Humans' innate talent in vocal learning is impressive, serving as a prerequisite for language formation.

When infants hear sounds, they form memories of them and then attempt to reproduce those sounds, refining them as they grow.

While most animals cannot learn to imitate sounds, primates can utilize innate vocalizations, yet they cannot learn to produce novel sounds. Interestingly, some more distantly related mammals, such as dolphins and bats, also possess this ability.

However, among the many sound mimickers, birds stand out as the most impressive.

Birds such as parrots, songbirds, and hummingbirds can learn new vocalizations. Their calls and songs share similarities with human language, such as intentionally conveying information and utilizing elements like phonetics, semantics, and syntax. Research suggests that this similarity is rooted in shared brain structures.

Columbia University animal behaviorist, Hélène Brunet, studies how sparrows learn to sing. "The parallels between these birds and human vocalization have sparked decades of research," says Brunet.

She studies sparrows because, unlike most migratory birds, they prefer communal living, enjoying small group travels and occasionally congregating into larger flocks. "It's intriguing how they learn vocalizations within these groups," adds Brunet, who authored a paper in the 2021 Annual Review of Linguistics comparing birdcalls to human language.

For instance, both bird songs and human language are passed down through vocal learning. Geographically distant populations of the same bird species can gradually adjust their calls over time, eventually forming a new dialect—a process somewhat akin to how humans develop different accents and dialects.

Given these similarities, one might reasonably ask whether birds themselves have language, though this may depend on how you define it. "They possess what we might call rudimentary oral languages," says neurobiologist Erich Jarvis of Rockefeller University in New York, a co-author of Brunet's paper on birdcalls and language.

Semantics is a key component of human language, the association between words and meaning. Scientists have long believed that, unlike our language, animal sounds are instinctual responses, merely reflecting the animal's emotional state without conveying any additional information. However, over the past 40 years, extensive research has shown that various animals have distinct vocalizations with specific meanings.

Many bird species use different calls for different predators. For example, Japanese tits nesting in tree holes emit a call to make their nestlings crouch, avoiding being pulled out by crows, while another call prompts the nestlings to fully evacuate the nest when facing a snake.

Siberian jays alter their calls based on whether the eagle is perching, searching for prey, or actively attacking, eliciting different responses from nearby jays with each call. Black-capped chickadees vary the length of their unique calls to indicate the threat of predators.

Recent studies suggest that the sequence of bird vocalizations may also influence their meanings. While this idea is controversial, it may represent a basic form of grammar akin to human language.

In one test, researchers repeatedly played a standard bird song with intervals, then inserted a whole section of artificially rearranged music, easily discernible to humans but surprisingly poorly recognized by birds; in another test, when scientists introduced variations by reversing one syllable in each standard song, the birds were adept at detecting these changes.

"Perhaps much of the meaning in bird song is assigned to individual syllables, with the arrangement of syllables being less crucial for conveying meaning," says Fishbein.

Exploring the mysteries of animal language learning reveals many surprising similarities and intriguing differences. These studies challenge our traditional understanding of language and prompt us to rethink the nature of animal intelligence and communication. We eagerly anticipate further revelations about the secrets of animal language abilities in the future!