the island, but instead that they were present in a remote but reasonably accessible area. For example, Kakapo were recorded numerous times across Patterson Inlet to the north fifty years prior to the Kakapo searches of the 1970s. While hunters are also adamant, birds remained in the Ruggedy Mountains in the north of Stewart Island in the 1980s.
To give an idea of how rapidly Kakapo had likely vanished across much of the island, Alan Munne himself found 128 track and bowl systems across the Tin Range during his time on Stewart Island. Usually, within a decade of not being used, most track and bowl systems are barely identifiable. So it’s easy to picture a scenario where the Tin Range Kakapo population had rapidly contracted in the preceding years to 1977, likely representing a wider trend followed by the rest of Stewart Island a couple of decades earlier.
A Final Set of Footnotes: 1997 - Present
Between 1982 & 1996 only three Kakapo chicks survived to adulthood.
In 1995, the known Kakapo population hit just fifty-one birds. Only three chicks were known to have been produced since the 1981 season. Kakapo had seemingly vanished from Fiordland, and without a reprieve, there was a real sense that the species would soon be beyond saving.
In 1997, as the breeding season began, a team returned to Stewart Island to search the Tin Range for additional Kakapo signs. Sure enough, a handful of feathers were found near a long-abandoned track and bowl system, indicating a female was likely searching for a mate.
A team returned the following winter with a tracking dog and began to search the most likely catchments around the Tin Range. On June 21st—the winter solstice—a new female was captured in Healy’s Creek to the south of Arena Ridge. Aptly named ‘Solstice,’ she was shifted to Whenua Hou. Her discovery was critical to the species. She appears to have no first-order relatives, and while somewhat inbred, she still introduced critical new genes to the Kakapo population. Her son Komaru, who hatched in 2011, was one of the youngest male Kakapo to ever breed and now has more than eleven living offspring. Solstice is still alive in 2025.
Yet the tale of Kakapo on Stewart Island is a sad one. For every bird that has survived to breed and pass on their genes to the modern population, two have not. While Stewart Island birds surprisingly contain fewer genetic mutations than mainland Kakapo, due to their long history of limited genetic variation, they also have much higher rates of infertility, early embryo death, and likely lower genetic fitness.
Much of the pain of the story of Stewart Island Kakapo could have been avoided with better funding and management. Alan Munne commented in 2023 that the programme was unstructured until 1982, when Ralph Powlesland became involved and began to head up Kakapo research alongside Andy Grant. Meanwhile, Brian Bell and Don Merton headed up the management side. It appears that Ralph Powlesland’s involvement really began to turn things around, and it’s unsurprising that it was under his watch that the three major successful translocations of 1982, 1987/8, and 1989 took place. Without his involvement in the programme, one wonders if Kakapo would have been rescued at all.
Yet despite this, many promising leads were not properly followed up across Stewart Island, especially in the early 1990s when it was evident that Kakapo likely remained on the island, but in low densities and deeply fragmented. As Alison Balance explains, "It’s not that anyone believed they’d found the last Kakapo on Stewart Island. But the resources simply were not there to find those that remained."
How many Kakapo remained is an open question. In 1999, a hunter came across a Kakapo on the far side of Mawson Bay. While I’ve heard two stories in the last twenty-five years from across the island that at least have a ring of truth to them, it seems likely that Kakapo have largely faded into memory on Stewart Island. However, with better resources and management, significantly more birds could have been saved while they were still present. This isn’t a criticism of the individuals involved, but of the political ecosystem they operated in, which refused to provide the necessary funding for Kakapo to be adequately preserved.
How this will impact the species as a whole remains to be determined, but it’s a sobering reminder of the challenges faced when attempting to save a species with limited resources.
All photos published under creative commons licence from Google or Canva. Thanks to Jake Osbourne, Mike Bodie, Ralph Powlesland, The Department of Conservation, Jake Osbourne again, Philip C, John The Ghost, The Department of Conservation, WikiMedia, Animala, Chris Pagani and Jake Osbourne.