[LINK] "Crows and parrots – brainy birds, but in different ways"

[rfmcdonald]

Ed Yong at Not Exactly Rocket Science has an interesting blog post up about the ways in which intelligence can differ between species. To illustrate this principle, Yong describes an experimenter who decided to see how individuals of two smart bird species would solve a problem.

[The scientist] presented five New Caledonian crows and six keas with the same set-up – a puzzle box with food, balanced on a central pole. If the birds could knock the food off the pole, it would roll down a sloped platform into their grasp. There were four ways of doing this: they could pull a string tied to the food; they could open a window and stick their head into the box; they could roll a marble down a chute to knock the food off; or, they could push the food off with a stick. Two of these solutions – the marble and the stick – involved tools, and the others didn’t.

The birds could approach the task in any way they liked. And every time they learned one of the four tricks, Auersperg closed it off, forcing them to find a different solution.

She found that at least one bird of each species – Uek and Kermit – discovered all four techniques, which shows that they’re certainly capable of doing so. But the similarities ended there.

Keas are notoriously inquisitive and attracted to new things. In its native New Zealand, it uses it beak to explore (and destroy) everything from nests to picnic baskets to windshield wipers. All of Auersperg’s keas immediately (and violently) explored all four openings in the box, pulling, tearing, scratching and probing at them. “They seemed to approach the apparatus in a playful, toddler-like manner,” she says. Most of them tried to overturn the box, which Auersperg had to nail to the floor. One of them, Luke, even broke the Plexiglas.

As a result of their gung-ho investigations, they picked up the four solutions to the puzzle far quicker than the crows did. After their first session, they had already discovered at least two or three, and when each one was blocked, they moved onto the next one with great speed.

In stark contrast to the keas, New Caledonian crows shirk from novelty. Rather than rushing in beaks first, they explored the box by sight before giving it some tentative pecks. One of them never even went near it. As such, it took them longer to pick up the different solutions.

But the crows had an edge – they’re natural tool users. In the wild, they manufacture their own tools to “fish” for insect grubs buried within decaying logs. In captivity, they’ve chosen the right tool for different jobs, combined different tools together, and improvised from unusual materials like wire hangers. Keas, however, aren’t natural tool users and their beaks are too curved to wield sticks with grace.

It’s not surprising then, that the crows were more adept than the keas at using the sticks to reach their food. All the crows managed it; of the keas, only Kermit did so with his complicated technique. The crows’ fondness for sticks didn’t always work to their favour. They would often try to poke the window with their sticks, while the keas soon learned to pull them open using handles. Even when [New Caledonian crew] Uek did lift the window, she still prodded at the food with her stick when she could have just stuck her head through.

The consequences of all this? We've got more proof that intelligence isn't a single homogeneous thing across all species, and that "intelligence" isn't the only thing going by far in relation to problem-solving.

This means that it’s hard to say anything about general skills such as problem-solving, memory or self-awareness based on an animal’s performance at a specific task. It’s important to use a battery of tests, such as the four “solutions” to Auesperg’s puzzle box. Even then, an animal’s performance may depend more on its attitude to novelty, motivation or body shape than its mental abilities.

Auersperg’s study is a breath of fresh air. It appreciates that “intelligence” looks very different from species to species based on their evolutionary context. Rather than simply ranking her birds against one another, she catalogued the differences between them and looked at why those differences exist. These are more interesting questions than the bland one of which one’s “better”.