The Ghost with Trembling Wings , by Scott Weidensaul

The Ghost with Trembling Wings by Scott Weidensaul (nonfiction; popular science) is a book about threatened, endangered and extinct species, people who search natural habitats in the hope of finding animals which haven't been seen in many years, and scientists who hope to use the new biotechnology to restore extinct species to life.

Naturalist Scott Weidensaul, already well-known as the author of several books about wildlife, focuses here on a subject close to his heart.

"While prolonged absence is often an indication of extinction," Weidensaul writes, "you can't always assume a species is gone just because it's been AWOL for a long time." [Page 73] Similarly, "It's a big world out there, and proving a negative -- the absence of a creature -- is a tall order." [17]

In the terminology of the Endangered Species Act of 1973, a threatened species is in more trouble than an endangered species. It is said to be threatened if its extinction is probable in the near future. It can be called endangered if it is likely to disappear from a continent or another geographical range, though it may survive elsewhere. [101]

When an animal on the endangered or threatened species list is believed to be extinct, it is "delisted." That doesn't necessary mean that scientists and government agencies stop searching for it. The blue pike in the Great Lakes was designated by the federal government as an endangered species in 1967 and it was delisted (believed to be extinct) in 1983 [101]. Nevertheless, in 1999, state and federal grants were allocated to "find and restore" [73] the species.

A number of animals are declared extinct after the last known individuals die in zoos. For example, the end of the passenger pigeon in 1914 and the Carolina parakeet in 1918 were announced after the last of these birds died at the Cincinnati Zoo [17]. But we shouldn't blame the zoos and other institutions for taking the animals from the wild, because these facilities remove the threat of predators and provide the animals with medical care.

For example, it was probably the sylvatic plague, caused by the same bacteria that cause bubonic plague in human beings, and transmitted by fleas, that most threatened the black-footed ferret [100]. People are now intervening by conducting vaccine research and building breeding facilities [118].

The black-footed ferret is rarely seen because it is both noctural and subterranean [95]. In the second half of the 19th century, the ferret was declared to be imaginary, the subject of a hoax, because it was known only from the diaries of Lewis and Clark circa 1805, the correspondences of trappers in the 1840s, and its depiction in a painting by an artist who died in 1851 [94]. In 1964, several of these ferrets were found on a farm in South Dakota [100].

The black-footed ferret has the most restrictive diet of any animal in North America. It will only feed on rodents known as prairie dogs [95]. In the Old West, when ranchers poisoned the prairie dogs with strychnine, they almost wipe out this species of ferret [96].

The ferret received good news twice in 1988. First, the Conservation and Research Center (CRC) of the Smithsonian Institution received some black-footed ferrets and had some success with "natural reproduction instead of artificial means." [112] The ferret has a gestation period of 45 days [100]. Also in 1988, the U.S. Fish and Wildlife Service (USFWS) drafted a recovery plan calling for breeding facilities which will produce ferret populations and then release them into the wild. The program's target is "1,500 wild ferrets in at least ten populations by 2010." [117]

To a lesser extent, Weidensaul also discusses endangered and extinct plants [18-20], but, outside of the field of botany, it is usually the protection of the animal kingdom that that gets the publicity and invokes the passions.

Island Species

The Ghost with Trembling Wings begins with a novel-like narrative form, which I personally don't prefer in nonfiction -- "The overnight rain had stopped, leaving the forest heavy with moisture and the trail slick with mud. I moved down the path in the dim green predawn light, beneath palms and tall mahogany trees hung with vines ...." [4] But there are only two-and-a-half pages of this narrative form, and then the book becomes hard-factual and profoundly informative.

Then, the first major point that Weidensaul drives home in chapter 1 is the special dangers confronting species confined to islands.

"Unfortunately, island species tend to be a bit less adaptable than their mainland counterparts, especially when confronted with new predators, and because of their limited range and population size, they are all the more susceptible to extinction. At the end of the last ice age, the West Indies were populated with an assortment of animals that would appear bizarre to modern eyes: giant ground sloths; rodents the size of small bears; several species of flightless owls on Cuba that were 3 feet tall, with long, heronlike legs for running down their prey; and a condor rivaling today's Andean condor in size. Many of these became extinct after the end of the ice age, 10,000 years ago, an extinction wave that intensified after Amerindians settled the islands, starting between 7,000 and 4,500 years ago. Paleontologists call these 'first-contact extinctions,' on the assumption that human hunting drove the losses. (But if humans took away, they also gave: agoutis like the one I saw were not native to the Caribbean but were apparently brought from South America by natives as a food supply.)"

[Excerpt from Chapter 1, Page 7]

The Thylacine

Scott Weidensaul's coverage of the thylacine project is exceptionally well done.

The thylacine -- whose genus and species name was Thylacinus cynocephalus [230] -- was a carnivorous marsupial that lived in Australia. Fossils and dated remains indicate that the thylacine populated Australia over 3,000 years ago. In 1986 the last known individual died in a zoo in Hobart, the capital city of Tasmania. In 1986, after a fifty year search, biologists declared the thylacine extinct. [233].

Although the thylacine was not a cat, but related to the family of dogs, it was been given the nickname Tasmanian Tiger because of its appearance [See the photograph taken in 1906 on page 232]. Imagine, as Scott Weidensaul describes it, the body of a dog, the head of a cat, and the stripes of a zebra [230].

While some scientists blame the extinction of the thylacine on changes in climate, others blame the extinction on the import by humans of dogs from Asia, thousands of years ago, introducing a competitor for the thylacine's food supply [231].

In 1999, Michael Archer, director of the Australian Museum in Sydney, announced to the press that he wants the cloning procedure to be used on a dead thylacine puppy that was preserved in alcohol in 1866, resulting in a living thylacine [233]. They would have to sequence the DNA and manufacture an artificial chromosome, which has never been done [233]. To the suggestion of bring back an extinct species, the public and scientific community responded with the full range from hope to skepticism. Later in 1999, the Rheuben Griffiths Trust was founded to raise funding for the necessary research. The government of New South Wales also provided a "small seed grant" of $10,000 [234]. Evolutionary biologist Dr. Don Colgan was asked to lead the cloning project [235]. Hopes rose in 2002, when the scientists were able to extract DNA from the preserved thylacine pup, and they were even able to use the chemistry of enzymes to make millions of replicates of it.

The ivory-billed woodpecker

Another topic that Scott Weidensaul covers exceptionally is the ongoing search for the ivory-billed woodpecker.

This species of woodpecker -- genus and species Campephilus principalis -- was, or is, if it still exists, a large black bird with a red head and a bone-colored beak, and the largest woodpecker in North America. It was "as large as a duck or a crow, with a 3-foot wingspan" [21, 47-49] Weidensaul says, "The ivory-billed woodpecker was nature's exclamation point, the personification of pizzazz ...." [47]

The bird was last seen in Louisiana in 1943, where it was nesting in a forest that is now destroyed by logging. There have been more recent but, according to the opinion of some, "unconfirmed", sightings of the bird, in Cuba in 1987, and in Louisiana in 1999. Author Scott Weidensaul is one of the searchers.

To some extent, Weidensaul believes that the 1999 Louisiana sighting of a pair of ivory-billed woodpeckers, by graduate student David Kulivan in the Pearl River Wildlife Management Area (WMA) [59] is accurate. The bird, he writes, "after being "written off as extinct ... forty years ago ... came out of the swamps ...." [12]. On the other hand, he gives a fair hearing to the arguments that the 1999 sighting was an error [62-64].

It was "the King of the Woodpeckers, famous for its affinity for big, old timber." [62] This woodpecker's dietary niche helped to endanger it. Unlike most woodpeckers, which can eat the insects in any live or dead trees, this bird, due to a "maladaptive mistake," could only eat the insects in trees that had recently died and were still covered with bark. "The primal South was a buffet table for a bird of the ivorybill's tastes" [49]. But the old growth forests are rapidly disappearing. The beginning of the end was in the 1930s, when "the notorious Chicago Mill and Lumber Company" [52] bought and clear-cut 80,000 acres. Weidensaul says, "If there is a Holy Grail of lost species, it is the ivorybill." [54]

The United States Fish and Wildlife Service (USFWS), the agency within the U.S. Department of the Interior responsible for the protection of endangered species, empowered by Endangered Species Preservation Act of 1966 and the stronger Endangered Species Act of 1973 [101], took up the cause of the ivory-billed woodpecker. In 1991 the USFWS hired Professor Jerry Jackson, of Florida Gulf Coast University and formerly of Mississippi State University, who had been searching for the bird for years, to thoroughly search the forest of the southern U.S. To date, while the search continues, the UFSWS has postponed moving the bird's name from the endangered species list to the extinct species list. In addition, the Cornell Laboratory of Ornithology, a department of of Cornell University in Ithaca, NY, in cooperation with the Louisiana Department of Wildlife and Fisheries, and with generous financial backing from the Zeiss Sports Optics company, a binoculars manufacturer, have been conducting expeditions to search for the bird in the area of Pearl River, Louisiana [64]. The Cornell lab's Bioacoustics Research Program plants microphones and tape recorders in forests in the hope of picking up the bird's characteristic knocking and yelling. Another tactic is to play old recordings of the woodpecker's sounds and listen for an answer. So far, the searchers have made sound recordings and found recently formed roost holes, which "they consider suggestive, if not definitive, evidence." [64]

Breeding-back, new breeding, and cloning

The proposed technique of breeding-back will involve the introduction of DNA from an extinct animal into a living animal which has descended from it. If it works, after the breeding of numerous generations, the extinct species, or something quite similar to it, may be restored.

Weidendaul discusses projects to breed cattle that will closely resemble aurochs, a species of cattle that became extinct in 1927 [196-197]. The auroch became rare at the end of the ice age about 12,000 years ago. [191] The author provides a few interesting paragraphs in which Julius Caesar describes the auroch in the first century B.C. -- he called it the uru, plural uri. Caesar hunted the animals and wrongly considered them incapable of being tamed and domesticated. [191-192].

Another animal that became rare at the close of the ice age was the woolly mammoth. It disappeared everywhere except in Siberia, and finally disappeared there as well about 4,000 years ago. [191] The Asian elephant is its closest living relative. Some scientists proposed extracting the DNA from the Jarkov mammoth, a frozen carcass discovered in Siberia, and using the DNA to produce a clone. They were quickly disappointed. "Almost from the instant of death, DNA starts to degrade," writes Weidensaul, "broken up by decomposition, microbes, oxidation, hydrolysis, and other forces." [228] Upon discovering that the artifact's DNA was too damaged to permit cloning, scientists next proposed trying to extract sperm from the animal which has been dead for 20,000 years, and using it to fertilize the egg of an Asian elephant. However, freezing is " rough on sperm, unless the semen is treated with chemicals like dimethylsulfoxide to prevent cell damage." [228] Despite the small probability of success, French explorer Bernard Buigues invested more than a million dollars of his own money into the project, and a documentary about the project on the Discovery Channel became the highest rated show in the history of the network [226].

Slightly different from the strategy of "breeding-back", i.e., restoring an extinct species from a living species which has descended from it, is another strategy called "new breeding", i.e. restoring an extinct species from a living species which did not descend from it, but which is genetically related to it [208].

New breeding is being contemplated in the case of the quagga, an extinct animal which had a dark brown body and stripes on its head and shoulders. It it believed that the modern zebra is related to the quagga, but did not descend from it. Reinhold E. Rau, a taxidermist at the South African Museum in Cape Town, has contributed a very well preserved tissue from a quagga. Its mitochondrial DNA (mDNA), which undergoes almost no changes across generations, even as DNA changes, has been compared to the mDNA of modern zebras, in the hope of proving the relationship [208-210].

Cryptozoology

In Chapter 6 Weidensaul covers the topic of cryptozoology, the search for animals which, according to one's opinion, are either rarely spotted or entirely mythical. Example of such animals are the reported "sea monsters" in Loch Ness and Lake Champlain. The author looks at the process of analyzing photographs to determine whether they are fakes. He also discusses the possible significance of the thermoclines which exist in both of these bodies of water, that is, layers of warm water, which, because they are less dense, float on top of the colder bottom layers. [162]

Weidensaul says, "If cryptozoology is ever going to hit pay dirt, the jackpot is most likely to be marine. Even inshore waters are largely a mystery, and we know so little of the open ocean that it is the height of hubris to think we've uncovered all the big surprises." [178] He cites the discovery in 2001 of a squid with 20 foot arms. "On land, the pickings are much slimmer." [179] He doubts some reports from the Congo, those of sightings of "an elephant-sized long-necked dinosaur," but he considers the search in the Congo for the Bili ape to be more realistic, "if one can judge the likelihood of discovering and unknown species by the caliber of scientists who look for it ...." [179]

Recommendation

We have taken away the animals' homes to turn the land into our homes; we have destroyed their societies to establish ours. We have much fondness for animals, inferring from the billions of dollars people spend each year on their pets. We need now to raise the public's consciousness about the importance of biodiversity in natural habitats. The Ghost with Trembling Wings is an essential addition to the bookshelf of every citizen seeking well-rounded knowledge of science and social issues. It is written with passion while it is exceedingly well documented.

Book review and commentary by Mike Lepore for crimsonbird.com