These clever mammals may know when two trunks are better than one
In a recent elephant study by researchers from the United States and Thailand, pairs of giant animals learned to work together to get some ears of corn. Other animals, especially some primates, are already known to work together to complete tasks, but now elephants have joined the club. Perhaps the finding is not too surprising: Scientists suspect that elephants, with their big brains and survival savvy, may be among the smartest animals on the planet.
Joshua Plotnik, who worked on the study, told Science News that the animals didn’t just learn a trick. Instead, the ways the elephants behaved show that they understand how working together brings benefits to everyone involved. Plotnik is a comparative psychologist now at the University of Cambridge in England. Psychology is the study of behaviors and mental processes, and comparative psychologists study how animals other than humans behave.
It's not easy to study elephant behavior. They're the largest mammals that walk on solid ground, and if they don't like a particular experiment, look out! Scientists have to be careful to keep their distance.
To figure out whether elephants can cooperate, Plotnik and Frans de Waal, a comparative psychologist at Emory University in Atlanta, built a test. The test was based on one that's been used to study the behavior of primates for more than 70 years. Primates include animals such as chimpanzees and monkeys. (Humans are also primates but these experiments didn’t focus on humans.)
The test is so simple to set up, you could build one yourself. You need a long piece of string, a book and a friend. First, sit next to your friend. Second, place the book in front of both of you. Third, lay down the string so that it starts in front of you, wraps around the back of the book, and then ends up in front of your friend. The string should form a u-shape, with the book inside.
Now for the experiment: Pull on the string by yourself, and you'll notice that it slides toward you without moving the book. If your friend pulls on the other end of the string without your help, the string slides in the other direction — but the book still doesn't move. If both of you pull on the ends of the string at the same time, though, the book slides toward you.
In other words, you and your friend must cooperate to get the book. In the case of elephants, they weren't trying to get a book. Instead, they were trying to get to some delicious corn sitting on a platform. The rope ran around the platform. Animals received corn treats only if both pulled the rope ends at the same time with their trunks. This cooperation brought the platform close enough for them to reach the corn with their trunks.
The scientists studied six elephants at the Thai Elephant Conservation Center in Lampang, Thailand. The elephants figured out how to get the corn, but Plotnik and his colleagues wanted to know if the animals had simply learned a trick, or if they understood some basic ideas about cooperation. So the researchers did more experiments. In one, a single elephant was led to the rope and stood, alone, waiting. The animal waited patiently for more than 25 seconds for another elephant to come along ― the animals seemed to know that sometimes, you have to wait for help to get the job done.
Sometimes an elephant waited as long as 45 seconds. “That’s a long time for an animal waiting for food,” Plotnik told Science News.
So far, only elephants and primates have successfully cooperated to master this kind of pull-together test. But that doesn't necessarily mean other animals don't cooperate. Plotnik says many behaviors in the animal kingdom may be explained by cooperation, but perhaps human scientists don't understand the rules. Experiments like the simple pull-together test give scientists a way to begin to learn.
POWER WORDS (adapted from Britannica.com)
comparative psychology The study of similarities and differences in behaviors among living beings, from bacteria to plants to humans.
primates A group of more than 300 species of animals that includes monkeys, apes, humans and others.
animal behavior Everything animals do, including movement and other activities, as well as the mental processes that drive those actions.