I cannot find anything about this online except dozens of pages saying "dizziness (or seeing stars) is often displayed by circling stars, or sometimes birds" and no one actually mentioning where the use of birds came from

~author/streamer/gamedev~ appreciator of colorful wigs
I cannot find anything about this online except dozens of pages saying "dizziness (or seeing stars) is often displayed by circling stars, or sometimes birds" and no one actually mentioning where the use of birds came from
It's, uh, brain trauma that causes that. It's very bad.
I know it's old - very, very old. When it was used in Looney Tunes it was considered an old gag.
I've seen it in newspaper comics from the 1910s so like, it's old. Odds are good it was something someone early on did as just a single individual idea and a lot of other people copied it - it doesn't feel like it's representing a meaningful universal experience/medical idea.
Man now you got me digging into this. I had a figure that it was popularized in looney tunes, but I cant find any proof of them specifically having birds circle around the head in that show, just plenty of other things.
The earliest thing I can find any actual proof of is from 1942 https://4.bp.blogspot.com/-fIRpOiMQumA/VDF4PPf0rFI/AAAAAAAAZio/V88bHYNto-0/s1600/Screen%2BShot%2B2014-10-04%2Bat%2B22.06.58.png where it specifically birds
The stars thing you can find a lot of earlier examples from comics in the 1910s, like the comic that came before popeye Thimble Theatre. Any time someone is hit in that comic in the head, little stars pop out of their head.
My best guess here, from the little research I've done, is that this started as a visual gag where it was stars exploding from the head/circling as a reference to the "seeing stars" thing.
Then over time, artists got more creative with it and changed it from stars to whatever caused the injury. There's a still of Wiley Coyote having the roadrunner run around his head for example. There are plenty of stills in early cartoons you can find where the object rotating around the head is just whatever caused the injury.
Then probably at some point, someone did a bird (I swear I have a memory of seeing it for Sylvester and Tweety but I can't find proof), and that one was funny enough/stand out enough to stick in other cases? Birds have the additional connotation cartoon wise for Cuckoo Clocks and so visually are also used to display disorientation or "crazyness", so you get a sort of double meaning.
That's all pure conjecture though.
It's something I've been curious to as well. (This particular trope and I have a long, long history, in fact). I'm sure there's an impressive historical line to follow here, but as far as I'm aware, sometimes the birds are because it's a possible /thing you can hear/ upon concussion? Sort of... on top of the usual ringing you tend to see in most media. (Though that's also why circling bells sometimes are depicted.)
If you do find a clear source on this, I'd be eager to see it!
There was some old ass thing in some language to say "those who stare at the birds" meaning "to daydream" and we all know that daydreaming was a thing to speak about of people with neurodivergencies. Pair that with the casual abuse/torture for fun of people who was deemed crazy but inofensive and you may get a response. Even makes more sense when you believe hard hits to the head can provoke neurodivergencies. Although all of this is speculation several persons in an art history career did some day out of boredom.
Perhaps there's some deeper 'ringing ears' sounding like twittering birds going on? But it feels like it may have come out of the need to express dizzyness through metaphor in comics? Or did it hit cartoons first, where the birds flying around serves as an interesting animation during otherwise "down" time with a 'dizzy' character?
I do recall older Sylvester and Tweety cartoons where the birds were explicitly Tweety, but I don't know which direction that reference is in, it might have started there, or could be a reference to the generic iconography. It seems like it's probably older.
There is a limited entry here: https://tvtropes.org/pmwiki/pmwiki.php/Main/CirclingBirdies