Words by Susan Prior, all photographs and video by Nick Bradsworth
From critically endangered to being declared extinct, then back again – the fate of Norfolk Island’s morepork owls hangs in the balance. But now there is some great news – with the dedication and care of researchers and Parks Australia – it can be revealed that two chicks successfully fledged in the 2019–2020 breeding season.
It’s 1 am. We’ve been in bed for hours but I can’t sleep. Outside it’s pitch black, perfectly calm, no breeze in the trees, and just the faint rush of surf on the rocks some 750 m distant. There’s something about being awake in the small hours. With the mind released from the workaday, senses are liberated, imagination becomes a free agent of the night.
Echoing into the darkness is a mournful, repetitive call. Every three seconds or so a morepork owl (Ninox novaeseelandiae undulata, also known as the Norfolk Island boobook) sends out his plea. I estimate him to be resident about 500 m away. To my sleep-deprived ear he sounds sometimes desperate, other times resigned, but always measured, always doggedly persistent. I am sure it is a male because his call is fuller with a warmer timbre, whereas the female call tends to be more vibrato (a slight exaggeration, perhaps, but think of the unlikely duo Tony Bennett’s creamy croon compared to the almost imperceptible quaver of Lady Gaga’s).
The Norfolk Island morepork owl – vital statistics
length: 26–29 cm
wing length: 183–222 mm
tail length: 135–146 mm
weight: 150–216 g
colouring: mottled warm-brown with buff and white in an irregular pattern
eyes: golden yellow
The females are usually larger and heavier than the males.
From The Owl Pages.
With its all-seeing, all-knowing owl eyes, this bird is one of the rarest in the world, and I feel a little bit privileged to be sharing my night with him. But from the sanctuary of my bed, the sadness of his plight, especially as I listen to him calling out for a partner to share his life’s journey, achingly hits home. I shift, feeling uncomfortable at the sound of his unyielding resolve.
We live on Norfolk Island – a tiny rock just 5 km by 8 km in the middle of the South Pacific Ocean and home to the Pitcairn descendants of Fletcher Christian and the other HMAV Bounty mutineers along with their Tahitian brides – and this morepork owl is just one of maybe 20 or 30 birds of this kind left in the world. The exact number is still open for debate, but one thing is for certain, there aren’t many of them.
The next morning, spurred on by thoughts of the loneliest morepork and to learn more about what is being done to try and save this bird from extinction, I contact Flossy and Nick. Flossy Sperring is a PhD candidate from Monash University. She completed her first degree in Advanced Science Research, with a year in Honours, majoring in Ecology, Conservation Biology and Zoology and is on-island researching the morepork owl with Nick Bradsworth, also a PhD candidate, and a specialist in owls from Deakin University in Victoria, Australia. Nick studied Environmental Science, Wildlife and Conservation Biology for his first degree, with an Honours project involving attaching GPS transmitters to the Powerful owl in Melbourne. It was this experience that saw Nick being invited to work with Flossy.
One of this year’s clutch
My night-time gloom lifts when I catch up with them, because I can see they both have an infectious enthusiasm for their quarry, and together they make quite a team – one we are so fortunate to have batting in the morepork owls’ corner.
This is a sad tale that goes hand in hand with the history of white settlement on the island when, in the early 1800s, the charismatic and very pretty crimson rosella (Platycerus elegans), known locally as the red parrot, is believed to have been introduced as a caged bird. Since then it has proved to be a very successful coloniser, taking over the nesting hollows of both the endemic Norfolk Island red-fronted parakeet – Cyanoramphus cookii (known locally as the green parrot) and the morepork.
The island’s owl population reached its crisis moment back in 1986.
Closely related to New Zealand’s morepork owl (Ninox novaeseelandiae novaseelandiae), that year the species was reduced to a solitary female known by the islanders as Miamiti – the name of Fletcher Christian’s Tahitian bride. On warm early spring nights she would call across the island in a futile attempt to find a mate. No one answered.
But help was in sight. In 1988, thanks to the hard work of Dr Penny Olsen and others, Miamiti mated with an introduced New Zealand morepork producing two successive clutches each with two offspring. When she was last seen in 1996 – after which it was assumed she had died – the islanders and scientists alike had their fingers crossed that this subspecies was on its way to being saved as the numbers gradually climbed. The Norfolk Island morepork had been plucked from the brink of extinction, at least as a hybrid.
On this topic, my conversation with Flossy and Nick turns to the matter of whether the combined New Zealand and Norfolk Island hybrid morepork owl is the ‘real deal’ or not. The International Union for Conservation of Nature (IUCN) is the global authority on the status of species. It maintains an inventory – the Red List of Threatened Species. The Norfolk Island morepork hybrid was, according to the organisation’s rules, deemed to be extinct. Originally, this was also the bird’s status with Australia’s own Environment Protection and Biodiversity Conservation Act (1999) (EPBC Act).
Researcher and specialist in threatened bird species, Professor Stephen Garnett from Charles Darwin University says:
Although the Norfolk island [sic] owl was reduced to just one individual, the hybridization event was a one off, with one just [sic] individual from outside contributing to the gene pool, and is not an ongoing process. Furthermore, if there is a selective advantage for the genes of the original subspecies, then those genes should again come to dominate the population.
In 2011, together with Dr Olsen and others, he produced a paper titled ‘Did hybridization save the Norfolk Island boobook owl Ninox novaeseelandiae undulata?’. In effect, he reports, ‘approximately half the nuclear genome of the original taxon [subspecies] and all the mitochondrial DNA is conserved in all living owls on the island.’ (My emphasis added.)
Flossy agrees, and enlarges on his argument for me:
There is mitochondrial DNA and there is cellular DNA. The mitochondrial DNA can only be passed down through a female, so that DNA is completely unique to this subspecies.
The other thing as well is it is a subspecies of the morepork … Breeding between different subspecies does occur naturally in the wild, so for two different subspecies to breed and create viable offspring is something that can happen naturally. We’ve had to induce that to save the morepork. Even as a hybrid, it is still completely unique in its own right.
It’s super-cool that you have this species here [on Norfolk Island] that has this history and to lose that would be such a shame.
It seems then, that this subspecies has risen like Lazarus from the dead, so that today its status under the EPBC Act is listed as ‘endangered’. Unfortunately, the Norfolk Island morepork has yet to be rehabilitated in the eyes of the IUCN’s Red List. But it’s a start.
Interestingly, local bird expert, Margaret Christian says the hybrid owl’s call is repeated more rapidly than that of the original Norfolk Island bird.
Whatever the arguments are – for or against this being the ridgy-didge, unique, original morepork – the owl as an apex predator is an important component of the Norfolk Island ecosystem, and that fact alone means it is incredibly important that we save it.
Top right, Flossy Sperring; bottom left, Nick Bradsworth
The owl’s critically endangered status has allowed it to be officially included as one of the Australian government’s 20 priority bird species. Selected for its uniqueness and importance to the island’s ecosystem and to the community, the owl is now benefiting from extra government funding. In October 2019, the Australian Government stumped up $400,000 specifically to help secure the futures of this owl and the green parrot on Norfolk Island. The parrot is faring better than the owl but it is still threatened with extinction.
Nola Marino MP, Assistant Minister for Regional Development and Territories, said of the funding:
[It] has been matched by three leading Australian universities, [which] will help us better understand the green parrot and morepork owl populations, range movements, breeding success, habitat preferences and genetic structure.
This 18-month project is a collaboration between Parks Australia, the Australian National University, Monash University and the University of Melbourne and will guide conservation management to ensure the futures of both bird species are in safe hands.
This government grant will enable the researchers to establish a baseline understanding of where the morepork is at today. The funds have been used to, among other things, buy equipment including the trackers or tags that are attached to the middle two tail feathers of the owl. Older-style trackers are fitted by a harness with the device sitting on the bird’s back. Although designed to break when snagged, these can sometimes get caught in the trees as the bird flies through. The new trackers used by Flossy and Nick are a much safer option for the welfare of the bird. About the size of a jellybean and weighing around 5 grams, they have a tiny aerial and are configured to track the owl’s GPS location every 30 minutes between the hours of 6.30 pm and 6.30 am when they are at their most active. A beacon signal from the device allows Flossy and Nick to locate the owl during the day. This configuration gives a battery life that allows for at least two weeks of data.
Flossy and Nick had ten trackers for the 2019 breeding season, and a further ten budgeted for the coming 2020 season. The cost of these, including all the software needed to run them, is about $1500 per tracker, but, as Flossy says, ‘The data we will get from these is invaluable: the home ranges of the owls, how much space they need, where they go, are they overlapping with other owls … it gives us the information to know how many owls can live in a certain area.’
At the conclusion of the 2019 breeding season, they manage to retrieve all ten tags for reuse in 2020, although if for some reason that hadn’t happened, Nick says, ‘The tracker will drop off when the owl moults and the tail feathers drop – within a year’.
It is thought that the owl was once distributed across the whole 35 square kilometres of Norfolk Island and also on nearby Phillip Island, six kilometres to the south. None survive on Phillip; however, Flossy and Nick say that having an insurance population there is not out of the question. Today, the owl is largely found in or near the Norfolk Island National Park, although increasingly private land will assume a greater importance for the owls’ long-term survival.
In a project funded by the National Science Program under the auspices of Minister for the Environment, the Hon Sussan Ley MP, a team from Norfolk Island Parks led by manager Mel Wilson has been actively placing nesting boxes in key areas around the island, and attempting to control the populations of feral red parrots, European starlings (Sturnus vulgaris), Polynesian rats (Rattus exulans) and black rats (Rattus rattus), all of which take their toll on the morepork owl population. Feral bees (Apis mellifera) are also known to have taken over at least one hollow. Flossy and Nick are looking at ways of deterring these invasive species; for example, a strip of carpet on the top of the nesting box lid seems to deter bees. Unfortunately, owls need a slightly larger entrance to their hollows compared with the red parrot, so making the hole smaller is not a viable option.
So where are we at today?
After the initial breeding success in the late 1980s into the 1990s, activity slowed. The last known successful breeding before the 2019 season occurred back in 2011, although Flossy and Nick suspect there has been some action in between whiles. Flossy and Nick want to discover why this is. There could be several reasons: Is the original population directly descended from Miamiti genetically compromised? Or are these birds now too old, perhaps? The most likely cause, though, is the lack of suitable habitat for breeding.
The Norfolk Island National Park, with the help of island residents, has undertaken community surveys for the last four years – from 2016 through to the 2019 breeding seasons (which run from September to December). This information, together with night surveys done by Nick at the beginning of the 2019 breeding season, helped the researchers get a handle on how many owls there are currently. Nick thinks there are between 25 and 30 birds on the island. Against that, we don’t know yet how many can be sustained – or in other words, the carrying capacity of the island.
Nick sums up his take on the morepork field season for 2019. In two months on Norfolk Island he and Flossy:
had 21 trapping nights
captured six owls
attached GPS tags to five of these
and recorded 1825 total GPS movement positions!
It seems the future of the Norfolk Island morepork is looking much better than it did a few years ago. In addition to the active research programme and the additional government funding, there are now signs of slowly increasing numbers. In the 2019 season, two breeding pairs were located. While one pair looked interested, but sadly they failed to breed; however, the other pair raised two chicks, and these two have now successfully fledged.
For me, my feelings about the poignant call of the little male owl down my street night after night are now of hope. I am keeping fingers and toes crossed that Flossy and Nick will be able build on this last season’s success and find a magic formula that will ensure the Norfolk Island moreporks’ survival. To get down to just one lonely morepork, to then be declared extinct, and now have that status ‘optimistically’ revised back to critically endangered, you’ve got to hope they are in with a chance.
