Category: Animal Behaviour

New research shows that elephants know how dangerous people are from how they speak

On By A.P.In Africa, Amboseli National Park, Animal Behaviour, behavioral ecology, cognitive biology, Colorado State University, Da Brayn, elephant, Graeme Shannon, Joyce Poole, Kamba, Karen McComb, Kenya, language, Maasai, Nature, Neuroscience, Proceedings of the National Academy of Sciences, Richard Byrne, Science, The Brain, University of St. Andrews, University of Sussex2 Comments

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.

Hatching Order Influences Birds’ Behavior

On By A.P.In Animal Behaviour, Birds, birth order, hatching asynchrony, Ian Hartley, Mark Mainwaring, Nature, Science, siblings, The Brain, zebra finchLeave a comment

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The hatching order of birds influences how they behave in adult life according to research from the Lancaster Environment Centre. Dr Ian Hartley and Dr Mark Mainwaring (LEC) are the authors of the study in Animal Behaviour, which looked at how the birds’ behaviour was affected by the way their parents cared for them as hatchlings.

They found that the youngest members of zebra finch broods are more adventurous than their older siblings in adult life.

Dr Hartley said that the study showed for the first time that hatching order influences birds’ “behavioural repertoires” in adulthood.

Hatching eggs over a period of time, rather than all at once, is known as “hatching asynchrony” and occurs when eggs are incubated as soon as they are laid. For a zebra finch, this means that birds born up to four days apart can share the same nest and must compete for food.

The researchers experimentally controlled hatching synchrony within clutches, so that some clutches hatched simultaneously, while others hatched over a period of days. They then tested the behaviour of over one hundred offspring as adults. They found the youngest birds from asynchronously hatched clutches explored their environment more widely.

They measured how explorative the zebra finches were by recording how many times they visited bird feeders within an unfamiliar test aviary. They found that the youngest offspring in a brood approached the feeders significantly more often than their peers within a 30 minute period.

Researchers wanted to know how the method of rearing affected the behaviour of offspring beyond the nest, once they were living as independent adult birds. The results have implications for understanding how environmental stability might influence behaviours, and how flexible animals might be at coping with environmental change.

Journal Reference:

1.Mark C. Mainwaring, Ian R. Hartley. Hatching asynchrony and offspring sex influence the subsequent exploratory behaviour of zebra finches. Animal Behaviour, 2012; DOI: 10.1016/j.anbehav.2012.10.009

http://www.sciencedaily.com/releases/2012/12/121207094343.htm

Birds hold funerals for the dead

On By A.P.In Animal Behaviour, Bird funeral, Birds, California, dead bird, funeral, Nature, Science, scolds, scrub jay, Teresa Iglesias, UC Davis, University of California, Western scrub jay, zeep-scolds, zeepsLeave a comment

 

When western scrub jays encounter a dead bird, they call out to one another and stop foraging.

The jays then often fly down to the dead body and gather around it, scientists have discovered.

The behaviour may have evolved to warn other birds of nearby danger, report researchers in California, who have published the findings in the journal Animal Behaviour.

The revelation comes from a study by Teresa Iglesias and colleagues at the University of California, Davis, US.

They conducted experiments, placing a series of objects into residential back yards and observing how western scrub jays in the area reacted.

The objects included different coloured pieces of wood, dead jays, as well as mounted, stuffed jays and great horned owls, simulating the presence of live jays and predators.

The jays reacted indifferently to the wooden objects.

But when they spied a dead bird, they started making alarm calls, warning others long distances away.

The jays then gathered around the dead body, forming large cacophonous aggregations. The calls they made, known as “zeeps”, “scolds” and “zeep-scolds”, encouraged new jays to attend to the dead.

The jays also stopped foraging for food, a change in behaviour that lasted for over a day.

When the birds were fooled into thinking a predator had arrived, by being exposed to a mounted owl, they also gathered together and made a series of alarm calls.

They also swooped down at the supposed predator, to scare it off. But the jays never swooped at the body of a dead bird.

The birds also occasionally mobbed the stuffed jays; a behaviour they are known to do in the wild when they attack competitors or sick birds.

The fact that the jays didn’t react to the wooden objects shows that it is not the novelty of a dead bird appearing that triggers the reaction.

The results show that “without witnessing the struggle and manner of death”, the researchers write, the jays see the presence of a dead bird as information to be publicly shared, just as they do the presence of a predator.

Spreading the message that a dead bird is in the area helps safeguard other birds, alerting them to danger, and lowering their risk from whatever killed the original bird in the first place, the researchers say.

Other animals are known to take notice of their dead.

Giraffes and elephants, for example, have been recorded loitering around the body of a recently deceased close relative, raising the idea that animals have a mental concept of death, and may even mourn those that have passed.

http://www.bbc.co.uk/nature/19421217