Could "from" replace "than"?

Yes. "Different from" is generally considered formally correct, but it is allowable to use "different than".

Would you ever write something like: "Weasels are different than ferrets"?

Would I? Short answer; no.

It grates — as do countless other instances of "allowable" usage.

"Different than" has been around for two or three hundred years, commonly used and widely understood, but I was surprised to learn how widely acceptable it had become.

I suspect that were we to use "Than" , to make it clear it'd have to include the sub,
"Than those of other birds". Sounds like a " stylemethods" manual instruction
course you d have to make all the numbers agree.

"The word different is an adjective, but it is not a comparative adjective. As a result, among some stylists you’ll find a distinct preference for the expression different from."

https://www.grammar.com/different-from-vs-different-than/#:~:text=The%20word%20than%20then%20serves,Thus%2C%20you%20would%20say%3A&text=So%20a%20big%20distinction%20between,be%20followed%20by%20a%20clause.


"The eclectus has a specialized digestive tract that is different from many other bird species. This bird needs to be fed a diet high in fiber and low in fat. It's also best to avoid too many vitamin and mineral supplements, which could lead to digestive tumors or abnormal behavior."

The original question may contain an error because it infers every other bird instead of many other birds.

I would say 'different to'.

Would the birds say to everything tern, tern, tern?

If you want to get it right, just remember that something is "bigger than" and "different from."

Thanks to all of you!