You could have saved yourself and everyone who bothers to read your comment a lot of trouble if you had merely posted : Dilbert is a cartoon with talking cats, dogs, rats and weasels. We've also seen absurd machinery like the one that brought us Anti-Dilbert. In this absurd universe, there's plenty of room for non-mammals using SONAR...
Brevity is not merely an art, it is a necessity in these short attention spanned times.
http://en.wikipedia.org/wiki/Animal_echolocation
"Oilbirds and some species of swiftlet are known to use a crude form of biosonar (compared to the capabilities of bats and dolphins). These nocturnal birds emit calls while flying and use the calls to navigate through trees and caves where they live."
But these are birds, using echolocation to navigate in darkness, not underwater. And the article for sonar says:
http://en.wikipedia.org/wiki/Sonar
"This article is about underwater sound propagation. For atmospheric sounding, see SODAR."
So, either
I) Scott does indeed need a refresher in biology, like you said
II) Scott knows that the joke falls apart if he has Wally talking about SODAR, since nobody knows SODAR. But everybody is familiar with SONAR, so he has Wally say "SONAR"
III) Wally is meant to look stupid in this frame, thinking that dolphins are fish, not mammals
IV) Wally knows that the girl doesn't know about SODAR, but since everybody is familiar with SONAR Wally uses that word instead.
V) Wikipedia is wrong about the distinction between SONAR and SODAR
VI) Dilbert is a cartoon with talking cats, dogs, rats and weasels. We've also seen absurd machinery like the one that brought us Anti-Dilbert. In this absurd universe, there's plenty of room for non-mammals using SONAR...