Rachel in Love by Pat Murphy

Rachel in Love by Pat Murphy (Asimov’s SF, April 1987) opens with a chimpanzee called Rachel finding her human “father”, Aaron, dead in bed one morning at their desert ranch. Rachel covers him up and continues taking care of the other animals at the ranch before eventually letting them go. During this period she thinks of the stories her father used to tell her, and we find out that Rachel is more than just an intelligent chimpanzee:

Rachel’s father worked at a university, studying the workings of the brain and charting the electric fields that the nervous impulses of an active brain produced. But the other researchers at the university didn’t understand Rachel’s father; they distrusted his research and cut off his funding. (During this portion of the story, Aaron’s voice took on a bitter edge.) So he left the university and took his wife and daughter to the desert, where he could work in peace.
He continued his research and determined that each individual brain produced its own unique pattern of fields, as characteristic as a fingerprint. (Rachel found this part of the story quite dull, but Aaron insisted on including it.) The shape of this “Electric Mind,” as he called it, was determined by habitual patterns of thoughts and emotions. Record the Electric Mind, he postulated, and you could capture an individual’s personality. Then one sunny day, the doctor’s wife and beautiful daughter went for a drive. A truck barreling down a winding cliffside road lost its brakes and met the car head-on, killing both the girl and her mother. (Rachel clung to Aaron’s hand during this part of the story, frightened by the sudden evil twist of fortune.)  p. 73

Aaron subsequently transfers the “Electric Mind” of his daughter into Rachel, who becomes a creature with a merged/dual personality and memories. Aaron then teaches Rachel American Sign Language.
After Aaron’s death Rachel continues to live on the ranch, but the police eventually turn up and find his body. Rachel runs into the desert—she reluctantly leaves as her father told her that it was the only place she would ever be safe—but is seen by the police; later she is tracked down, and shot and drugged, by people from the Primate Research Centre. After she is taken to their facility, Rachel lies paralyzed but conscious while she is roughly handled (a TB injection into her eye socket, and a flea treatment that burns her skin). She is then put in a cage next to another chimpanzee, an elderly and traumatized individual with an electrode sticking out of his head.
The central part of the story initially sees Rachel keep her language ability to herself, something that she is glad of when she sees scientists talking to her neighbour with sign language and learns about their experimental requirement for ASL-able chimpanzees. Later though, despite her wariness, Rachel strikes up an odd relationship with Jake, the Centre’s deaf and alcoholic janitor, when she sees him give her neighbour a banana and talk to him with ASL. Rachel subsequently manages to convince Jake to let her out of her cage to help him clean the labs, and he agrees as he wants to get to the night’s drinking more quickly.
During the many nights they spend together at the end of his shift, Rachel watches Jake drink and look at his men’s magazines. She eventually develops emotional and sexual feelings for him—something that culminates with her trying to seduce him when she comes into heat. (I should add that a significant chunk of the story deals with Rachel trying to process the memories and feelings she has inherited from Aaron’s daughter, a blonde haired girl—something that competes and conflicts with her natural chimpanzee behaviour.) However, when Jake ignores her advances, Rachel goes back to the cages and releases a male chimpanzee called Johnson. She mates with him before they go on the run.
The final part of the story (spoiler) starts with the two chimps walking back through the desert to Rachel’s ranch when they are spotted by a woman driver. She sees that one of them is wearing a baseball cap and carrying a carrier bag, and her account of this eventually leads to press interest in the two escapees.
The two chimps later shelter in a cave; Rachel thinks while Johnson sleeps:

The rain lets up. The clouds rise like fairy castles in the distance and the rising sun tints them pink and gold and gives them flaming red banners. Rachel remembers when she was younger and Aaron read her the story of Pinocchio, the little puppet who wanted to be a real boy. At the end of his adventures, Pinocchio, who has been brave and kind, gets his wish. He becomes a real boy.
Rachel cried at the end of the story and when Aaron asked why, she rubbed her eyes on the backs of her hairy hands. —I want to be a real girl, she signed to him. —A real girl. “You are a real girl,” Aaron told her, but somehow she never believed him.  p. 93

The newspaper reporter who originally wrote up the woman’s sighting of the pair as a humour item subsequently finds the carved names on the wall of the cave. He writes another article, and publishes a photo of what he found. As a consequence of this, when the two chimpanzees are surprised by a woman when they are using a tap outside a house, the woman addresses Rachel by name and brings her and Johnson food (when she doesn’t respond to Rachel’s ASL thank you, Rachel scratches out the words in the soil). The woman is subsequently interviewed by the newspaper, and investigations into the Primate Research Centre and Aaron intensify. Then, after Jake the janitor is interviewed and reveals what he knows about Rachel, the ACLU appoint a lawyer to the case.
The final scene sees Rachel and Johnson arrive at the ranch where there are TV crews waiting but, just before they get there, Rachel recalls a recent dream in which she was looking through a window:

The face that looks in at her has jug-handle ears and shaggy hair. When she sees the face, she cries out in recognition and opens the window to let herself in.  p. 96

This is a very moving piece, even if you just view it as a prisoner/anti-vivisection story. What makes it more impressive is the secondary story where Rachel struggles to come to terms with her identity.
***** (Excellent). 11,700 words.