Our Changing World

Giant penguins weighing up to 150 kilograms once roamed the waters around New Zealand. Claire Concannon speaks to a palaeontologist and learns about penguin evolution, extinct species that dwarfed today's emperors, and why Aotearoa is such a great place to study these birds that 'fly' through the water.

Evolution spins out some crazy designs. 

Bats that can hunt in the dark using echolocation, spiders that use water surface tension to detect prey, and rugby-ball-shaped birds who look like they are wearing formal attire as they dive through the water to hunt.

Marching penguins, dancing penguins, surfing penguins. These birds have found their niche in both the oceans, and on our movie screens.

What made penguins the beloved birds that they are today?

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From flying in air, to flying in water

Our story begins 62 million years ago. "I recognise that that's just a number," says Dr Daniel Thomas, of Massey University. "But to put that into context - at 66 million years, that is when the non-avian dinosaurs disappeared from the planet." 

Once a dinosaur-obsessed kid, Daniel continues to follow his passion, now with a focus on one of the descendants of avian dinosaurs. He studies penguin fossils and their evolution across time. 

The earliest penguin fossils come from right here in Aotearoa, from North Canterbury. Dated to a mere four million years after the dinosaur extinction event - a blink of the eye in geological time - these bones indicate that early proto-penguins had already committed to life in water, although they may not have been very efficient divers. 

Birds that fly in the air - like the once-ancestor of the penguin - have hollow bones. But these early fossil bones found in Canterbury are dense, better suited to diving under water. 

Across the next 6-13 million years, the wings of these birds underwent significant changes. No longer were they able to tuck back in after a stroke, instead the joints would stiffen so that they effectively became fixed paddles, driven by the shoulder. 

The time of the giants

Penguin evolution is constrained by many factors: the difficulty of 'flying' in dense viscous water, the issue of constant heat loss, the need to also go on land to breed. But that didn't stop evolution from testing all the penguin size and shape possibilities within these constraints. And early on in penguin evolution, something interesting happened - penguins get very large.  …

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What happens to our muscles as we age? Claire Concannon finds out why muscles get weaker as we get older, and speaks with a researcher investigating why Olympic athletes live up to three years longer than the general population. Claire also meets a scientist studying what happens to muscles in children with cerebral palsy, seeking clues that could help.

'Use it or lose it!' is the rallying cry to exercise. But what happens to our muscles as we grow and as we age?

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In this episode, Claire Concannon explores these questions.

With World Cerebral Palsy Day fast approaching, she speaks to a researcher looking at muscle development in young patients.

Plus, evidence overseas shows that former Olympic athletes live up to three years longer than the general population. A New Zealand study is investigating how former athletes' lifelong commitment to exercise is good for their bodies.

Cerebral palsy and muscle development

Cerebral palsy is the most common cause of physical disability for children in Aotearoa. It results when impairment in the developing brain either during pregnancy or shortly after birth leads to problems with movement and posture.

Dr Geoffrey Handsfield of the musculoskeletal modelling group at the Auckland Bioengineering Institute wants to understand what is happening in the muscles of children with cerebral palsy across time. 

To do this, he is working with Mātai Medical Institute in Tairāwhiti on a longitudinal MRI study of children both with and without cerebral palsy. 

He hopes to figure out how muscle development is impeded in those with cerebral palsy and perhaps find some clues for how to help. 

Muscle changes as we age

At the other end of the life spectrum, Dr Lara Vlietstra of the School of Physical Education, Sports and Exercise Science at the University of Otago is interested in what happens to our muscles as we age. 

There are physiological changes that occur - while we only lose a little bit of muscle mass, the muscle fibres themselves change.

Over time, many of our Type 2, or fast-twitch, muscle fibres (related to power and speed) change to Type 1, or slow-twitch.

On top of this, communication between the nerves and the muscles gets impeded.

Reduced physical activity, along with these physiological changes, can result in loss of function in older adults, and susceptibility to falls. 

Lifelong commitment to exercise

These changes are both preventable and treatable, says Lara, with - you guessed it - exercise…

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The southern New Zealand dotterel is a true underdog of the bird world, with just 126 individuals at last population estimate. Claire Concannon tags along with a team of researchers attaching trackers to the birds. Their mission is to figure out where the dotterels go to breed, so these "plump little tomatoes" can be protected from introduced predators.

As the tide closes in on Awarua Bay in Southland, a collection of wading birds gathers closer together, pecking away at the last stretches of sandbar and seagrass. 

Grey plovers, knots, bar-tailed godwits, banded dotterels, oystercatchers, and a single Terek sandpiper, nicknamed Derek. 

And among the crowd, a little flock of southern New Zealand dotterels clusters together - at a quick count: 54 birds. Just under half of the total population. 

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Declining numbers

"Since 2010 the  dotterel population has more than halved," says Daniel Cocker, a member of the Department of Conservation (DOC) Southern New Zealand Dotterel recovery team. The annual count in April of this year revealed that the population has dropped to just 126 birds.  

Plump and handsome - especially when sporting their red-chested breeding plumage - these little birds would once have been widely distributed and bred on mountaintops around Southland. Now, they are restricted to breeding on some of the peaks of Rakiura Stewart Island. 

The breeding site secret

It's during this breeding phase that they are most vulnerable to predation, and the main culprit is feral cats. Daniel, and the rest of the recovery team based on Rakiura, are focused on predator control in the areas that these birds are known to breed. But they only know the breeding locations for about 20 percent of the birds - most of them go to mountaintops unknown. 

That's why DOC staff and researchers from the University of Otago have teamed up to attach satellite tags to some of the southern New Zealand dotterels in Awarua Bay. When not breeding, the birds flock here, and in a few other bays on Rakiura, feeding up on the bugs in the sand. 

Master's student Oscar Thomas is hoping that by adding these tags to the birds, the team will be able to discover where they go. 

Listen to the episode to get to know this Southland underdog, hear the story about how Daniel first got involved in their conservation at age 14 and learn how the satellite tags are fitted to the birds. 

To learn more: …

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Broccoli and chocolate. Prawns and vanilla. According to food pairing theory, these culinary matches should go together as well as macaroni and cheese, or peanut butter and jam. But do they really? Senior producer Justin Gregory meets two researchers digging into the sensory science of food.

Hungry? How does a nice meal of milk chocolate and asparagus sound?

Or maybe prawns and vanilla? Kiwifruit and gorgonzola cheese?

If scientific theories about the science of food pairing are right, these should be delicious flavour combinations.

Maybe they are. Maybe they aren't... but there's certainly more to it than we currently know.

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Food pairing theory works on a pretty simple chemical basis: foods that share more flavour compounds (mostly smell) will taste better together than foods that don't.

For example, ham and eggs. Macaroni and cheese. Perhaps less obviously, caviar and white chocolate.

But there's a big geographic and cultural hole in this theory.

"Research has shown that there is this tendency for western cuisines to comprise recipes that are combining different ingredients that have shared these flavour compounds', says Dr Rebecca Jelley, a research fellow in the School of Chemical Science at the University of Auckland.

"But in fact, the complete opposite was seen for east Asian cuisines."

And there's another element this theory might be overlooking.

"They seem to have forgotten about the sensory aspects of food," says Dr Danaé Larsen, who is a lecturer in the School of Chemical Science.

By sensory, she means the texture, sound and sight of food and it is this area that the two have begun a research project hoping to find some better answers.

They want to know if adding sensory stimulation while chewing texturally complex foods adds enjoyment and a feeling of fullness after eating.

To test this, the pair are running a series of experiments using New Zealand foods with shared aromatic compounds. Danaé is in charge of the sensory aspects of the study while Rebecca analyses the chemical compounds of the foods used.

The hope is to one day have a local food pairing network backed by solid science - which Central Otago Pinot Noir goes best with which local cheese, for example.

There's also a possibility of positively affecting the way people feel about healthy foods they may not enjoy eating. One day, there might even be a healthier chocolate bar!

To learn more:…

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The Great Ireland vs. New Zealand Bird-off returns for part 2 to decide once and for all which island nation boasts the best birds. Our avian aficionados return to argue their case in front of judge Claire Concannon. Who will fly to victory? Listen to find out - plus learn about the crazy life cycle of the cuckoo and the weird feathers of the kiwi, among many fascinating facts and tales from the world of birds.

Aotearoa New Zealand may call itself the land of birds, but numbers-wise, the title doesn't stack up. 

There are just over 200 bird species breeding here in Aotearoa. But Ireland has more than twice as many at over 450 species.  

Then why the title? Is it because birds here fill interesting ecological niches that elsewhere are taken up by various mammals? Is it because many of the birds are endemic - found nowhere else on earth? 

Or is it simply birding bluster?  

There's only one way to find out. 

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Welcome back to the Great Ireland versus New Zealand Bird-off. A sporting contest against Ireland taking place this spring that New Zealand actually has a chance of winning. 

Last week's opening salvos saw the white-crested sea eagle defeat the moa - on account of not being extinct - and the kea outsmart the northern raven. 

Tītipounamu was gifted a win over the goldcrest, in a move Ireland might yet regret, and we finished up with a mighty showdown - Sirocco the kākāpō versus the swallow, herald of summer. 

In a controversial decision prompted by childhood memories, the swallow was given the win, to leave everything tied up at two all. 

And so, we are back. To sort this out once and for all. We've brought back our two avian aficionados who have answered their nation's calls. 

Ireland - Ricky Whelan

Biodiversity officer at Offaly County Council, and co-host of the In Your Nature podcast with Niall Hatch and Birdwatch Ireland, Ricky has been working with birds and in conservation for over 15 years. He is a walking encyclopaedia of bird facts and conservation concerns - and can also bring the smack talk. 

If you haven't had your fill of Ricky bird facts after listening to the episode you can find some more on X (Twitter) or Instagram. 

New Zealand - Jamie McAulay …

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Welcome to the great Ireland vs New Zealand bird-off. Two islands, a world apart - but which country has the better birds? Two bird nerds champion their nation's birds across four categories in an avian battle for the ages, with Claire Concannon judging the best of the feathered best. Which country will emerge victorious? Listen to find out.

Two islands, a world apart. 

One sits at the edge of the Atlantic, cosy and close with its European neighbours. One spun out into the wild Pacific, with 2,000 kilometres of ocean between it and Australia.  

New Zealand and (some of) Ireland were once both part of the super continent Gondwana before they went very separate ways. 

Cue millions of years of plate movements, of ice ages and warming, of mass extinctions and evolution. 

Which leads us to the most important question of our time: which nation ended up the richer, the weirder, the better off for birds? 

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Welcome to the Great Ireland versus New Zealand Bird-Off. Undoubtedly the most important contest between these two nations likely to happen any time soon. 

In a unique and unknowable competition format and scoring system, representatives from each nation will put forward candidate birds for each category to be judged by presenter Claire Concannon. 

Let's meet the representatives. 

Ireland - Ricky Whelan

Hailing from the very centre of the country, Ricky is the biodiversity officer at Offaly County Council, and has been working as a conservationist and ornithologist for over 15 years. He likes long walks in the bog, topping up his bird feeders and extolling the virtues of crows to whoever will listen to him. 

Ricky also co-hosts the In Your Nature podcast with Niall Hatch and Birdwatch Ireland. Ask him your corvid questions on X (Twitter) or Instagram. 

New Zealand - Jamie McAulay

A conservation biologist based in Te Anau, Jamie loves big mountains, deep fiords and lots of rain. Oh, and birds. He really likes birds. Out on the front lines of conservation, Jamie's got tales of cuddling kiwi, catching tītipounamu in the snow, and crazy kea antics. 

Jamie posts about his research and conservation work on Instagram and you can learn about his research on alpine pests on YouTube. 

The match-ups …

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We've probably all experienced a little bit of tinnitus, or ringing in the ears, at some stage in our lives. But for some people this phantom sound in their brain can be loud, and permanent, and completely debilitating. Claire Concannon speaks to a group of scientists at the University of Auckland who've been researching ways to help for years, and have developed a digital therapy with promising trial results.

Imagine the whistle of a kettle boiling, turned up to full blast, permanently on.

In your head.

How would it affect your mood? Your attention and focus?

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"It's difficult to describe but it just has such an impact on every facet of your life. You know, your sleeping habits, your mental health, your relationships with other people."

Emily Lane was born with a hearing disability and has had tinnitus on and off all her life. But in 2006 it turned up permanently, and it was loud. "It's like a chorus of cicadas living permanently on full blast inside my head."

Many of us will experience a form of tinnitus at some stage in our lives, what Professor Grant Searchfield terms 'nightclub tinnitus'. After a loud night out, we might wake in the morning with a ringing or buzzing in our ears, but it's likely to fade after a few hours.

Head of Audiology at the University of Auckland, Grant became interested in tinnitus when, as a practising audiologist, he didn't have any answers for patients who came to him for help.

Since then, he has been investigating how to help chronic tinnitus sufferers - people who have experienced this phantom sound for more than six months, and whose lives are significantly impacted by it. And one thing has become very clear - this is a condition that varies widely from person to person, therefore the treatment must also vary. 

And it's not just the sound that varies, but also the person's response to the sound, and to treatment. This idea underpins the design of the digital therapeutic the team have developed to help tinnitus sufferers. Users get an app on their phone that allows them to select what they need - whether it's nature soundscapes to help the person relax, complex sounds to help them get relief from their tinnitus, or active sound-based games to help retrain the brain.

The team ran a trial using a prototype of this digital therapy and found that, after twelve weeks of use, 65% of patients showed a clinically meaningful change in how badly their tinnitus impacted their lives. This was compared to 43% in the other group, which was given a popular sound therapy app…

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Dr Kate Thomas has exercise on the brain. As an exercise physiologist, she researches how exercise and fasting can change the energy sources our brain uses. And as an ultramarathon runner, she chases that runner's high on gruelling mountain races.

Dr Kate Thomas is a self-described "exercise evangelist". An exercise physiologist, she spends her time researching the impacts exercise has on the body. 

But she also practises what she preaches.

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Based at the University of Otago, Kate is investigating what energy sources the brain uses when you put the body under stress due to exercise and/or fasting. While glucose is the preferred energy source for the brain, it can switch things up if glucose is depleted, and this opens different metabolic pathways and products. 

"As we age our brain's ability to use glucose declines and that's even more the case in neurodegenerative diseases like Alzheimer's," Kate explains.

"What is important is that the brain can actually use other fuels. And some of these for example are ketone bodies produced during fasting and lactate produced during high intensity exercise.

"One of the theories and what we're trying to explore in this study is whether if we provide the brain with alternative substrates, how it chooses to use those and what that does for the brain's environment. We think that by switching the brain away from using glucose as its main fuel to one of those other substrates, ketone bodies or lactate, that that triggers a bunch of pathways in the brain that help promote neuroplasticity, cognitive function and general resilience to stress."

In particular, Kate is trying to figure out what combination of fasting and exercise might trigger release of a protein called BDNF - brain-derived neurotrophic factor. BDNF plays a role in preserving existing nerve cells and encouraging the growth of new ones. Our levels of BDNF decrease naturally as we age, and in some chronic neurological conditions such as Parkinson's disease. 

Dr Kate Thomas monitors data during an exercise experiment.

Study participants are asked to do a series of four trials - the hardest of which involves a three-hour cycle and a three day fast - while Kate monitors effort, blood glucose, products of metabolism and cognitive ability. In this mechanistic study, Kate is "pulling the levers" as she terms it, to figure out which conditions promote greater production of BDNF.  …

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How can swaying buildings help diagnose breast cancer? Katy Gosset meets a team of engineers taking inspiration from earthquake engineering to design a new, cost-effective device to help detect breast cancer. Listen to find out how the device works, and how it could help more women get tested sooner.

Every year, more than 3,000 people are diagnosed with breast cancer, according to the Cancer Society.

Eligible women aged between 45 and 69 can get free mammograms, but younger women must decide whether to fund the test themselves.

Researchers might have found a cost-effective way to screen for breast cancer earlier than we do now. Their inspiration? Earthquake engineering.

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"When you're looking at the motion of buildings, you can identify the underlying ground tissue properties," says Dr Jessica Fitzjohn from the University of Canterbury. "By looking at those vibrations, you can know what the soil properties are underneath."

So, why not apply that same concept to breast tissue?

The team have developed a low-cost tool that applies a small vibration and analyses the resulting surface motion. Cancerous tissue is around 4-10 times stiffer than healthy tissue. 

The hope is that this device will give more New Zealand women early access to breast screening.

Senior producer Katy Gosset pays a visit to the research team to find out more.

To learn more:

Listen to other episodes from the Our Changing World catalogue on treating and detecting cancer, including this 2022 episode on new cancer immunotherapies and this 2021 episode on medical detection dogs trained to sniff out cancer.

Katy Gosset previously spoke to Professor Geoff Chase about his work with student engineer Francis Pooke on designing a new device that helps tracheostomy efficiency. 

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This year marks the 75th anniversary of the rediscovery of the takahē. Claire Concannon sits down with former Our Changing World presenter and takahē superfan Alison Ballance to chat about her new book, Takahē: Bird of Dreams. Plus, we replay Alison's 2018 episode marking the 70th anniversary of the momentous rediscovery, and discuss what's happened in takahē conservation since.

On 20 November 1948, Dr Geoffrey Orbell and three friends headed into a hidden valley in Fiordland's Murchison Mountains with a dream in mind: to find the thought-to-be-extinct takahē.  

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When he and the group returned victorious, it made headlines around the world. 

November 2023 will mark the 75th anniversary of this rediscovery. So, what's happened in the time since? 

Someone who has been following the fortunes of the takahē closely is former Our Changing World producer and presenter, natural history book author, and lover of birds, Alison Ballance. 

In November 2018 she joined the celebrations of the 70th anniversary, which involved the release of two takahē into Takahē Valley, the place where they were rediscovered, with family members of the original party who found them. 

Alison has just released her latest book: Takahē - Bird of Dreams. 

She sits down with Claire Concannon to talk about writing the book, her experiences of seeing takahē in the wild, and how the takahē have fared in the five years since the last celebration. 

Listen to hear the recent interview with Alison Ballance, and a replay of the 2018 episode she produced.

To learn more: 

Alison also spoke to Kim Hill about the rediscovery and recovery of the takahē. 

Turnaround in takahē's fortunes covers the inital release of takahē into Kahurangi National Park in 2018.

Looking for more bird conservation stories? Listen to the Voice of the Kākāpō series - produced by Alison Ballance, all about the rollercoaster ride of the 2019 kākāpō breeding season. 

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