The behaviours we observed could represent grief, but they could also reflect maternal attachment, confusion or instinctive caregiving
It was a tragic sight.
One day last July, a newborn humpback whale calf lay motionless on the seafloor, just a kilometre off Australia’s Gold Coast. The encounter was captured through underwater video.
Proposed laws in Queensland would restrict who can object to a mine and give politicians greater control over whether objections are heard in court.
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Forests and woodlands cover millions of hectares across Australia, from tropical rainforests and temperate eucalypt forests to the vast woodlands and shrublands of the arid interior. They store enormous amounts of carbon, support biodiversity, regulate water supplies and help buffer the impacts of climate change. Yet we know surprisingly little about how these important ecosystems are changing over time.
Australia has world class ecological research sites and monitoring programs. But until now, we haven’t had a coherent, long term national monitoring network able to track the health of forests across the continent.
As a result, it’s hard to answer fundamental questions. Are forests becoming more vulnerable to drought? How quickly do these ecosystems recover after fire? How much carbon is being stored in forests and woodlands and how might that change in the future? Right now, we don’t know.
As climate change loads the dice for more frequent and intense droughts, heatwaves and bushfires in Australia, it’s vital we understand which ecosystems are at most risk, and which have more resilience.
Our new project aims to help fill this gap. We are upgrading thousands of existing solar-powered sensors so they can transmit data close to real time via satellites in low-Earth orbit. If our demonstration project in western New South Wales is successful, it could be expanded across the state – or the entire country.
Tracking changes to forests and woodlands in remote parts of Australia has long been a challenge.
Researchers have installed sensors in many areas highly exposed to climate extremes, such as the arid west of NSW.
These sensors measure soil moisture, microclimate, tree growth and plant water stress in near real time.
In many remote locations there’s no practical way to transmit the data continuously. It can be an ordeal to access data from these sensors as it must be done manually. It doesn’t help when they are located far from towns, roads and telecommunications infrastructure. As a result, data is often collected a couple of times a year.
That’s not ideal. It means we don’t have access to the continuous observations needed to detect change as it happens. This data would be particularly valuable after major events such as droughts, heatwaves and bushfires, when ecological conditions can change rapidly.
Without it, we can’t gauge how ecosystems respond to disturbances or recover over time. That makes it harder to judge how they will respond to future climate extremes.
When most people think about using satellites to track environmental change, they might picture images taken from space.
These are valuable as a way to track logging or illegal roads, for instance. But photos aren’t enough. We still need to take measurements on the ground.
This is why our project doesn’t rely on satellites as eyes in the sky. Their communication abilities are much more valuable. Satellites in low Earth orbit let sensors continuously transmit data from regions far too remote to have mobile phone coverage.
While satellite communication has existed for decades, newer low-Earth-orbit satellite systems make it possible for small, low-power environmental sensors to transmit data more efficiently and at lower cost than before.
The benefits of near real-time monitoring will go well beyond science. Graziers, land managers, conservation organisations and carbon projects will be able to get early warning if ecosystems are under new strain.
Environmental monitoring has always been difficult in a country as large and sparsely populated as Australia. Satellites offer a practical way to overcome the tyranny of distance.
To make this a reality, researchers (including this article’s authors) at Western Sydney University and UNSW are working with satellite communications company OQ Technology, with support from the NSW Smart Sensing Network.
At present, we are working to expand the network of monitoring plots from the wet sclerophyll forests and rainforests of the Greater Blue Mountains World Heritage Area to the arid woodlands of the far west of NSW.
Climate, rainfall and vegetation differ dramatically across this area. But all ecosystems are feeling increasing pressure from drought, bushfire and extreme heat.
We have installed satellite-enabled sensors at plots in the Blue Mountains and mulga woodlands in western NSW. Our next step is to test how well the sensors communicate with the satellite.
The network includes sensors that measure soil moisture using probes buried in the soil, monitor local weather conditions, track changes in stem growth, and estimate plant water stress
Over time, flows of data from these sensors will build the datasets we need to make better forecasts of future risk.
Policymakers, industry and conservationists rely on models and predictions to understand how Australia’s ecosystems are responding to worsening climate change.
But forecasts are only as reliable as the observations used to build and validate them.
Tracking change with satellites and sensors won’t prevent droughts, fires or ecosystem decline. But this approach can help spot emerging threats, improve forecasts and give the evidence needed to make better decisions in an increasingly uncertain future.
Brendan Choat receives research funding from the Australian Research Council, the NSW Smart Sensing Network, the Terrestrial Ecosystem Research Network and the NSW Natural Resources Commission. This project is supported by the NSW Smart Sensing Network and undertaken in collaboration with researchers from UNSW and industry partner OQ Technology.
Daniel Falster receives funding from the Australian Research Council.
It was a tragic sight.
One day last July, a newborn humpback whale calf lay motionless on the seafloor, just a kilometre off Australia’s Gold Coast. The encounter was captured through underwater video.
For more than an hour, the mother repeatedly returned to the same spot, gently touching the calf with her head and pectoral fin and resting beside it eye-to-eye. Our new research suggests this is the first described case of a humpback whale mother caring for her deceased newborn calf.
The encounter offers a rare window into one of the least understood aspects of whale behaviour: how these highly social animals respond to death.
And it raises the question: do whales, and other highly social animals such as elephants, grieve?
Humpback whales are famous for their spectacular migrations and acrobatic breaches. However, they are equally remarkable for the way they respond to other animals in distress.
Humpback whales often defend their calves from killer whales. Researchers have also observed them remaining alongside whales that are injured or entangled in nets, circling them, resting nearby and attempting to assist. Humpback whales may even intervene when killer whales attack seals, sea lions and grey whale calves.
These responses of care and attention are known as epimeletic behaviour and are common among cetaceans, a group of marine mammals including whales, dolphins and porpoises. Dolphins and killer whales often remain close to distressed companions, evidence of their strong social bonds. These animals may even risk their own lives for others. This happened in April off Scotland’s northwest coast, when multiple pilot whales became stranded after following a birthing female.
Read more: Whale of a problem: why do humpback whales protect other species from attack?
Killer whale mothers have repeatedly been observed carrying their dead calves for hours, days and, in exceptional cases, weeks. The most famous example is the killer whale Tahlequah, who in 2018 carried her dead calf for 17 days over more than 1,500 kilometres. Scientists have observed similar behaviour in pilot whales and dolphins.
Such prolonged responses illustrate the strength of the bond between mother and calf. Maternal instincts and hormonal changes after birth may contribute to mothers remaining with their deceased offspring. But exactly what the animals understand about death remains unknown.
Until now, scientists have almost exclusively documented these epilemetic behaviours towards deceased calves in toothed whales. The research on baleen whales, including humpback whales, is scarce. This is likely because dead newborn baleen whales often sink quickly, making it extremely difficult to observe such cases.
Humpback whale mothers give birth after almost a year of pregnancy and spend the next few months feeding their calf with nutrient-rich milk. Right after the delivery, mothers often lift their calf to the surface to help it take its first breath. During the first months of its life, a calf relies entirely on its mother for nourishment, protection and guidance during migration.
Tragically, some calves don’t survive. This may be due to disease, pollutants or a mother’s lack of fat reserves that help female whales cope better with pregnancy and better care for their calves.
Read more: What the grieving mother orca tells us about how animals experience death
Our new study aimed to help fill this research gap.
We observed two adult whales off the Gold Coast of northeast Australia. The two whales stayed in the same area for several hours, after what appeared to have been a stillbirth. The female humpback whale released an ammoniac membrane shortly after the birth, but a placenta was not seen.
Underwater footage revealed the calf resting motionless on the seafloor while the presumed mother repeatedly approached it. She remained close to the calf, continuing to touch it with her head and pectoral fin. A second adult whale, likely an escort, also stayed nearby.
The humpback mother did not try to lift the calf to the ocean’s surface. This may indicate that she recognised the calf had died or was unable to carry it up from the seabed.
Members of the public reported two adult humpback whales remaining in the area over the next two days. However, our research team could not confirm they were the same animals.
To our knowledge, this is the first detailed scientific study of a humpback whale mother attending her deceased newborn calf. It provides crucial insight into how baleen whales cope with death.
Many of the behaviours we observed – including remaining close to the calf and suspending normal behaviours such as travelling or socialising with other whales – resemble how other species respond to death. Elephants, great apes and some toothed whale species care for dead offspring in similar ways.
However, we can’t directly measure the emotional state of whales. The behaviours we observed could represent grief, but they could also reflect maternal attachment, confusion or instinctive caregiving. For this reason, researchers use broader terms – such as post-mortem attentive behaviour – rather than concluding that whales grieve in the human sense.
Nevertheless, these behaviours reveal that humpback whales maintain strong maternal bonds even after the death of a calf. Our study suggests similar cases may have gone unnoticed because scientists rarely observe whale births at sea.
In good news, researchers are increasingly able to observe these animals as whale populations recover and scientific equipment makes at-sea studies more feasible.
So while there’s much more to learn about whales, their emotional lives may be infinitely more complex than we once imagined.
Read more: Humpback whales may have bounced back from near-extinction, but it’s too soon to declare them safe
Olaf Meynecke receives funding from a private charitable trust through the Whales & Climate Research Program. He is affiliated with the NGO Humpbacks & Highrises.