The Endangered Ailuropoda melanoleuca: A Classical Illustration of the formidable environmental and ethical problems and issues involved in attempting to preserve an endangered species.
By Julie Osland '93
Issues in Science
Writing Objective: Write a seven to ten-page term paper on an environmental issue that interests you.
With their Mickey Mouse ears, roly-poly appearance and their huge black eyespots, it is no wonder that the World Wildlife Fund (WWF) uses the giant panda as its symbol (“Poaching” 53). However, there are currently less than 800 members of this species, Ailuropoda melanoleuca. or giant panda In existence, and of those 800, seven hundred are roaming free in the highland forests of China; the rest are held in captivity around the world (Oliwenstein 51). Given the panda’s appearance, I find it difficult to imagine what our world would be like without the giant panda. I find it equally difficult to believe that in spite of the extensive protective measures we have for these internationally adored animals, they remain continually threatened.
In order to best understand the plight of the giant panda, it is necessary for one to have a basic understanding of its genetic and biological makeup and evolution, which plays an Intrinsic role in its current predicament. Likewise, it is equally important to have knowledge of the giant panda’s habitat and prey and to comprehend the delicate balance that must be maintained in the panda’s environment in order to ensure its well-being. Needless to say, the enormous rural population of China plays a major role in the giant panda’s endangerment. I will show how this panda led a quiet, reclusive and stable life in Its environment until human encroachment into its habitat and other human-related factors caused their numbers to steadily decrease. In addition, I will also show how some programs of intervention implemented on behalf of the panda have inadvertently hurt it, i.e., the “rescuing” of “abandoned” panda cubs, and panda loans. Finally, I will not only bring to attention the various proposals concerning what measures must be taken in order to ensure the giant panda’s future, but I will also mention some ethical questions that are raised when asking, “Why should we save this endangered species? What value does this species have?” Through the example of the giant panda I hope to illustrate the complex series of problems that arise when humans invade the habitat of another species, the extent of damage that can be done, and the difficulty of repairing that damage, which often is the basis for many ethical questions.
For over one hundred twenty years, numerous biologists have debated and questioned the correct taxonomic placement of the giant panda; some have wanted to place it with the bears, in the family Ursldae. while others have wanted to place it with the raccoons, in the family Procvonudae. Yet there are those who want to place it in its own family, the Ailuropodidae. However, the mystery of the giant panda’s taxonomical placement was solved by Stephen O’Brien and his colleagues at the National Cancer Institute. O’Brien wondered if electrophoresis, a process by which genetic parentage is easily determined, could be used to answer the panda’s ancestral mystery (O’Brien 104).
The process of electrophoresis involves isolating proteins from tissue samples of the possible parents and the offspring and then placing those proteins on a gel matrix. The proteins are then separated and exposed to an electric field. By comparing the patterns of separation to the patterns of the possible parents, the offspring’s parentage is then determined. The parent has a pattern of separation similar to that of his offspring (ibid. 104).
According to the rules of homology, one could expect the proteins of the giant panda to be most like those of its closest relative. Using a process called DNA hybridization, fibroblast cells from several species from the family Ursldae (which includes the brown bear, the polar bear, the sloth bear and the American black bear), and from the Procvonidae family (which includes the red panda and the raccoon) are grown in a medium containing radioactive nucleotides. As the fibroblasts divide, they incorporate the radioactive nucleotides into their newly synthesized DNA. Single stands of this radioactive DNA are mixed with single strands of non-radioactive DNA from another species. These two types are then allowed to form double-strand hybrid DNA molecules. The extent of hybridization is determined by measuring the radioactivity of the new DNA. The sequence of homology of DNA from the two species is revealed b the temperature at which the hybrid strands unwind when subjected to heat. This melting temperature is inversely proportional to the differences in composition of DNA strands. Through this procedure O’Brien and his colleagues were able to determine that the panda bear did in fact belong to and has evolved from the bear family, Ursldae (ibid. 105-107).
Biologically, Mother Nature dealt the giant panda a tough hand. The average panda does not reach its sexual maturity until it is five or six years old (Dongjing 37). Once sexual maturity is reached, the females go into heat only once a year and there are only two to three days when the female can conceive. When the females do conceive, they give birth to one or two cubs, whereas most bears give birth to a litter of at least four. The typical gestation period lasts approximately five months. The mother panda nurses her cubs from three to five months and does not go into heat right after nursing. She usually misses an entire year’s breeding season. The panda population grows tediously slowly: at best at the rate of one panda every other year (Dolnick 71-72).
In addition, the panda is an herbivore that is not particularly good at what it does. Anatomically speaking, it Is an herbivore living inside of a carnivore’s body. A panda spends most of its day trying to consume 25-85 pounds of bamboo because it does not get as many nutrients out of its food as do other herbivores. Most herbivores have intestines 15-25 times longer than their bodies so that more time Is available for the extraction of nutrients. Pandas, in comparison, have intestines only six times as long as their bodies, thus making consumption of massive amounts of bamboo necessary. Moreover, they lack the enzyme-producing microorganisms in their intestines that break down the tough cellulose in the bamboo into digestible food material. Most herbivores can digest eighty percent of the food they take in; pandas can digest a meager seventeen percent (ibid. 72). Given this inefficient intake of energy, it is no wonder that the panda is so frugal in expending energy for reproduction and raising of young. This provides insight into why courtship lasts only a day and why new-born panda cubs weigh only two ounces (Sundquist 9).
The pandas’ diet consists of an almost exclusive consumption of bamboo shoots, stems, and leaves. Currently, twenty-one different species of bamboo have been identified as having been eaten by giant pandas. However, their preferred species of bamboo are the Bashanla fanglana and the Fargesia spathacea. commonly known as the arrow and umbrella bamboo, respectively. Experts have recognized the suitable panda habitat as a bamboo forest, consisting of preferably more than seventy percent coniferous forest canopy, and also containing at least two of the previously mentioned preferred species of bamboo. Currently, the remaining wild panda are living in six small pockets of mountainous land totaling about 30,000 square kilometers, mainly in the Sichuan province of China (O’Brien and Knight 758; Taylor 111).
The fact that pandas are squeezed into these small, isolated pockets of land poses some serious problems. Due to the little energy that they obtain from bamboo, pandas must consume 25-85 pounds of it each day In order to survive. Furthermore, the bamboo itself has become a threat to the pandas now that they are forced to live on small patches of land. Depending on the species, every 15-120 years, a whole bamboo species will flower, go into seed, and then die. The unusual nature of bamboo has puzzled many people, but Truman Young, an ecologlst at the Gallmann Memorial Foundation in Kenya has an interesting hypothesis about the bamboo’s peculiar reproductive cycle. Bamboo has evolved to rid itself of the panda nuisance, since it is the panda’s sole diet. The bamboo starts off by first proliferating asexually, thus providing the panda with an abundance of food. This allows the notoriously slow-breeding panda to gradually increase its numbers. Then, when the panda population has Increased, the bamboo dies off suddenly, leaving the pandas on the brink of starvation (Shlpman 22).
In addition to the effects of the pandas’ natural habitat and prey, human factors have also contributed to the demise of the giant panda.
Three million years ago, the giant panda lived throughout China: as far south as Burma, as far east as the Pacific, and as far north as what we now know as Beijing. Over time, the population of China grew, and the pandas were pushed farther and farther west. Along with the increase in population came the destruction of the bamboo forest habitat of the panda (Dolnick 72). Currently there are 1.2 billion people in China who are continuing to fight for living space.
In the Sichuan province, the six blocks of land on which the pandas live have been further fragmented by the rural Chinese who are rapidly cutting the old growth forests for much needed wood and then using the deforested land for grazing and farming. These old growth trees are essential to the well being of the giant panda since they are used by the female pandas to construct maternity dens. Within the fragmented land the panda populations, ranging in size from groups of ten to fifty, are becoming isolated by roads, rivers, clear-cut forest and human settlement. George Schaller of the New York Zoological Society has called the situation “a blueprint for extinction” (Johnson and Johnson 33; Roberts 529-530).
With the natural habitat of the panda fragmented, the effects of bamboo die-off are magnified. On those small plots of land only one or two species of bamboo are usually found; once the bamboo dies, so does the panda—which is exactly what happened in the mid-1970s in the Min Mountains of China. Three species of bamboo flowered, seeded and died simultaneously resulting in the death of 138 pandas (Roberts 531). Another problem that has arisen as a result of habitat fragmentation is inbreeding, since each fragmented plot contains only ten to fifty pandas. According to an article in the Beijing Review, a research group studied the problem of Inbreeding on a group of over 200 pandas and concluded that, “If inbreeding continues at the current rate of 5.4 per thousand, after about eighty years all of the pandas in the Qinllng population will be cousins” (“New Discoveries” 45). Considering the fact that inbreeding can cause infertility and an increased susceptibility to disease and the fact that the majority of the pandas are on tiny patches of land. It is easy to see that it will not be long before the effects of inbreeding on the panda populations are seen (Dolnick 73). Lastly, the panda population is threatened by poachers who prey on the fewer than 1,000 pandas remaining in the wild. Although no one knows for sure how many pandas have been poached over the years, in 1988 alone, 150 panda skins were found in a sweep of villages in the Sichuan province. Their skins are reportedly worth thousands of dollars on the black market, but the heavy sanctions against poaching i.e., long sentences in jail and even the death penalty have evidently not been enough of a deterrent (“Poaching” 53; Drewl4).
However, not all of the damage inflicted upon the panda was done intentionally. The wild panda population has also decreased due to well-intentioned “rescues” of starving pandas, even though most, if not all of the pandas “rescued” were in no danger of starving. Nevertheless, once these “rescued” pandas are captured, they are rarely reintroduced to the wild (Roberts 530). Furthermore, zoos are not proving to be a good potential “last ditch” option for the pandas. Since 1963, China has tried to breed pandas in captivity. However, out of the ninety cubs that have been born, only thirty seven managed to live to the age of six months (Dolnick 74). Finally, panda loans to Western zoos have been stopped. Initiated at the Los Angeles Zoo during the 1984 Olympics, these loans garnered approximately half a million dollars per exhibit, most of which went to giant panda conservation. As has been stated earlier, pandas are notoriously difficult to breed in captivity; therefore, when a female panda on loan to the Bronx Zoo started to ovulate, conservation groups started to protest stating that the panda should have been in China increasing the panda population. In response to that protest, China banned its short term panda loans (Drew 14-16; Roberts 1594).
Given the failure of the previous well-intentioned interventions, what must be done in order to preserve the giant pandas future?
First and foremost, the panda habitat must be re-established. This entails restricting lumber harvesting, planting more trees in non-wooded areas, and planting “migration corridors” consisting of at least two different kinds of bamboo and some forest canopy between fragmented bamboo patches. In addition, a captive management program has also been suggested to complement the previous measures. A stud book, to match far-flung but potentially compatible pandas, is also a prerequisite. Finally, stricter poaching laws and more poaching patrols need to be put in to effect in order to protect the pandas from intentional human harm (Roberts 530; Dolnick 76; Dongjing 37; O’Brien and Knight 759).
I sincerely believe that if the latter measures, which interestingly enough don’t rely heavily on “modern technology,” are implemented, then the giant panda will have a fair chance of slowly but surely regaining its numbers.
But why should we go to all of this trouble to save the pandas? Should we save them because they are cute? Because they represent a unique genetic evolution in their own right? Should we save them because we want future generations to be able to enjoy the pandas? Or should we save them in order to maintain a wide diversity of life? Which of these answers are “right,” and which ones are “wrong?” Maybe we are barking up the wrong bamboo tree. As Henry Beston aptly put it in his book The Outermost House, “For the animal shall not be measured by man. In a world older and more complete than ours they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voice we shall never hear. They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net and life of time, fellow prisoners of the splendour and travail of the earth.”
Beston, Henry. The Outermost House. New York: Holt, Rhlnehart and Winston, 1928.
Dolnick, Edward. “Panda Paradox: How is it that the panda, an animal the world would dearly love to save, seems doomed to extinction?” Discover, Sept. 1989: 70-76.
Dongjing, Chen. “Pandas—Blueprint for Survival.” Beijing Review. 21 Mar. 1988: 37-37.
Drew, Lisa. “Are We Loving the Pandas to Death?” National Wildlife. Dec/Jan. 1988-1989: 14-17.
Johnson, Kenneth G., and Jenny Freeman Johnson. “Mystery of the Red Panda.” International Wildlife. Nov.-Dec. 1990: 30-34.
“New Discoveries in Giant Panda Research.” Beijing Review. 11 June 1990: 44-45.
O’Brien, Stephen J. ‘The Ancestry of the Giant Panda.” Scientific American. Nov. 1987: 102-107.
O’Brien, Stephen J. and John A. Knight. The Future of the Giant Panda.” Nature. 18 June 1987: 558-559.
Oliwensteln, Lori. “What’s Black and White and Fading Fast?” Discover. Jan. 1988: 51. “Poaching the Pandas.” World Press Review. Mar. 1988: 53.
Roberts, Leslie. “China Bans Panda Loans.” Science. 23 Sept. 1988: 1594. —. “Conservationists in Panda-mo nium.” Science. 29 July 1988: 529-531.
Shlpman, Pat. “Killer Bamboo.” Discover. Feb. 1990: 22.
Sundquist, Fiona. ‘The Strange, Dangerous World of Folivory.” International Wildlife. Jan./Feb. 1990-1991:4-10.
Taylor, A. H. and Q. Zisheng. “Bamboo Flowering and Pandas.” Nature. 14 Sept. 1989: 111.
Wenshi, Pan. The Last Refuge of the Giant Panda.” UNESCO Courier. Feb. 1988: 24-25.