Based on the given statements:
1. All animals are vegetables implies that every animal is a vegetable.
2. All fishes are vegetables implies that every fish is a vegetable.
3. All birds are fishes implies that every bird is a fish.
Now, let's check each conclusion:
Conclusion I: "Some birds are animals." This is not necessarily true because it contradicts the first statement.
Conclusion II: "Some vegetables are fishes." This is true because all fishes are vegetables.
Conclusion III: "Some vegetables are animals." This is true because all animals are vegetables.
Conclusion IV: "All birds are vegetables." This is true because all birds are fishes, and all fishes are vegetables.
Thus, conclusions II, III, and IV follow.