Archive for the ‘University of St. Andrews’ Category

When an elephant killed a Maasai woman collecting firewood near Kenya’s Amboseli National Park in 2007, a group of young Maasai men retaliated by spearing one of the animals.

“It wasn’t the one that had killed the woman, says Graeme Shannon, a behavioral ecologist at Colorado State University, in Fort Collins. “It was just the first elephant they encountered—a young bull on the edge of a swamp.”

The Maasai spiked him with spears and, their anger spent, returned home. Later, the animal died from his wounds.

Elephants experience those kinds of killings sporadically. Yet the attacks happen often enough that the tuskers have learned that the Maasai—and Maasai men in particular—are dangerous.

The elephants in the Amboseli region are so aware of this that they can even distinguish between Ma, the language of the Maasai, and other languages, says a team of researchers, who report their findings today in the Proceedings of the National Academy of Sciences.

The results add to “our growing knowledge of the discriminatory abilities of the elephant mind, and how elephants make decisions and see their world,” says Joyce Poole, an elephant expert with ElephantVoices in Masai Mara, Kenya.

Indeed, previous studies have shown that the Amboseli elephants can tell the cattle-herding, red-robed Maasai apart from their agricultural and more blandly dressed neighbors, the Kamba people, simply by scent and the color of their dress.

The elephants know too that walking through villages on weekends is dangerous, as is crop raiding during the full moon.

They’re equally aware of their other key predator, lions, and from their roars, know how many lions are in a pride and if a male lion (the bigger threat because he can bring down an elephant calf) is present.

And they know exactly how to respond to lions roaring nearby: run them off with a charge.

Intriguingly, when the Amboseli elephants encounter a red cloth, such as those worn by the Maasai, they also react aggressively. But they employ a different tactic when they catch the scent of a Maasai man: They run away. Smelling the scent of a Kamba man, however, troubles them far less.

“They have very clear behavioral responses in all of these situations,” says Karen McComb, a behavioral ecologist at the University of Sussex, in the United Kingdom. “We wondered if they would react differently to different human voices.”

To find out, she and her colleagues played recordings to elephant families of Maasai and Kamba men, as well as Maasai women and boys, speaking a simple phrase in their language: “Look, look over there, a group of elephants is coming.”

Over a two-year period, they carried out 142 such playbacks with 47 elephant families, each time playing a different human voice through a concealed speaker placed 50 meters (164 feet) from the animals. They video-recorded the elephants’ reactions to the various human voices, including a Maasai man’s voice they altered to sound like a woman’s.

As soon as an elephant family heard an adult Maasai man speak, the matriarch didn’t hesitate, the researchers say. “She instantly retreats,” Shannon says. “But it’s a silent retreat. They sometimes make a low rumble, and may smell for him, too, but they’re already leaving, and bunching up into a defensive formation. It’s a very different response to when they hear lions.”

In contrast, the voices of Kamba men didn’t cause nearly as strong a defensive reaction: The elephants didn’t consider the Kamba a serious threat.

“That subtle discrimination is easy for us to do, but then we speak human language,” says Richard Byrne, a cognitive biologist at the University of St. Andrews, in Scotland. “It’s interesting that elephants can also detect the characteristic differences between the languages.”

The Amboseli elephants were also sufficiently tuned in to the Maasai language that they could tell women’s and boys’ voices from men’s, seldom turning tail in response. “Maasai women and boys don’t kill elephants,” Shannon points out. Nor were the elephants tricked by the man’s altered voice; when they heard it, they left at once.

“The elephants’ decision-making is very precise,” McComb says, “and it illustrates how they’ve adapted where they can to coexist with us. They’d rather run away than tangle with a human predator.”

Why, one wonders, don’t elephants retreat when poachers descend on them?

“Unfortunately, there are going to be things they cannot adapt to, things such as humans’ ability to come after them with automatic weapons or mass poisonings,” McComb says. “And in those situations, we have to protect them—or we will lose them, ultimately.”

http://news.nationalgeographic.com/news/2014/03/140310-elephants-amboseli-national-park-kenya-maasai-kamba-lions-science/?google_editors_picks=true

Thanks to Da Brayn for bringing this to the It’s Interesting community.

elephant

The next time you need to show an elephant where something is, just point. Chances are he’ll understand what you mean.

New research shows elephants spontaneously understand the communicative intent of human pointing and can use it as a cue to find food.

Richard Byrne and Anna Smet of the University of St. Andrews tested 11 African elephants on what’s known as the object-choice task. In this task, a food reward is hidden in one of several containers and the experimenter signals which one by pointing to it.

People understand pointing, even as young children. But the track record of other animals on the object-choice task is mixed. Domesticated animals, such as dogs, cats, and horses, tend to perform better than wild ones. Even our closest relative, the chimpanzee, typically struggles to understand pointing when it’s used by human caretakers.

What’s so remarkable about the elephants’ success on the object-choice task is that they did it spontaneously. Byrne says that in studies of other species, the animals have had the opportunity to learn the task. This is usually during the experiment itself, which consists of a prolonged series of tests over which the animals come to realize they will get rewarded with food if they follow the line of the human’s pointing.

But the elephants performed as well on the first trial as on later tests and showed no signs of learning over the course of the experiments. The elephants Byrne and Smet tested are used to take tourists on elephant-back rides in southern Africa. They were trained to follow vocal commands only, never gestures. Smet recorded the behavior of the elephants’ handlers over several months and found they never pointed their arms for the elephants. What’s more, the elephants’ ability to understand human pointing did not vary with how long they had lived with people, nor with whether they were captive-born or wild-born. “If they have learned to follow pointing from their past experiences, it’s mystery when and how,” Byrne says. “Rather, it seems they do it naturally.”

In the experiment, Byrne and Smet varied several parameters that often affect children’s and animals’ performance on the task: whether the pointing arm was nearest the correct choice or not; whether the pointer’s arm crossed the body or was always on the side of what was pointed at; and whether the arm broke the silhouette from the elephant’s viewpoint or not. None of these made any difference. Even when the experimenter stood closer to the wrong location than the correct location, the elephants performed a little worse but still mostly responded to where her arm was pointing.

The only condition that truly stymied the elephants was when the experimenter simply looked at the correct location without pointing. Byrne says that elephant eyesight is poor compared to our own, and researchers who work with elephants have commented on how bad they are at identifying things by sight. “It would perhaps have been surprising if they had spontaneously responded to the rather subtle movements of a small primate’s head!” Byrne says.

Elephants are only distantly related to humans, which means that the ability to understand pointing likely evolved separately in both species, and not in a shared ancestor. But why would elephants attend to and understand pointing? One thing elephants do share with humans is that they live in a complex and extensive social network in which cooperation and communication with others play a critical role. Byrne and Smet speculate that pointing relates to something elephants do naturally in their society. “The most likely possibility is that they regularly interpret trunk gestures as pointing to places in space,” Byrne says. Elephants do make many prominent trunk gestures, and Byrne and Smet are currently trying to determine if those motions act as “points” in elephant society.

Reference:
Smet, Anna F. and Byrne, Richard W. (2013). African Elephants Can Use Human Pointing Cues to Find Hidden Food. Current Biology http://dx.doi.org/10.1016/j.cub.2013.08.037

http://www.wired.com/wiredscience/2013/10/elephants-get-the-point/

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.