A Bertram Chandler's "The Cage" (short story, science fiction): A shorter version of Pierre Boulle's "Planet of the Apes"
While there are many stories with "men as zoo animals" theme, these two are the only ones I've read where this is the main theme.
Because of shorter length, this is a simpler & less nuanced story than "Planet of the Apes". But plot idea is the same: A group of humans happen to be in a condition where they are mistaken as non-sentient animals by beings that are otherwise intellectual & technological peers. The humans get hunted, caught, & put in zoo & laboratory cages.
Problem for these zoo animals is to convince their captors that they are sentient & deserve better treatment.
Story summary.About half the story is about how this group of humans ended up in the unfortunate situation; later half is about their capture by an alien "survey ship", life as zoo animals, & eventual release.
"At least two hundred days had passed since their landing on the planet without a name" - these human "survivors from the interstellar liner Lode Star". Ship had to make emergency landing. There was something wrong with its atomic "Ehrenhaft generators"; they had landed on a world in an unexplored region of galaxy & had only chance to send SOS (but not receive acknowledgment).
50 odd passengers were parceled off to a place somewhat away from wrecked ship while Captain & a small crew tried fixing things. They failed; the explosion destroyed both the ship & crew, & left a crater where ship stood. Survivors were stranded on this unfriendly world - always hot, always drizzling, though no hostile local animals, ample local food & water, & breathable air.
They have degenerated into a primitive existence in this period. And there is very skewed sex ratio. "There are fifty-three of us here, men & women. There are ten married couples... That leaves thirty-three people, of whom twenty are men. Twenty men to thirteen ... women... What sort of marriage set-up do we have?" They choose monogamy. If two men want the same woman, they must fight it out; winner takes the woman!
It's during one such fight with the crowd cheering that 6 of them are picked up by an alien hunting helicopter; alien spaceship is parked a little distance away.
"The world to which they were taken would have been a marked improvement on the world they had left, had it not been for the mistaken kindness of their captors. The cage in which the three men were housed duplicated ... the climatic condition of the planet upon which Lode Star had been lost." So hot atmosphere & constant drizzle, & same boring fungi as food that they had adapted to on the world they were taken from!
Of the 6 humans captured, 3 men in this cage are "Hawkins, Boyle, & Fennet". In a nearby cage is "Mary Hart". Remaining two - "Clemens & Miss Taylor" - probably ended up on the vivisection table.
Their captors "aren't the same shape.. And we, were the situations reversed, would take some convincing that three six-legged beer barrels were men & brothers." They try Pythagoras's Theorem with pictures made from twigs to interest their captors, without luck.
They try showing their "manual dexterity by the weaving of baskets" from stuff within their cage. Captors think its a mating ritual - like beaver's dams! So "Mary Hart was taken from her cage and put in with the three men"!
It's during the night of her stay in men's cage that Mary made a racket - when Joe, a little local mouse-sized animal, passed over her when she was asleep. Men consider Joe a kind of friendly pet. She insists men kill Joe; they instead make a basket type cage & put Joe there after trapping it.
It's this trapping & caging of Joe that reaches out to captors. They will be recognized as sentients & gain their freedom because "Only rational beings ... put other beings in cages"!
Fact sheet.First published: F&SF, June 1957.