In "The Ghost With Trembling Wings," Scott Weidensaul lives the dream of many birders. He searches the humid mountains of St. Lucia for the small, drab Semper's warbler presumably extinct but perhaps overlooked. He braves the mosquitoes, snakes, heat, and sloughs of Louisiana's Pearl River Wildlife Management Area, drawn there, like so many before him, by a hunter's claimed sighting (on April Fool's Day in 1999) of America's most famous "ghost bird," the ivory-billed woodpecker.
In the western reaches of Brazil's Mato Grosso, a state half again as large as Texas, he tries for the cone-billed tanager. Known from a single specimen shot in the 1930s, it, too, is thought to be extinct, yet Mato Grosso is vast, and its bird life is not well documented, so maybe the six-inch tanager hangs on.
Weidensaul's book chronicles the nearly two years he has spent "following the faint track of lost animals" mainly birds and mammals that refuse to disappear, even though many are considered extinct.
Some probably exist only in the minds of wishful thinkers, but enough have popped up to give Weidensaul and others (including respected scientists) hope that the extinction label is not necessarily forever.
Leaving the "bruised" mountains of his home in the Pennsylvania Appalachians, where his studies focus on hawks and owls, Weidensaul, goes as far as Tasmania, hunting ground of the strange thylacine. The last thylacine died in a zoo in 1936, but no one can say for sure that the species is gone.
Unconfirmed sightings of this 65-pound predatory marsupial shaped like a dog and striped on its hindquarters like a zebra have persisted. The most credible was in 1982, when a forest ranger in northwest Tasmania claims to have spotted a thylacine in his truck's headlights.
Even if the thylacine is extinct, it may yet be recreated so say officials at the Australia Museum, which in 1999 announced a controversial plan to cloneathylacine using DNA from a baby taken from its mother's pouch and preserved in a jar of alcohol for more than a century.
Weidensaul did some scrambling through the mountainous forests of Tasmania's Western Tiers in search of a living thylacine, his effort more a tribute to the phantom "Tasmanian tiger" than an attempt to prove its existence.
Such fieldwork seems to be Weidensaul's preferred way of gathering material he also traveled widely for "Living on the Wind," his Pulitzer-nominated book on bird migration (1999). He can, however, comb the literature and interview experts with the best of them, and in "The Ghost With Trembling Wings," his research confirms that some animals have truly risen from extinction.
He tells the story, for example, of an ornithologist who picked up a road-killed Australian night parrot in a remote part of Queensland in 1990 the first specimen to materialize since 1912.
There haven't been any confirmed sightings of living night parrots, which are strictly nocturnal, in nearly a century. But that's not enough to quell Weidensaul's optimism. "No one seriously believes the species is extinct," he says.
It's not only presumably extinct species that fascinate Weidensaul. He also writes about the nearly extinct, such as North America's black-footed ferret, and the extirpated, such as the cougar, now largely absent from the eastern United States.
Although he dismisses most cougar reports in the Eastern United States as wishful thinking, he's not above wishing that the big cat would return to his Pennsylvania hills. Weidensaul even devotes a chapter to "cryptids" such as the Loch Ness Monster, delicately balancing skepticism and sensitivity.
Throughout "The Ghost With Trembling Wings," Weidensaul interweaves history, science, and personal experience as he shifts between species, settings, and time periods. Somehow, he makes almost all of these transitions smoothly.
The book's best parts come when Weidensaul, turning from reporter to participant, describes his field work his squalid quarters in St. Lucia, the Pearl River Wildlife Management Area's "paradoxical mix of accessibility and remoteness," the "astounding" number of road kills in Tasmania, and the perils of riding through the western wilds of Brazil's Mato Grosso in a VW van.
"The Ghost With Trembling Wings" is a virtuoso presentation that can be dizzying, even exhausting, yet in this it reflects the wild world as Weidensaul found it. "Much of it is still unknown." he writes. "The blank spots are disappearing beneath the unblinking eyes of satellites and the probing fingers of chain saws, bulldozers, and the farmer's hoe, but great swaths of the planet remain a mystery to polite society, fit habitat for myths and monsters, a place where dreams can live."
Robert Winkler is a nature writer whose work has appeared in The New York Times and Travel & Leisure magazine.