i’m beginning to think you’re doing this on purpose…
I know it’s not a perfect translation, but it seems that this line – as well as the lines from later episodes – has a very distinct meaning in Japanese. I’m sure it does in Japanese-English too, but, well, as far as my reading goes it feels like a very strong case for “this line makes sense in Japanese”
Which birds have beards is a really deep and interesting question.

(Source)
Well, bearded vultures, for one, of course.
![[Description] The comic book page is white, with a speech bubble. Text: ` [Text] IS A BIRD [newline] WHICH BIRDS [newline] HAVE BEARDS?!](https://64.media.tumblr.com/64cee0a9d9036f7c49c274cc66884acb/14f7bbf195dfe506-95/s500x750/0eee5a20ae093a40bd103517669bd2757afab54e.png)