The Secrets of Kakapo: Lesser-Known Facts for Superfans
Even superfans might be surprised by some of these
Being a New Zealander keen on understanding conservation can be challenging. Due to the unique state of our wildlife, most articles and information are tailored for those just beginning to explore our distinctive species. While this approach serves a purpose, providing basic information for those discovering the Kakapo for the first time, it can be limiting for locals who wish to delve deeper into the world of Kakapo.
My intention is to take the opposite approach. I aim to offer well-written, in-depth articles that both entry-level readers and those familiar with New Zealand Conservation can enjoy. With that in mind, here are three Kakapo facts that even a super fan might not know!
Rangi: Master of Kakapo Hide and Seek
Rangi is often credited as the reigning Kakapo hide-and-seek champion. In 1987, Rangi was released alongside three other male Kakapo on Whenua Hou, off the Southland Coast. All four males had recently been discovered living on Stewart Island, and they were translocated to shift them away from feral cats, which had decimated the Kakapo population.
Back in the 1980s, Kakapo transmitters cost exorbitant sums of money, and the decision was made to minimize costs and release the males without transmitters. Whenua Hou is a small island, and it was reasoned that it wouldn't be too hard to relocate the Kakapo again. All four would be turned loose over several months, and none would ever be seen again. For twenty-one years, they were believed to be dead or lost forever.
In the summer of 2009, a ranger was working in a remote area of the Whenua Hou coastline when he was surprised to hear booming. Few male Kakapo inhabited the area, so he quickly moved in to investigate. Amazingly, he discovered Rangi, who was in both good health and unperturbed at having been missing for so long.
News traveled quickly, shocking many worldwide. Hundreds of scientists and thousands of volunteers have visited Whenua Hou over the years. How could a bird escape detection for two decades on one of the most intensively studied islands in the world?
It's helpful to remember that Kakapo are nearly invisible in the forest. They've evolved to evade detection from predators by blending into the background of the canopy. Prior to the introduction of pests to New Zealand, Kakapo faced predation mainly from raptors such as the Eyles Harrier and Haast Eagle. Freezing allowed them to avoid detection from the air.
Such was the effectiveness of this camouflage that hand-reared Kakapo Hoki would evade detection for hours in her aviary. At one stage, she blended so well into the bushes in her enclosure that she was declared to have escaped. Only when she blinked did she reveal herself.
Kakapo can remain hidden for decades
Behind the Leg Bands : The Lost Kakapo
What isn't apparent to most people is that Rangi isn't the best-hidden Kakapo. He might have the longest tenure of a bird caught so far, but compared to his peers, he's got a long way to go.
Rangi was translocated with three other birds: Pierre, Tramp, and Gunter. Each was identifiable by a metal band fitted to their leg. In the 1980s, leg bands were considered the most cost-effective way to identify individual Kakapo; nowadays, they've been replaced by microchips and transmitters. All leg bands were removed years ago. Imagine the surprise of rangers when, in 2013, a bird was spotted with a leg band on! Unfortunately, it was not able to be captured before disappearing off the track, nor has any amount of searching since uncovered the bird.
In 1985, a study team visited Mount Rakiahua on Stewart Island and observed a bird booming. The weather was atrocious, and the landscape hard to navigate. Between gaps in the storm, the team could hear a second bird booming nearby. Though they couldn't locate where. Five years later, they would return and capture the first bird, a male named Piripi. The second bird and its track and bowl system could not be located, even with the help of a dog. Given no record exists of any Kakapo killed by cats after 1983, it's entirely possible this bird still exists, especially as a Kakapo was sighted by a hunter in 1997, not far from there.
Little Barrier Island may still hold Mike, the Kakapo who has been missing for forty years. In 1987, three Kakapo were heard booming in the Transit Valley in Fiordland; several were captured and inspected before having their transmitters removed and released. Over the following two years, their distinct feeding sign would be observed before they disappeared without a trace. In 2006, the Kakapo recovery team visited the valley and found some possible Kakapo grubbing, though it was not immediately clear if this was the work of Kakapo or Kea.
All that changed in 2012; a team of three trampers would report booming in a separate area of the valley. A Department of Conservation team headed by Vercoe Scott landed in six locations and installed audio transmitters. In late February, on two separate evenings near Lake Liz, Kakapo-like calls would be picked up in the distance.
The true record holder is likely Mike on Little Barrier Island. Despite her name, Mike is a female Kakapo who was translocated from Stewart Island in 1982 and promptly vanished. In 2018, an unknown Kakapo was sighted by a team visiting the island; it disappeared before being captured. Upon examination of Kakapo home ranges on the island, a strange phenomenon was observed: all the birds seemed to be avoiding a key feeding area, suggesting it might be the home territory of this unknown Kakapo. Sadly, rugged terrain has hampered searches since then, and nothing has been uncovered. However, given Little Barrier has no predators, we have every reason to believe Mike is still alive forty years later.
Kakapo Mike has been 'missing' for forty years.
Troubling Genetics : The Deep Inbreeding of Kakapo
According to the Kakapo Recovery Team, between 1974 and 1997, 65 Kakapo were translocated from Stewart Island and Fiordland to offshore islands. Today, the Kakapo population stands at approximately 250 birds. However, these numbers may mask something a little more sinister: how badly Kakapo are affected by inbreeding depression.
Exact estimates vary, but it’s generally believed that it takes approximately fifty unrelated individuals in a population for a species to survive the negative impacts of a genetic bottleneck. Much beyond that point, there is serious concern that the species may see a genetic collapse, and a high risk of eventual extinction.
Theoretically, Kakapo should have just enough unrelated individuals to avoid such complications. Sadly, upon closer examination, this is not the case.
Firstly, it’s helpful to understand where that figure comes from. It's the cumulative total of birds who were translocated from Fiordland and Stewart Island and survived until release. Unfortunately, it’s a rather arbitrary figure, primarily because we're examining data across a 23-year period. Certain Kakapo were born, lived, and died during that period, all without being included in that figure. Other Kakapo who died prior to them are counted.
Things become even more muddled when you consider that we count birds who died immediately after translocation, but not those who died during the process. I think a better way of understanding the genetic bottleneck Kakapo have gone through is to examine how many birds actually survived to pass on their genes.
It's not fair to compare Kakapo populations either. Intensive search efforts between 1974 and 1981 would reveal a population of 100 to 200 Kakapo on Stewart Island, and eighteen birds in Fiordland. Though only 95 Kakapo were ever actually found during intensive searches of Stewart Island, and from that number, an estimate of 100 to 200 individuals was extrapolated.
In Fiordland, eighteen birds were found, the majority of whom were found in Milford Sound. However, only twenty percent of the Milford area was searched, and no population estimate was made. Examination of the Kakapo search notes indicates the presence of birds that were never captured. In fact, if we were to take the total Kakapo sign seen and multiply it by the size of the catchment region, it's not unreasonable to believe the two populations were of comparable size. Though the Fiordland birds were likely located in a much more inaccessible area.
Not all Kakapo survived their transfers
Kakapo Population Puzzle: The Heartache of Inbreeding's Impact
Of the 113 Kakapo actually found across both locations, forty-nine would die or disappear prior to translocation. In the majority of instances, these birds would have been killed by introduced predators, either cats or stoats. The Kakapo recovery team would attempt to translocate the remaining sixty-nine individuals, though mortality would be high, particularly amongst birds of advanced age. Only fifty-three Kakapo would survive more than two years on offshore islands, including just one Fiordland Bird, Richard Henry.
Unfortunately, the bottleneck would only be exacerbated from there. Since the first successful offshore breeding season in 1991, only thirty-nine of these birds would go on to produce living offspring. Nor does that paint a full picture. In 2002, the development of genetic testing allowed researchers for the first time to examine Kakapo micro-satellite DNA paternity markers. The results were grim: Merty, Sarah, Wendy, Zephyr, and Heather were, in fact, second-generation chicks, who had both parents still living.
In 2009, the technology was advanced several steps further, allowing researchers to begin confidently assigning family relationships between birds. Many birds share enough markers to suggest either a sibling relationship or that they are first-order relatives. We now believe that Lisa and Ralph are probably siblings, which isn't ideal because they're both also the parents to Merty. Moreover, two prolific females, Margret Marie and Suzanne, appear to be sisters.
That isn't the end of things either. Four pairs of birds appear to be closely related, though how isn't clear. These include Arab & Sass, Smoko & Whiskas, Barnard & Jean, and Ox & Waynebo. These birds may share a parent, grandparent, or be the grandparent of the other.
In addition to these birds, two founders, John Girl and Pegasus, died after producing a single chick together in 1991, effectively merging their genetic potential into a single lineage through their chick Stumpy. All up, there seems to exist about twenty-nine distinct Kakapo lineages, only half the number needed to guarantee a species will survive a bottleneck.
This doesn't necessarily mean Kakapo will become extinct, however, it does indicate that there will be some unique challenges the species will face when it comes to fitness, fertility, and the risk of disease. These factors will leave them vulnerable to new threats.
Thankfully, some recent evidence suggests this isn't the first bottleneck Kakapo have survived, and they may have evolved to be better suited to surviving bottlenecks than other parrots.
But that's something we will save for another story.
Only a handful of Kakapo contributed to the modern population
Interconnected Worlds: Exploring the Link Between Kakapo and Kokako Sightings
The South Island Kokako and Kakapo appear to have inhabited the same areas. In November 2021, hikers near the Percy Burn Viaduct in Southern Fiordland reported hearing potential Kokako calls. The Percy Burn Viaduct leads into a set of hills containing the Wairaurahiri River headwaters, commonly known as the Angus Burn. In 1992, these headwaters were the focus of a major search for Kakapo after hikers reported booming from the slopes of these hills.
In January 2022, audio records of Kokako calls were submitted to the Department of Conservation from the Heaphy track, where Kakapo were reported booming until 1981, and possible track and bowl systems were found as late as 1984. In 1998, Dan McKinnon reported seeing a Kokako east of Punakaiki. This is notable because a Kakapo nest was found here by prospector C.W Wilks in 1948, marking the last recorded nest on Mainland New Zealand. Additionally, Kakapo were seen here by Wilks and other prospectors in 1955, 1958, 1959, and 1964.
The similarities do not end here. A potential Kokako sighting was logged in 2021 from the Coupland Valley track, less than a kilometer from a set of bluffs where a Kakapo was observed in 1985. In 2007, a Kokako was heard calling in Ships Creek South Westland, just two kilometers from where a Kakapo was observed running across a road in 1984. In 2011, a Kokako sighting was observed from the Paringa River, near where a Kakapo was observed by two brothers tramping some decades earlier.
South Island Kokako seem linked to the Kakapo
Kakapo and Kokako: A Linked Legacy
In 2000, a Kakapo was heard calling in the Tutuko Valley, several kilometers from where Kakapo were last recorded in 1988. In 2006, possible South Island Kokako feathers were found in Crayfish Heights, just below a ridge where Dick Decker observed an active Kakapo track and bowl system in 1985.
Many of the most recent Kokako sightings have come from Fiordland. In 1987, a Kokako was sighted on the Carrick River, where a Kakapo had been observed booming in both 1983 and again in 1985. Moreover, active track and bowl systems were found in the nearby Oho Creek at the same time. A Kokako was heard by Mo Turnbull in Big River in 2004, and the same year, a Kakapo was reported by Wayne Durant in the headwaters of the same river in the Jeanie Burn.
Even on Stewart Island, Kakapo and Kokako reports came from the same locations. A team searching for Kakapo in 1985 made note of three instances of hearing or seeing Kokako. An additional three more reports would come from the same area in 1986 and 1990, near the Southern end of Mason Bay. In 1997, a hunter observed a Kakapo in the same area.
All this serves to reinforce the validity of these claims. It seems extremely unlikely that two critically endangered birds would have such an overlapping distribution of claimed sightings unless there was some truth to them.
Many sightings of Kokako and Kakapo are from the same locations
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Thanks to Dr Andrew Digby for the use of his photos
