Why do people say "night owl"? Aren't all owls nocturnal? Why not just say "owl" instead of "night owl"?

Question

Really? Interesting. That's what I always thought (that all owls are nocturnal). Thanks. I'll read up on it.

Answer 1

The point is not precisely whether certain owls are nocturnal or not, certainly NOT to distinguish nocturnal from non-nocturnal owls The expression is based not on careful scientific study of species and their habits, but on common popular understanding. The point is simply to EMPHASIZE that the speaker is comparing THIS particular aspect of owl-ish behavior with that of some people.

It may help to note that people may be compared to owls in OTHER ways. In particular, we may call someone a "WISE old owl".

So, if you were simply to refer to someone as "an owl", it might not be so clear what point you are making. But "night owl" makes it very clear.

(We add adjectives in this way to all sorts of other similes or metaphors we use for people, again to specify the point of comparison. )

Answer 2

night owls refer to people who tend to stay up late at night, right?

and, not all owls are nocturnal (i.e. burrowing owl)

check wikipedia for more information