We rise, nature droops

In June 2004, I encountered my first Galápagos tortoise in the wild. The contact came three days into an inland backpacking journey on the island of San Cristóbal, part of an expedition led by Frank Sulloway, an historian of science, to retrace Charles Darwin's footsteps.

Heaving 30kg backpacks over razor-sharp broken shards of lava, we finally stumbled upon a magnificent tortoise specimen, nearly 1m in length, chomping away on a cactus. I readied my camera to capture my first contact for digital posterity when the beast turned away from me to reveal on its back the number five painted in bright yellow paint. Nature in the raw indeed!

The tracking of all live tortoises in the wastelands of the Galápagos archipelago is part of a vital programme to preserve the flora and fauna of this delicate ecosystem, and there is no greater symbol of this worthy goal than Lonesome George, the last tortoise of his kind who was plucked off the remote island of Pinta on December 1, 1971. He has resided at the Charles Darwin Research Station on Santa Cruz ever since.

Despite the $10,000 (£5,300) reward offered to zoos and collectors around the world, a female Pinta tortoise has yet to be found. George is the loneliest animal on earth.

Henry Nicholls's Lonesome George: The Life and Loves of a Conservation Icon will do for the cause of science and preservation in the Galápagos what Jonathan Weiner's The Beak of the Finch did a decade before - entertain, enlighten and encourage us all to do our part to preserve not just these islands, but Earth itself. For Lonesome George is indeed a conservation icon. Some 1.5m long and weighing in at 75kg, George is estimated to be about 80 years old, the last 30 of which he has spent in regal splendour at the Darwin station as scientists coax and cajole him to mate with females.

As Nicholls tells the story, a Swiss graduate student named Sveva Grigioni undertook the tried and true method of semen extraction as practised by animal breeders. In tortoises, the penis is tucked away inside the tail for safekeeping while the creature traverses across sharp lava rubble. When aroused, the penis emerges and becomes erect, allowing an ejaculation to occur. Scientists have had some success in capturing an ejaculate for artificial insemination by, well, a form of human-tortoise foreplay.

Nicholls describes the process employed by one scientist on another tortoise: "She began to touch his rear end and stroke his legs, causing the beast to raise himself off the ground. She then began to caress his tail. Eventually the penis flopped out and with more gentle rubbing produced an ejaculate."

Grigioni first practised this process on other male tortoises, and she was able to produce an ejaculation inside ten minutes. But George has been lonesome for a very long time, and when she entered his pen "he was very shy at the beginning. He was such a big animal and he was so afraid".

Grigioni spent days becoming familiar to him so that she could finally touch and stroke him. Nothing. Grigioni then smeared her hands with genital secretions from females of a closely related tortoise species, and as a result she at least got a look at George's penis, which appeared to be in good working order. But subsequent attempts to get an ejaculation, or to get him to mount a female, failed.

Herein lies a tale for our times: human degradation of the environment and exploitation of the flora and fauna can result in nature's impotence. If we wait too long, we may not know how to make right our environmental wrongs.

But it is not too late. Lonesome George is an emotional but fact-filled call for action, and Lonesome George himself deserves our care and concern for he represents the last animal of his kind on Earth.

Michael Shermer is the publisher of Skeptic magazine, and author of In Darwin's Shadow: The Life and Science of Alfred Russel Wallace .