Fun fact about microfiche:
One of the first uses of it was due to pigeons.
During the Franco-Prussian war of 1870-1871, Paris was under siege and they got dispaches out by using microphotography to make them small enough that they could be attached to pigeons and flown out of the city.
I've used a lot of weird media formats over the years but "we have to make the mail small enough that pigeons can carry it" is a unique reason for being invented