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Plant behaviour: How they eat is similar to people at a buffet table

When a bear finds a rich patch of berries, it gorges for a while but moves on before cleaning out all the fruit. It is the same with deer that wander into a rich meadow: They stop and graze, but leave before devouring every shoot.

Two researchers at the University of Alberta have found that plants have similar foraging strategies. They get their nutrients from their root tips, and it is well documented that roots produce more tips when they hit a patch of nutrient-rich soil. Using an underground camera to study yarrow, a common Alberta plant, James Cahill and Gordon McNickle found that the roots move on before those rich patches get depleted.

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"All organisms when they find a patch of resources will stay there, but they won't stay there forever," Dr. Cahill says.

He and his colleague argue that this is plant behaviour, a controversial notion among animal biologists but one Dr. Cahill says is bolstered by evidence that plants do things such as eavesdrop on each other and can detect the chemical compounds their neighbours release when under attack from hungry cater-pillars so they can marshal their own defences.

This is behaviour without cognition, Dr. Cahill explains, and by studying it he hopes to learn more about behaviour in all organisms.

"It is behaviour, but it is created by mechanisms we aren't used to. Plants behave through growth. We behave through temporary muscle movement."

It turns out humans have something in common with plants when it comes to how we fill our plates. "At a buffet, no one wants to take the last piece of meat on the tray," Dr. Cahill says. "Especially if there is a big, full tray nearby. They will move over to that one."


When does memory begin? A new study done in the Netherlands found that fetuses develop short-term memory at 30 weeks. By then, fetuses don't get startled when they hear a short burst of sound from a device held against their mother's abdomen 10 minutes earlier.

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The work, published in the journal Child Development, also suggests that at 34 weeks a fetus can store information about a noise and retrieve it four weeks later.


A robot at the University of California that looks remark-

ably like Albert Einstein has learned to smile, narrow its eyebrows and make other facial expressions.

The Einstein robot head was equipped with software that analyzed its facial expressions as it twisted and turned its face in front of a mirror using 30 facial "muscles." The San Diego researchers say the software was designed to try to mimic the way babies learn to control their bodies through "body babbling," or systematic exploratory movements.

You can see Einstein's facial contortions at

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Locusts go into a coma when they are drowning or caught in a heat wave. The series of chemical reactions that shut down their little brains in dire circumstances are similar to disturbances that lead to migraines and epileptic seizures in humans.

When locusts are drowning, their brain cells become overexcited and turn off. Queen's University biologists Mel Robertson and Gary Armstrong have found a combination of drugs that dramatically shorten the period in which distressed locusts stay comatose.

They say the work, published in the Journal of Neuroscience, could lead to a new approach in preventing or limiting the duration of migraines or epileptic seizures in humans.

"I think it is hard for the general public to understand how work with an insect can tell you anything about your pounding headache," Dr. Robertson says. "We aren't saying anything about pain, we are talking about the neural disturbance that leads to it."

So why would humans have the same chemical pathway in the brain that puts locusts into protective comas? It is found in many mammals, which means it must offer some benefit.

And experiments with lab animals suggest that the chemical pathway helps the brain become resistant to damage caused by sudden increases in temperature.

Videos showing comatose

locusts can be found at




The northernmost public tribute to Michael Jackson was an outdoor version of Thriller, performed by about 20 scientists and visitors at the Toolik Field Station in northern Alaska.

The seemingly giant mosquitoes buzzing the camera add a suitably creepy element to the video, which has been posted on YouTube. And in their bug jackets and hats, the video's dancers manage to look zombie-like despite the bright sunshine.

The research station is run by the University of Alaska, but two Canadians took part in the performance. Melissa Gervais, a University of Toronto graduate student in atmospheric physics, taught everyone the steps, and Jude Isabella, the managing editor of YES Mag, a Canadian science magazine for children, was one of the dancers.

Anne McIlroy is The Globe and Mail's science reporter.

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About the Author

Anne McIlroy has been a journalist for more than 25 years. She joined the Globe in 1996, and has been the science reporter as well as the parliamentary bureau chief. She studied journalism at Carleton University in Ottawa. More

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