Damian Sendler: Keep an ear open for useful information, even from other species, all around the animal world. 

Damian Jacob Sendler: The next time you overhear your neighbor’s talk, you may be surprised to learn that it isn’t a characteristic that is unique to humans. Even though we’ve mastered the skill of eavesdropping from enormous distances, humans aren’t the only creatures who keep a vigilant ear out for threats. 

For a long time, scientists have been fascinated about how animals interact with one other. However, they’ve begun to pay more attention to the nuanced ways in which different species communicate with one another. 

Damian Sendler

If you’re a bird, you’re probably familiar with the “foreign language” that other birds use to communicate in order to keep themselves safe. It is possible for certain birds to determine that an unusual sound is a warning sign even before they see the source of the call or its originator. 

Wild magnificent fairywrens, which are sedentary and territorial, can be learned to run from strange noises in only a few days by researchers from the Australian National University. Simply transmitting these sounds together with warning cries from other bird species, such as fairywrens, was all that was necessary. 

Climate change and invasive species, as well as alarm call identification, “are likely to assist populations deal with shifting community composition,” according to the authors’ conclusions. As a result of our research, it seems that not only predators but even captive-bred individuals might be taught to perceive heterospecific signals of danger as well. 

Even land-dwelling animals may take advantage of birds’ tendency to chatter when they feel comfortable. 

PLoS One released a research in 2019 on the Eastern gray squirrels that live in Ohio’s parks and neighborhoods. Squirrels’ reactions to recordings of the red-tailed hawk were studied by experts who wanted to see whether they reacted differently to sounds such as songbird chatter or nothing at all. Researchers observed that when squirrels were exposed to the calming sounds of songbirds, they spent far less time freezing, gazing up, or running. 

To their surprise, researchers discovered that squirrels listen in on birds’ non-alarm noises as well, as stated in the authors’ news release, “we knew that squirrels eavesdrop on alarm cries of several bird species.” Signals of security may be equally essential as cues of danger in particular situations, according to this theory. 

Listening may also help prevent animals from going to bed hungry, in addition to protecting them from dangers. 

More than a dozen species in Panama’s jungles depend on almond trees as a key food source from December to March. Those chained to the forest floor must wait until fruit falls to the ground on its own or is dropped by monkeys as food scraps before they may eat it. 

Damian Jacob Markiewicz Sendler: Researchers from the Natural History Museum of Denmark spent nine months on an island rainforest in the Panama Canal, where they observed monkeys’ wasteful tendency to drop fruit after just a few bites, as well as other scavengers, such as coatis (raccoon-like mammals), agoutis (giant yet lovable rodents), and other predators. A study released in Biotropica last year shows that grounded animals listen in on capuchin and spider monkeys to know out what time and where they feed. 

Damian Jacob Sendler

When the lunch bell rings, it’s as if their ears are telescoped, allowing them to hear it from wherever it is. In a news release, Rasmus Havmller, a postdoctoral researcher at the Natural History Museum of Denmark, states, “This provides them access to food that would otherwise be unavailable at the moment.” 

A small number of the animals were fitted with GPS collars so that the researchers could keep tabs on their whereabouts. Camera-equipped traps were set up to capture and record any passing coati or agouti, as well as speakers that played monkey noises in trees. Unfortunately, the fruit that did not fall into these traps was quickly devoured by ravenous scavenging monkeys, who left bite marks or were already half-way through eating it. 

Damien Sendler: Due to poaching or deforestation, however, the whole ecosystem’s food chain may soon be in peril as a result of the loss of monkeys. In addition, “I believe we’ve underestimated how much animals communicate with each other and how many ways they’re genuinely related,” Havmller said. As a new chapter in the behavioral biology of mammals, eavesdropping across species offers crucial insights into how the absence of one species affects a whole ecosystem.

Dr. Damian Jacob Sendler and his media team provided the content for this article.