please can u check my work. Thank you.

example of a passive sentence:
Macaws eat nuts and berries.
Nuts and berries are eaten by the Macaw.

1) Capuchin monkeys eat fruit, insects, leaves, small birds and frogs.

my answer: Frogs, small birds, leaves, insects and fruit are eaten by Capuchin monkeys.
Is this right?

Yes, your sentence is right.