The Secret Language of Pigs

Animals have their own language. They communicate with each other, and they communicate with us if we listen. You may not be able to carry on a philosophical conversation with them, but they do have their own intelligence level, and it is incredible if you are paying attention.

STUDYING PIG LANGUAGE

An international team of researchers from Denmark, Switzerland, France, Germany, Norway, and the Czech Republic has translated the emotions behind pig grunts. The team developed an algorithm to decode the possible emotion behind the various sounds made by pigs.

The researchers collected over 7,000 audio clips from pigs in commercial and experimental settings. The recordings were collected in a wide range of good and bad experiences from different stages of their lives, from birth to death. Findings indicate that pigs have a variety of vocalizations for other emotions.

DECODING HOW PIGS COMMUNICATE

The co-leader of the study, Associate Professor Elodie Briefer of the University of Copenhagen’s Department of Biology, says, “With this study, we demonstrate that animal sounds provide great insight into their emotions. We also prove that an algorithm can be used to decode and understand the emotions of pigs.”

Examples of positive situations the pigs were recorded experiencing include things like piglets suckling from their mothers or pigs being reunited with their families or huddling with litter-mates. Examples of negative situations include separation, fights, castration, and slaughter.

Researchers also created mock scenarios designed to elicit more subtle emotions along the middle of the spectrum—these included areas with toys and food and regions with no stimulation. Many pigs were also presented with new and unfamiliar objects to interact with. As the pigs (interacted and played), the researchers monitored their behavior and heart rates and recorded as many sounds as possible.

ANALYZING PIG VOICES

After recording thousands of sounds, the researchers analyzed them and looked for patterns between the sounds and positive and negative emotions. In adverse situations, high-frequency calls such as screams or squeals were noted. On the other hand, low-frequency calls like barks and grunts showed up in positive and negative cases. However, the most exciting discoveries came from the situations between the positive and negative extremes. Researchers found new patterns revealing even more detail.

“There are clear differences in pig calls when we look at positive and negative situations. In the positive situations, the calls are far shorter, with minor fluctuations in amplitude. Grunts, more specifically, begin high and gradually go lower in frequency. By training an algorithm to recognize these sounds, we can classify 92% of the calls to the correct emotion”, explains Briefer.

Researchers hope that the algorithm will turn into an app that farmers can use to better care for their animals. But as animal rights advocates, we hope that it helps gain rights and freedom for these billions of sentient beings who are used and abused globally.