Palm oil puts squeeze on Asia's endangered orangutan
By Gillian Murdoch Mon May 28, 12:08 AM ET
PALANGKARAYA, Central Kalimantan (Reuters) - Bound hand and foot, disheveled orangutans caught raiding Borneo's oil palm crops silently await their fate as a small crowd of plantation workers gather to watch.
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Lacking only hand-cuffs and finger-printing to complete the atmosphere of a criminal bust, such "ape evictions" have become part of life for Asia's endangered red apes.
Thousands have strayed into the path of international commerce as Indonesia and Malaysia, their last remaining habitats, race to convert their forests to profitable palm crops.
Branded pests for venturing out from their diminishing forest habitats into plantations where they eat young palm shoots, orangutans could be extinct in the wild in ten years time, the
United Nations said in March.
Fighting against this grim prediction is the Nyaru Menteng Borneo Orangutan Survival (BOS) centre in Central Kalimantan, which rescues orangutans and returns them to the wild at the cost of US,000 per ape.
"They will kill the animals if we don't go ... It's cheaper to kill the orangutan than put up a fence or snares," said Lone Droscher-Nielsen, the Danish-born founder of the centre.
While harming the apes is illegal, her centre has amassed a slew of photographs of the grisly fates of some plantation trespassers: Apes with their hands cut off and slashed to death with machetes, and others with bullets through their foreheads.
With dozens captured this year, cages are full, and finding secure land for releases is a constant challenge for the centre.
"It's not just orangutans -- bears, gibbons -- everybody is losing their home," said Droscher-Nielsen.
"If it was only the orangutan, people just say: 'Well it's only one species that's going to go extinct'. But it's not just one species. Those forests have millions of animals in them that are all going to go extinct if we continue."
SQUEEZED OUT
Indonesia and Malaysia together produce 83 percent of the world's palm oil. Made by crushing fresh fruit, the reddish-brown oil is riding high in the commodities charts, with crude prices up over 15 percent this year after rising 40 percent in 2006.
Used in cookies, toothpaste, ice cream and breads it is the world's second most popular edible oil after soy.
Demand is also soaring for palm oil-derived biofuel, despite objections from critics who slam the "green" alternative to pricey crude oil as "deforestation diesel" because of the destruction wreaked on forests to make way for palm plantations.
Of 6.5 million hectares cultivated in Malaysia and Indonesia in 2004, almost four million hectares was previously forest, environment group Friends of the Earth calculated.
For orangutan, the clearances are a matter of life and death.
"You can see how desperate the situation is," said forestry department official Sugianto, 43, as he gestured at row after row of palms in the ape's last stronghold, Central Kalimantan.
"The company knows the orangutan has a protected status ... if they have a permit to clear 60,000 hectares they clear 60,000 hectares, orangutan or not. They only care about their profit."
Caught and reported to the Borneo Orangutan Survival centre by plantations who say they are trying to be responsible stakeholders, healthy animals are re-released deep in the forest. Those too injured or too young to survive alone join 600 others at the rehabilitation centre.
Forty local Dayak women look after the current crop of 18 palm oil "orphans," whose mothers have been killed; bottle-feeding them milk, administering medicine and supervising their climbing and nest-building.
"Some people still think it is a strange job, but others think it is normal now," said 31-year old Sukawati.
After "forest school," the apes graduate to eventual release.
"They are cute and funny," said Sukawati. "They make me laugh."
BALANCING ACT
Orangutans once ranged across Southeast Asia. Now an estimated 7,300 remain on Indonesia's Sumatra island and 50,000 on Borneo island. An estimated 5,000 disappear every year.
Decades of habitat loss through rampant illegal logging, lethal annual forest fires, and poachers who earn hundreds of dollars for capturing orangutans for the illegal pet trade have all taken their toll.
But this latest threat is the worst, experts said.
"The orangutans can withstand a certain degree of logging, as most loggers don't take the orangutan food trees," said Bhayu Pamungkas of the World Wide Fund for Nature.
"But they have no chance with oil palm -& there's no chance for the orangutan if they clear-cut all the forest."
To rescue the industry's green credentials, several Indonesian and Malaysian palm oil companies have joined the Roundtable on Sustainable Palm Oil (RSPO), whose voluntary criteria include a ban on clearing primary forests and areas of high conservation value, such as forests containing orangutan.
Its more than 150 members also include major European end-users like Cadbury-Schweppes, Unilever and the Body Shop, that together take 40 percent of Asian exports, and who want to buy non-destructive palm oil.
But securing private sector support is a balancing act, said Fitrian Ardiansyah, 32, an RSPO board member.
"There is some genuine intention from progressive companies to distinguish between them and the bad guys," he said.
"But if the push is too hard for them it's not going to be too difficult to switch the market to China and India, and emerging markets like the Middle East and Africa."
TREES AND PRIORITIES
Like whales, pandas, polar bears, and tigers, shaggy orange orangutan are classed "charismatic megafauna" by academics - endangered animals whose plight provokes compassion and concern.
Cute as they may be, their supporters need to keep perspective, said Derom Bangun, executive chairman of Gapki, the Indonesian Palm Oil Association, and an RSPO member.
"We should see the whole picture, not only the orangutan. They try to manipulate emotional side of orangutans so that housewives in Europe find it very pitiful," he said.
The country's clearance of almost 1.9 million hectares of forest a year between 2000 and 2005, Asia's worst deforestation rate, also needs to be seen in its economic context, Bangun said.
While the government does need to better define which forest areas are to be preserved, not all will be kept, he said.
"Other countries chopped down their forests when they were developing their countries. If they would like us to preserve more than we can, they should do something to help us."
But while plantation workers have some choice whether they want to buy into the motorbikes and mobile phones offered by palm's economic opportunities, orangutans have no such choice, those on the front-line point out.
"I'm not against palm oil," said Droscher-Nielsen. "(But) if there's not proper protection of the forest the orangutans are not going to make it."
(Additional reporting by Mita Valina Liem in Jakarta)
NOVES CONVOCATÒRIES ESTIU 2007
Fundació Mona organitza des del passat mes de març de 2007 cursos d’Introducció a l’Etologia de Primats. L’objectiu fonamental d’aquests cursos és estudiar i comprendre el comportament dels primats no humans, no tan sols des d’una vessant teòrica sinó també pràctica.
La duració estimada del curs és de 15 hores (8,5 de teoria i 6,5 de pràctica) distribuïdes en dos dies (divendres i dissabte) amb un horari de 10:00 a les 18:30h. El preu de la inscripció inclou carpeta amb llibreta de camp, material en CD-ROM i certificat d’aprofitament del curs.
NOVES CONVOCATÒRIES ESTIU 2007 (Nivell Bàsic):
JULIOL: dies 20 i 21
AGOST: dies 17 i 18
SETEMBRE: dies 21 i 22
Informacions i reserves:
Miquel Llorente
e-mail: recerca@fundacionmona.org
telf: 972 477 618
**********************************************************************************
Nuevas Convocatorias para el Curso de Etología de Primates de Fundación Mona
Fundación Mona organiza desde el pasado mes de marzo de 2007 cursos de Introducción a la Etología de Primates. El objetivo fundamental de estos cursos es estudiar y comprender el comportamiento de los primates no humanos, no solo desde una vertiente teórica sino también práctica.
La duración estimada del curso es de 15 horas (8,5 de teoría y 6,5 de práctica) distribuidas en dos días (viernes y sábado) con un horario de 10:00 a les 18:30h. El precio de la inscripción incluye carpeta con libreta de campo, material en CD-ROM y certificado de aprovechamiento del curso.
NUEVAS CONVOCATORIAS VERANO 2007 (Nivel Básico):
JULIO: días 20 y 21
AGOSTO: días 17 y 18
SEPTIEMBRE: días 21 y 22
Informaciones y reservas:
Miquel Llorente
e-mail: recerca@fundacionmona.org
El virus ébola amenaza a la población del gorilas del Congo
El parque nacional de Ozdala, en el corazón del Congo, es una extensión de bosque tropical que cubre más de 13.200 kilómetros cuadrados y que constituye uno de los ecosistemas más misteriosos e impenetrables. Cincuenta kilómetros al suroeste del parque se localiza una región llamada Lossi. Con una extensión de unos 320 kilómetros cuadrados, el lugar acumula una concentración tan excepcional de gorilas que no se da en ningún otro lugar del mundo.
En este mundo de penumbra donde el equipo del que forma parte José Domingo Rodríguez-Teijeiro,catedrático de biología de la Universidad de Barcelona, liderado por la antropóloga Magdalena Bermejo, viene denunciando una matanza sin precedentes: más de 5.000 gorilas de llanura (Gorilla gorilla gorilla) podrían haber sucumbido ya al zarpazo del virus Ébola, el organismo más letal que se conoce, según afirman en el estudio más reciente publicado en la revista Science.
Se calcula que quedan unos 94.000 de estos animales. De acuerdo con otras estimaciones procedentes del Instituto Max Planck, el Ébola y la caza furtiva podría haber acabado ya con el 25 % de los ejemplares. "Lo que está haciendo el virus es atacar a las poblaciones grandes", explica Peter Walsh, antropólogo del Instituto Max Planck. "La mayor parte de todos los que hay en el mundo se concentran en una zona donde la gente los mata para comer, por lo que el virus y la caza pueden colocarlos en un estado de extinción ecológica". Un escenario plausible en las siguientes décadas, que presenta a los gorilas en poblaciones de unos pocos individuos, que requerirían de vigilancia y continuas intervenciones médicas para que no desaparecieran: un parque zoológico en plena selva.
Bermejo lleva observando a los gorilas desde 1994, acostumbrándolos a la presencia humana, dentro de un proyecto del programa ECOFAC (Conservación y Utilización Racional de los Ecosistemas Forestales de África Central), para incentivar el turismo ecológico en la región. Es un trabajo lento y difícil. "Hay que tener paciencia, y estar quieto, sobre todo al principio", explica Rodríguez-Teijeiro, describiendo las experiencias de su colega. "Ella ha tenido la valentía de aguantar el ataque de un espalda plateada, 200 kilos de musculatura, a medio metro, mientras el macho produce unos alaridos espantosos y muestra sus grandes incisivos. De ahí el apodo de dama de hierro con que se la conoce". Este tipo de ataques pone a prueba los nervios del observador, hasta que los animales se habitúan a su presencia.
El Ébola ha irrumpido en el proyecto de forma desastrosa. Los gorilas a los que Bermejo se ha ido aproximando con lentitud para ganarse finalmente su confianza se han desvanecido casi de la noche a la mañana. En el otoño de 2002, la epidemia se propagó hasta el límite este del santuario, y pareció detenerse en los márgenes del río. El equipo español observó entonces que varios grupos de gorilas habían sobrevivido, quizá por algún tipo de inmunidad natural, lo que alimentó las esperanzas para reemprender el programa. Fue un respiro pasajero. El virus continuó su expansión, esta vez hacia el sur, y en enero de 2004 eliminó a 91 de los 95 individuos reconocibles por el grupo de españoles. Los dos años siguientes cuentan una historia pesimista; el equipo de Bermejo cree que el virus ha limpiado de gorilas una zona de 2.700 kilómetros cuadrados.
El Ébola ha matado en África a más de 1.200 personas en un cuarto de siglo, de acuerdo con la OMS (Organización Mundial de la Salud); una cifra que, estadísticamente, es una gota en la mortalidad ocasionada por otras enfermedades tropicales, como la malaria (entre uno y cinco millones de muertes anuales), las infecciones respiratorias (más de cuatro millones), la diarrea (2,2 millones) y el sida (3 millones). Lo cierto es que, al tratarse de un "virus caliente", con una letalidad muy alta en los humanos entre el 41 % y el 100 % , la atención que despiertan los brotes de Ébola desplaza a menudo a los otros grandes matadores, menos espectaculares, aunque siniestramente más eficaces.
Las reacciones que causa el Ébola cuando irrumpe en las pobres aldeas africanas cristalizan en una palabra: terror. Al principio sólo es un dolor de cabeza que no desaparece con los analgésicos. Luego, tras una incubación extraordinariamente variable, entre 2 y 21 días, sobrevienen las fiebres y hemorragias, y la irrupción de la enfermedad es rápida y mortífera.
El patrón suele ser el mismo. Una partida de caza termina con el hallazgo de una carcasa de gorila o chimpancé infectado. Alguien lo toca, se pone enfermo y queda bajo el cuidado de la mujer en su casa. Más miembros de la familia mueren, cunde el pánico y se produce una desbandada. Si el virus ya no tiene a quien matar, el brote queda extinguido. Si alguno de los familiares llega al hospital local, contagia el virus a otras personas en la sala de espera, que retornan a sus aldeas recorriendo decenas de kilómetros a pie, extendiendo la epidemia. En las fases más virulentas de ésta, la gente simplemente abandonaba aterrorizada a sus familiares que agonizaban, o dejaban cartas en los hospitales con instrucciones de quemar sus casas y los cuerpos de sus seres queridos.
Lo que sigue trayendo de cabeza a los investigadores es el misterioso reservorio natural del virus, qué animal lo porta sin sufrir la enfermedad. La alta mortandad que ocasiona en los grandes primates los descarta de un plumazo. Algunos estudios apuntan a ciertas especies de murciélagos frugívoros y sus cuevas como los focos iniciales de transmisión, aunque no existe certeza de este hecho.
Fuente: EL PAIS. Luis Miguel Ariza
Female-led Infanticide In Wild Chimpanzees
Science Daily — Researchers observing wild chimpanzees in Uganda have discovered repeated instances of a mysterious and poorly understood behavior: female-led infanticide. The findings, reported by Simon Townsend, Katie Slocombe and colleagues of the University of St. Andrews, Scotland, and the Budongo Forest Project, Uganda, appear in the journal Current Biology.
Infanticide is known to occur in many primate species, but is generally thought of as a male trait. An exception in the realm of chimpanzee behavior was famously noted in the 1970s by Jane Goodall in her observations of Passion and Pom, a mother-daughter duo who cooperated in the killing and cannibalization of at least two infant offspring of other females. In the absence of significant additional evidence for such behavior among female chimpanzees, speculation had been that female-led infanticide represented pathological behavior, or was a means of obtaining nutritional advantage under some circumstances.
As the result of new field work involving the Sonso chimpanzee community in Budongo Forest in Uganda, the St. Andrews researchers now report instances of three female-led infanticidal attacks. Alerted to the killings by sounds of chimpanzee screams, the researchers directly observed one infanticide, and found strong circumstantial evidence for two others. Evidence suggested that in two of the cases, the killings were perpetrated by groups of resident females against "stranger" females from outside the resident group. Infants were taken from the mothers, who were injured in at least two of the attacks; in at least one case, adult males in the area exhibited displaying behavior, with one old male unsuccessfully attempting to separate the females.
The authors point out that these new observations indicate that such female-led infanticides are neither the result of isolated, pathological behaviors nor the by-product of male aggression, but instead appear to represent part of the female behavior repertoire in chimpanzees.
What drives the behavior is not yet clear, but may stem from demographic shifts that alter sex ratios and put increased pressure on females competing for foraging areas. In their report, the authors note that the Sonso community had experienced a significant population increase in the ten years prior to the infanticide observations (42 individuals in 1996 to 75 in 2006), and that there had been an influx of at least 13 females with dependent offspring since 2001. The population changes resulted in a highly skewed male:female sex ratio of 1:3, with relatively few males available to increase the home range.
According to the authors, the new findings indicate that although low-level aggression between female chimpanzees is more commonly seen, the observed instances of infanticide indicate that deadly aggression is not a gender-specific trait in this species.
Townsend et al.: "Female-led Infanticide in Wild Chimpanzees." Publishing in Current Biology, 15 May 2007, R355-356.
Note: This story has been adapted from a news release issued by Cell Press.
Chimps knocked off top of the IQ tree
The original meta-analysis of research on relative primate mental ability which is discussed in James Lee's paper was carried out by a team led by Robert Deaner, assistant psychology professor at Grand Valley State University, Allendale, Michigan. Further research on primate intelligence by Deaner and his colleagues is appearing in the journal Brain, Behavior and Evolution.
ORANG-UTANS have been named as the world’s most intelligent animal in a study that places them above chimpanzees and gorillas, the species traditionally considered closest to humans.
The study found that out of 25 species of primate, orang-utans had developed the greatest power to learn and to solve problems.
The controversial findings challenge the widespread belief that chimpanzees are the closest to humans in brainpower. They also suggest that the ancestry of orang-utans and humans may be more closely entwined than had been thought.
“It appears the orang-utan may possess a privileged status among human kindred,” said James Lee, the Harvard University psychologist behind the research. “It is even possible that an orang-utan-like forager occupied a pivotal link in the chain of descent leading to man.”
Both orang-utans and chimpanzees share about 96% of their DNA with humans, although molecular studies suggest that chimpanzees are more closely related.
The study comes at a time when orang-utans are endangered as never before. Once widespread throughout the forests of Asia, they are now confined to just two islands, Sumatra and Borneo, and are highly endangered as a result of habitat loss and poaching.
Lee’s work involved collating a series of separate studies into the intelligence of different primate species. However, his research first had to overcome a much greater hurdle: would it be possible to compare different species of primates at all?
Spider monkeys, for example, have developed brains to cope with a fast-moving life in the tree tops, while slow lorises are small and leisurely nocturnal hunters.
The conventional belief is that comparing the intelligence of different species is meaningless because separate evolution over millions of years will have given them very different brains.
Lee, a junior psychology researcher at Harvard, found that in primates, at least, different rules seem to apply — the development of one set of mental skills seems to prompt the primate brain to develop other mental abilities as well.
“A primate genus with a high rank in an experiment testing particular mental abilities appears to have high ranks in all of them,” said Lee.
He also found that the single most important factor in deciding a species’ intelligence was simply the size of its brain: “The correlation of brain size with mental ability found in humans appears to extend throughout the primate order.”
This “remarkable finding” suggests, he said, that all primate brains work in much the same way, however they have evolved, allowing comparisons between species.
Lee’s research threw up some other surprises, too. Gorillas, for example, emerged as less intelligent than spider monkeys while baboons, often considered relatively bright, were ranked 14th.
Recent field work by Carel van Schaik, a Dutch primatologist who is now at Duke University, North Carolina, appears to bear out Lee’s findings.
Studying orang-utans in Borneo, he found them capable of tasks well beyond chimpanzees’ abilities — such as using leaves to make rain hats and leakproof roofs over their sleeping nests. He also found that in some food-rich areas the creatures had developed a complex culture in which adults would teach youngsters how to make tools and find food.
He and Lee both suggest that the key factor in such developments is the orang-utans’ life-style, spent mostly in the tops of trees where there is little risk from predators. This has allowed them to establish long and settled lives similar to humans’ and also to develop culture and intelligence.
In his own research papers, Van Schaik has suggested that since the ancestors of modern orang-utans split from the human lineage about 15m years ago, the seeds of human culture must go back at least as far.
Chris Stringer, professor of human origins at the Natural History Museum in London, agrees that the sociable lifestyles of primates are the driving force behind the development of intelligence. “Primates and early humans had not got the claws and teeth of predators so they had to rely on brainpower to communicate and protect themselves,” he said. “They are sociable creatures and living in small groups seems to have driven brain development.”
The idea that sociability and intelligence are linked is borne out by research into the relative brain power of diverse animal groups including cetaceans (whales and dolphins) and birds.
Dr Vincent Janik, of the sea mammal research unit at St Andrews University, said that some dolphin species had developed the ability to communicate far beyond that of great apes. “Dolphins have some abilities that great apes don’t have, such as copying new sounds. No primate apart from humans can do that,” he said.
Additional reporting: Max Colchester
Non-human primates in order of intelligence
1 Orang-utan
2 Chimpanzee
3 Spider monkey
4 Langur
5 Macaque
6 Mandrill
7 Guenon
8 Mangabey
9 Capuchin
10 Gibbon
11 Baboon
12 Woolly monkey
El bressol de Selam
Fuente: El Periódico de Catalunya
BARCELONA
Alemseged, investigador de l'Institut Max Planck d'Alemanya, va estar la setmana passada a Barcelona, convidat per l'Obra Social La Caixa, per pronunciar una conferència sobre el descobriment que l'ha fet famós. Selam, presentada en societat l'any passat, és un fòssil d'Australopithecus afarensis d'un valor excepcional per qualsevol dels següents tres motius: la seva gran antiguitat, uns 3,3 milions d'anys; la seva excel.lent conservació, amb l'esquelet complet al 60% i alguns ossos extraordinaris per a èpoques tan remotes, com el hioide i l'omòplat, i finalment el seu desenvolupament anatòmic, ja que és un individu infantil d'uns tres anys, escassíssims en el registre fòssil mundial.
"¿Va ser sort? Jo crec que no. La troballa va ser possible gràcies a un treball sistemàtic que vaig iniciar el 1999 --explica Alemseged en una entrevista amb aquest diari--. Quan vaig arribar a Dikika, volia explorar sediments més antics que els trobats a Hadar, on va aparèixer Lucy (el famós A. afarensis que va ser descobert el 1974 en una zona pròxima), i em vaig plantejar una àrea de 500 quilòmetres quadrats. El 10 de desembre del 2000, quan vaig trobar els ossos, estava analitzant una de les zones previstes".
La desèrtica Dikika era fa 3,3 milions d'anys una regió molt biodiversa, amb sabanes i boscos on vivien hipopòtams, lleons, antílops, elefants i, per descomptat, australopitecs, unes curioses criatures d'aspecte simiesc que caminaven bípedes. "Avui és un desafiament viure allà --reitera el jove investigador--, però en temps de Selam i Lucy era una regió molt favorable perquè hi poguessin viure els nostres avantpassats".
Potser hi va haver altres enclavaments pròxims amb presència d'australopitecs, però a Dikika va ocórrer un succés miraculós: possiblement, la nena estava bevent o jugant arran d'un riu quan va ser sorpresa per una riuada que va descarregar en un llac. El seu cos va quedar cobert per sediments d'argila que es van soldar i van contribuir a la conservació. "La majoria dels paleontòlegs han de recompondre ossos trencats i buscar restes disperses de l'esquelet, mentre que jo vaig tenir el repte contrari: tenia els ossos units en una gran roca sedimentària i havia de separar-los amb molt de compte perquè no es fracturessin". Com que no es pot utilitzar àcid perquè les restes es fan malbé, el treball dels investigadors va durar cinc anys.
A la regió d'Afar, el moviment de les plaques terrestres ha anat traient a la llum fòssils que van quedar enterrats fa milions d'anys. Alguns afloren a la superfície. La riquesa paleontològica de la regió no té cap parangó al món per a èpoques tan remotes, ja que també hi han aparegut ossos d'Australopithecus anamensis (4,1 milions d'anys) i d'Ardipithecus ramidus (4,4 milions), però no és fàcil que Afar se'n beneficiï, assumeix l'investigador. "Els turistes que busquen llocs com Hadar o Dikika són molt escassos. El turisme vol veure obeliscos i esglésies".
Jaciment de primer ordre
Les restes es conservaran al museu nacional d'Addis Abeba, però Alemseged aspira a crear un centre d'interpretació situat relativament a prop de Dikika. "¡Com hem de tenir un museu al costat si no hi ha ni clínica ni escola! Però s'ha de vigilar, perquè els fòssils estan a l'aire lliure". A Dikika, convertit en un jaciment de primer ordre, ja hi treballen 35 persones amb patrocinis diversos.
L'investigador està orgullós de servir d'exemple per a una nova generació d'etíops: "La paleontologia va començar aquí en temps de Haile Selassie, es va paralitzar amb el règim comunista i ara es torna a despertar, però al meu país no hi ha ni la més mínima tradició investigadora. Tot i que afortunadament no sóc l'únic, sí que som pocs". Fins ara, tots els paleontòlegs a l'Àfrica eren estrangers. Alemseged és jove, però ja té deixebles.
Like humans, apes can communicate manually
The Atlanta Journal-Constitution
Published on: 05/01/07
Before there was speech, there was the gesture — a hand outstretched to beg for food, or a "come hither" sweep of a beckoning forearm.
Monkeys may see. But when it comes to gestures, only apes — and humans — do.
That discovery, by researchers at Emory University's Yerkes National Primate Research Center, offers new fuel for the theory that the evolution of human language began, not with words, but with a wave of the hand or a flick of the wrist.
"Our research suggests that just as human babies can learn certain gestures before they speak, our ancestors may have been gesturing to each other before they talked," says Yerkes researcher Frans B.M. de Waal.
Language, the fundamental mechanism by which humans share information, is thought to have emerged about 100,000 years ago. But the study by de Waal and Yerkes co-researcher Amy Pollick, published Monday in the Proceedings of the National Academy of Science, suggests that nonvocal communication — perhaps hand gestures exchanged by prehistoric hunters — may have appeared much earlier.
Although monkeys and other primates have a wide range of facial expression and body postures, de Waal says only the apes — chimps, bonobos, gorillas and orangutans — use controlled manual gestures. Those gestures, like spoken language, are flexible enough to have different meanings in different contexts and vary from group to group.
"The difference in control is dramatically illustrated by past failure to teach chimpanzees to speak, even though they have no trouble learning the gestures of American sign language."
From their daily observations of two groups of chimps at the Yerkes center in Atlanta and two groups of bonobos at the San Diego Zoo, the researchers documented 31 distinct manual gestures — including pointing, waving, beckoning, and rapping knuckles, whose meanings varied enormously from group to group.
"A chimpanzee stretching out an open hand toward a possessor of food, for instance, signals a desire for food, but stretching out an open hand toward a third party during a fight signals a need for support," explains de Waal. "You can see similar contextual differences in someone begging on the street."
The British primatologist Jane Goodall first noted gesturing among chimpanzees in the wild in the 1960s. But de Waal, the author of "Our Inner Ape," "Chimpanzee Politics," "Peacemaking Among Primates," and other books, says the ability has since been documented in all apes, which are humans' closest relatives on the evolutionary tree.
