Reviving Ecological Functioning with Dingo Restoration
A project undertaken at the School of Marine & Tropical Biology, James Cook University, and supervised by Arian Wallach and Chris Johnson
"A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise" Aldo Leopold
Almost half of all mammalian extinctions worldwide in the past 200 years have occurred in Australia. This crisis has been directly attributed to the introduction and spread of exotic species such as foxes, cats and rabbits. Ecosystem restoration is a growing field dedicated to the rehabilitation of degraded environments. In Australia this has taken the form of widespread pest control and reintroduction programs of threatened species into intensively managed landscapes. Because this approach relies on heavy-handed human intervention, it does not provide a sustainable solution. Our project proposed an alternative working-model for ecological restoration, one that focuses on ecosystem function and resilience.
Our basic ecological philosophy recognizes that once an exotic species has successfully established in a new environment, it becomes deeply intertwined in the complex web of nature. Exotic species cannot, and should not, be eradicated or controlled. Our challenge instead is to restore ecosystems to a state that enables native species to persist alongside these new immigrants. To accomplish this our focus must turn to promoting the inherent ecological mechanisms that enable ecosystems to maintain resilience to change. During the course of this project we have found that this can be accomplished in an elegantly simple and effective manner: through the restoration and conservation of large (apex) predators.
Apex predators are recognized as keystone species in virtually all terrestrial and marine ecosystems worldwide. By suppressing the abundance and modifying the behavior of their prey and smaller predators, apex predators maintain ecosystem structure and stability. When apex predators are removed from wilderness areas, smaller predators (mesopredators) and herbivores are released from regulation causing widespread biodiversity loss. Yet, where apex predator populations have been restored, biodiversity rapidly recovers and productivity is enhanced. Research and conservation focus is therefore increasingly turning towards apex predators: wolves and cougars promote tree recruitment by regulating moose and elk in the United States; lions and leopards protect small ungulates from baboon troops in Africa; coral reefs benefit from the presence of large sharks; and the dingo is the guardian of Australia’s unique fauna and flora.
Our research has demonstrated that dingoes have a profound influence on ecosystem structure. Dingoes suppress mesopredators (foxes and cats) and herbivores (rabbits, kangaroos, emus, goats and donkeys), which enables small mammals (such as hopping mice, dunnarts and kowaris) to increase in abundance. Where predator control is relaxed vegetation cover and diversity also increase. The ecological influence of dingoes is so important in fact, that many native species can only persist where dingoes are present. Because dingoes (like other wolves) are socially complex, they are particularly sensitive to lethal control. Dingoes are deeply social and intelligent beings. They care for each other, hunt together, maintain territories and traditions, and their ecological influence is tightly linked with their pack structure. To recover Australia’s wilderness, predator-control practices must be eliminated entirely, and dingoes afforded full protection.
Since European occupation, dingoes have been persecuted over much of the continent. Many leading ecologists now recognise that the disruption of dingo populations has been the ultimate driving force of extinction and land degradation in Australia. We now also know that wilderness does recover when dingo populations are restored. Thus, we have at our fingertips a simple and elegant solution to landscape degradation and extinction. All we have to do is allow the dingo to assume their ecological role. Ecosystems of mixed nativity, those that contain both the bilby and the fox, the quandong and the wild goat, can and do flourish where the melodic howling of the dingo fills the night air.
We thank the Hermon Slade Foundation for their substantial support.