For millennia, Indigenous knowledge holders have passed down lore to the next generation. Much lore describes the relationships between people and Country, including custodial responsibilities to care for other species as kin.
Each species carries a history of movement and change in its DNA. By quantifying how related one individual of a species is to another, evolutionary ecologists can infer how a species migrated in the deep past.
When we combine both types of knowledge – lore and genetics – we can make new discoveries. Our recent body of research uses genomic techniques and interviews with First Nations knowledge holders to investigate whether First Nations Peoples moved two culturally important food sources, bunya pines and black bean trees.
Bunya pines
The bunya pine (Araucaria bidwillii) is an ancient native conifer of cultural and spiritual significance to several language groups in eastern Australia. It’s known as bonyi bonyi in Wakka Wakka and bunyi in Kabi Kabi.
For thousands of years, Indigenous groups gathered to share the edible nuts at bunya gatherings at locations such as Wakka Wakka Country in the Western Downs and Kabi Kabi Country in the Sunshine Coast hinterland. The last major known gathering took place in 1902, but they have restarted in recent years.
Bunya pines grow throughout Queensland’s southeast. They’re also found 1,400 km north, in the Wet Tropics near Cairns. In a recent study, co-author Patrick Cooke interviewed First Nations groups in both locations in southeast Queensland and the Wet Tropics to record Indigenous biocultural knowledge on the use of bunya.
In a companion study, Traditional Owners and this article’s lead author collected DNA samples from bunya pine leaves to retrace the conifer’s historical movement in its northern and southern locations. Genetic results were interpreted in the context of biocultural knowledge and archival evidence.
What did we find? In the Wet Tropics, we could not find traditional names or biocultural knowledge for bunya. DNA samples showed no evidence of its dispersal by people or animals. This suggests the species was not an important food source for First Nations groups in the region. In the absence of human-assisted dispersal, the remnant stands of bunya have become genetically isolated.
By contrast, groups in southeast Queensland had rich biocultural knowledge of bunya. DNA samples showed clear evidence of movement, consistent with people actively moving the species around. But when we analysed bunya patches pre-dating European colonisation, we found genetic patterns suggesting planting was sporadic and fairly localised.
Our Indigenous knowledge interviews and historical literature give crucial context. Knowledge holders told us only those with custodial rights to bunya were permitted to collect and share the edible cones, which likely restricted the movement of bunya out of existing Country.
This changed when First Nations people were displaced by European settlers. Wakka Wakka people planted bunya at Cherbourg mission in southeastern Queensland and Mulli Mulli mission on Githabul Country in northern New South Wales to maintain cultural connections.
Black bean trees
Like bunya pines, black bean trees (Castanospermum australe) have been an important food source for thousands of years. While the large seeds are toxic, they can be made edible.
Here, we have found evidence this rainforest species was spread on purpose – and rapidly.
The tree does not need to have its toxic seeds eaten. Instead, it relies on its seed pods floating down rivers to new locations. Curiously, the tree can be found far from any waterways. How did it get there?
We found evidence Bundjalung groups spread black bean thousands of years ago, as they walked the ridgelines of the Nightcap, Border and McPherson ranges in northern New South Wales. This route follows the Nguthungulli Songline, a cultural pathway tracing the journeys of an ancestral spirit (likely to represent a real person) who left “bean tree” seeds as he journeyed inland from the east coast.
Samples taken adjacent to the Nguthungulli Songline showed higher levels of genetic diversity compared to other sample sites. This is what we would expect to see if seeds from different areas had been deliberately walked uphill along the songline and subsequently spread downstream through the waterways.
Ongoing genetic analyses suggest the black bean tree remained in small coastal pockets until Bundjalung groups walked its seeds northwards into southeast Queensland.
The Bundjalung story of Three Brothers tells of the arrival or return of key ancestors of Bundjalung peoples and related language groups Githabul and Yugambeh to coastal northern NSW. All three language groups use the name “bugam” for the black bean seed, which suggests a rapid transfer or shared ancestral connection to the species.
The black bean tree produces large quantities of seeds – but they are poisonous without proper treatment.Renae Grace 333/Shutterstock
Walking plants
These stories raise interesting questions about why Indigenous groups carried and nurtured plants in some cases and not others.
In the Wet Tropics, for instance, the lack of evidence for movement of black bean and bunya could be linked to different dietary preferences and alternative edible nuts.
In northern NSW and southeast Queensland, bunya gatherings brought far-flung groups and kin together. We speculate these social and cultural reasons may have been seen as more important than simply increasing food production by planting the tree in new locations.
But the deliberate movement of black bean along the Nguthungulli Songline shows some groups took the tree with them to ensure access to its nuts.
For years, researchers thought domesticating a plant for human use was relatively straightforward. But newer research suggests it was a lengthier and more complex process than we thought.
Unpicking the deeper past using First Nations lore and genetic analysis is a promising combination to shed light on domestication. We hope it will become more widely used.
As we continue, we are likely to find examples of where Indigenous movement of plants worked to domesticate landscapes. That is, social and cultural preferences of ancestral groups drove ecological transformations which seem, at first glance, to be natural.
Monica Fahey works for the Research Centre for Ecosystem Resilience, Botanic Gardens of Sydney. She received funding from the Australian Research Council. She is also affiliated with Macquarie University.
Emilie Ens receives funding from the Australian Research Council, The Nature Conservancy, NSW DCCEEW and the Origin Energy Foundation.
Oliver Costello is a Bundjalung Custodian and Executive Director at Jagun Alliance Aboriginal Corporation. He receives funding from The University of Melbourne; Bush Heritage Australia; the University of Queensland; the Ian Potter Foundation; the Hermon Slade Foundation; CSIRO; the Victorian Government Department of Environment, Land, Water and Planning (DELWP); Natural Resource Management (NRM) Regions Australia, The Nature Conservancy and The Australian Conservation Foundation.
Patrick Cooke is a Gangalidda Custodian and affiliated with Macquarie University.
Maurizio Rossetto does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
The recent proposal by Vanuatu, Fiji and Samoa to recognise ecocide as a crime against humanity is timely and could provide a global framework of accountability for environmental damage.
Ecocide is defined as acts of “unlawful or wanton” environmental destruction, committed in the knowledge of their likely severe, widespread or long-term effects.
Last week, the Pacific Island nations formally requested an amendment to the principal treaty of the International Criminal Court (ICC) to add ecocide alongside genocide, war crimes and aggression to the international community’s list of most serious crimes.
There is a long way to go before ecocide is recognised by the ICC, if it ever happens. Discussions of the proposal will likely take several years and much will depend on the level of support the proposal gains from the 124 countries party to the ICC.
But for Aotearoa New Zealand, this is a chance to champion a progressive legal response and show leadership in the region.
In the Pacific, it is vitally important to equip the region with the necessary tools to mitigate and adapt to grave ecological change. This includes legal tools. An offence of ecocide could be used to significant effect, particularly if given an international dimension.
Alleged offenders are unlikely to live in the Pacific Islands. Domestic climate litigation in Pacific nations would have little impact. This is why the proposal for ecocide to be made an international crime is so critical.
Few states will want to publicly oppose a proposal aimed at countering the most serious acts of ecological damage at a time of growing awareness of the state of nature.
For New Zealand’s government, early and vocal support for acknowledging the crime of ecocide would line up with public attitudes. Nearly two thirds of New Zealanders support more ambitious emissions targets in response to climate change, while more than 80% consider improving water quality as important.
Supporting this initiative, brought by Pacific neighbours, would also further cement Aotearoa’s reputation and role as a regional leader.
Arguing ecocide in New Zealand courts
Since it became operational in 2002, the jurisdiction of the ICC is limited by the principle of complementarity. In other words, the ICC exists to complement national judicial systems, not to replace them.
This means the ICC can only proceed with an investigation or case where a state party is unable or unwilling to do so. Legislation exists in New Zealand to ensure genocide, crimes against humanity and water crimes can be dealt with in domestic criminal law, with the consent of the Attorney-General.
However, it is important to note that crimes listed in the Rome Statute are not automatically incorporated into domestic law. For instance, the crime of aggression is not currently included in New Zealand criminal law.
In time, ecocide could find its way into domestic legislation. This could offer a more appropriate legal response to acts causing severe environmental damage than those currently available, for example in the Resource Management Act or as currently under consideration in tort law.
A recognition of ecocide could open the possibility for more effective environmental protection through robust deterrent.
Creating a new offence to meet a new challenge
Should ecocide eventually be included as an international crime (and even a domestic one), it would doubtless raise many substantive and procedural legal questions.
For example, current ICC procedures include reparation for victims and allow them to participate in proceedings. For crimes with widespread environmental damage and potentially millions of victims, this may not be practical.
But such considerations should not stand in the way of an innovative and important new criminal offence.
The crime of genocide was adopted in 1948 as a result of the horrors of the second world war, and much work was necessary to define and delimit it. Faced with an array of existential threats from ecological crises, it is timely that an ecological crime has been proposed.
Aotearoa was the first country in the world to give a river the legal status of a person. It should now follow that we support this proposal to criminalise ecocide, for the sake of our own environment and that of our neighbours.
The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
Productivity Commission chair Danielle Wood says she welcomes concessions made by the Albanese government to put clearer scrutiny of proposals for industry assistance into its Future Made in Australia legislation.
The notoriously shy yellow-eyed bird edged out other New Zealand birds to win the annual competition designed to raise awareness of threatened species.
Earth’s majestic “apex predators” are some of the most prolific hunters in the world. But which ones kill the most?
Our new research showed solitary hunters such as bears, tigers and Eurasian lynx have higher individual kill rates than social predators such as wolves and lions. And smaller species, such as cheetahs and pumas, tend to kill relatively more prey because their kills are often stolen by more dominant carnivores.
Such information allows us to better understand how different predators affect their environment. It can also guide hunting quotas and help evaluate how humans affect carnivores.
Our research was a systematic, world-first literature review into the predatory behaviour of large land-based carnivores. In particular, we examined carnivore “kill rates” – the number of prey killed over time. We did this to better understand their foraging and impacts on prey populations and ecosystems.
We examined 196 papers that either quantified large mammal carnivore kill rates, or reported data we could use to calculate the rates ourselves.
We focused on the large land-based carnivores weighing 15?kg or more. We also searched for kill rate studies on four smaller species — coyote, wolverine, fossa (a cat-like predator found in Madagascar) and the Tasmanian Devil — as they’re all considered apex predators in certain regions and ecosystems.
We only found kill rate estimates for 17 (55%) of the 31 carnivore species included in our review. Studies came from 27 countries across five continents.
We found kill rates differ between carnivores with different social structures and hunting strategies.
Social predators, such as wolves and lions, tend to kill fewer animals per carnivore than solitary hunters such as bears, tigers and Eurasian lynx. For example, on average grey wolves made a kill every 27 days per wolf, compared with every four days per Eurasian lynx.
Larger wolf packs can bring down large animals such as bison more easily. Similarly, groups of cheetahs can tackle larger prey than solitary cheetahs. This could mean they don’t need to hunt as often.
Working as a team may also reduce losses to scavengers, as groups can better defend their kills through sheer numbers. Or they might be better at scavenging and stealing (“kleptoparasitism”) from others.
Canine predators such as wolves and African wild dogs often rely on high-energy pursuits over long distances. For example, grey wolves can pursue prey for more than 20km. In contrast, cats rely on stealth, using an ambush hunting strategy. This saves energy.
Solitary large carnivores such as tigers, leopards and Eurasian lynx, which mainly hunt hooved mammals, have similar kill rates regardless of body mass. This suggests large land-based carnivores are compelled to hunt prey closer to their own size or larger, to compensate for the energy used in the hunt.
Smaller carnivores such as cheetahs, pumas and African wild dogs often kill more prey than their larger counterparts, but only consume about half of what they kill.
If you’ve seen the Lion King movie, you’d be forgiven for thinking hyenas largely steal and scavenge their food. But that’s not the case. Lions often steal from hyenas, as well as from other carnivores such as cheetahs and African wild dogs.
Making a kill is the first challenge, avoiding having it stolen by more dominant predators is also difficult.
Bias in kill rate research
More than half (55%) of all kill rate studies have been conducted in North America. Africa follows with almost a quarter (24%), then Europe (12.5%).
Asia was a long way behind with 7% of all kill rate studies. That’s just 13 studies covering six species. This is despite being the largest continent, home to 17 (55%) of the 31 large carnivore species included in our review.
No reliable kill rate studies have been published from Australia.
A third (33%) of all kill rate studies focused on grey wolves, followed by pumas (20%), lions (12%) and Eurasian lynx (8%). This means we know little about the predatory behaviour and roles of other large carnivores.
Grey wolves are considered a threat to livestock and wildlife that humans value. This has prompted significant investment in research to understand their predatory behaviour and that of other large North American carnivores.
Such work has subsequently been used to inform appropriate management and conservation of these predators and their prey.
Kill rate studies provide more than just a tally of carnivore behaviour. They offer deeper insights into the relationships between predators and prey, and their effects on ecosystems.
Large carnivores shape ecosystems by scaring and killing prey, which can change their behaviour, distribution and abundance. They also supply food to other species, affecting the flow of nutrients and energy.
In many ways, large carnivores also help people. They can reduce the risk of vehicle collisions, by killing deer that might otherwise wander onto roads. They may limit the spread of disease by preying on sick animals, and control herbivores, aiding livestock producers.
Yet carnivores, including Australia’s dingo, are still widely persecuted. We need to do all we can to maintain their pride of place at the pinnacle of Earth’s ecosystems.
Of course, if you really want to know which species is the biggest killer, it’s humans. We are the dominant predator across Earth.
Euan Ritchie receives funding from the Australian Research Council and the Department of Energy, Environment, and Climate Action. Euan is a Councillor within the Biodiversity Council, a member of the Ecological Society of Australia and the Australian Mammal Society, and President of the Australian Mammal Society.
Luke Emerson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
It’s not easy finding food at sea. Seabirds often stay aloft, scanning the churning waters for elusive prey. Most seabirds take fish, squid, or other prey from the first few metres of seawater. Scavenging is common.
But there are other tactics. Frigatebirds, skuas, and gulls rely on the success of other seabirds. These large, strong birds chase, harry, and attack their targets until they regurgitate or drop the prey they’ve just caught. They’re the pirates of the seabird world, stealing hard-earned meals from other species. This behaviour is known as kleptoparasitism, from the Ancient Greek word klépt?s, thief.
The strategy is brutal, effective, and a core behaviour for these important seabirds. But as our new research shows, it comes with major risks for the thieves. The new strain of avian flu is killing birds by their millions – and we found kleptoparasitism could spread the virus very easily.
Food thieves at sea
It’s not that frigatebirds, skuas, and gulls can’t hunt. They can and do catch their own food. But hunting fish and squid is hard work. It’s much easier to use extortion tactics to win the food from other seabirds.
These tactics have made these birds very successful as foragers. They hang around the breeding sites of birds such as gannets and terns waiting for a tired parent to return from the sea with a crop of food.
For the seabirds being targeted, these kleptoparasitic birds are just one more threat. The world’s 362 species of seabird can be found across every ocean and many islands. At sea, they prey on fish and squid. When they nest or rest on islands, their nutrient-rich guano shapes soil and plant communities, defining entire ecosystems.
But they are not doing well. Just under half of all seabird species (155) are now classified between “near threatened” and “critically endangered” on the world’s list of threatened species, the IUCN Red List. Of those with known trends, 56% have populations in decline.
The threats they face are daunting. Invasive predators such as mice and rats eat eggs or chicks on breeding islands. Many are caught by fishing boats as accidental bycatch, while overfishing depletes their prey. Then there’s climate change, habitat loss, and many other threats, including disease.
Seabirds are generally long-lived. They often raise only one chick every one or two years. Many species breed in only a few locations. They take many years to mature. Put together, these traits make recovery from population declines slow.
Three years ago, a more lethal strain of avian influenza virus emerged. This HPAI H5N1 2.3.4.4b strain has spread around the world, killing at least 280 million wild birds. The strain can also infect and kill marine mammals such as seals.
“HPAI” stands for Highly Pathogenic Avian Influenza, meaning the virus can more readily cause severe disease and death. The strain has become an animal pandemic (formally, a panzootic). It’s made it to Antarctica, but not yet to Australia or the rest of Oceania.
We know seabirds are particularly at risk. Our new research has shown kleptoparasites are at an even higher risk relative to other seabirds.
During the 2022 northern hemisphere summer, the virus killed roughly half of the world’s great skua (Stercorarius skua).
Food-stealing behaviour can enable the virus to spread. When a great skua harasses a gannet and makes it regurgitate food, the skua gets a fish meal – coated in saliva. If the gannet is infectious, its saliva will likely have a high viral load.
Once infected, these pirate birds can drive spread faster. Skuas, frigatebirds and gulls can cover great distances across polar regions and the tropics. They can transmit the disease to their mates, chicks, and other seabirds.
This means we could see outbreaks in new populations or places, hundreds or even thousands of kilometres apart. We have already seen signs of this in skua populations in the northern and southern hemispheres, with brown (Stercorarius antarcticus) and great skuas being some of the first detected H5N1 infections at new locations.
Skuas more often steal food from other seabirds when away from their breeding sites – including when they’re migrating back to these areas. If skuas get infected en route, they could bring the disease to their breeding sites and then beyond.
Frigatebirds are known for the red pouches on the necks of the males, which they inflate during breeding season. But they have other remarkable traits, such as travelling tens of thousands of kilometres across oceans outside breeding season. These travels are often broken up by “island-hopping”, where they will encounter and potentially infect other seabirds.
Frigatebirds are known for the large red pouches male birds have on their necks.buteo/Shutterstock
Frigatebirds and skuas have already suffered mass deaths from this strain of avian influenza.
While the virus is now almost everywhere, it hasn’t reached Australia, New Zealand, Oceania, and parts of Antarctica and the subantarctic. We can monitor skuas, frigatebirds and gulls for signs of illness to give us early warning that the virus has arrived.
By itself, avian influenza is a major threat to seabirds. But the outlook is even more dire when this is compounded with further human-caused threats. Identifying, managing, and reducing these threats is critical for their conservation, and the health of our islands and oceans.
Simon Gorta is a PhD student at the University of New South Wales and his PhD research is supported by the Australian Government Research Training Program scholarship.
Richard Kingsford is a Councillor on the Biodiversity Council
Rohan Clarke does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
