I’ve read three reports on studies which indicate to me that dingoes can suppress feral cat numbers in a particular area directly but not indirectly. They are not very effective therefore in controlling feral cat numbers in Australia.
Complex interplay between Australia’s feral cats, invasive rabbits and native mammals
Direct suppression
When dingoes and feral cats are sympatric i.e. live in the same place, the cats avoid the dingoes because dingoes can kill cats. Dingoes scare cats completely away from a hunting ground. This was decided by scientists when they counted the number of feral cats, dingoes and major prey animals on both sides of the world’s longest fence which is the border between South Australia and New South Wales.
There are far fewer dingoes in New South Wales (NSW) then there are in South Australia and therefore the fence is a useful means to test the impact of dingoes on feral cat populations. Prof Mike Letnic of the Centre for Ecosystem Science, UNSW School of Biological, Earth and Environmental Sciences, said that over the six-year course of the study between 2011 and 2017 they found that on the South Australian side where dingoes were common, “the cat numbers were consistently lower [than in NSW]”.
They counted dingoes, cats and two major prey animals: rabbits and hopping mice with spotlight searches and scat analysis to compare diets.
Comment: dingoes push feral cats out of an area. This must mean that feral cats travel to another area where there are fewer dingoes if that’s possible. I suppose if it is not possible, they might procreate less and therefore reduce numbers that way. Or they will change their behaviour to do their best to avoid dingoes. For example, dingoes are mainly active at dawn and dusk for predation which is the same time that feral cats are most active. However, in order to avoid dingoes, feral cats may become more active during the daytime. This would be a form of timeshare and it’s quite common when two predators live in the same area and in the interests of survival, they deliberately avoid each other. Effectiveness in suppressing feral cats: 6/10.
Indirect suppression
Another study recently published on the PHYS.ORG website asks if dingoes are the answer to Australia’s feral cat and fox problem?
It was carried out by a Harry Butler Institute scientist, Prof Trish Fleming, Director of the Centre for Terrestrial Ecosystem Science and Sustainability.
They concluded that dingoes, feral cats and foxes do not compete for the same food and “it is therefore unlikely that dietary competition with dingoes would suppress cat or fox numbers”.
What they’re saying is that if feral cats and dingoes live in the same area, they don’t compete for the same prey animals because foxes have a very diverse diet and therefore, they can switch foods to reduce the effect of competition in chasing the same food. Dingoes are also omnivores and therefore they are more flexible in what they eat. And cats are also reasonably flexible in their prey animals despite being strict flesh eaters. Dingoes also prey on larger animals than feral cats.
So, although there are some common prey animals for all three of these predators, they can be selective and eat different prey animals. That’s my interpretation.
And therefore, dingoes do not suppress feral cats indirectly by eating the prey animals of feral cats thereby making it harder for feral cats to survive. Another factor is that if there is plentiful prey it doesn’t matter whether all three predators eat the same prey animals because there will always be enough.
Prof Fleming said: “Cats consume mostly birds, reptiles and small mammals and are also reasonably flexible about what they eat, while dingoes consume more medium-sized and large mammals, including livestock.”
Effectiveness in suppressing feral cats: 2/10.
Conclusion: my conclusion would be that dingoes are not very effective in suppressing feral cat numbers overall although they will suppress numbers where they are present. This does not necessarily reduce feral cat numbers absolutely or overall.
It should be noted once again that the authors of the PHYS.ORG article state the obvious, namely that the extinction of 33 mammalian, nine bird and three reptile species, the highest extinction rate anywhere on the globe, is mainly due to habitat loss from land clearing, grazing and altered fire regime all of which is due to human behaviour to which we add predation by the introduced species: cats and foxes. Australians should tackle their behaviour first for the most effective solution to the extinction of their nature species.
Hypocritical Australians are the most destructive non-native species on their continent
Reason why TNR is ‘illegal’ in Australia except for ACT (Australian Capital Territory)