Heat-detecting drones are a cheaper, more efficient way to find koalas



Pixabay

Ryan R. Witt, University of Newcastle; Adam Roff, University of Newcastle; Chad T. Beranek, University of Newcastle, and Lachlan G. Howell, University of Newcastle

This article is a preview from Flora, Fauna, Fire, a multimedia project launching on Monday July 13. The project tracks the recovery of Australia’s native plants and animals after last summer’s bushfire tragedy. Sign up to The Conversation’s newsletter for updates.


Last summer’s catastrophic bushfires burnt about one quarter of New South Wales’ best koala habitat. On the state’s mid-north coast, an estimated 30% of koalas were killed.

Collecting the most accurate possible information about surviving koala populations, in both burnt and unburnt areas, will help save these precious few.

But at the moment, accurate information can be hard to come by. A NSW parliamentary inquiry into koala populations last week found that the fires, and general population decline, meant the current estimate of 36,000 koalas in the state was “outdated and unreliable”.

The report warned that without government intervention, wild koalas in NSW were on track for extinction by 2050. It recommended exploring the use of drones, among other detection methods, next fire season.

For the last year, we’ve been developing the use of heat-detecting drones to find koalas at night. This efficient method will save on costs. It will also help better assess koala numbers – a key step in saving the species.

Accurate koala counts are key to successful conservation efforts.
IFAW

Promising results

Koalas camouflage well and are notoriously difficult to detect. Traditional methods such as scat surveys or spotlighting with head torches are often considered either too localised, or too labour intensive and costly to efficiently locate and count koalas.

We tested our new koala-locating technique in Port Stephens, NSW, in the winter of 2019. Fortunately, the bush we visited did not burn in the later summer fires. Our method, to be published as a study in the journal Australian Mammalogy, was more efficient and cost effective than traditional koala population survey techniques.




Read more:
Scientists find burnt, starving koalas weeks after the bushfires


How much more efficient? Well, by searching forests at night on foot with spotlights we found, on average, about one koala every seven hours.

Flying the thermal drone at night in the same forests, we found an average of one koala every two hours. And this was in an area with a notoriously dispersed population.

This method could potentially be used to assess koala populations in fire-burnt areas over winter this year.

Koala night-time detection and daylight verification. On average, a koala is 17.1% brighter than the surrounding canopy.
A. Roff/NSW DPIE

Drones have big potential

Victorian authorities used drones during the 2020 summer fires – while fires were still active – to assess the damage in remote areas. Scientists also used drones to help detection dogs find starving koalas in the weeks after fire.

Our work takes the use of drones further, by detecting koala heat signatures at night.

On several occasions we flew the drone back to a possible koala detection at first light and confirmed the thermal signatures were indeed koalas.




Read more:
Koalas are the face of Australian tourism. What now after the fires?


We travelled to potential koala habitat in the Port Stephens area. Using a drone with a thermal and a colour camera, we flew a lawnmower pattern (meaning back and forth, so no spots are missed) about 70 metres above the ground. We then checked the results in real-time on a handheld tablet.

We flew the drones mostly at night, as initial surveys suggested koalas were more likely to be detected in the early morning before sunrise. Each flight was around 22 minutes long and simultaneously captured thermal and colour video recordings.

During and immediately after each flight, we checked the footage for signs of koalas. If we saw a large infrared “blob” in the tree canopy, we paused the drone to capture GPS data and detailed images.

Real-life checks

To make sure these “blobs” really were koalas, we needed to lay eyes on the animals. We did this at first light in two ways: one, by physically walking to the suspected koala location to check with binoculars and two, by programming the drone to fly back over the potential koala detection during the day.

This allowed us to simultaneously collect thermal and very high-resolution colour images. It also meant we could verify night-time detections, even in difficult to reach places.

We learnt that koalas noticed the drone approaching but were not bothered by it.

The drone also detected wallabies, possums, grey-headed flying foxes and a number of birds, highlighting the future potential applications of the technology.

Our team comprised experts from the University of Newcastle and the NSW Environment, Energy and Science Group of the NSW Department of Planning, Industry and Environment. We were helped by several local government and not-for-profit groups such as Port Stephens Koalas, Tilligerry Habitat and FAUNA Research Alliance.

On ground observers sight drone detected koalas and identify tree species.
A. Roff/NSW DPIE

How could this help in future?

Under climate change, increasingly frequent and severe fires are likely to drive animal population declines.

A thermal camera won’t be much help in a recently burned area that’s still hot. But our technique could be used to monitor fire-affected bushland in the weeks, months and years following bushfire – even in isolated refuges or difficult terrain.

Heat-detecting drones can help koalas after future fire seasons.
Ben Beaden/AAP

In future fire seasons, our method may also be useful for wildlife rescue, localised population monitoring, pre-land use surveys (such as before development, logging or hazard reduction burning), and after rehabilitation to check on released koalas.

Australia has an opportunity to lead the innovative use of emerging technologies such as drones to help find koalas and other hard-to-detect wildlife.

Other species that can be monitored using drones include bears, monkeys, sharks, whales, green sea turtles and albatrosses.

We plan to continue this work in the winter of 2020 in fire-affected areas of NSW to help understand and conserve koala populations.




Read more:
Stopping koala extinction is agonisingly simple. But here’s why I’m not optimistic


The Conversation


Ryan R. Witt, Conjoint Lecturer | School of Environmental and Life Sciences, University of Newcastle; Adam Roff, Conjoint Lecturer | School of Environmental and Life Sciences, University of Newcastle; Chad T. Beranek, PhD candidate, University of Newcastle, and Lachlan G. Howell, PhD Candidate | School of Environmental and Life Sciences, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Marine life found in ancient Antarctica ice helps solve a carbon dioxide puzzle from the ice age



Chris Fogwill, Author provided

Chris Turney, UNSW and Chris Fogwill, Keele University

Evidence of minute amounts of marine life in an ancient Antarctic ice sheet helps explain a longstanding puzzle of why rising carbon dioxide (CO₂) levels stalled for hundreds of years as Earth warmed from the last ice age.

Our study
shows there was an explosion in productivity of marine life at the surface of the Southern Ocean thousands of years ago.




Read more:
Ancient Antarctic ice melt caused extreme sea level rise 129,000 years ago – and it could happen again


And surprisingly, this marine life once played a part regulating the climate. Hence, this finding has big implications for future climate change projections.

Walking into the past

Our research took us on a four-hour flight from Chile to the Weddell Sea, at the extreme southern end of the Atlantic Ocean, to land on an ice runway at a frigid latitude of 79° south.

Our Ilyshion aircraft landed on the Union Glacier (Antarctic Logistics and Expeditions).
Chris Turney, Author provided

The Weddell Sea is frequently choked with sea ice and has been hazardous to ships since the earliest explorers ventured south.

In 1914, the Anglo-Irish explorer Ernest Shackleton and his men became stuck here for two years, 1,000 kilometres from civilisation. They faced isolation, starvation, freezing temperatures, gangrene, wandering icebergs and the threat of cannibalism.

Surviving here is tough, as is undertaking science.




Read more:
What an ocean hidden under Antarctic ice reveals about our planet’s future climate


We spent three weeks in the nearby Patriot Hills, drilling through ice to collect samples.

Normally when scientists collect ice samples, they drill a deep core vertically down through the annual layers of snow and ice. We did something quite different: we went horizontal by drilling a series of shorter cores across the icescape.

That’s because the Patriot Hills is a fiercely wild place strafed by Weddell Sea cyclones that dump large snowfalls, followed by strong frigid winds (called katabatic winds) pouring off the polar plateau.

Those katabatic winds blowing hard.

As the winds blow throughout the year, they remove the surface ice in a process called sublimation. Older, deeper ice is drawn up to the surface. This means walking across the blue ice towards Patriot Hills is effectively like travelling back through time.

A walk across the blue ice is a walk back in time.
Matthew Harris, Keele University, Author provided

The exposed ice reveals what was happening during the transition from the last ice age around 20,000 years ago into our present warmer world, known as the Holocene.

The Antarctic Cold Reversal

As Earth was warming, carbon dioxide levels in the atmosphere were rising rapidly from around 190 to 280 parts per million.

But the warming trend wasn’t all one way.

Starting around 14,600 years ago, there was a 2,000 year-long period of cooling in the Southern Hemisphere. This period is called the Antarctic Cold Reversal, and is where CO₂ levels stalled at around 240 parts per million.

Why that happened was the puzzle, but understanding it could be crucial for improving today’s climate change projections.

Finding life in the ice

Over three weeks we battled the winds and snow to make a detailed collection of ice samples spanning the end of the last ice age.

We collected sample of ice to study later in the lab.
Chris Turney, Author provided

To our surprise, hidden in our ice samples were organic molecules – remnants of marine life thousands of years ago. They came from the cyclones off the Weddell Sea, which swept up organic molecules from the ocean surface and dumped them onshore to be preserved in the ice.

Antarctic ice, which forms from snowfall, usually only tells scientists about the climate. What’s exciting about finding evidence of lifẻ in ancient Antarctic ice is that, for the first time, we can reconstruct what was happening offshore in the Southern Ocean at the same time, thousands of years ago.

We found an unusual period, displaying high concentrations and a diverse range of marine microplankton. This increased ocean productivity coincided with the Antarctic Cold Reversal.

Melting sea ice in summer sustains marine life

Our climate modelling reveals the Antarctic Cold Reversal was a time of massive change in the amount of sea ice across the Southern Ocean.

Sea ice formed in winter melts in summer, and dumps nutrients into the ocean.
Shutterstock

As the world lurched out of the last ice age, the summer warmth destroyed large amounts of sea ice that had formed through winter. When the sea ice melts, it releases valuable nutrients into the Southern Ocean, and fuelled the explosion in marine productivity we found in the ice on the continent.

This marine life caused more carbon dioxide to be drawn from the atmosphere as it photosynthesised, similar to the way plants use carbon dioxide. When the marine life die they sink to the floor, locking away the carbon. The amount of carbon dioxide absorbed in the ocean was sufficiently large to register around the world.

What this mean for climate change today

Today, the Southern Ocean absorbs some 40% of all carbon put in the atmosphere by human activity, so we urgently need a better understand the drivers of this important part of the carbon cycle.




Read more:
The last ice age tells us why we need to care about a 2℃ change in temperature


Marine life in the Southern Ocean still plays an important role in regulating the amount of atmospheric carbon dioxide.

But as the world warms with climate change, less sea ice will be formed in polar regions. This natural carbon sink of marine life will only weaken, increasing global temperatures further.

It’s a timely reminder that while the Antarctic may seem remote, it’s impact on our future climate is closer and more connected than we might think.The Conversation

Chris Turney, Professor of Earth Science and Climate Change, Director of the Changing Earth Research Centre and the Chronos 14Carbon-Cycle Facility at UNSW, and Node Director of the ARC Centre of Excellence for Australian Biodiversity and Heritage, UNSW and Chris Fogwill, Professor of Glaciology and Palaeoclimatology, Head of School Geography, Geology and the Environment and Director of the Institute for Sustainable Futures, Keele University

This article is republished from The Conversation under a Creative Commons license. Read the original article.