Mammals Show Emotional States

Are you as happy as a clam? Well, who knows, because that idiom is just about meaningless.

In that case, are you as happy as a pig in… okay, I’m not going to finish writing out that phrase because I’ve always found it repulsive.

But since we’re now on the topic of pigs’ emotions, did you know that these social, intelligent beings may actually empathize with one another?

Scientific American reports that scientists from the Dutch Wageningen University ran an experiment where they separated six groups of 16 pigs. The next stage involved taking a pair of pigs from each group and trying to train them to anticipate negative and positive outcomes. To do so, the researchers played the pigs certain musical tracks to accompany good experiences, like getting fed, but played different music during pigs’ bad experiences, such as social isolation and handling.

After, the “trained” pigs were placed back in pens with two untrained ones and played said music. While most of these trained animals weren’t actually trained at all and didn’t exhibit any reactions, others seemingly were. If the swine heard the music associated with good experiences, they’d play, bark, or wag their tails, while the bad-experience music influenced them to show signs of stress like pointing back their ears, urinating, and defecating (a behavior that possibly negates the essence of that disgusting aforementioned idiom).

The researchers then observed that when some of the untrained pigs noticed that the trained pigs were reacting to the music, the circumstances would, at times, influence them to exhibit the same mannerisms. It was found that the untrained pigs showed signs of shared behavior more so when the trained pigs seemed stressed than when they were happy. The scientists concluded that the actions evidenced empathy; when untrained pigs heard the music in the absence of their trained counterparts, the former showed no emotional reactions.

Photo courtesy of Steve Bates.

Speaking of the emotional states of livestock, Alan McElligott, senior lecturer in animal behavior at the Queen Mary University of London, had something to say about goats’ place in animal welfare studies: they were “underrepresented.”

The notable absence in this area of human knowledge motivated McElligott and his colleagues to take it to the goat fields, specifically during the summer months–apparently because the animals detest the cold and rain.

The researchers executed actions that would make the goats feel happy, such as shaking food in a bucket and then feeding the animal, or to feel upset, like separating goats into two pens and only feeding one. By observing their behaviors, the human goat watchers determined that the four-legged creatures displayed signs of happiness by pointing their ears forward. Also, when the goats called out gleefully, the pitch would sound more stable. There were more fluctuations in the goats’ calls in their negative states.

That’s helpful news considering that, as of 2014, we share the world with almost 900 million goats, according to NPR.

Other mammal species are known to vocalize particular sounds when they are in a good mood. Ferrets, for instance, have the tendency to “dook”–a noise that resembles chuckling and clattering. According to veterinarians Doctors Foster & Smith, if a ferret dooks while jumping towards a person, that means the pet is trying to play.

Purring may be synonymous with feline happiness. However, research suggests that cats don’t only purr when they are in a pleasant state, but when they are scared, hungry, or injured. Some researchers even believe that cats purr in order to offset bone regeneration.

Personally, I’ll never forget how my cat was purring when she was giving birth to kittens, but since I’m not an animal communications specialist, I can’t tell you how happy or scared she truly felt at that time.

However, one Sussex University scientist who does study animal communication, Karen McComb, once investigated a phenomenon she calls the “solicitation purr.” Perplexed by the strangely compelling purr noises her cat would emit each morning, McComb sought out to see what that annoying, alluring behavior was all about.

“Solicitation purrs” are described as sounding urgent but unpleasant. McComb found that cats reserve this practice for one or two humans they are close with and receive ample attention from.

Photo courtesy of Rachael Towne.

The noise is basically two sounds at once: a “low-frequency purr” and a “high-frequency cry” that resembles that of a human baby. Cats figure out how to engage their muscles to purr and use air to cause the high pitch.

“The embedding of a cry within a call that we normally associate with contentment is quite a subtle means of eliciting a response–and solicitation purring is probably more acceptable to humans than overt meowing,” McComb told The Guardian.

Well, we can give our regards to McComb for being smart and motivated enough to figure out the tricky tactics of the world’s most popular household furry friend. Because of the hard work of such curious, committed scientists, humanity can now better understand the behaviors and emotional states of the animals our species has domesticated, and even how they employ certain practices upon us.

Feature photo courtesy of liz west.

recommendations