Trilobites: Owls See the World Much Like We Do


Barn owls have simpler brains than primates, but they can process information about things moving in their environment in a similarly complex way.

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Even though barn owls have simple brains, a new study suggests they can visually process objects in ways similar to that of animals with more sophisticated perception.CreditJean-Christophe Verhaegen/Agence France-Presse — Getty Images

Owl eyes are round, but not spherical. These immobile, tubular structures sit on the front of an owl’s face like a pair of built-in binoculars. They allow the birds to focus in on prey and see in three dimensions, kind of like humans — except we don’t have to turn our whole heads to spot a slice of pizza beside us.

Although owls and humans both have binocular vision, it has been unclear whether these birds of prey process information they collect from their environments like humans, because their brains aren’t as complex. But in a study published in the Journal of Neuroscience on Monday, scientists tested the ability of barn owls to find a moving target among various shifting backgrounds, a visual processing task earlier tested only in primates.

The research suggests that barn owls, with far simpler brains than humans and other primates, also group together different elements as they move in the same direction, to make sense of the world around them.

“Humans are not so different from birds as you may think,” said Yoram Gutfreund, a neuroscientist at Technion Israel Institute of Technology who led the study with colleagues from his university and RWTH Aachen University in Germany.

The owls were able to spot the target. They were better at finding it when the contrasting dot direction was uniform rather than scattered. Even though the elements were all black dots, the direction they were moving made a big difference in the owl’s perception of the world — and how its brain responded.

The researchers also recorded activity from the ocular tectum, a brain area involved in basic visual processing in owls and many other vertebrates. They found that it activated more or less depending on the movement of the dots, suggesting it was responsible for performing this seemingly complex task.

“What we find is considered higher level processing in an area that is not traditionally considered a higher level area,” Dr. Gutfreund said. He thinks this ability was conserved through evolution in a similar part of the human brain called the superior colliculus, which helps direct attention among other functions.

The researchers found that an owl’s ocular tectum, a brain area involved in basic visual processing in vertebrates, activated according to the movement of dots in the experiment.CreditRonaldo Schemidt/Agence France-Presse — Getty Images

But how the ability evolved, or how it may play out differently in birds and mammals is still a mystery, Dr. Gutfreund said. For now, they want to determine the path traveled through the owl’s brain by these movement-grouping signals.

“It’s not so easy to do these experiments,” said Dr. Gutfreund, but he believes this motion grouping ability is widespread in the animal kingdom. “I think that the visual system basically evolved to identify targets for behavior. This is why we have the brain.”

Trilobites: Can Crows Make Mental Pictures of Tools?


New Caledonian crows were trained to seek rewards by tearing paper of a certain size, demonstrating what researchers say is quite advanced toolmaking.

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A New Caledonian crow manipulating a paper “tool” in an experiment. Researchers report in a new study that the crows can make simple tools from memory.CreditSarah Jelbert

New Caledonian crows are known for their toolmaking, but Alex Taylor and his colleagues wanted to understand just how advanced they could be.

Crows from New Caledonia, an island in the South Pacific, can break off pieces of a branch to form a hook, using it to pull a grub out of a log, for instance. Once, in captivity, when a New Caledonian male crow had taken all the available hooks, its mate Betty took a straight piece of wire and bent it to make one.

“They are head and shoulders above almost every other avian subjects” at toolmaking, said Irene Pepperberg, an avian cognition expert and research associate in Harvard University’s department of psychology. “These crows are just amazing.”

Dr. Taylor, a researcher at the University of Auckland in New Zealand, and several European colleagues wondered how the crows, without an ability to talk and showing no evidence of mimicry, might learn such sophisticated toolmaking.

Perhaps, the scientists hypothesized in a new paper published Thursday in Scientific Reports, they used “mental template matching,” where they formed an image in their heads of tools they’d seen used by others and then copied it.

“Could they look at a tool and just based on mental image of the tool — can they recreate that tool design?” Dr. Taylor said. “That’s what we set out to test, and that’s what our results show.”

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In a series of steps, the researchers taught the birds to feed pieces of paper into a mock vending machine to earn food rewards. The scientists chose a task that was similar enough to something the animals do in the wild — while also brand new. The birds had never seen card stock before, but learned how to rip it into big or little shapes after being shown they would get a reward for the appropriate size.

The template used to show the birds the right size of paper was not available to them when they made their “tools,” yet the crows were able to use their beaks to tear off bits of paper, which they sometimes held between their feet for leverage.

Read more about smart birds

Dr. Marzluff said that there was always more research to be done, but that he was comfortable with the group’s conclusions that such thinking occurs. And, he said, he’s never heard of another animal accomplishing such a task.

“The tool use and the progressive accumulation of proficiency or of complexity in tools is something that hasn’t been demonstrated in species other than humans to my knowledge,” he said, adding that this should teach humans some humility about our own position in the world. “We’re not so unique ourselves. Just perhaps better or more advanced at doing certain tasks.”