In Australia, the culling of dingoes is a relatively common practice to protect livestock. However, these culls are often strongly opposed on the grounds of the ecological effect they may have on the trophic cascade. According to the mesopredator theory, culling a top predator such as the dingo will result in an increased abundance of mesopredators – feral cats, red foxes and goannas – which in turn increases predation in lower trophic levels.
In a recent study published in Frontiers in Zoology, Benjamin Allen from the University of Queensland, and colleagues investigate the outcomes of top-predator control on smaller sympatric mammal and reptile predators in Australia.
Allen and colleagues conducted a series of manipulative experiments at nine sites spanning five ecosystem types across the Australian continental rangelands to investigate the responses of mesopredators to contemporary poison-baiting programs. They show that culling dingoes within conventional limits does not result in an increased presence of mesopredators, and therefore contradicts the idea that this effect can result in conservation issues for smaller threatened Australian species.
The researchers suggest that careful planning of dingo culls, such as around the peak cattle calving season, provides livestock producers with a window of opportunity to reduce livestock predation during high-risk times while still maintaining ecological diversity of the trophic cascade.
Allen, who led the study, explained, “Dingo populations recovered to pre-control levels within months, which means that baiting does not create the conditions required for mesopredators to increase. This helps us to understand why, despite years of control measures the numbers of dingoes in Australia is at an all time high.”