I understand that, in English, people sometimes use a singular noun to represent an entire group and they generally use "the" before the noun.
The owl is a wise bird. Many cultures share this belief. There are many folk-tales about the wisdom of owls found in various countries which indicate how wide spread this belief is.
Is the meaning exactly the same if you say "Owls are wise birds." instead of "The owl is a wise bird" in this case?
Are there rules for when to use each?
Your understanding is correct for verifiable facts:
'The owl is a nocturnal predator'.
'Owls are nocturnal predators.'
When we ascribe human attributes to animals we have to say
'The owl is said to be a wise bird' or 'In folklore, owls are said to be wise birds.'