The Giant Pandas of Wolong
Many animals, including Jesse James, Alexander the Great, and the giant panda, must, Janus-like, show two faces to the world—one required by legend, the other given by nature. The hortatory faces are, in sequence, honest (in the largest sense), virtuous, and cuddly; the natural visages tend to thievery, rapacity, and ennui.
George B. Schaller and his colleagues, in the finest study yet completed on the second panda, write in their introduction:
There are two giant pandas, the one that exists in our mind and the one that lives in its wilderness home. Soft, furry, and strangely patterned in black and white, with a large, round head and a clumsy, cuddly body, a panda seems like something to play with and hug. No other animal has so entranced the public…. The real panda, however, the panda as it lives in the wild, has remained essentially a mystery.
The Giant Pandas of Wolong, an attempt to decrease the mystery surrounding panda number two, provides extraordinary testimony to another phenomenon, more often part of legend than of fact—international cooperation in science. Only about one thousand pandas survive in nature, all in six small blocks of bamboo forest (29,500 square kilometers) along the eastern edge of the Tibetan plateau—though historical records indicate a former distribution up to one thousand kilometers further east, nearly to the Pacific coast.
The Wolong Natural Reserve, largest of China’s panda sanctuaries, contains between 130 and 150 animals. Chinese scientists began an in-depth study of the Wolong pandas in 1978. George B. Schaller, from Wildlife Conservation International, arrived in December 1980 to work with a Chinese team headed by Hu Jinchu of Nanchong Normal College. This book summarizes the joint work that continues today.
Since this book is about the second panda, it will rarely delight and charm. The Giant Pandas of Wolong is a technical treatise, not a contribution to the distinctive genre of popular books that describe a naturalist’s intimate life with one interesting species in the wild (including several by Schaller, most notably his Year of the Gorilla). We can sense what’s coming when we read on page three (I shall provide a translation upon request) that “the zygomatic arches are spread widely, and the sagittal crest is prominent…. A typically carnivorous dentition (I33 C11 P44 M32=42, but P1 may be absent) has been strongly modified for crushing and grinding food.” And the relentless passive voice of conventional scientific prose imparts no charm or grace of composition, especially in such lines as “apparent itches are scratched with fore- or hindpaw.”
Pandas are rare and elusive animals even in the relative abundance of their Wolong reserve. We dare not recognize them as the cute stuffed toys of our children; indeed, we have to struggle mightily to see them at all. Between March 1978 and December 1980, Schaller and company saw pandas only sixteen times; the enlarged team recorded thirty-nine additional observations between January 1980 and May 1981. They write: “Most of our contacts were brief—a glimpse as an animal crossed an opening or ambled up a trail.”
Researchers must therefore rely upon indirect methods, primarily two in this case—one old fashioned, the other new-fangled. Fortunately, pandas defecate prodigiously, and with such regularity that number of droppings provides an adequate clock for time spent in any particular spot. It is, I suppose, a kind of ultimate dethronement for panda one (of legend) when we recognize that brown cylinders, rather than furry bodies, form the major source of direct evidence.
Schaller and his team then trapped six pandas and fitted them with radio collars. These sophisticated devices transmit different signals during times of panda activity and rest. The resulting data on geographic ranges and energy budgets indicate that pandas live in relatively small, well-defined areas, averaging just 4.5 square kilometers for females and 6.1 square kilometers for males, females tending to concentrate their activity within a smaller core area of the range, males roaming more widely.
During most (indeed nearly all) of their day, pandas just don’t do anything calculated to inspire sustained human interest. Basically, they eat bamboo during active periods (about 60 percent of a day) and rest for the remaining 40 percent—all the while emitting the vast undigested bulk of their labor by the rear exit. Other activities—traveling, scent marking, and grooming, for example—consume only a percent or two of an average day. More, of course, happens during the mating season; Darwin’s ultimate game of passing one’s genetic heritage into future generations rarely passes without interest, energy, and (in most cases among animals of our ilk) strife.
In the midst of this bamboo-directed monotony, any peculiar burst of activity must kindle our excitement. Thus, we read with pleasure about the panda that stood on its hands and arched its back end up a tree for scent marking. And we almost shout for joy in learning that one subadult slid downhill (on chest and belly) when it could have walked in snow—and that, mirabile dictu, it once walked back uphill to do it again.
And yet, in a sense, I am glad that panda life is so dull by human standards, for our efforts at conservation have little moral value if we preserve creatures only as human ornaments; I shall be impressed when we show solicitude for warty toads and slithering worms. If we continue to treasure the panda even when we learn that it will not return, in basic human delectation, the warmth and playfulness that we once inferred from its appearance, then we are well on our way to a proper respect for nature. (If we can then come to admire pandas for what they are, and even learn from them some of the lessons that nature’s diversity always teaches, then we shall finally understand, and to our greatest benefit in both practical and spiritual terms, what Huxley called, in the language of his day, “man’s place in nature.”)
Moreover, the very monotony of panda behavior as bamboo-eating machines defines their major interest for evolutionary theory; Schaller’s treatment of this central subject also provides my only major unhappiness with his fine book. Pandas, by evolutionary descent, are members of the order Carnivora—but they belie their name by subsisting almost entirely upon bamboo. It seems clear that their ancestors once ate meat but then switched to the plentiful bamboo surrounding them. By constraint of a heritage so contrary to their current life, pandas must struggle to process enough bamboo. Their digestive apparatus is not well designed for herbivory. Schaller et al. specify three major reasons for the difficulty:
Pandas cannot digest bamboo leaves and stems efficiently. “The panda,” they write, “has retained the simple digestive tract of a carnivore: it lacks a special chamber to retain food, and it has no symbiotic microbes to ferment cellulose into available nutrients.”
Pandas must therefore derive nutrients from the easily digestible cellular contents and not from the valuable cell walls. (Pandas defecate so prodigiously because they cannot digest most of what they consume.)
Leaves and stems are mostly water and structural carbohydrates; pandas therefore obtain low nutritional return for amounts eaten.
Schaller’s calculations show that pandas live on the very edge of sufficiency. They eat bamboo all day long because they must spend every waking hour at it to get enough for their low ratio of return to investment. An amusing insight into this marginality came from Schaller’s efforts to determine how many hours a panda must eat (at its observed rate of foraging, speed and size of bite, and value of food) in order to fuel its minimal requirements. His figure of 19.4 hours is impossibly high since pandas only averaged 15.4 hours of eating per day. (This calculation recalls another presented earlier in the book—that pandas defecate more than they eat.) Obviously, these calculations must leave something out (unless pandas subvert the laws of physics). Small increases in speed or bite size (or an occasional munching of two stems at once) would put pandas over their obvious edge of viability. But Schaller’s effort does dramatically demonstrate that pandas, though surrounded by food, can barely extract enough from their bounty.
Nonetheless, Schaller’s entire discussion proceeds within the prevailing adaptationist model. He interprets everything that pandas do as adaptations to their curious mode of life. He identifies, as the major goal of this study, an understanding of “how the panda is adapted to bamboo.” In some trivial sense, of course, pandas are “adapted”—they are getting by. But this sense of adaptation has no meaning—for all animals must do well enough to hang in there, or else they are no longer with us. Simple existence as testimony to this empty use of adaptation is a tautology. Meaningful adaptation is actively evolved good design for local circumstances, not mere muddling through with inherited features poorly suited to current needs.
Pandas do, of course, display a suite of secondary true adaptations to their primary, unsurmounted dilemma of trying to eat bamboo with a carnivore’s digestive tract. They pick, prepare, and chew with efficiency that has actively evolved; they have even invented a famous false “thumb” to abet their struggle. But surely, despite the conceptual thrall cast by adaptation over this book, the primary theme of panda life is a shift of function that has been poorly accommodated by a minimally altered digestive apparatus. When anatomical structures are coopted for new functions from previous uses in a different past, we may not speak of adaptation. When, as with pandas, the coopted organs work so precariously, appeals to adaptation are even less appropriate.
When, in unguarded moments, Schaller lets the conceptual blinders slip, he reports the panda’s dilemma forcefully: “The longer food remains in the digestive tract, the more fully will it be utilized; thus a long intestine, as found in herbivores, might benefit the panda…. The panda’s digestive tract lacks physical and physiological adaptations for processing a bulky, herbivorous diet.” (Deer intestines may be fifteen times longer than the body, sheep twenty-five times; pandas rank with other carnivores in having intestines that are four to seven times as long.) But allegiance to adaptation soon usurps any subtle discussion of history, and we return to Gleason’s mode—“how good it is.” The authors even argue that the wild panda’s failure to accumulate body fat should be viewed as an adaptation to their stable food supply. (They mention that zoo pandas do store fat, so physiology does not preclude obesity.) Might I suggest the obvious alternative—that a little fat might be a good thing, but that pandas, eating all their waking day simply to get by, remain slim by constraint rather than design.
The debate about adaptation is not a petty, abstract nicety of academic life. It embodies our basic attitudes toward history. Evolutionary biology is the primary science of history; strict adaptationism, ironically, downgrades history to insignificance by viewing the organism’s relation to environment as an isolated problem of current optimality. How inappropriate to clamp this conceptual lock upon the panda—a demonstration, if ever one existed, that past histories exert a quirky hold (through inefficiencies imposed by heritage) upon an imperfect present.
Writing so brilliantly about the hold of theory upon our ability to observe, Geoffroy Saint-Hilaire stated in 1827: “At first useless, these facts had to remain unperceived until the moment when the needs and progress of science provoked us to discover them.” It is time to rescue history from the subverting power of Pangloss’s spectacles.
Everyone knows that the panda’s current plight extends well beyond the intrinsic dilemma of its unbreakable contract with bamboo (intensified by the tendency of most species of bamboo to undergo mass flowering with the subsequent death of edible plants and long periods of no food until the new seedlings grow). People have relentlessly cut the forests and driven pandas into ever-smaller natural areas in this land of more than a billion human beings. Chinese authorities, pushed by world opinion and their own affection for pandas, have responded admirably, but ever so late. The giant panda will probably survive, marginally in its few natural reserves, more dependably in zoos.
We will probably save most of the large species that interest or amuse us (we will lose—are losing at an accelerating pace—untold numbers of smaller, unnoted creatures). But salvation will not be in nature. Zoos are changing their function from institutions of capture and display to havens of preservation and propagation. We may applaud this revolution in concept, and we rejoice in the success of so many breeding programs. Yet the idea that most conspicuous species—like the panda—will survive only under human management fills me with sadness. Some of the reasons are practical—the problems of inbreeding, the disappearance of geographic variation as a subject for evolutionary study. But the primary reason is deeper, and hard to express. “Natural” and “artificial” represent a dichotomy not easily breached in human attitudes. An animal outside its appropriate historical place loses more than a home. When the Shunammite woman built a room for Elisha and furnished it with bed, table, stool, and candlestick, the holy man asked, “what is to be done for thee? wouldest thou be spoken for to the king?” (2 Kings 4:13). She replied, with beautiful conciseness, that she wanted nothing, for she lived in greatest satisfaction: “I dwell among mine own people.”
On the subject of biblical metaphor, please do not forget that Elisha arranged for her to conceive a son nonetheless, and later raised him from the dead. Good luck to the panda.