Over abundant rabbit populations lead to high densities of feral cats – and a correspondingly high impact of cats on native species, especially small mammals. What happens when rabbit numbers drop?
Research to see if cats prey-switch (eat more small mammals) or if their numbers drop instead (not impacting native animals) has concluded that:
- Cat activity and survival dropped by 40% following a reduction in rabbit numbers by 80%.
- Surviving cats increased their consumption of reptiles, birds and invertebrates.
- Small mammal activity declined, although there was no change in the proportion of cat scats containing the remains of small mammals, or the rate at which cats were recorded killing small mammals.
It was concluded that both prey-switching and a reduction in cat numbers occurred; which may result in net, long-term benefits for native prey threatened by cats. Running rabbit and feral cat control programs in tandem would be expected to enhance the net benefits.
For more information, see the article by Hugh McGregor et.al. in Biological Invasions (2019).