Excerpt from Animal Wise by Virginia Morell, plus links to reviews, author biography & more

Over the years, I noticed that many scientists were increasingly at ease talking about the likely mental states and experiences of the animals they were watching—just as Goodall had predicted. Some scientists, such as elephant researcher Joyce Poole, evidenced an almost complete indifference about anthropomorphizing or earlier ideas that denied animals their minds. As we drove through Kenya's Amboseli National Park, Poole addressed the elephants that came up to her Land Rover's window as old friends. When they reached their trunks inside the car to sniff her, she laughed, "Yes, it really is me. And, yes, I know. I've been gone a long time." From her time among the elephants, she knew (and had the data to show) that they had long-term memories and recalled individual elephant friends. They remembered humans, too, distinguishing between those who had never harmed them and those who had heaved spears their way.

In Tanzania's Serengeti National Park, ethologist Sultana Bashir spoke with sorrow about what fate surely lay in store for a male cheetah we were watching. Several months prior to my visit, she and other members of the Serengeti Cheetah Project had placed a radio collar on this sleek cat. We'd driven long hours over the plains, while tracking the collar's ping, before Bashir spotted the cheetah among the grasses. He was standing at the base of a rocky kopje—his lookout—and crying in a piteous tone. Sometimes he climbed his rocks to gaze into the distance, other times he paced away, then suddenly swung about and climbed back to the top of his lookout. "Mrrrroow; mrroowww; mrroww," he called, making a low bleating sound, almost like the cry of a wounded sheep. "That's his distress call," Bashir said. "He's looking for his friend. But I'm afraid he's gone; he was elderly, and I think he's died. Otherwise, he would be here, or nearby."

Male cheetahs maintain large territories that overlap those of several females, and they fight other males—sometimes to the death—to secure their borders. In such battles, it helps to have a friend; indeed, a single male cheetah without a partner is almost assured of losing any fi ght and all his territory. We sat with the unhappy male until late in the afternoon, and he never ceased his cries. At last, he left the kopje behind and headed off at a trot into the plain's tall grasses. What would become of him if his friend did not return? I asked. "He'll go off to die, I think," Bashir said. "Another male will kill him, or he'll stop eating, get mange—always a sign of stress in cheetahs—and become too weak to defend his territory. Really, he'll die of a broken heart."

I didn't ask Bashir or Poole for evidence to back up their statements. I simply jotted down their words, because the experiences were affecting and because the scientists didn't talk in jargon but spoke openly and simply about what was happening: an elephant had come to visit an old friend; a cheetah was dying from a broken heart.*

* Animals and humans are known to develop health issues from stress; they may even die, particularly after losing a mate. There is also increasing acceptance of the idea that social species are badly affected by the loss of a friend or mate. For instance, Laysan albatrosses are monogamous. They nest on Midway Atoll and don't breed until they are eight or nine years old. If they lose their mate, they "go through a year or two of a mourning period," says John Klavitter, a U.S. Fish and Wildlife Service biologist at Midway. "After that, they will do a courtship dance to try to find another mate."

In 2006 National Geographic asked me to write an article about how animals think. The resulting cover story, Minds of Their Own, was published in the March 2008 issue and became the genesis for this book. Reporting took me around the world—from my home in Oregon to several states as well as to Japan, Venezuela, Costa Rica, Australia, Germany, England, Hungary, Austria, and Kenya—to meet researchers and their animals. At each lab or field site, I watched raptly as scientists unveiled some aspect of the minds of insects, parrots, crows, blue jays, fish, rats, elephants, dolphins, chimpanzees, wolves, and dogs—and what the animals were thinking.

Excerpted from Animal Wise by Virginia Morell. Copyright © 2013 by Virginia Morell. Excerpted by permission of Crown. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.