This is a fascinating comparative study on diet of cats, foxes, and dingos. Interestingly, it also includes changes in diets through time. The paper is well written, and the analysis seems sound. I think the results are not only interesting from an ecological point-of-view, but will also be important in informing conservation policy-makers and practitioners. I thought the discussion was a little speculative in places, and I think there is more than enough related to the results that could perhaps have greater emphasis in the conclusions. I would recommend some more discussion of the interpretation of the results for conservation management. For example, in some settings, one of the species might be more (or less) problematic for native species of interest – therefore resourcing priorities might be adjusted to tackle the more “damaging” predator in that context. I can see a whole range of implications from these interesting results.

Detailed comments
Line 74 – “no change in cat diet” – fascinating!
Line 115 -118 – worth also mentioning that presence of an animal in the diet does not necessarily mean it was preyed upon by the predator. The animal may have been scavenged – and this has implications for the interpretation of the impact of the predator. Scavenging may be a minority source of the dietary item, but still important to flag with the reader.
Line 134 – 137 Are you sure? I had a quick look at Google Scholar and could see a few papers that certainly have elements of what you have done. OK to keep this statement – but recommend that you check this is definitely the case.
Line 181-183 – see above comments re: scavenging.
Line 242 – Check the manuscript for consistency in the use of numbers versus spelling out in the text. Usually, it should be 1 – 9 should be spelled out, then numbers thereafter. Also, numbers at the start of the sentence should be spelled out. The format is inconsistent in the manuscript – for example – “7 main food categories” but “Nine native mammal taxa” a few lines below.
Line 254 – see comments above about scavenging.
Line 279-281 – as above, you acknowledge the difference between diet items being scavenged versus preyed upon – but I think you need to discuss somewhere what the implications for interpretation are of the two ways in which food is derived.
Line 369 – is this lack of a relationship unexpected? Worth discussing in the Discussion. Also, do you mean to include the word “neither”?
Line 389 – replace “of” with “between”.
Discussion – I think the discussion would benefit from a bit more discussion of what the findings mean for conservation management.
Line 604 – 607 – Isn’t this statement contradicted by the finding that there was no relationship between mammal prey body mass and presence in the diet?
Line 621 – 623 – this should be discussed more.
Line 624-627 – doesn’t this logic also apply to the finding about fox diet also?
Line 648 – “three years”
Line 678 – reference needed.
Line 694 – “even when dingoes kill foxes, they may not eat them” – perhaps, but the lack of fox in the diet does not prove they kill but don’t eat – it could also mean they don’t kill them. Potentially this raises questions about whether suppression (if it is occurring) is via lethal control. The alternative pathway could be through landscapes of fear.
Line 703 – or they might not kill them at all…
Line 702 – 705 – “Interference competition” – I think you should mention the theory of landscape of fear – this links into other work internationally.
Line 722 – 723 – this is quite speculative, and I think your results are strong enough that you don’t need to speculate.
Line 723 – “could avoid competition” – but you say above that they didn’t change their diet.
Line 723 – 726 – this example does not support the preceding sentence.
Line 739 – this is speculative.
Line 747 – are there any biases associated with the distribution of datasets across biomes/ecosystems?
Line747 – Something that I think is worth discussing is the relative abundance of prey species i.e. common species like rabbits are more likely to appear in scats and stomachs than rare species. Further, in terms of impacts – a rare species appearing in the diet that has been preyed upon has more implications for the population of that species than when a common species appears in a diet. In short, the weighting of the importance of the diet items in terms of conservation impact varies.
Conclusion
I think the conclusion could stay a bit closer to the findings and evidence. Line 782 – 784 is particularly speculative. I think you have more than enough to talk about with the interesting results, and it would be good to shift more focus onto the conservation implications of what has been discovered.