Excerpted from Goodall's new book, From Hope for Animals and Their World:How Endangered Species Are Being Rescued From the Brink, written with Thane Maynard and Gail Hudson.

In 2008, during my lecture tour in Australia, a very large, very black, very friendly Lord Howe Island stick insect (Dryococelus australis) crawled across my hands, my face and my head. The encounter sent shivers up my spine—knowing, as I did, the incredible story of how it came to be there.

The forests of Lord Howe Island, about 300 miles off the coast of New South Wales, Australia, were the only known home of the Lord Howe Island phasmid, also called a “stick insect” or “walking stick”—a creature about the size of a large cigar, four or five inches long and half an inch wide. In 1918, black rats arrived on the island after a shipwreck, relentlessly adapting to their new environment and probably finding easy and delicious prey in the giant phasmid, which lacked wings. At some point in the 1920s, the Lord Howe Island phasmid was presumed extinct.

Then, in 1964, rock climbers found the dried-out remains of a giant stick insect on Ball’s Pyramid, an 1,800-foot-tall spire of volcanic rock 14 miles from Lord Howe Island. Five years later, other rock climbers found two other dried bodies incorporated into a bird’s nest on a remote pinnacle of the spire, a place almost entirely without vegetation. It seemed impossible that a large, forest-loving vegetarian insect could be surviving in such a bleak environment. And so biologists ignored these reports until, in February 2001, a small group of people—David Priddel, the senior research scientist of the Department of Environment and Climate Change in New South Wales, his colleague Nicholas Carlile, and two other intrepid souls—decided to settle the matter once and for all.

The seas around Ball’s Pyramid are rough, and the team of three men and one woman had to leap from their small boat onto the rocks. (“Swimming would have been much easier, but there are too many sharks,” Carlile said.) They put up a small camp and set off to climb about 500 feet up the spire of rock where the main vegetative patches clung to life. They searched thoroughly but found nothing other than some big crickets, and eventually the heat and lack of water drove them back down. Then, in a crevice 225 feet above the sea, they came upon another tiny patch of comparatively lush vegetation, dominated by a single melaleuca bush. Here they found the fresh droppings of some large insect.

Back in camp, over supper, they discussed the situation. Priddel knew that stick insects were nocturnal and that the group would have a better chance of seeing them if they went back to that bush at night. Carlile and team member Dean Hiscox—a local ranger and expert rock climber—volunteered to make the almost suicidal climb in the dark. Finally they reached the vegetated area and saw one, and then two, enormous shining, black-looking bodies spread out on the bush. “It felt like stepping back into the Jurassic age, when insects ruled the world,” Carlile said.

Early the next morning, the whole team climbed back up and made a thorough search. They found some frass (the proper terminology for insect poo) and about 30 eggs in the soil. They were all convinced that the only population of Lord Howe Island’s giant phasmid in the world lived on that one melaleuca shrub.

How did the little colony get to that isolated pillar of rock? Perhaps a female, full of eggs, had made the 14-mile journey from Lord Howe Island clinging to the legs of some seabird, or floating on some vegetation after a storm. And once there, she had found the one and only suitable habitat on the entire pyramid, that little bush. The point is, she got there somehow. How her descendants survived for 80 years in that desolate environment we shall never know.

As soon as they returned, the biologists got to work on a recovery plan for the stick insect. They faced many battles with bureaucracy, and two years elapsed before they had permission to return—and they were allowed to catch only four individuals. When they arrived, they found that there had been a big rockslide on Ball’s Pyramid. How easily the entire population could have been wiped out during those two frustrating years. However, on Valentine’s Day in 2003, they found the colony still thriving on its one bush. To transport the incredibly rare insects, a special container had been prepared, and this presented a problem when they arrived in Australia. It was not long after 9/11, and security was very tight, yet the scientists had to convince officials not to open the precious box! One pair of insects went to a private breeder in Sydney, and the other two, Adam and Eve, went to the Melbourne Zoo. To everyone’s delight and relief, Eve soon began laying pea-size eggs.

Within two weeks of arriving in Australia, the pair in Sydney died and Eve became very, very sick. Patrick Honan, a member of the Invertebrate Conservation Breeding Group, worked every night for a month desperately trying to cure her. He scoured the Internet for help, but no one knew anything about the veterinary care of giant stick insects! Eventually, based on gut instinct, Patrick concocted a mixture that included calcium and nectar and fed it to his patient, drop by drop, as she lay curled up in his hand. To his joy, she seemed to get better and laid eggs for a further 18 months. But the only ones that hatched were the 30 or so that she had laid before she fell sick.

In 2008, when I visited the Melbourne Zoo, Patrick showed me his rows of incubating eggs: 11,376 at the last count, with about 700 adults in the captive population. He showed me a photo of how they sleep at night, in pairs, the male with three of his legs protectively over the female beside him. As further insurance for the survival of the species, eggs are now being sent to other zoos and private breeders in Australia and overseas. The 200 eggs that were sent to the San Antonio Zoo in Texas have already begun to hatch.