Distinctive diets of eutherian predators in Australia

Area of Science:

• Ecology and Conservation Biology
• Invasive Species Management
• Wildlife Ecology

Background:

• Introduced predators, specifically domestic cats (Felis catus) and red foxes (Vulpes vulpes), have caused significant declines in Australian native fauna.
• Understanding the dietary habits and interactions of these invasive predators, alongside native dingoes (Canis lupus dingo), is crucial for effective conservation strategies.
• Previous research indicates substantial impacts on native species, but detailed comparative dietary analyses are needed.

Purpose of the Study:

• To synthesize Australian diet analyses of cats, foxes, and dingoes.
• To identify prey traits, frequency, and distinctiveness in each predator's diet.
• To quantify the dietary overlap between these three predators and assess implications for native fauna conservation.

Main Methods:

• Compilation and synthesis of existing Australian diet analyses for cats, foxes, and dingoes.
• Analysis of prey species composition, frequency, and distinctiveness across predator diets.
• Quantification of dietary overlap using established ecological metrics across various locations and time points.

Main Results:

• Nearly half (45%) of all Australian terrestrial mammal, bird, and reptile species were found in the diets of at least one predator.
• Cats preyed more frequently on birds, reptiles, and small mammals, with little dietary change over 55 years.
• Dingo diets remained consistent over 53 years, focusing on larger prey, while foxes exhibited greater dietary overlap with cats and dingoes, showing significant heterogeneity suggesting prey switching.

Conclusions:

• The study reinforces concerns about the impact of mesopredators (cats and foxes) on threatened native Australian species.
• Extensive dietary overlap exists between invasive predators and native dingoes, complicating conservation efforts.
• Control of introduced foxes and cats is essential for Australian fauna conservation, though the role of dingoes in suppressing these mesopredators remains unresolved due to low incidence in dingo diets.