Australia’s Wedge-Tailed Eagles Are Thriving Without Rabbits: A Surprising Discovery
It’s a common belief: Australia’s wedge-tailed eagles, the continent’s largest birds of prey, rely heavily on European rabbits for survival.
After all, rabbits are an invasive species that has overrun much of Australia’s landscape, damaging ecosystems along the way.
So, it’s understandable that we’ve come to think of them as the perfect food source for these majestic eagles.
But new research has uncovered something that may change everything we thought we knew about these powerful predators.
A groundbreaking study reveals that wedge-tailed eagles have a far more varied diet than we ever imagined—and it’s not just reliant on rabbits. In fact, eagles are thriving without them.
This discovery challenges long-standing assumptions that have led to policies and practices meant to protect rabbit populations in order to support eagle survival.
The study, published in Wildlife Research, reveals that even when rabbit numbers dropped drastically due to a disease introduced in the 1990s, the wedge-tailed eagle population not only survived but flourished.
The truth about their diet and ecological role is far more complex than we thought, and understanding this could be crucial for both eagle conservation and future ecological management in Australia.
The Wedge-Tailed Eagle: A Majestic but Mysterious Hunter
The wedge-tailed eagle, known for its impressive wingspan of up to 2.3 meters, is an iconic Australian predator.
These eagles can be found across the continent, often soaring high in search of prey.
But despite their imposing size, scientists have long struggled to fully understand the complexities of their diet.
Historically, researchers assumed that European rabbits made up a significant portion of the wedge-tailed eagle’s food source, especially given the role rabbits played in Australian ecosystems.
Introduced to Australia in the 18th century, rabbits quickly became one of the most abundant species on the continent, and their rapid population growth wreaked havoc on native plants and animals.
By the 1990s, a disease known as rabbit hemorrhagic disease (RHD) was deliberately introduced to control their numbers.
The disease was wildly successful, decimating rabbit populations across Australia.
However, this success also led to fears that wedge-tailed eagles, so often linked to rabbit consumption, would suffer as their primary food source dwindled.
This belief was so entrenched that many conservationists feared that as rabbit numbers dropped, so too would eagle populations, potentially causing an ecological imbalance.
Ian Warden, a columnist for the Canberra Times, summed up these concerns by writing:
“This belief means that there are fears that when the biological control agent rabbit hemorrhagic disease is used with great success against the accursed rabbits, our eagles, bereaved of an important food, are sorely afflicted.”
But a closer look at the evidence tells a different story.
Challenging the Rabbit-Eagle Connection
Recent research has put the rabbit-eagle relationship under the microscope, and what scientists have found is not what most people would expect.
A team of researchers from the Institute for Applied Ecology at the University of Canberra conducted a comprehensive review of studies examining the diet of wedge-tailed eagles.
They concluded that eagles have a much more varied and flexible diet than previously believed—one that is not dependent on rabbits at all.
In fact, a pivotal study conducted by master’s student Esteban Fuentes between 2002 and 2004 provides clear evidence that wedge-tailed eagles survived—and even thrived—without relying on rabbits.
During this time, when rabbit populations were at their lowest, the eagles not only managed to adapt, but their breeding success improved.
Fuentes’ research involved studying eagle “castings”—large pellets that eagles regurgitate containing the indigestible parts of their prey, such as bones and fur. These castings revealed a surprising diversity in the eagle’s diet.
They had consumed a total of 57 different prey species, including 19 mammals, 20 birds, seven reptiles, and even one crustacean.
Dominating the eagles’ diet were native species, particularly the eastern grey kangaroo, along with a variety of birds such as Galahs and other native species.
Far from being reliant on rabbits, the eagles were making the most of what nature provided, even as rabbit populations dwindled.
The results were clear: there is little evidence to support the idea that rabbits are a vital food source for wedge-tailed eagles.
As the rabbit population declined, the eagles simply adapted, shifting their focus to kangaroos, birds, and reptiles instead.
The Shift in Conservation Strategy
What does this revelation mean for the future of wedge-tailed eagles and their conservation?
For one, it calls into question the prevailing assumption that maintaining high rabbit populations is critical for eagle survival.
In fact, the new study suggests that conservation efforts should be refocused.
Rather than continuing to invest resources in trying to preserve a rabbit population that’s causing ecological damage across Australia, researchers believe it’s more important to study the broader dynamics of eagle populations.
Understanding how eagles interact with their environment on a continental scale is a more rational approach to conserving the species long-term.
As Jerry Olsen, one of the authors of the review, explains, “Rather than perpetuating the idea that high populations of rabbits are needed for wedge-tailed eagle conservation, resources would be better re-directed into understanding continental-scale eagle population dynamics.”
By shifting focus to understanding how eagles thrive in diverse environments with varying prey, conservation efforts can be more effective and better tailored to the unique needs of the species.
This finding also has implications for the management of biological control agents like RHD.
While these agents may have successfully reduced rabbit populations, they can also disrupt ecosystems in ways that are not immediately clear.
The new research suggests that we should be looking at the broader impact of such biological control measures, taking into account all species that may be affected, not just rabbits.
More Than Just Rabbits: Wedge-Tailed Eagles Are Ecological Experts
The resilience of wedge-tailed eagles in adapting to different food sources is a testament to their versatility as apex predators.
These birds are not just opportunistic hunters—they are ecological experts, capable of adjusting to changes in their environment and their prey base.
By relying on a variety of mammals, birds, and even reptiles, the eagles play an essential role in controlling populations of other species and maintaining a balanced ecosystem.
For instance, the wedge-tailed eagle’s preference for native species like kangaroos and reptiles means they contribute to the regulation of herbivore populations, which in turn helps preserve vegetation and other plant life.
This natural balance is critical for maintaining the health of Australian ecosystems, and wedge-tailed eagles are an integral part of that process.
Their role as natural regulators of wildlife may have been underestimated in the past, but as more research emerges, it’s clear that these birds are not just surviving without rabbits—they are thriving, and their dietary habits are far more complex than anyone could have imagined.
The Bigger Picture: Rethinking Ecosystem Management
The discovery that wedge-tailed eagles are not dependent on rabbits offers a crucial lesson in ecosystem management.
While the rabbit issue has been a central focus of Australian wildlife conservation for decades, it’s becoming clear that the ecological health of Australia’s ecosystems cannot be solved by focusing on one species alone.
Instead, we need to adopt a more holistic approach to conservation, one that considers the entire food web and the interconnections between species.
In the case of wedge-tailed eagles, their adaptability to different prey species shows that nature can find a balance on its own if given the opportunity.
This research also raises important questions about the role of invasive species like rabbits in ecosystems.
While they may have caused significant damage to native plant and animal populations, they have also become an essential part of the food chain for some predators, including wedge-tailed eagles.
This underscores the need for a more nuanced approach to managing invasive species—one that takes into account the complex relationships that exist within ecosystems.
A New Era for Eagle Conservation
As we move forward, the focus on wedge-tailed eagle conservation must shift from the preservation of specific prey species like rabbits to a broader understanding of their ecological role.
By studying their diet and population dynamics on a continental scale, we can ensure that eagles continue to thrive, even as their environments change.
The lesson here is clear: ecosystems are complex, and the interactions between species are often more intricate than we might assume.
By embracing this complexity, we can better understand and protect the remarkable species that help shape our world.
In the case of the wedge-tailed eagle, it’s not about saving the rabbits. It’s about understanding the eagles—and the ecosystems they inhabit—on their own terms.
This approach may just be the key to ensuring the survival of one of Australia’s most iconic birds of prey for generations to come.
