Biruté Galdikas's life with orangutans—and the iconic story that helped change their fate

I had left the forest and was limping back to camp in the rain. My left leg was soaked with blood from a wound made by my machete, which had slipped as I cut a vine. 

Suddenly I stopped. I could scarcely believe my eyes. In the tall grass less than thirty feet from me an orangutan was warily crossing a ladang—a dry-rice field gone to grass and fern—to reach the distant trees on the other side. This "person of the forest," as orangutan means in Malay, didn't see me through the drizzle. He moved silently across the path and then disappeared into the grass. 

The orangutans I had observed during many months in Borneo's jungle had confirmed the traditional view of their behavior—they had stayed up in the trees. Now this encounter was my first clue that not only do wild orangutans spend more time on the ground than anyone had ever suspected, but also that they sometimes venture out of the tropical rain forest that is their home. 

My leg quickly recovered, and so did my spirits, which had been despairing since my husband, Rod, and I had first reached the lowland jungle of the Tanjung Puting Reserve in the Indonesian sector of Borneo. 

(Climbing into the secret world of an ancient Bornean rainforest.)

I never imagined in those first months that during the next four years Rod and I would spend more than 5,000 hours observing wild orangutans. We studied not-so-wild subjects too, for we became a "halfway house" through which young orangutans, accustomed to captivity, were returned to their natural life in the forest. 

In social behavior the orangutan has always been considered very different not only from man but also from all other monkeys and apes, including its African cousins, the gorilla and chimpanzee. Primates have been characterized as social animals par excellence, but the wild orangutans Rod and I saw in those early months were almost invariably solitary: lone males, or adult females accompanied only by their dependent young. Yet I knew that orangutans must meet and interact—if only to breed—and I longed to know the extent of such relationships.

Leeches welcome new blood

In the course of our research we occupied three campsites in our 14-square-mile study area. The first camp, by the Sikunir Kanan River, we called Camp Leakey, in honor of the late Dr. Louis S. B. Leakey, who encouraged me to study the wild orangutan and who helped me obtain funding. The other two camps we named, in time, Camp Wilkie and Camp Dart. 

We reached Camp Leakey in November 1971. The swamps, swollen by rains, were waist deep and impassable. Leeches were everywhere. Bloated with our blood, they fell out of our socks, dropped off our necks, and even squirmed out of our underwear. 

The camp itself was simply a small bark-walled, thatch-roofed hut surrounded by a swamp forest. To afford better access to our study area, Rod began cutting a crisscrossing network of small trails through the forest. 

My earliest observations were of orangutans feeding, moving through the trees, and nesting. Generally they made a new tree nest each night out of branches and leaves; sometimes they built nests during the day too, for naps and to sit out rainstorms. Also, unlike the other great apes, orangutans made overhead platforms or covered themselves with branches as protection against downpours. 

Orangutans seemed to prefer fruit, but they ate considerable quantities of young leaves and the soft material on the inside of bark as well. One fruit that intrigued us was banitan, a perfect sphere encasing two pits so hard that nutcrackers won't open them. Inside each pit is a tiny bit of substance that reminded me of coconut. The orangutans would spend endless hours crushing these pits with their teeth. Juveniles and infants, lacking the enormous jaws of their mothers, could not usually open them, so instead took bits and pieces from their mothers' mouths. 

Youngster's rage leaves mother unmoved

Sometimes a mother would refuse to share, causing the youngster to throw a violent tantrum. I thought one squealing juvenile might just hurl himself out of the tree headfirst in his fury. When he returned to his mother, she nonchalantly allowed him a piece as though nothing had happened. 

Perhaps my most vivid memory, though, is of that scorching day I came face-to-face with a large adult male on the ground. It was almost a showdown. I was rounding a turn in a ladang path when a huge orangutan appeared, heading straight toward me. He was just ambling along, head down, oblivious to my presence. Then he stopped dead in his tracks less than twelve feet away. For long seconds he stared and stared. I guess he was evaluating the bizarre sight in front of him a pale—faced primatologist with large black sunglasses, clutching an enormous bag full of dirty laundry. 

We were on a collision course. The narrow path was fenced in by tall ferns that formed an arch overhead. But, strangely, I felt no fear. I simply marveled at how magnificent he looked with his coat blazing orange in the full sunlight.

Abruptly, he whirled around and was gone. There was nothing but the sound of his feet padding off along the path. 

My confrontation with this big male seemed to bear out a traditional belief that the wild orangutan is mild and retiring. Back at camp, though, our workman, Ahmad, told us of a relative in Kumai who had lost half his hand and part of one foot to an orangutan male he had encountered in a ladang. But it turned out that the relative had been chasing the animal with dogs. A full accounting of incidents like these always led to the same conclusion: Humans who were bitten or wounded had invariably provoked the apes.

Orang forgoes his penthouse bed

By now, meeting an orangutan on the ground came as no surprise. One mature male sometimes spent as long as six hours a day traveling and foraging on the ground, though on other days he stayed totally in the trees. Another large male came down from the trees daily and did almost all his long distance traveling along the forest floor. 

I was, however, amazed to see a subadult male sleep for 45 minutes on the ground during the day. He didn't make a nest but merely bent a sapling under him as he lay down. This was the first time that anyone had seen a wild orangutan sleeping on the ground. Since then we have found three actual "ground" nests. In these instances the nests were built on fallen logs less than a yard off the forest floor. 

Rarest of the apes, wild orangutans are restricted to diminishing ranges on the islands of Borneo and Sumatra. It has long been illegal in Indonesia and Malaysia to own, kill, or export them, but until recently the laws were not strictly enforced. The threat of extinction still hangs over the orangutan because of the slaughter of mothers by poachers trying to capture their infants and the whole sale destruction of their habitat by logging and agricultural land-clearing operations. For years captive orangutans have brought high prices from zoos and laboratories around the world, though lately conservation groups have reduced the illegal trafficking.

When the Nature Protection and Wildlife Management arm of the Indonesian Forestry Service began confiscating captives, it asked that our camp in Tanjung Puting Reserve be developed into an Orangutan Rehabilitation Center, where captive youngsters would be reintroduced to life in the wild. There are other such centers in Malaysian Borneo and northern Sumatra. Ours was to serve Kalimantan (Indonesian Borneo). 

But what do you do with "repossessed" young orangutans? Without expert guidance these unfortunate animals usually die from disease, malnutrition, and neglect. Rod and I hoped to teach them the ways of the forest, and how to become "wild" again.

The first orangutan youngster to reach our camp was year-old Sugito, who had been kept in a small crate before he was confiscated. Normally, orangutan infants cling almost continually to their mothers until they are 1 1/2 years old. Sugito decided I was his mother. 

Determined to give him as normal an upbringing as possible, I allowed Sugito to cling to me. I had little choice. Even shifting him from one part of my body to another involved much fighting and howling. Changing clothes became a major undertaking, with Sugito screeching and clutching at whatever was coming off. He slept curled up next to me and would not abandon me even when I bathed in the river.

Released pet becomes a raider

At first Rod and I had the idea that ex-captives, if only old enough, would eagerly return to life in the forest. The first one we freed, 4 1/2-year-old Sinaga, ran off into the forest the moment he was freed. 

"We'll never see him again," I predicted—naively, as it turned out. Sinaga was back the very next day, raiding our camp for food. His raids continued. He would lurk in the trees until we went to the river to bathe. Then he would strike. We would return to find our hut a shambles. 

After about a month Sinaga stopped his forays into our camp. We assumed he must have been finding enough wild fruits and young leaves to sustain him on his own. We saw him again a few times foraging in the trees near camp, but he never came back. He was our first successful rehabilitant. 

Next came Akmad, a small 2 1/2-year-old female confiscated from a logging camp. Akmad was a gentle creature with dainty hands and refined manners. She never grabbed—she reached. Finding a package, she would make a neat tear in one corner instead of ripping it to shreds as other orangutans did. 

I remember watching Akmad put a bottle down after drinking from it. Because the floor was slanted, the bottle kept rolling away. Akmad would quickly retrieve it, looking around guiltily as if to see whether anyone had caught her faux pas. She must have placed that bottle on its side a dozen times before finally standing it upright. 

The establishment of our second outpost, Camp Wilkie, just inside the forest, marked a turning point in our research. We no longer had to walk through the ladang or go through the swamps. The camp consisted of a small raised platform with a thatch roof. There were no walls. We slung our hammocks from the roof supports. Later we added another roofed platform to serve as a kitchen hut where we cooked over an open fire.

Sounds betray orangs' presence

Early every morning I went out in search of wild orangutans. As I walked I listened. The wild orangutans sometimes disclose their presence by the snap of a twig or the regular dropping of fruit stones as they eat, sometimes by the crashing of branches as they move through the trees. 

Once I had located an orangutan, I followed it, if possible, until it nested for the night. Next morning I'd be back before sunup, hoping to find the orangutan still in the nest, so that I could continue to follow and observe its behavior. I would sometimes walk three miles to reach a nest by the first glimmer of dawn. 

On one such search I encountered a pregnant female and her juvenile son. We named them Cara and Carl and started a continuing study of them. Cara was a problem. She had a dangerous habit of breaking off branches and dropping them without any of the usual vocal warnings. One dead branch—a veritable log—missed me by about an inch.

Cara, unlike most females, also toppled branchless dead trees. Once, when I was tangled up in a windfall below her, she suddenly started rocking one such enormous snag in my direction. Had she the strength of the much heavier males, I would have been killed. As it was, the snag teetered but didn't fall. 

Despite Cara's initial hostility, she and Carl after about a year and a half came to accept us more fully than did most of the others. And they gave us our first glimpses of social interaction among wild orangutans. One instance sticks in my mind. The two had been joined by a subadult male, one of several who occasionally followed Cara when she was in heat. The newcomer romped good-naturedly with Carl and feverishly examined Cara's genital region. At the end of the day the animals bedded down close together. Cara and Carl occupied one nest, the male another. 

All was still. It was slowly becoming darker. Suddenly some trees began to shake as if in a hurricane. Snags crashed and there was a piercing bellow as an adult male emitted his "long call"—a hair-raising, minutes-long sequence of roars and groans that can carry a mile. The subadult male didn't hesitate; he leaped out of his nest and dashed down to a perch a yard above the ground. He listened until the call ended, then slid to the ground and vanished in the undergrowth.

Despite the sound, little fury 

Amid wild shaking of trees and snapping of branches, a gigantic male emerged. He had the pronounced cheek pads and throat pouch that males acquire when they reach adulthood at age 12 to 15; the throat pouch probably acts as a resonator for the long call. He peered over the edge of the occupied nest. Cara and Carl could not have slept through the commotion, yet their bed never once quivered or shook. Satisfied this was only a female and her offspring, and not a sexual rival, the big male moved away. 

Subsequent observations began to fill out the patterns of orangutan distribution and organization in the study area. Adult males were almost invariably solitary. In 3 1/2 years we witnessed only two meetings between lone adult males not in the presence of females. Not only did adult males generally avoid each other, but they also were intolerant of subadult males—which usually fled when a big male appeared. 

A good example of the solitary ways of grown males in the wild was given us by the first animal that accepted our presence; we named him Throat Pouch, or T. P. During 23 days of continuous observation, T. P. met other orangutans only four times, and these were females and their young. The encounters totaled only a few hours.

At times, of course, adult males found females willing to mate. During T. P.'s consortship with Priscilla we gathered probably our most significant single set of observations. 

Priscilla and her son, the ugly Pug, were with a subadult male. T. P. appeared and the smaller male prudently vanished. T. P., Priscilla, and Pug slowly traveled on, foraging. Suddenly another male orangutan appeared low in the trees ahead. T. P. immediately charged the slightly larger stranger. 

They grappled furiously, biting one another; they fell repeatedly and chased each other into the trees again to resume the fight. Their backs glistened with sweat, its pungent odor lingering on the ground long after they were back in the trees. A few times they pulled apart and stared intently at each other. Then, after more than 20 minutes, they separated and sat in adjacent trees. With a mighty heave T. P. threw a snag and roared. The other male disappeared.

We were absolutely elated: We had observed the first and only combat ever recorded between two mature wild orangutan males. 

Three days later T. P. and Priscilla mated, and approximately nine months later Priscilla gave birth to a male we named Pete. We are almost certain T. P. was the father. 

We never did see T. P.’s reaction to his putative son. We did, however, discover through a frightening incident that T.P. was irritable with infants. Sugito, by this time, had reached a stage of development probably analogous to that of a crawling, inquisitive year-old child. He would climb higher and higher into forest canopy, oblivious to everything. I marveled at his audacity as he swung around and played in the branches, practically under the nose of the feeding T. P., who seemed unaware of him. I suspect naive little Sugito thought this big orange fellow would make a fine playmate.  

Unsuccessful in attracting T. P.’s attention, Sugito started climbing toward me. Halfway down he emitted one tiny squeal. I barely heard it. T. P. instantly became incredibly enraged. He flew down the tree after Sugito. Sugito was terrified. He slid down the last few feet of the tree as though it were a greased pole and leaped into my arms. T. P. was right behind him.

I stood up, panic-stricken, and backed away. Had Rod not been there, I think I would have run for my life. And, doubtless, T. P. would have chased me. But Rod calmly stood up with machete in hand and, looking directly at T. P., sliced through a small sapling just in front of him. 

At this T. P. stopped; he was about six feet directly above us. He glared menacingly, climbed to a more secure perch, and bellowed. This was the closest that a wild orangutan ever came to attacking us. 

Then one day during the month that Pete was born, January of 1973, T. P. abruptly vanished. We searched and searched throughout the study area and listened for his particular call, which we had learned to recognize. We found no trace of him, and reluctantly concluded he was dead.

Five's company, seven's a crowd 

Adult females were more social than the adult males, but they too led what seemed to us rather lonely lives. However, we did occasionally see two or three adult females and their assorted offspring traveling together or foraging in the same vicinity. 

Once again it was Cara and Carl who introduced us to this new situation. We were following them early one morning when they joined five other orangutans: Beth, carrying infant Bert, and Priscilla, followed by her son Pug and an independent adolescent. They stayed together for several hours, but the peaceful camaraderie didn't last. 

The seven were quietly feeding in one tree when suddenly horrible sounds began to emanate from the forest canopy—noises I had never heard before. The uproar came from Priscilla and Cara, who tumbled down out of the branches, chasing and jostling each other. An hour later the two were at each other again. Then Priscilla moved away, followed only by her son. The remaining five roamed together the rest of the day, nested together, and split up the next morning. 

Beth and Cara never touched each other, but upon meeting, Beth would sometimes follow Cara closely and Cara would wait for her. Twice they and their offspring traveled together for the better part of three days. Such long periods of association were never observed among other adult females.

Compared with the adults, the immature orangutans were almost gregarious, although they too often traveled alone or with their mothers. The large adolescent Georgina sometimes traveled with one or two smaller friends, Maud and Fern, as well as an occasional subadult male. They would sometimes play, touch, and even briefly groom.

Maud and Fern had different mothers, so Georgina could be the sibling of one but not both. It was obvious that age group as well as kinship ties determine associations among immature orangutans. Pregnancy and the birth of her first infant ended Georgina's adolescence and these friendly relationships. 

Youthful males occasionally played together, but more often sought the company of females. Indeed, we observed a friendship between a subadult male and an adolescent female that lasted for years. We began thinking of Mute and Noisy as a unit, although occasionally we saw each of them alone.

Mute's partners not always willing

Determined to investigate the precise nature of this regular association, we followed them into the inland swamps. We were exhausted after ten days, but Mute and Noisy were still close together. This relationship was not sexual. Mute, in fact, liked to mate forcibly with unwilling females and would do so while Noisy hovered in the background. Once while Mute was attempting to mate with a very uncooperative partner, Noisy attacked her. Jealousy? We don't know. 

Later we followed Noisy out into the dark waters of the river-edge swamp where even the local latex tappers didn't go. We watched for five days, often wading waist deep. My mind kept turning back to crocodiles, which were found in the open pools near the river. 

Noisy must have been in heat, for she had abandoned Mute for Nick, a large, fully adult male. Nick had moved into T. P.'s home range after T. P.'s disappearance. Nick and Noisy mated several times, each time apparently at eager Noisy's instigation. 

Mute appeared occasionally, only to be chased off by Nick. He slunk around in the trees about fifty yards from the couple, sneaking looks from behind tree trunks. Neither Nick nor Noisy, feeding close together in the same tree, seemed to be aware of him.

Biggest males get the nod 

The evidence was piling up that competition between males for females was an important factor in orangutan adaptation. All the adolescent females we met preferred large mature males as sexual partners to the smaller subadult males who were their more frequent companions. 

This female preference combined with male competition would go far in explaining the size difference between males and females. If males had to fight or chase other males before they could reproduce, the larger and fiercer males would have an obvious advantage and probably leave more descendants. The females have probably remained smaller because largeness gives them no reproductive advantage and a small female can find sufficient food more easily than a large one.

Apart from our scientific curiosity about orangutan mating preferences, we had a practical interest in the processes by which the young became independent of their mothers. If we could find out how the wild mothers taught their offspring to fend for themselves, we could do the same for the young apes reared in captivity that were sent to us for rehabilitation. 

Wild orangutan Cara, as always, was a ready source of information. We knew that she had weaned Carl before the birth of her infant Cindy. After the birth she tried, not always successfully, to prevent Carl from sharing her nest. Carl was persistent. But Cara became downright mean. Occasionally she attacked Carl when he followed her into small trees, as if she were saying, "This tree isn't big enough for both of us." 

Carl sometimes winced and squealed if Cara so much as looked in his direction. But, paradoxically, Cara also became frolicsome for the first time, making "play faces" as she gently grappled with her son. About a year after the birth of his sister, Carl began wandering the forest on his own. Occasionally he encountered Cara, but he and she might have been total strangers for all the emotion either displayed. They didn't touch or make a sound; they barely looked at each other. Yet Carl often followed her for a while. At times he met other immature orangutans, but never traveled with them for long. Carl was taking the first steps toward the solitary existence of the fully mature wild males.

We wished the same could be said for Sugito and the five other human-influenced apes still sharing our hut with us. They were growing bigger and much more active. Nothing was safe from the orange monster-babies. 

Akmad and Subarno, at least, were nesting in the trees nearby but Sugito, Sobiarso, and Rio still slept on the hut floor, wrapped in old clothes and burlap sacks. Then our troubles were compounded by the arrival of Cempaka—the biggest “baby” of them all.  

Cempaka had been raised by an old couple who treated the 7-year-old ape almost as their own child, sometimes even allowing her to sleep with them at night. After talking with us and Widajat Eddypranoto, head of the provincial forestry, the couple became convinced that it would be best for the adolescent Cempaka to return to the forest. 

At first the forest totally disconcerted Cempaka. She seemed incapable of making a nest and spent her first days sleeping propped up on a branch. But like almost every rehabilitant before her, she soon discovered the joys of our bed, climbing up the ladder to the mattress on top of the storeroom roof. Not only did she sleep on it; she tore open our pillows and mattress to get at the edible seeds in the white kapok stuffing. Time and again we climbed up the ladder to bed, only to find Cempaka sitting up there looking like the Abominable Snowman in a blizzard.

Wily apes lay claim to bed 

With great effort and emulating wild orangutan Cara’s meanness, we had at last succeeded in keeping Sugito out of bed at night. Now, encouraged by Cempaka’s success in flouting the rules, the other rehabilitants began sneaking up the ladder in the middle of the night. We often woke to find not one, but four orangutans in bed with us. We were literally being crowded off our own mattress. There was little we could do. We could not prevent them from entering our flimsy bark walled hut; they tore down the walls. Our thatch was leaky from the holes caused by orangutans walking along the roof peak. What was worse, Akmad periodically poked her head through the thatch during a rainstorm to see if it was still raining. During heavy rains, everything in the hut got soaked. We decided to build an ape-proof house. 

Meanwhile we continued to live in the deteriorating old hut and to observe our houseguests. We learned that Cempaka, though not adept at the ways of the forest, was incredibly clever in learning the ways of humans. She and Sugito, raised in the closest association with people, were our best tool users and biggest troublemakers. Subarno and Akmad, both successfully rehabilitated to forest life, did not use tools. No surprise there: Wild orangutans don't use them either. 

Cempaka displayed a flair for using sticks. She would sit with a long stick in each hand and dexterously manipulate everything within reach—plates, cups, other orangutans, nearby cats. She also enjoyed digging holes with sticks. Watching her, I often wondered why the wild orangutans, so laboriously clawing up termite nests from the ground with only their bare hands, never used branches or sticks to aid them. 

Once Cempaka even fashioned a crude tool. She found a long stick on the ground, broke it in half and threw away one end before commencing to dig with it. I also saw her use a long stick to pull burning pieces of wood from a large fire. Once the charcoal on the end of the wood cooled, she munched on it contentedly. 

But Cempaka's best performances were her attempts at "cooking." She would scoop handfuls of sugar and flour into a glass. Then she would go find where the eggs were hidden, break one into the glass, and stir vigorously. It was very similar to the procedure Bahriah, our workman's wife, followed when making pancakes. 

Sugito was handy at using tools, too. He and Cempaka occasionally startled us by eating with forks or spoons. They must have picked up the idea by observing humans.

Apes treat garden like a pantry 

By the time our new wooden house was nearing completion, many months later, our situation had become intolerable. Most of our garden had been demolished—despite the barbed wire we had imported to keep raiders out. It stopped the deer but not the wild pigs or the rehabilitant orangutans. What the pigs left intact, the apes destroyed. 

Cempaka would raid the garden and then picturesquely eat her loot sitting atop the large "Orangutan Project" sign. Our potentially large jackfruit harvest was totally annihilated by Cempaka's practice of picking and dropping all the unripened fruit—after taking only one bite from each. 

There was nothing in our hut, no matter how esoteric or unlikely, that had not been tasted, chewed, or at least mouthed by an orangutan. Everything had orangutan tooth marks on it. Nothing was immune. For nesting material, the curious youngsters ripped apart our clothes, our books, and even our umbrella. They carried our mosquito net into the trees, ate our candles, chewed on the binoculars, tasted batteries, and drank our shampoo. They found tubes of toothpaste and glue irresistible, and opening our purportedly fail safe, toddler-proof medicine bottles was child's play for the animals. 

(Orangutan seen using medicinal plants to heal a wound for first time ever.)

The first time Sugito tested a bottle of antiseptic I almost went into hysterics. Bedecked with skull and crossbones, the label promised an untimely end. Sugito showed no ill effects at all. But his lips, hands, and feet remained bright red for days. He looked like Minnie Mouse wearing lipstick. 

Sugito developed a curious oral habit: He took mouthfuls of any available food and transferred it into the nearest receptacle—which was often my untasted cup of tea. His capacity and patience were astounding. He would sit innocently, his mouth apparently empty, and then, as soon as my back was turned, spit out a good half cup of tepid milk or chewed rice into the most improbable place. The apes' mouths were like bottomless pits. I once took two flashlight batteries out of Sugito's mouth. Satisfied he was "clean," I was just going to leave when he rolled out another one onto his bottom lip and looked at it. 

The rehabilitants never just drank their milk; they gargled and burbled it. And if it wasn't to their complete satisfaction, they would spray it out at one another. I was sometimes convinced that they were using their high ape intelligence to maximum capacity just thinking up new ways of driving me crazy. Cempaka would dump bowls of salt in my tea. Sobiarso would eat flashlight bulbs, and both she and Rio would suck all our fountain pens dry. I would find old socks in my morning coffee. It was a continual battle of wits, and they won!

Would-be sanctuary wasn't

We moved into the new wooden house long before it was completed, confident that the gaping holes which served as windows were too high for the apes to reach. It took a howling Sugito about two minutes to solve the problem. He dragged a stick to the nearest window, leaned it against the wall and climbed right up. 

It wasn't until June 1974 that we finished the doors and all the wire screening on the windows. Now, with a relatively orangutan-proof house, we could begin rehabilitating in earnest. Sugito, Sobiarso, Rio, and Binti—all skinny, bald infants when first brought to our camp—were now big, bouncing, healthy juveniles with shining coats. It was time for them to enter the forest permanently. We built a feeding station, consisting of a small platform, 250 yards from camp. If our charges wanted food, they had to go out to the forest to obtain it. 

After we moved into the wooden house, we left the old hut to the orangutans. And they demolished it within a few weeks. Once their habitual sleeping place was destroyed, the rehabs had no choice but to move into the forest to sleep as well as to feed. Even Sugito was now regularly nesting and sleeping in the trees. I felt like a proud parent whose off spring had finally graduated.

As time passed, the apes returned less and less frequently. Sometimes weeks went by without my seeing one of them. I must admit to a twinge of regret—a regret at the passing of the unique relationship we once shared. But the feeling passes whenever I see them so magnificent and free in the trees to which they were born. 

In our fourth year of fieldwork, we felt there were few surprises left. But then in March wild orangutan Nick's home range was suddenly invaded by other adult males. Nick was frantically racing about. Strange calls were coming from several parts of his home range at once. One, though, seemed familiar. For days we searched for that caller. On April Fools' Day we found him. Out of a nest emerged T. P.—for more than two years presumed dead. Where had he been all this time? We don't know, but we hope to find out.

(Orangutan adopts little sister after their mother's death.)

New knowledge brings new puzzles

The past four years have been exciting. We have learned much about the wild orangutan and added many new facts to the fund of primatological knowledge. We have cataloged two hundred types of orangutan foods, begun charting family histories for a number of wild orangutan units, mapped home ranges, and gathered much data on the social interactions among these normally solitary animals. 

But much remains to be done. The more we learn about the wild orangutan, the more questions arise. Our study sampled only a tiny fragment of any one orangutan's life span. We now have two Indonesian biology students working with us. We hope, with their help, to continue our study for many years. One of the big problems we have to solve is where the huge males like T. P. go when they disappear. And where did Nick come from after T. P. vanished? Perhaps T. P. himself will lead us to the answer.