Monday, August 01, 2016

Smarter Than A Second Grader? Crow Smarts: Inside the Brain of the World's Brightest Birds by Pamela S. Turner

Waaah! WAAAH!

The begging call of a juvenile gets louder. Little Feather stakes out a position at the end of the log.

The adult bird hops to the ground, picks up a dried leaf stem, hops back onto the log. Holding the stem in its bill, it probes the hole with sharp jabs. After a few seconds, it flips the stem around. Jab jab jab. Yet Little Feather's parent still seems dissatisfied. It discards the stem. Luckily the forest floor is covered in sticks, twigs, and stems. It's a crow Home Depot.

The adult returns with a different leaf stem. Jab-jab-jab-jab. Little Feather's only contribution is a stream of woooh-whoohs. After four minutes of delicate work, the grub clamps onto the crow's tool like a bulldog. Little Feather's parent hauls out its catch. It's big and lumpy: the Jabba the Hut of grubs!

What we have just seen is a crow using a tool and its greedy fledgling being homeschooled in the family trade.

For years anthropologists believed that only humans used tools, naming the first-discovered users Homo habilis, "handy man." Famed for his discoveries of early toolmaker hominid fossils, Lewis Leakey suggested that one of his graduate students, Jane, try to observe chimpanzees to see if they made any use of tools. That star pupil, Jane Goodall, came through in a big way, observing chimps not only using twigs to fish termites out of their mound holes, but also selecting and shaping those twigs into new-and-improved tools. And the science of animal tool intelligence was launched.

One early naturalist on the Pacific island of New Caledonia observed crows there dropping candlenuts onto rocks to crack them in 1882, and in 1928, another reported crows using sticks to extract insects from logs. And eventually one naturalist reported observing parent crows there persistently displaying tool-using behaviors and young crows studying and practicing the same skills until they became proficient. Then the crows of New Caledonia were observed deliberately shaping better grub catchers--breaking off one branch of a Y-shaped twig and shaping it into a hook with their bills. Other observers noted even cleverer crows shaping a strip of a long, fibrous pandanus leaf with a serrated edge, snipping it to just the right length, and graduating its width to provide a stiff end for holding in the beak, actual tool making. Animal scientists began to wonder just how smart crows really are.

Enter Betty, the valedictorian of crows. Betty was able to shape a strip of wire into a hook, using her feet and beak, and use it as a hooked probe to extract a piece of meat from a tube. Could she do it with something less stick-like? Yes! Betty could do the same with a curly strip of aluminum! Could Betty generalize that behavior into fashioning a wire to hook over the handle of a tiny treat bucket in a tube? No sweat! Betty scored 90%! Was Betty just a fluke, the Einstein of the crow community?

Not at all! Some crows may be bird brains, but many were able to pass even more complex IQ tests, such as pulling up a short stick dangling by a string from a perch, untying the stick, using it to fish a longer stick out of a barred box, and finally using that stick to retrieve a chunk of beef from a deep tube. Some even figured out how to drop pebbles into a tube with a treat floating at the bottom until the water level rose enough to lift the treat within beak reach. They even learned to choose solid metal objects instead of hollow ones to do a better job. In fact, these summa cum laude crows outdid most second grade humans at a similar task!

As Pamela S. Turner's forthcoming Crow Smarts: Inside the Brain of the World's Brightest Bird (Scientists in the Field Series) (Houghton Mifflin Harcourt, 2016) shows, crows are no dim bulbs. Animal culture, learning passed down from parent to offspring, has also been observed among apes and monkeys. Even those geniuses of the sea, dolphins, have been observed passing down tool-using hunting skills through at least two subsequent generations (see my review of Turner's amazing The Dolphins of Shark Bay (Scientists in the Field Series) here). Crows seem able to do the same.

It seems that the search for intelligent life in the universe still has a lot to discover on our own planet.

Author Pamela Turner knows how to combine carefully paced text with humor in her newest book, perfect for animal-loving and scientifically minded young naturalists. With plenty of color photos, this new study of animal intelligence in Houghton Mifflin Harcourt's award-winning Scientists in the Field series will inspire middle readers toward this exciting area on the frontiers of science and should be a first purchase for libraries and for kids who can't get enough of animals and their fascinating behaviors.

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