A recent study by Japanese researchers observing that dogs cry happy tears when reuniting with their guardians should surprise no one. Science long ago proved that dogs, like all animals, experience a full range of emotions, including joy, sorrow, empathy, grief and doubt. The evidence is both academic and empirical.
Elephants repeatedly return to the graves of deceased loved ones to pay their respects. Rats giggle when they're tickled. Crows hold grudges when they see others who have offended them--even years later.
Captive rhesus monkeys refused to pull a switch to obtain food if it meant another monkey would receive a shock, even when they were hungry. And when given the choice between feasting on chocolate or saving a drowning companion, rats chose the latter.
Video footage of a bullock carefully nudging an overturned tortoise until the reptile flipped upright garnered millions of views online. A bear at the Budapest Zoo was filmed gently plucking a drowning crow out of the water, carefully placing the bird on the ground and then going about his business. Dogs and cats routinely alert their guardians to house fires.
Animals often express their feelings very clearly. Mother cows and their calves bawl inconsolably when they're separated so that people can steal the milk.
Researchers have found that--just like us--dolphins love to gossip and gab. Those clicks and whistles are complex conversations, sharing news, relaying important tips, such as plentiful fishing spots, or expressing concern for an ill friend.
Individuals within a pod of orcas all communicate with one dialect, and can communicate with individuals in other pods who have their own dialect. The pods make up larger groups called clans, and the languages of the clans are as different as Russian is to Arabic.
Wild parrots use unique calls to name their babies, who are then instantly identifiable. When hearing a name called, other parrots can distinguish gender as well as the mate and family that the parrot belongs to, just as we can when someone calls for "Mrs. John Smith." Sometimes we can understand these keenly intelligent birds. Neighbors in one Florida neighborhood called the police when they thought they heard a woman screaming, "Help! Help! Let me out!" but it turned out to be a parrot.
When a kitten companion of Koko, the gorilla who had been taught American Sign Language, got tired of playing with her, Koko would sign, "Obnoxious. Cat." But when she was told that the kitten had been killed after getting hit by a car, she whimpered and cried and signed, "Sleep. Cat."
It has now been unequivocally established that animals aren't things to exploit but rather living, breathing, feeling beings who have families, interests, intelligence and emotions. To believe otherwise is species-ist. And as our society continues to evolve and reject that mindset, we will finally look back with shame for once having viewed animals as inferior to us.
Dr. Heather Rally is a senior veterinarian with People for the Ethical Treatment of Animals.