♪♪ BUCHANAN: As a cameraman, I've filmed wildlife all over the planet, but there are limits to where I can go.
She's returning to the place that I can't follow her.
So in this series, it's the animals that are doing the filming, to reveal the secret side of their lives we've never seen before.
-Oh, that's so cool.
-That is lovely.
BUCHANAN: Over the years, we've designed pioneering mini cameras for a huge range of animals.
It's like a job interview.
Everything is made to measure.
Just figuring out what her new bit of bling is.
And we've teamed up with scientists who want to see the world from an animal's perspective to learn about the challenges they face and help protect them in the future.
JOHNSON: She is potentially showing us parts of the ocean that no one has seen before.
♪♪ BUCHANAN: In this special episode... we head to Australia.
Are koalas' evening activities at odds with their dozy-daytime reputation?
Can kangaroos survive on the edge of urban expansion?
And what has drawn 20,000 bats to life in a new city?
♪♪ This is "Animals with Cameras."
♪♪ ♪♪ BUCHANAN: On Australia's east coast... ♪♪ ...high in the towering trees of Queensland, is one of the country's most iconic species... best known for their love of eucalyptus leaves and dozing through the heat of the day... ♪♪ ...the koala... with specialized claws for gripping tree trunks up to 100 feet up... ♪♪ ...and an excellent sense of smell for seeking out the freshest gum leaves.
These marsupials are superbly adapted to their environment.
With speckled bottoms to help with camouflage... these specially toughened rumps enable koalas to wedge themselves comfortably in tree forks, where they can sleep for up to 20 hours a day.
Their tree-hugging posture is more than an affectionate arboreal embrace, too.
Tree trunks can be as much as 10 degrees cooler than the surrounding air temperature -- which, in this region, can reach over 100 degrees Fahrenheit in the height of summer.
♪♪ Tree-hugging is a means to keep cool, as well as look effortlessly chilled.
This one may look blissfully happy nestled in her tree, but Koalas are in trouble.
♪♪ The open forest and bushland they call home is rapidly disappearing... ♪♪ ...lost to agriculture, urban development, and ever-increasing bush fires.
♪♪ There are now fewer than 35,000 left in this corner of Queensland.
And each year, over 2,000 homeless koalas are taken into care.
♪♪ While much is known about koalas' daytime habits... what they do at night is still a mystery.
This information, however, could be crucial to help conserve their population in the future.
♪♪ This is Hidden Vale, a 12,500-acre private property where the land and koala population are protected.
♪♪ It could be a candidate location to release koalas who have lost their homes... ♪♪ ...but first, it's vital to know how much space the ones that already live here need to avoid overcrowding.
♪♪ Andrew Tribe and Karmen Butler have been tracking the resident population here for the past 2 1/2 years.
♪♪ TRIBE: We have we estimate about 60 koalas, but at the moment, we are tracking about 20 of those.
All our koalas of course are named, and we've found that they each have their own personality.
BUCHANAN: Miriam, Dave, and Karen are just a few of the characters that call Hidden Vale home.
Using lightweight GPS collars and VHF ear tags, Andrew is able to monitor their movements.
TRIBE: Every 12 hours, we get a reading of where each koala is, which means we know where it's been, how far it's traveled.
We also physically go out and track them.
We've been able to establish how big their home ranges are, where they like to go, with whom they like to interact, although we still don't know about their behavior at night.
BUCHANAN: So what do they get up to in the dark?
Although Andrew's GPS collars track the koalas' movements, he can't see what the animals are actually doing.
To find out, he needs on-board cameras.
TRIBE: We know they sit in trees, and we know they eat leaves and that sort of thing, but what I'd like to find out is a bit more detail about that.
How much time do they spend eating?
How far do they move?
How far do they move in the one tree?
BUCHANAN: Footage of this behavior could really help Andrew's ongoing tracking studies and, crucially, identify whether any rescued koalas could be introduced here.
For the koala camera build, it's time to call on designer Chris Watts.
♪♪ An expert in bespoke camera technology, Chris has made cameras for animals of every shape and size.
WATTS: The koalas currently wear a collar like this, with a GPS unit on the top, and it has a counter weight underneath, which keeps the aerial pointing upwards, which is really good for signal.
We're going to take this weight away, and that is where we are going to put our camera.
And it's kind of fixed on a hinge, which means that when the koala is upright, it can hang against the body, and that's really good because you don't want a camera sticking out because they hug the trees.
BUCHANAN: With the cameras built and ready to deploy, it's time to recruit a koala camera unit.
♪♪ The koalas at Hidden Vale are captured regularly for health checks.
♪♪ On the catch list this week are koalas Robyn, Tom, and Hunter.
♪♪ Andrew's team use a technique called flagging to encourage the koalas down from the gumtree and capture them with a minimum of stress.
♪♪ TRIBE: Get ready, mate, get ready.
♪♪ Stay still, stay still.
♪♪ Okay, well-done.
♪♪ BUCHANAN: Safely in their crates, the koalas make the short trip back to the vet center for a health assessment and to be fitted with the cameras.
♪♪ Hunter is first.
He's lightly anaesthetized and checked over by the veterinary team.
WOMAN: Zero two... MAN: Still growing.
♪♪ KIRSTEN: He is approximately 3 1/2 years old.
And he is in really nice body condition.
♪♪ BUCHANAN: All checked over, Chris gets to work attaching the camera to Hunter's collar.
♪♪ WATTS: The camera looks like it's fitting really nicely.
And the thing that I wasn't able to test until now is to see how that hinge is working and see how it sits against the chest, and it looks like it is spot on, so that's really good.
[ Monitor beeping ] BUCHANAN: After a few hours' recovery, Hunter is ready to be released back into the tree where he was found.
♪♪ BUTLER: He's ready already.
WATTS: He's definitely seen it, hasn't he?
BUTLER: And if we just stay really still and really quiet... ♪♪ WATTS: That was a pretty calm release.
BUTLER: Yeah, he's a pretty good boy, pretty calm.
BUCHANAN: But although reunited with his tree, Hunter soon decides he'd prefer a different one... ♪♪ ...an interesting insight into how fast koalas can move, if they want to.
WATTS: So, although we released Hunter from the tree in which he was found, he came down and ran across and found this tree just over here.
♪♪ BUCHANAN: And as Hunter settles into his new tree unhindered by his camera, Robyn and Tom are also returned to the treetops.
♪♪ TRIBE: So now the big test will be what shots do we get?
BUCHANAN: And what do these shots tell us about their night-time movements?
♪♪ After a night of recording, at first light, Chris, Andrew, and Karmen are keen to retrieve the cameras.
Armed with the koalas' GPS coordinates, it's not long before they track down Tom.
TRIBE: Well, he's in a good position, not too high.
BUCHANAN: With everyone poised for a catch, it's time for the release... ♪♪ WATTS: Three, two, one.
BUCHANAN: ...and the camera drops.
[ Laughter ] WATTS: Well, it's worked!
TRIBE: He's now moved higher, so that's alright, but he's otherwise undisturbed.
WATTS: Okay, that's great.
BUCHANAN: Next on the retrieval list is Hunter, who is snoozing through the heat of the day in an ironbark tree.
WATTS: So I'm really excited about this one.
Hunter is the big male, isn't he?
TRIBE: He is, yes.
WATTS: And he is quite high, so I'm thinking maybe we use the tarp on this one.
Don't want it to land on our heads.
BUCHANAN: Oblivious to the plans being made below, Hunter remains fast asleep... firmly hugging his camera to the tree trunk.
Tarp at the ready, Andrew releases Hunter's camera...
BUCHANAN: ...but nothing happens.
WATTS: Does it say released?
TRIBE: It said sending, released.
BUCHANAN: Hunter, it seems, is asleep on the job.
[ Laughter ] TRIBE: I think, Hunter, we need you to move.
BUCHANAN: Eventually, Hunter obliges... WATTS: Oh, he's moving.
TRIBE: Here we go!
BUCHANAN: ...and this time, the team have more luck with the catch.
-WATTS: Good reaction.
-BUTLER: Better than last time.
WATTS: Yeah, amazing.
BUCHANAN: While Hunter looks on bemused, the team head off to find Robyn and the final camera.
♪♪ With everyone at a safe distance, Chris releases the camera.
WATTS: Three, two, one, releasing.
♪♪ Oh, there we go.
TRIBE: Missed the tarpaulin by that much.
BUCHANAN: With all the cameras back and mostly in one piece, time to see what they reveal.
♪♪ At dusk, the team reconvene to have a look.
♪♪ For Karmen and Andrew, it's a tantalizing glimpse inside a koala's world.
And it's a raucous start from Hunter.
[ Hunter bellowing ] BUTLER: Ah, wow, that is cool.
BUCHANAN: He is what's known as bellowing.
And this the first time a koala bellow has been recorded at this proximity.
[ Bellowing ] Dominant males call out like this to advertise themselves to nearby females and alert other males to stay away.
Territorial call complete, it's time for dinner.
♪♪ By the looks of the thin branches, Hunter is precariously high in the treetops, reaching out for the newest, lushest growth.
TRIBE: It's interesting here with this footage to see how their fingers, their claws, their digits actually work as they are climbing.
BUCHANAN: Koalas have two opposable thumbs on each front paw to help clasp tree trunks and grip branches.
TRIBE: They've got a very strong grip.
You haven't been gripped by a koala yet, have you?
-TRIBE: [ Laughs ] It's strong.
BUCHANAN: Koalas almost exclusively feed on low-nutrient eucalyptus leaves.
And they can nibble through almost a pound in one evening.
These leaves are poisonous to most animals, but koalas have evolved to digest the toxins.
♪♪ The camera records Hunter eating for three hours straight.
Tom, on the other hand, is on the move.
WATTS: It's so easy to forget when you are watching this night-time footage that that's not what they are seeing.
They are in total darkness.
BUCHANAN: A koala's eyesight is their weakest sense, so while on the ground, Tom regularly makes stops to check his surroundings.
TRIBE: But he's obviously sort of orientating himself.
He's obviously deliberately stopping.
BUCHANAN: Tom is using his highly developed sense of smell to navigate and assess his surroundings for danger.
And he presses on, covering almost 600 yards of ground in 30 minutes.
For an arboreal species, this is a midnight marsupial marathon.
So what about Robyn?
TRIBE: It is interesting, seeing what she is seeing, and seeing how she is moving and how she is behaving.
BUCHANAN: Her footage begins with a dedicated hunt for a new tree.
TRIBE: You wonder if she has got a destination in mind?
BUCHANAN: Female koala home ranges are usually smaller than the males.
The amount of time Robyn is spending on the ground is unexpected...and dangerous.
TRIBE: I thought she might have got up a tree much quicker.
If there is any predators around, particularly dogs, they can pick up her scent and chase her down.
♪♪ BUCHANAN: After stopping at eight different trees along the way, Robyn finally finds one she likes.
WATTS: Wow -- made a very quick jump at that tree, yeah.
TRIBE: It's almost like, "I've made up my mind.
I'm going for it."
Perhaps it's got a good eucalypt smell that maybe means it's some good food up there.
BUTLER: A lot of trees have different tannin levels, so she's sniffing those trees and deciding, "Do I want to go up there and eat?"
BUCHANAN: Koalas choose trees for specific reasons.
Some are chosen as dedicated food trees and others are selected for the shelter they offer.
♪♪ Within minutes, Robyn is in the very top of the tree she has been searching for... ♪♪ ...and as dawn breaks, she settles in for a snooze.
♪♪ WATTS: That's a great shot.
♪♪ BUTLER: She's sitting up with both paws this way.
TRIBE: Looks like that.
WATTS: Yeah, yeah, a bit of an embrace.
She's holding her paws in her lap.
TRIBE: Dozes off.
WATTS: Oh, wow, the sun has really come up now.
TRIBE: It has, hasn't it?
BUCHANAN: The koalas have revealed themselves to be anything but dozy at night... ♪♪ ...a stark contrast to the lazy layabouts they appear to be during the day.
While it was known that koalas climb down each night to pick a different tree... from observing Tom, Robyn, and Hunter, it's clear that koalas scale many trees over the course of an evening... and are incredibly picky.
They spend more time on the ground than anyone expected.
It suggests that koalas need sizable reserves and many different types of trees to safeguard their future.
♪♪ Combined with Hidden Vale's tracking data, the camera footage is key for reserve managers like Andrew...
TRIBE: This sort of information I think is vital if we're going to manage koalas and koala populations better.
In South East Queensland, more than 2,000 koalas get brought into care every year, often because of habitat clearing.
Many of those koalas can be rehabilitated and released back into the wild.
But if they are going to survive, if they are going to contribute to the wild population, we have to find suitable habitat in which to release them.
BUCHANAN: While the camera findings help Andrew better understand the needs of the population at Hidden Vale, they can also help identify other suitable habitats in Australia and ensure relocated koalas get exactly what they need to survive.
♪♪ It's a quick hop to our next story, an altogether very different marsupial... the kangaroo... renowned for the spring in their step... able to leap up to nine yards in a single stride.
They can cover ground as fast as a racehorse.
Of the four different species of kangaroo, the most numerous is the eastern grey.
I've come to find them here, in Coffs Harbour, 300 miles north of Sydney.
This picturesque coastline is a growing metropolis and a popular holiday destination.
It's also home to one of the most dense populations of eastern grey kangaroos in Australia.
These veracious herbivores have a huge appetite for grass, grazing as much as 10 hours a day.
But the kangaroos here have taken to hanging out with the surfers on the beach.
The question is, why?
Just trying to get a sense of this place and a sense of the kangaroos that live here.
And this seems like a really unlikely place for kangaroos to come.
And the big question I have is what are they -- what are they doing here?
And if I can't answer that question, I'm hoping that our cameras can.
Despite their numbers, local highway expansion and new housing developments means this mob is under threat.
And this is a key factor -- the Pacific Motorway.
At 490 miles long, this coastal road connects Sydney in the south to the Gold Coast in the north.
♪♪ But it's confined the roos of Coffs Harbour to a narrow strip of land between road and sea.
If four lanes of traffic aren't enough, the fences either side make it impossible to cross.
So the kangaroos are trapped here, with less and less food to go around.
♪♪ Kangaroos don't come in all shapes, but they do come in all sizes.
You've got the big males.
They're called boomers.
At the opposite end of the scale the little ditty ones, they're called joeys, and the females are called flyers.
Because of the urban development, because of the highway, it has changed the dynamics of this population.
To my untrained eye, these animals are not in peak condition.
You see that they are on the skinny side.
♪♪ With limited space and food on offer between the motorway and ocean, the roos have already been pushed onto the headland and even the dunes, as they desperately attempt to find food.
But are they going one step further and feeding on the beach itself?
And can the cameras prove it?
Dr. Cathy Herbert, from the University of Sydney has been studying the population here for the past five years.
DR. HERBERT: We've just noticed, literally within the last year, that we are seeing more and more animals on the beach.
They're actually foraging on some of the vegetation on the sand dunes, but we are also seeing some interesting signs in terms of their tracks on the beaches.
It's possible that maybe they're foraging on some sort of food source.
Which would be a really interesting and unique observation for this particular species.
The eastern grey kangaroo tends to be most active early in the morning and at dusk when we can't see them, so by getting video footage, particularly overnight and really early in the morning, we might be able to unravel this mystery and figure out what they're doing.
BUCHANAN: Kangaroos are crepuscular -- feeding at dawn and dusk.
So if they are going down to the waterline in the early hours, the tracks are gone by daybreak.
And these kangaroos coming down on to the beach, they're motivated by something, and that is the mystery, that is the question.
DR. HERBERT: We can see them hopping down.
We see them slowing down, and then the tides wash the tracks away.
Nobody's really done a thorough investigation of what they are doing and how they are utilizing that beach environment.
♪♪ BUCHANAN: The shoreline is certainly not an ideal habitat for these ravenous roos.
So what could they be feeding on by the water's edge?
It's something I hope the cameras can reveal... but how do you create a camera that can withstand being bounced around?
It's another unique challenge for Chris.
Hey, Chris, alright, let's talk kangaroos and cameras.
WATTS: We've tried to use neoprene, which is kind of a stretchy material, so it will move with the animal.
And we have got a release mechanism, which is controllable by us.
It's a small nylon cord that basically gets cut when we trigger it, and then that will drop the whole thing away.
But as a backup if this failed, we've got a failsafe, which is kind of a weak point in the collar, just made with a natural cotton.
So we've got to make it strong enough but also weak enough that if they didn't like it or want to get it off that it would easily come away.
♪♪ BUCHANAN: With the cameras ready, we now need kangaroos.
♪♪ To get close enough to conduct her research, Cathy uses a tranquilizer gun.
♪♪ Sedated and safe, the roo is transferred so Cathy can assess its health.
♪♪ And we discover this female has a surprise in store.
DR. HERBERT: She's got a little one in the pouch.
BUCHANAN: Oh, does she?
Oh, my word, look at that.
That is extraordinary.
That just defies belief.
DR. HERBERT: Yeah, so this one...is probably about 10 weeks old, and we should be able to tell what sex it is.
BUCHANAN: Gosh, so delicate.
DR. HERBERT: It's a female.
We can just see a little pouch.
BUCHANAN: It's just extraordinary.
The anesthetic that Cathy uses won't pass into the mother's milk, so this little joey is completely unaffected by the procedure.
Yeah, that's the most amazing thing of the year, I think.
As Cathy takes the rest of her measurements, Chris carefully attaches the camera.
And she's left under a tree to wake up... ♪♪ ...but this roo is giving us the run-around.
When we go back to check on her, all we find is a camera on the ground.
It seems the quick-release collar is proving a little too easy to get out of.
Its failsafe -- just a few strands of cotton -- is still too fragile.
WATTS: It's a fine balance.
BUCHANAN: You were going to say fine line, which is exactly what this is.
Maybe we need a less fine line.
WATTS: Yeah, I think we can up it a bit more, and what I'll do is we'll go back and I'll thicken it up and just have a few practices at breaking it and just get a feel for how much force.
BUCHANAN: Chris is going to redesign the collar overnight, but will it be enough to get the kangaroo shoot underway?
♪♪ From a species grappling with urban sprawl to one which has chosen to live right in the middle of it.
♪♪ For the next camera candidate, we're heading straight into the heart of the city... Adelaide, South Australia.
In 2010, a small group of pioneers embarked on an epic journey to set up camp here.
50 or so new arrivals have now grown to more than 22,000.
Meet the grey-headed flying foxes.
Usually found along the east coast, these intrepid travelers have flown over 600 miles to settle in South Australia.
Never before seen here, their sudden appearance was a complete mystery.
♪♪ Despite their foxlike faces, these are no canines.
They are, in fact, one of Australia's largest species of bat.
Weighing up to two pounds, these magnificent flying mammals have a wingspan of over three feet... and unlike the smaller microbats, these giants don't echolocate or feed on insects.
Instead, they eat flowers and fruit, giving them their other name -- fruit bats.
But can they find the right foods in their new city home?
What has drawn them all the way to Adelaide?
Although entirely harmless to humans, they are often unpopular for their large, noisy camps and appetite for food crops.
To most, the sudden arrival of flying foxes in Adelaide was puzzling.
But for wildlife vet Wayne Boardman and bat specialist Terry Reardon, their arrival was the perfect opportunity to study the species in more-depth.
BOARDMAN: What I love about them is that they are very smart, very intelligent.
They've got this incredible physiology.
They have developed great senses of smell, good eyesight, great hearing, and they've got this ability to move across the landscape.
BUCHANAN: Wayne and his team at the University of Adelaide have tracked the flying foxes' nocturnal movements using GPS collars and discovered that they travel up to 50 miles a night when they fly off to forage.
BOARDMAN: It would be really nice to find out what they do when they go out traveling.
Do they feed?
What do they feed on?
BUCHANAN: Could food preference could be a key reason behind the flying foxes' arrival in the city?
BOARDMAN: Flying foxes primarily eat gum flowers and the nectar from gum flowers, and also fruit.
BUCHANAN: These mega bats can eat important agricultural crops, which is why many people consider them to be a pest.
♪♪ Their hunger for fruit is a particular worry for local farmers.
♪♪ The Adelaide region is home to numerous sugar-rich crops.
♪♪ Safe to say, Adelaide's new arrivals were not a welcome sight for local fruit producers.
♪♪ BOARDMAN: When we have a species that's quite contentious, in terms of causing problems with commercial fruit, we want to try and find out exactly what they're eating.
If we know that they are eating a lot of commercial fruit, what can we put in place to stop them?
If they are not eating commercial fruit, then we can be happy that they are part of the landscape and we should enjoy them.
BUCHANAN: And these much-persecuted animals really should be celebrated.
An individual flying fox will not only pollinate many plants, but disperse up to 60,000 seeds across the landscape every night.
♪♪ From a scientific point of view, flying foxes are extremely valuable for the environment... ♪♪ ...which is why Wayne is studying the ongoing health of the population here.
♪♪ But, the only way to really understand their world is to get amongst it.
Something that is tricky enough during the day, but practically impossible at night.
To answer Wayne's question of where they go and what they feed on, a wearable nighttime camera is called for.
♪♪ Yet another task for Chris.
And safe to say, this build has given him the most sleepless nights.
WATTS: So putting a camera on a bat has got to be the most challenging thing I've been asked to do yet.
♪♪ Although they are one of the biggest bat species, around 800 grams, that only gave me a weight limit of 35 grams, and that is equivalent to maybe two packets of chewing gum.
BUCHANAN: And, for that tiny payload, Chris has built a camera complete with infrared lights, a programmable onboard computer, and a VHF tracker.
WATTS: Another design consideration with this camera has been the placement.
So, we've decided to put it on the back and that's, hopefully, going to mean it's not in the way when the bats are flying and they also spend a lot of time hanging upside-down, so, if it's on the back, it's out of the way.
If it was a collar camera, it's kind of right under their chin.
It's going to be really annoying.
So much of this is the animals being as comfortable wearing these cameras as possible because that gives us the best chance of them staying on.
[ Creature calling ] BUCHANAN: As night falls, the flying foxes depart for their evening adventures.
♪♪ Just a few hours later, Chris and the team arrive at the Botanic Park to prepare for the flying foxes' return.
♪♪ It's a 3:00 am start for scientists Wayne, Terry, and a team of expert bat catchers.
BOARDMAN: So, if you want to come and have a look at the ropes, Chris.
BUCHANAN: Wayne surveys the health of the flying fox population here twice a year.
A process that involves capturing them, weighing them, and taking samples, which also gives us the perfect opportunity to attach the cameras.
The flying foxes will be caught in a fine net suspended between two trees.
BOARDMAN: So, everyone knows what they're doing?
♪♪ WATTS: So, this is our first morning that we might actually catch a bat.
It's very exciting to see this all work.
It's quite an operation, getting this net up in the tree.
So, yeah, now, we wait.
BUCHANAN: And it's not long before one hits the net.
♪♪ [ Voices overlap ] Go!
BUCHANAN: Each flying fox caught is weighed as part of its checkup and, if one tips the scales at 1.5 pounds or more, it's also big enough to carry one of the cameras.
BUCHANAN: While the survey continues, already-captured bats are hung in a bag, for the short wait before going to the vet facility.
For animals that naturally hang upside-down, this has a calming effect.
REARDON: Yep, that's it.
♪♪ BUCHANAN: By 5:30 am, six flying foxes have been caught for Wayne's checks and, hopefully, the cameras.
♪♪ Back at the clinic, it's time to meet the first flying fox camera cadet.
BOARDMAN: So I'm just going to get the mask.
BUCHANAN: The process begins with a light anesthesia.
Safely asleep, Wayne conducts his research.
As well as weight, he takes a blood sample, checks for body condition, and collects some key measurements.
WATTS: So, it's amazing to see these animals up close.
They're actually bigger than I was expecting.
They've got these really sharp teeth, which I'm a little bit worried about, because, obviously, these cameras are so light, they're not very well-protected.
BUCHANAN: Gloves on, it's time for the camera.
And...it's a great fit.
BOARDMAN: I'm quite happy with that.
WATTS: Sitting between the shoulder blades nicely.
BOARDMAN: So we can wake it up?
WATTS: Yes, yeah, good.
♪♪ BUCHANAN: After Wayne fits the rest of the cameras and the anesthetic has worn off, the flying foxes are ready to be returned to the camp.
♪♪ Wayne gently places the first crewmember on the tree.
And it seems completely unfazed by its new high-tech backpack.
But, in a camp of 22,000, it's not long before it disappears from view.
WATTS: I mean, this is part of the argument for putting a camera on a bat, isn't it?
Is how quickly we've lost sight.
WATTS: Our camera is now capturing it all for us.
BUCHANAN: Thankfully, our long-lens camera finds it high in the treetops.
As this is the first deployment, Chris wants to keep the flying fox in sight to make sure it's okay.
WATTS: The bat's actually just taken off.
That's the first time we've ever had actual flying footage from a bat.
[ Laughs ] ♪♪ BUCHANAN: Over the next hour, four more are released back into the camp, each of these carrying a camera, to reveal their all-important nocturnal feeding habits.
♪♪ ♪♪ The setting sun is the cue for the flying foxes to depart and find food.
♪♪ Among the thousands that fill the sky are an aerial film unit of five.
And, as they disappear into the night, it's over to them, to film for us.
But will the cameras survive and will the flying foxes bring their precious footage back tomorrow morning?
♪♪ Overnight, the filming flying foxes have been out on their errands and are now back in the camp.
Chris is really hoping they've brought their cameras home with them.
WATTS: We're just driving back to the location this morning, hoping to find the cameras that have been out overnight.
They're going to have been out over 24 hours, so, it's going to be really interesting to see how it survived the night and, you know, is the release going to work?
♪♪ BUCHANAN: By plugging in the VHF frequency of the camera's transmitter, Chris and Terry manage to locate the first flying fox.
♪♪ Remarkably, within the minuscule one-once cameras, Chris has built in a remote-control dropoff mechanism.
♪♪ But, as Chris hits release, the flying fox takes flight... ♪♪ WATTS: Okay, triggering now.
BUCHANAN: ...taking our footage with it.
♪♪ WATTS: Don't fly away!
Look at that!
[ Applause ] Wow.
Couldn't be happier than that.
Just as planned.
BUCHANAN: And, with the rest of the cameras retrieved just as smoothly, it's time to see what the mega bats' mini cameras have captured.
♪♪ [ Squeaking nearby ] [ Wings flapping ] ♪♪ [ Brush rustling ] REARDON: Oh, gosh.
A lot of people studying flying foxes are going to be really fascinated to see this, I think.
BUCHANAN: Time for the all-important reveal of what this flying fox is going to feed on.
♪♪ BOARDMAN: Looks like gum of some description there.
REARDON: It'll be easy to get that identified, I think.
BOARDMAN: Yeah, I think so.
BUCHANAN: It's a South Australian blue gum, a different variety to their usual East Coast food.
This eucalyptus is an Adelaide native.
♪♪ It's an encouraging sign that the flying foxes aren't targeting crops and have, instead, adapted to a local species.
♪♪ BOARDMAN: This close proximity to feeding, we've never seen this sort of thing before.
But it's reassuring to know that this flying fox hasn't gone into any commercial fruit.
BUCHANAN: And we quickly learn that flying foxes don't spend time in one place for very long.
[ Wings flapping ] BOARDMAN: [ Laughs delightedly ] That sound is incredible, isn't it?
[ Wings continue flapping ] BUCHANAN: After a short flight, a new tree is selected and the flying fox announces its arrival.
[ Screeching ] BOARDMAN: So this is really interesting.
It looks like they're going from -- Just in a few minutes, they've gone for three or four different feeding sites, which is nothing that we've ever seen before.
We just think they're going to one area and probably stay in a tree for a period of time, but it looks like they're flying around every minute or two to find some food.
♪♪ BUCHANAN: And it's off again.
And, this time, we're in a different tree species.
It is technically a fruit tree -- a Port Jackson fig -- but this is not a food crop.
♪♪ It's an ornamental tree, commonly found in gardens and civic centers.
♪♪ A short flight later, it's back in a native blue gum.
REARDON: This is a surprising thing... BOARDMAN: Yeah.
REARDON: ....I think, just, you know, how quickly they're moving and eating, blossom to blossom.
BOARDMAN: But they clearly are eating it really quickly and moving on.
BUCHANAN: And, even though they can fly tens of miles a night, this flying fox has chosen to stay close to the city and his back-mounted camera provides a great aerial perspective.
REARDON: [ Laughs ] BOARDMAN: So he's going over the road.
REARDON: This is extraordinary.
[ Laughs ] ♪♪ BOARDMAN: So that's a car park, I'm sure... REARDON: Yeah.
BOARDMAN: ...like you said, but it'll be really interesting to know where it is.
♪♪ BUCHANAN: With ornamental trees to feed on in the heart of the city, this flying fox doesn't need to go far.
♪♪ By first light, the filming flying foxes are back in the roost, hanging alongside their neighbors.
[ Cacophony of squeaking ] So what do Wayne and Terry make of their first foray into the flying foxes' nighttime world?
REARDON: I don't know whether I really had any full idea of what we might actually see.
BOARDMAN: You know, this is incredible.
We're seeing flying foxes flying around and seeing what they're doing like we've never seen it before.
♪♪ BUCHANAN: Importantly, the cameras have revealed that these flying foxes, at least, aren't targeting commercial fruit.
♪♪ It suggests that grey-headed flying foxes have simply relocated to Adelaide, not because of its outlying crops, but because of the many other food resources on offer in the city.
♪♪ The footage has also revealed unexpected insights for Wayne and Terry.
BOARDMAN: It's certainly given us a great deal to work with.
REARDON: You watch these animals from the ground and you try and imagine what it's like and you see them feeding in trees, but, yeah, I wouldn't have imagined you would ever see that, you know, from a bat's point of view.
It's just remarkable technology.
♪♪ BUCHANAN: These cameras have not only changed our understanding of Adelaide's population, but of grey-headed flying foxes, as a species.
[ Screeching ] ♪♪ Back at Coffs Harbour, on the East Coast, this population of kangaroos is feeling the urban squeeze.
Trapped between a motorway and the ocean, they are struggling to find food.
♪♪ Dr. Cathy Herbert hopes that onboard cameras will reveal if these isolated roos are foraging on the beach to survive.
However, so far, we've not got a camera on.
The camera collars, made with a quick release to come off if the animal gets snagged, are falling off too easily.
It has to be strong enough and weak enough.
It's just finding that sweet spot... WATTS: That's right, yeah.
BUCHANAN: ...so it doesn't just drop off.
WATTS: Well, at the moment we're using three strands of cotton, so I think, if we up that, to maybe eight or nine pieces, that'll, hopefully, just give us the edge we need.
♪♪ BUCHANAN: Camera modifications made, we head out to, hopefully, find a kangaroo for our crew.
♪♪ Are you happy with everything?
HERBERT: Yeah, so that's all our samples.
WATTS: Yeah, camera's good to go.
HERBERT: Yeah, so we'll put her in a shady spot to recover.
♪♪ BUCHANAN: Time to put Chris' handiwork to the test.
♪♪ Good luck.
♪♪ HERBERT: Okay, she's hopped off.
She's hopped off.
She's got the camera.
She's looking good.
♪♪ BUCHANAN: It's a huge relief and, knowing that the collars work, we deploy another five cameras.
♪♪ WATTS: That's the tracker on the VHF working, so.
BUCHANAN: It's now up to the kangaroos to capture the challenges they face.
♪♪ The next morning, the search is on for the camera roos.
Chris leads the way, listening for the cameras' VHF beep, and, before long, we find one of our crew.
She's just there.
WATTS: Just the other side.
Just through there.
HERBERT: Oh, yes.
BUCHANAN: She knows that we're here, but she doesn't know that we're here to relieve her of her camera.
To get the camera off, Chris triggers the release.
WATTS: Okay, here we go.
[ Beep ] BUCHANAN: And, as she hops away, [ Beeping ] it comes loose.
There we go.
Here it is.
♪♪ BUCHANAN: With the first camera back, we successfully retrieve the others.
[ Beeping ] ♪♪ WATTS: So -- BUCHANAN: ♪ Ahhhhh ♪ [ Laughter ] BUCHANAN: With any luck, they will show us what these resourceful roos are surviving on here.
♪♪ Time to take a look.
♪♪ Here we go.
This is the big moment, the culmination of everyone's efforts, just over to the roos.
[ Wind whipping ] Set to record at first light, when the roos are most active, this individual is already on the move.
It's a really intimate view.
And, as dawn breaks, we can see her joey is with her, too.
HERBERT: Aww, so sweet.
BUCHANAN: Oh, that's great.
WATTS: Returning the favor.
[ Chuckle ] HERBERT: Oh, the little one licking the mother.
WATTS: Oh, look at that.
HERBERT: [ Laughs ] BUCHANAN: Are you allowed to say cute, as a scientist?
HERBERT: You are.
That is gorgeous.
♪♪ BUCHANAN: Joeys are weaned at around 18 months old, but they often stay close to their mums for months after.
♪♪ Spending time alone with their mothers, like this one is, rather than being in the larger group, also means they have a better chance of survival.
♪♪ Any head start is good for the youngsters here, as the camera shows us just how poor this habitat is.
♪♪ The headland may look like a well-kept lawn, but, there's little on offer here.
With over 200 roos in such a small area, this grass has been grazed to the ground.
♪♪ The density of animals also means, where there is food, there's feces.
HERBERT: A lot of the areas where they're grazing are contaminated.
You know, there's a little piece of fecal matter right there, where she's grazing, and that fits with what we're seeing, in terms of the high levels of intestinal parasites.
BUCHANAN: Poor feeding grounds lead to poorly conditioned animals and grazing here risks spreading disease and infection amongst the population.
♪♪ But then, we get the footage Cathy has been hoping for.
♪♪ One of the camera kangaroos hops onto the beach.
Oh, they're right out on the sand.
WATTS: Oh, wow.
♪♪ HERBERT: So this is those hopping marks that we can see where they're moving on the beach.
♪♪ BUCHANAN: At first, she nibbles on dune grass, something Cathy has observed before.
♪♪ WATTS: Not a lot to eat there, though, is there?
But then, she moves further down the beach and begins to forage.
♪♪ Oh, yes.
HERBERT: Oh, wow.
♪♪ BUCHANAN: It's slim pickings amongst the pebbles and shells, but, it's food, nonetheless.
♪♪ And the cameras give Cathy the all-important opportunity to see what they're eating.
♪♪ I'm not a kangaroo, you may have noticed, but that vegetation doesn't seem particularly nutritious.
It's kind of wispy and dry.
HERBERT: There's just a little bit of grass coming up in between the shells and the stones that have washed up from the ocean and maybe that's because the grass is a little bit longer there.
There's not a lot of it, but, other animals aren't there, grazing with this animal, so maybe there's less competition.
♪♪ This footage shows how these marginalized marsupials really are doing everything they can to survive.
But grass and weeds on the shoreline is not enough food to sustain them long-term.
♪♪ HERBERT: It all comes down to the way humans have modified the environment.
They can't move the way they normally would move in the environment.
♪♪ BUCHANAN: I think for us to have a future and for these animals to have a future, it's about coexistence.
It's about people.
HERBERT: And, hopefully, through this footage and the other research that we're doing, that we can really try and figure out how best to manage the landscape.
BUCHANAN: After watching the footage, Cathy wants to see changes in urban planning, to ensure new roads and suburbs consider the needs of kangaroos and enable them to move freely across the landscape.
♪♪ This will not only help the kangaroos here at Coffs Harbour, but many others living up and down this busy coastline.
♪♪ Our "Animals with Cameras" adventures in Australia have given scientists an insight into how we can help conserve some of the country's unique and precious animals... ♪♪ ...identifying how diverse koalas' habitat needs to be... ♪♪ ...how adaptation to new food is a vital survival strategy, and how much space kangaroos need to live on this great continent.
Let's hope this footage can go some way to safeguarding the future of these species, in this truly magical country.
♪♪ ♪♪ ♪♪ ♪♪ ♪♪ To learn more about what you've seen on this "Nature" program, visit pbs.org.