It’s not unusual, when an article appears discussing any kind of research on animals’ capacity to communicate with humans, for at least one irate pet owner to comment: “Yes well, anyone with a dog could have told you that.”

In my case, the response would be literal. Nearly anyone with a parrot could regale you with stories about precious Polly using just the right word at the right time. And let me tell you, the meme is right: cat people and dog people don’t always agree, but they know one thing. There is nobody in the world as weird as bird people.

I think I may have fallen in love with parrots for life when my childhood budgie chose a particularly awkward moment to demonstrate hitherto unrealised creativity, landing on a visitor’s shoulder and saying in a theatrical whisper: “Piss off, spoilt brat.”

Of course, that’s the thing: it’s really us humans projecting expression and context most of the time. Parrots – as mine did – can string together any number of combinations they pick up from television, each other, or the humans around them. Often it’s just word salad. Other times it’s perfect.

If it’s repeated often enough, the animal learns, much like we do at a very basic level, that certain words at certain times result in certain outcomes, hence the cliché of Polly wanting a cracker, or the dog owner that has to spell out W-A-L-K.

But there are more intriguing questions. Dr Irene Pepperberg, best known for her studies in animal cognition, gained widespread recognition for her work with Alex the African grey. Pepperberg believed that beyond mimicry, the birds’ vocal behaviour shared some characteristics of human language. Needless to say, her study was hugely controversial. Pepperberg reported that Alex had the vocabulary, syntax and communication skills of a child of approximately two, and the problem-solving skills of a child of five.

And why does this matter, one might ask, except to further delight already nauseating parrot owners?

Well, according to Wikipedia, “Some researchers have suggested that studying avian cognition might allow a useful artificial intelligence to be built without requiring many resources, as for some applications a parrot or corvid level complexity brain would be adequate, such as for image sorting.” Then there is the model/rival technique, used to train Alex, which some argue holds promise in the (human) classroom.

Dolphins have raised similar questions. Can the study of dolphin intelligence aid in the advancement of AI? And vice versa, for that matter – will we finally know what those tuna-loving buggers are skinnering about? Early, and admittedly rather horrible, studies include the case of Peter the bottlenose dolphin, who eventually committed suicide after a failed experiment funded by Nasa. Margaret Howe Lovatt was assigned as a companion to Peter in an attempt to advance interspecies communication in the 1960s. Lovatt lived with Peter in an underwater apartment, sleeping in a bed on an elevator and doing her admin on a desk suspended over the water.

“It never occurred to me not to do it,” Lovatt explained. Lovatt gave Peter twice-daily speech lessons, at which Peter reportedly worked very hard. An unfortunate detour came up when Lovatt found it was easier to relieve Peter’s sexual urges herself, manually, rather than send him to relieve himself with the female dolphins; the story wound up in Hustler entitled “Sexplay: Interspecies sex.” Eventually, as experimentation with giving LSD to dolphins became the next big thing, the lab lost its funding and Peter was moved. His and Lovatt’s bond was broken, and Peter didn’t survive it.

Since then, research into dolphin communication has evolved somewhat. National Geographic describes them as “extraordinarily garrulous”.

“Not only do they whistle and click, but they also emit loud broadband packets of sound called burst pulses to discipline their young and chase away sharks. Scientists listening to all these sounds have long wondered what, if anything, they might mean. Surely such a large-brained, highly social creature wouldn’t waste all that energy babbling beneath the waves unless the vocalisations contained some sort of meaningful content. [D]espite a half century of study, nobody can say what the fundamental units of dolphin vocalisation are or how those units get assembled.”

And yet what has emerged is that dolphins, amazingly, appear to use language referentially. They don’t simply signal food, danger, etc. They can actually speak about things or each other. They also have the capacity for problem-solving and planning ahead. As for their language use, they may call each other by name.

“A century ago, human-like traits were excessively attributed to animals. During the 20th century, the scientific pendulum swung back, to the point where animals were assumed unintelligent unless their abilities could be experimentally demonstrated in controlled settings. For most animals, including dolphins, that’s logistically difficult, and animal intelligence may be deeply under-appreciated as a consequence,” noted Brandon Keim in Wired.

Primate studies, too, have their share of horror stories. There’s Lucy the chimp, who was integrated into a family (spoiler alert: she did not end up going off to college and marrying a nice doctor).

Watch and decide for yourself – Animal communicator Anna Breytenbach:

There’s Washoe, also a chimp, who was the first non-human to learn sign language. Something of an overachiever, Washoe taught her son Louis some sign language as well.

Readings of Washoe’s progress are mixed. Washoe referred to a swan as “water bird”, a thermos flask as “metal cup drink” (she didn’t know the word “thermos”). When new trainers worked with her, she would slow down her signing until they adapted. She reportedly sympathised with her caretaker, Kat, when she miscarried. One recalls, after Kat missed work for several weeks:

People who should be there for her and aren’t are often given the cold shoulder – her way of informing them that she’s miffed at them. Washoe greeted Kat [the caretaker] in just this way when she finally returned to work with the chimps. Kat made her apologies to Washoe, then decided to tell her the truth, signing “MY BABY DIED”. Washoe stared at her, then looked down. She finally peered into Kat’s eyes again and carefully signed “CRY”, touching her cheek and drawing her finger down the path a tear would make on a human (Chimpanzees don’t shed tears). Kat later remarked that one sign told her more about Washoe and her mental capabilities than all her longer, grammatically perfect sentences.

But there are also multiple cases of research into primate communication that is not successful. Even in the successful experiments, there are transcripts that amount to word salad, not much better than the conversations I had with my childhood budgie. A prime example (primate example? Sorry, I had to) is Koko the gorilla, who made headlines for her relationship with Robin Williams. At the time of Williams’ death, her mourning was described by Slate as “selective interpretation”, which seems to apply to a number of stories of animal communication – or the “clever Hans” effect, as others put it.

“But,” admitted writer Jane Hu, “conceding that the scientific jury is still out on whether gorillas are capable of sophisticated emotions doesn’t make headlines, and admitting the ambiguity inherent in interpreting a gorilla’s sign language doesn’t bring in millions of dollars in donations.”

Well, quite. It’s just not that appealing to say we don’t know. But considering we humans are still figuring out how to talk to each other, the ambiguity of understanding animals is hardly surprising. DM