Sort of, yes, but I've seen it mis-represented a lot.

I have seen headlines like "man stores PNG file on bird!" which categorically did not happen, the image was analog.

A common tool that is used in amateur radio practice is called a Waterfall Display. It works a little bit like the visualizer in Windows Media Player if you remember those, you get a window that shows a section of radio (or audio) spectrum. A signal (or sound) at a particular frequency will make that spot on the graph glow, the louder the signal, the brighter that spot will glow. The entire chart continuously scrolls to represent the passage of time, so you end up with kind of a graph of what signals are being made over a brief amount of time.

If you made a signal that swept up in frequency over time, it would be seen as a diagonal line on the waterfall. Using that concept, you can make all kinds of weird signals to draw pictures in the waterfall. Youtuber Ringway Manchester shows off several examples of this that he recorded that were played as part of the Ukraine/Russia conflict. this video. Here it was done out of jamming military communication frequencies, propaganda and trolling. See also UVB-76 for a tangentially related rabbit hole to fall down. If you play these sounds out of a radio's speaker, they just sound like a strange warbling noise.

Play that strange noise to a bird that is good at mimicking, like a mockingbird or starling, and it'll mimic that sound. Point a microphone hooked up to a waterfall display at the mimicking bird, and the bird will draw the image on the waterfall display when it sings.

Yup - Super obscure steganography! (Shitty baud/bandwidth though)

and whether the Internet is doomed to be slow in locations where the only avian carriers available are flightless.

Where would that be? Even inland Antarctica has skuas.

The coffee pot protocol is such an interesting anachronism. Nobody would make a hardware control protocol by extending HTTP like that anymore.

For good reasons, really. It's unnecessary to do it that way.

Its a series of tubes.

Its seared in my brain.

https://what-if.xkcd.com/31/

That's kinda how aws got companies into cloud storage.
A truck that would duplicate a companies disks, then drive to a data center and make the data available on s3 or whatever.
Retired now, tho.

https://www.datacenterdynamics.com/en/news/aws-retires-snowmobile-truck-based-data-transfer-service/

But shitty round trip time.