The problem
The 2021 State of the Environment report (Australian government) notes that rabbits affect species and ecosystems by competing with native animals for food, through gazing and preventing regeneration of seedlings, and by supporting populations of pest predators such as feral cats, foxes and wild dogs.
- The decline and extinction of many mammal species has been attributed to impacts caused by rabbits, particularly in the arid and semi-arid zones. They remain a risk to over 300 threatened plant and animal species.
- Feral cats and foxes prey upon native species, causing heavy losses and putting the survival of species at risk. Cats are known to eat over half, and foxes 40%, of Australian land mammal species, and nearly half and 18% of all Australian bird species. Feral cats kill an estimated 2,414 million animals and foxes an estimated 567 million annually – mostly native species.
- Feral cats and/or foxes have been a major factor in the extinction of 27 of the 34 native mammals, 2 of the 9 native birds, and all of the 3 native reptiles lost in the last 200 years, and are a continuing risk to many more.
Rabbits, feral cats and foxes have been described as an ‘unholy trinity’ (Moseby). Rabbits compete with native animals and degrade their habitat, and become food for feral cats and foxes – sustaining and growing their populations; resulting in increased predation of native animals. Rabbit control may cause some temporary shifts in prey for cats and foxes, but over time the net outcomes are usually positive as vegetation rebounds, predator populations decline, and there is a resurgence of ‘at risk’ fauna.
Managed sanctuaries
Because of difficulties with the ongoing, effective control of rabbits, cats and foxes across whole landscapes, “island arks” have been established to provide sanctuary to some of our most vulnerable threatened species and ecosystems, and to enable their reintroduction to areas where they have become locally extinct.
A few recent opinion pieces collectively paint a picture of the growing importance of privately and publicly managed sanctuaries in nature conservation (Possingham and Woinarski et.al), a need for caution and not becoming over-reliant on such sanctuaries (Moseby & Read), and a requirement to shift attention from managing single species to a stable system of ecosystem management for effective conservation (Krebs).
It is clear that managed sanctuaries are playing a significant and increasingly important role in conserving Australia’s native plants and animals. They are also providing opportunities to learn more about the ecology of lost ecosystems. Whenever a ‘new’ element is added to an ecosystem (even if it is reintroducing a species from a previous time), there will be uncertain consequences. Close monitoring and adaptive management is needed and new understandings are the output, as evidenced in the account of a reintroduction by John Read.
Securing the future
However, it is also apparent that more must be done outside of fenced and island safe havens. For a secure future, to avoid the collapse of some entire ecosystems, and to see healthy functioning ecosystems and their many ‘services’ expand, it is essential that rabbits, cats and foxes are effectively controlled outside of reserves, as well as within them.
A systems approach is needed to ensure threatened species survive outside of managed sanctuaries. Integrated rabbit, feral cat and fox control, will be an important foundation to those efforts in many parts of Australia.
Rabbit control is often an essential precursor to vegetation and habitat recovery, and to the management of feral predators. Removing rabbits takes away a key source of sustenance to feral cats and foxes in many areas, reducing their populations to more manageable numbers and leaving them more likely to take baits. Vegetation recovery following rabbit removal results in better habitat for native animals and more protection for them, allowing their populations and their distribution to increase (Pedler et.al, Finlayson et.al & Peacock et.al).
Effective broadscale control of feral cats and foxes gives a further boost to the prospects of native animals in their prey range and is likely to have resulted in the successful reintroduction, or in-situ recovery, of many threatened mammal species known to be predated by these to pest species (Stobo-Wilson et al 2021).
As the Australian Government’s Nature Positive Plan notes, if things don’t change, ‘our trajectory of environmental decline will continue’. Efforts to better coordinate the management of vertebrate pests across Australia give some insight into what may work to enable change that better manages landscapes outside of managed reserves.
The solution
Experience shows that effective pest management will require collaboration between private and public investors, community engagement and contribution, assistance to land managers, and an ever-improving scientific base to help manage the uncertainty of ecological management. Plans for integrated programs at a regional scale will need to be developed with their communities to ensure they are practical, locally endorsed and committed to by the sectors involved.
Collaborative, integrated planning sets a framework for on-ground action by land managers where:
- Rabbits, feral cats and foxes may be managed together,
- Actions are coordinated across property boundaries, regardless of tenure and ownership, and
- There is on-going support, monitoring and assistance to the land managers involved.
For more information
Blogs:
- Hugh Possingham, in The Conversation – The new major players in conservation? NGOs thrive while national parks struggle (theconversation.com)
- John Read, Blog (2023) ‘Sharing the secret (7) treecreeper nightmares’.
- John Read & Katherine Moseby, in The Conversation – Threatened species recover in fenced safe havens. But their safety is only temporary (theconversation.com)
- Charley Krebs, in Ecological Rants – On Conservation Complexities | Ecological Rants (ubc.ca)
Australian Government Reports:
References:
- Finlayson G et.al. (2021) Recovering Australia’s arid-zone ecosystems: learning from continental-scale rabbit control experiments. Restoration Ecology doi: 10.1111/rec.13552
- Peacock D et.al. (2021) Benefits of rabbit control in Australia: An Update. Centre for Invasive Species Solutions. (CISS)
- Pedlar R D et.al. (2016) Rabbit control and landscape-scale recovery of threatened desert mammals. Conservation Biology. Vol 30, Issue 4. https://doi.org/10.1111/cobi.12684
- Stobo-Wilson A B. et.al. (2021) Reptiles as food: predation of Australian reptiles by introduced red foxes compounds and complements predation by cats. Wildlife Research, 48, 2021, 470-480. doi.org/10.1071/WR20194
- Stobo-Wilson A B. et.al. (2021) Sharing meals: Predation on Australian mammals by the introduced European red fox compounds and complements predation by feral cats. Biological Conservation, 261 https://doi.org/10.1016/j.biocon.2021.109284
About the authors:
- Gillian Basnett. National Feral Cat & Fox Management Coordinator.
- Peter Day. Executive Officer, Foundation for Rabbit-Free Australia.
May, 2023.