Passage Summary: Australia has plenty of meat-eating reptiles but very few meat-eating mammals, probably because mammals need to eat way more and Australia's environment doesn't offer much food.

Conclusion: The lack of food in Australian ecosystems is the likely reason why there are so few species of carnivorous mammals compared to reptiles.

Reasoning: Mammals have higher caloric requirements than reptiles, making it harder for them to survive in environments where food is not abundant.

Analysis: The phrase 'This is probably a consequence of' is a major clue that the author is offering an explanation for the observed phenomenon. The rest of the passage provides the biological 'why' regarding metabolic differences to support that explanation. Focus strictly on the sentence that identifies the cause of the disparity between mammal and reptile species counts.